Steven Wallander, Marcel Aillery, Daniel Hellerstein, 

and Michael Hand

The Role of Conservation Programs 

in Drought Risk Adaptation

Economic

Research

Service

Economic 

Research 

Report 

Number 148

April 2013

United States Department of Agriculture
Economic Research Service 

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Wallander, Steven, Marcel Aillery, Daniel Hellerstein, and Michael Hand. The 

Role of Conservation Programs in Drought Risk Adaptation, ERR-148, U.S. 

Department of Agriculture, Economic Research Service, April 2013.

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United States Department of Agriculture
Economic Research Report Number 148  A Report from the Economic Research Service  April 2013

Abstract

This report evaluates the extent to which farms facing higher levels of drought 

risk are more likely to participate in conservation programs, and fi nds a strong link 

between drought risk and program participation. Prior research has shown that 

climate-related risk exposure infl uences production decisions such as crop choice; 

our research shows that adaptation also includes program participation decisions. 

Programs like the Conservation Reserve Program and Environmental Quality 

Incentives Program play a role in drought preparedness and climate adaptation even 

if they do not directly target such behavior. Conservation program outcomes are 

infl uenced by regional differences in production risk, so participation choices due to 

drought risk can be an important consideration in designing such programs. 

Keywords: Climate, conservation programs, drought, adaptation, irrigation effi -

ciency, land retirement, risk, tillage

Acknowledgments

The authors would like to thank Mike Hayes with the National Drought Mitigation 

Center for his contribution to the report. Also, the authors thank USDA Farm 

Service Agency; Natural Resources Conservation Service, and Offi ce of the Chief 

Economist, World Agricultural Outlook Board employees who contributed to 

this report; and ERS staff members Roger Claassen, Ryan Williams, Dale Simms 

(editing), Cynthia Ray (graphics), and Curtia Taylor (design) for their comments 

and input.

Steven Wallander, swallander@ers.usda.gov

Marcel Aillery, maillery@ers.usda.gov

Daniel Hellerstein, danielh@ers.usda.gov

Michael Hand, mshand@fs.fed.us

The Role of Conservation Programs 

in Drought Risk Adaptation
ii The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iii

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Conservation Programs and Drought Risk. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Adaptation to Drought Risk and Climate Change . . . . . . . . . . . . . . . . . . . . . . . . 3

Defi ning Drought Risk Adaptation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

How Harmful Is Drought? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

How Is Drought Measured? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

What Is Drought Risk? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

What Is Drought Risk Adaptation? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

The Conservation Reserve Program and Drought Risk Adaptation . . . . . . . . . . . . 17

Enrolling Land in CRP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Modeling Drought Risk Adaptation and the CRP . . . . . . . . . . . . . . . . . . . . . . . 19

Data and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Results: Base Case and Policy Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

The Environmental Quality Incentives Program and Drought Risk Adaptation . . 29

Enrolling in EQIP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Modeling Drought Risk Adaptation and EQIP: Irrigation 

and Tillage Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Data and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Potential EQIP Design Responses to Drought Risk. . . . . . . . . . . . . . . . . . . . . . 36

Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Drought Risk Adaptation in the Animal Sector . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Grazing Land Resources and Drought Prevalence . . . . . . . . . . . . . . . . . . . . . . 40

Drought Impacts and Adaptation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Conservation Programs and the Livestock Grazing . . . . . . . . . . . . . . . . . . . . . . 42

Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Appendix A: Constructing a Measure of Drought Risk . . . . . . . . . . . . . . . . . . . . . 54

Appendix B: Modeling CRP Participation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Appendix C: Modeling EQIP Participation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Contents
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 iii

Summary

During the summer of 2012, almost 80 percent of U.S. agricultural land suffered 

drought. In terms of severity and geographic extent, the 2012 drought approached 

the peak Dust Bowl year of 1934. However, agricultural production has grown more 

adaptive since the 1930s, aided by crop genetics, crop insurance, and conservation 

programs. This report examines the relationship between drought risk and patterns 

of conservation program participation, and whether regional differences in drought 

risk can be incorporated into conservation program design. 

What Is the Issue?

A major drought is among the most serious production shocks a farm can experience. Over the past decade, total drought-related crop insurance indemnities and 

disaster relief payments averaged about $4 billion annually, after averaging less than 

$1.3 billion per year in the 1980s. The rise in total payments is due to a combination 

of expanded enrollment in crop insurance, increased liabilities due to higher yields 

and commodity prices, and a series of major droughts in recent decades. Farms in 

more drought-prone regions may adapt to higher levels of risk by adjusting their 

crop choices or investing in more effi cient irrigation systems. But do existing farm 

programs encourage or discourage farmers from reacting to drought risk? 

What Did the Study Find?

Most prior research on this question has examined the role of crop insurance. Here 

we hypothesize that participation in the Conservation Reserve Program (CRP) and 

the Environmental Quality Incentives Program (EQIP) is responsive to drought 

risk, as evidenced by the role of many funded practices—retirement of sensitive 

lands, investment in technology that improves irrigation effi ciency, and adoption of 

tillage practices that conserve soil moisture—in improving drought preparedness. 

Therefore, program outcomes can vary widely between low-risk counties, which are 

expected to experience fewer than 6 severe or extreme droughts per century, and the 

highest-risk counties, which are expected to experience between 12 and 20.

We fi nd that differences in climate infl uence conservation program participation. 

Farms in more drought-prone regions are more likely to offer eligible land for 

enrollment in CRP—a 1-percent increase in drought risk leads to a 2.4-percent 

increase in the offer rate. Irrigators facing higher drought risk are more likely to be 

enrolled in EQIP contracts with irrigation practices. And crop farms facing higher 

drought risk are more likely to be enrolled in EQIP contracts with conservation 

tillage practices. 

CRP bid caps for retiring farmland are designed to set the maximum CRP rental 

rate equal to the expected cash rental rate for a given cropland parcel, so most landowners should be fairly indifferent between putting land into CRP and leaving land 

in crop production. However, idling cropland can be an important way to replenish 

soil moisture and recharge aquifers, and special grazing provisions under the CRP 

provide a means of drought response for livestock operations. To demonstrate how 

existing program designs constrain drought risk adaptation, we create a number of 
iv The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

policy scenarios, through which we model changes in factors such as contract rankings or county enrollment caps.

• Revising the Environmental Benefi ts Index (EBI) to assign points for land in 

counties facing higher drought risk would lead to a small increase in offer rates 

and a 1.4-percent increase in total acres offered. Raising the EBI in high-risk 

counties effectively reduces offer rates in other counties. This suggests that a 

moderate increase in EBI points, granted to medium- and high-drought-risk 

(HDR) counties, would have a limited impact nationally (increasing total acres 

offered by less than 2 percent) but a more pronounced impact within droughtprone counties. 

• Since drought risk increases offer rates, HDR counties are more likely to hit 

the county enrollment caps. Increasing the county CRP enrollment cap from its 

current 25 percent of cropland acres to 70 percent would increase offered acres 

almost 28 percent compared to the baseline, over a third of which come from 

the HDR counties.

We observe a similar relationship between drought risk and program outcomes 

under EQIP. Irrigators who install improved technology are often able to reduce 

water lost to evaporation and infi ltration, which allows them to provide more water 

for their crops, particularly during drought years. Similarly, crop producers who 

utilize conservation tillage are often able to improve the capture and storage of soil 

moisture, which provides their crops an important buffer against drought impacts. 

For livestock producers, prescribed grazing plans provide some private benefi ts 

in coping with drought risk: forage management, prescribed animal stocking rates 

or planned grazing, and water supply augmentation for livestock. EQIP program 

design may also limit the extent to which producers rely on fi nancial assistance for 

drought risk adaptation, but the impacts of specifi c policy changes are not as readily 

modeled given differences in data on program participation.

If climate change increases drought risk, as many studies predict, this may lead to 

increased demand by farmers for participation in conservation programs. However, 

both CRP and EQIP have policy designs that may discourage or limit the extent to 

which farmers rely on the programs for drought risk adaptation, with unintended 

effects on the geographic pattern of participation. For example, factors that limit 

participation in CRP, particularly county enrollment caps and program eligibility requirements, are most often binding constraints in the highest drought-risk 

counties. 

How Was the Study Conducted?

Drought risk is measured by the variance in the Palmer Modifi ed Drought Index 

over the past 100 years. To assess the response of farmers to variation in drought 

risk, we develop econometric models to separate the effects of drought risk from 

other factors that infl uence program participation.

With CRP, we evaluate the effect of drought risk on the probability that eligible 

land is offered for enrollment. Based on newly constructed estimates of the amount 

of eligible land within each county, we econometrically estimate a likelihood-to-
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 v

offer model. With EQIP, we evaluate the effect of drought risk on the share of farms 

in a county using EQIP contracts for fi nancial assistance with practices—irrigationrelated and conservation tillage—that have been demonstrated to have droughtmitigating benefi ts. 

For the livestock sector, we discuss a number of features within conservation 

programs that may help producers respond to drought risk. CRP includes emergency 

haying and grazing provisions that are helpful to farms facing severe reductions 

in forage production. EQIP includes funding for a number of practices that help 

address water shortages for livestock and drought damages on pastureland. While 

we do not perform the same type of empirical analysis as for cropland, the available 

livestock sector data indicate that the connection between drought risk and conservation program participation is not limited to the crop sector.
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 1

Introduction

During the summer of 2012, almost 80 percent of U.S. agricultural land suffered 

drought. In terms of severity and geographic extent, the 2012 drought rivaled 

the 1988 and 1954 droughts and approached the peak Dust Bowl year of 1934. 

However, many aspects of agricultural production have changed since 1934, 1954, 

and even 1988. With respect to drought, three very signifi cant changes are crop 

genetics, crop insurance, and conservation programs. In this report, we examine the 

relationship between conservation programs and drought.

While a number of reports examine the role of agricultural policy in encouraging 

drought preparedness (NDPC, 2000), very few empirical studies assess the factors 

that infl uence farmer preparedness efforts. This report examines drought risk 

adaptation, defi ned as the choices that farmers make in response to drought risk 

exposure. Many practices cited as potentially effective adaptation responses to 

drought—including land retirement, irrigation effi ciency improvements, and conservation tillage—are already an important focus of USDA conservation programs.

To conduct our analyses, we gather data on farm-level eligibility for and participation in conservation programs. We then aggregate that data to the county level to 

measure variation in participation rates. We use econometric models to estimate the 

effect of drought risk on participation while controlling for other factors that also 

infl uence program participation.

Conservation Programs and Drought Risk

A new era for U.S. resource conservation emerged from the Dust Bowl years of 

the 1930s. With the establishment of the Soil Conservation Service—precursor to 

the Natural Resources Conservation Service (NRCS)—in 1935 and the formation 

of local soil conservation districts, the Federal Government joined with the farm 

community to promote agricultural resource conservation through information 

dissemination, technical assistance, and fi nancial assistance. 

Today, the majority of agricultural conservation funding is allocated within two 

broad program areas. Working lands programs provide fi nancial and technical 

assistance for adoption of eligible conserving practices on working farms and ranchlands. Land retirement programs remove environmentally sensitive cropland from 

production under long-term contracts or permanent easements. Participating farms 

may receive annual rental payments, a one-time permanent easement purchase 

payment, and fi nancial assistance to establish and maintain vegetative cover (see 

box, “USDA Conservation Programs”).

Federal funding for agricultural conservation has expanded signifi cantly under 

successive farm legislation since 1985. Land retirement programs dominated 

conservation funding from 1987 through 2002 (fi g. 1). Since the 2002 Farm Act, 

Congress has increased the level of fi nancial support for working lands programs. 

In evaluating the role of Federal programs in promoting adaptation to drought risk, 

we focus on two major USDA conservation programs—the Environmental Quality 
2 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

There are many different USDA conservation programs, including a number of pilot 

programs. Here we present brief descriptions of the largest programs.

Working lands programs

Environmental Quality Incentives Program (EQIP)—Provides fi nancial and technical 

assistance to encourage voluntary adoption of farming and ranching systems that 

conserve resources and enhance environmental performance. 

Conservation Stewardship Program (CSP)—Provides fi nancial and technical 

assistance for conserving systems; targets farmers and ranchers who have 

demonstrated high levels of conservation stewardship (formerly the Conservation 

Security Program).

Wildlife Habitat Incentives Program (WHIP)—Provides fi nancial and technical 

assistance for habitat enhancement on farm and ranch operations. 

Emergency Conservation Program (ECP)—Provides emergency funding and 

technical assistance to rehabilitate farmland damaged by natural disasters, including 

drought, and to provide drought-emergency water supplies for livestock. 

Land retirement programs

Conservation Reserve Program (CRP)—Targets retirement of highly erodible 

lands and other environmentally sensitive lands from agricultural production under 

long-term lease agreements. Most land is enrolled through general signup, but other 

variations include: 

CRP continuous signup—Administered under the CRP, provides additional fi nancial 

incentives for primarily partial fi eld enrollment in priority conservation practices. 

Conservation Reserve Enhancement Program (CREP)—Administered under the 

CRP in collaboration with States, tribes, and other entities, provides additional 

fi nancial incentives for retirement of environmentally sensitive lands targeted to local 

priorities. 

Wetlands Reserve Program (WRP)—Provides fi nancial and technical support for 

restoration of wetlands under permanent easement or long-term agreements. 

Farmland preservation

Farm and Ranch Lands Protection Program (FRPP)—Provides funds to States, 

tribes, and other entities to help purchase development rights that keep production 

farmland in agricultural uses. 

Grassland Reserve Program (GRP)—Provides fi nancial and technical assistance to 

preserve and improve native-grass grazing lands through long-term contracts and 

easements.

USDA Conservation Programs
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 3

Incentives Program (EQIP), the largest of the working lands programs, and the 

Conservation Reserve Program (CRP), the largest of the land retirement programs. 

Since 2008, these two programs together have comprised more than 70 percent of 

direct conservation payments.1 Neither program has drought response nor climate 

adaptation as a primary focus, but both may have added appeal to producers in 

more drought-prone regions.

Adaptation to Drought Risk and Climate Change 

Since farms vary in their exposure to drought risk, we expect farmers to vary in 

their levels of drought preparedness. Drought risk adaptation is the variation in 

drought preparedness that is due to differences in drought risk and is a form of 

climate adaptation. Climate change is already affecting the agricultural sector 

(Hatfi eld et al., 2008), and drought risk is likely to increase in most areas of the 

United States (Hirabayashi et al., 2008; Strzepek et al., 2010). 

The climate change literature draws a distinction between “autonomous” adaptation to climate change, or adjustments by individuals, and “planned” adaptation, 

or adjustments by policymakers. Planned climate adaptation consists of changes in 

1 Direct conservation payments include rental payments and fi nancial assistance 

payments. Indirect conservation payments include conservation technical assistance, which 

supports the development of conservation plans.

Figure 1

Trends in USDA conservation expenditures, 1983 to 2011

0

1

2

3

4

5

6

1983

$ Billion (inflation adjusted to 2010 dollars) 

Other working land programs

Environmental Quality Incentives Program

Agricultural land preservation

Wetland Reserve Program

Conservation Reserve Program

Conservation technical assistance

84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 2000 01 02 03 04 05 06 07 08 09 10 11

Notes: The 1985 Farm Act introduced the CRP. The 1996 Farm Act introduced the EQIP to replace and consolidate earlier working lands 

programs. EQIP expenditures include the Agricultural Water Enhancement Program (AWEP), the Ground and Surface Water Conservation 

Program (GSWC), and the Klamath Basin Program. “Other working land programs” include the Conservation Security Program, the Conservation Stewardship Program, and the Wildlife Habitat Incentives Program (WHIP). Expenditures are inflation-adjusted to 2010 dollars using the 

Bureau of Economic Analysis first quarter Gross Domestic Product deflator. 

Source: ERS calculations based on Office of Budget and Policy Analysis reports. Data are for authorized outlays.
4 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

institutions, policies, and infrastructure, generally in advance of expected changes 

in climate. Agricultural policies often involve voluntary participation by farmers, 

so any effort at planned adaptation is contingent on farm-level production decisions 

(fi g. 2).2 Autonomous adaptation to risk, and particularly drought risk, may be costly 

(Just and Pope, 2002). This report assumes that producers understand the costs of 

alternative strategies for drought risk adaptation and that participation in a conservation program will make sense for some producers and not for others. 

An empirical link between drought risk and conservation program participation 

would suggest that conservation program design may affect program participation in 

a changing climate. Such a link would also imply a potential tradeoff between crop 

2 One notable exception, a policy that is mandatory (conditional on other program 

participation), is conservation compliance.

Figure 2

Research framework: farm production decisions, climate, and conservation programs

Drivers of agricultural production

Climate

• Temperature

• Precipitation/aridity

• Drought risk

Markets

• Commodity prices

• Exchange rates

• Energy prices

• Input supply

Resources

• Soil

• Hydrology

• Topography

• Water availability

Agricultural policies

• Conservation programs

• Crop insurance

• Disaster assistance

• Commodity programs

•

Output choices

• Crop selection

• Crop diversification

• Cropland retirement

• Livestock selection

Input choices

• Irrigation adoption

• Irrigation efficiency

• Tillage adoption

• Livestock stocking rates

Crop cultivars

Risk management choices

• Crop insurance and disaster relief

• Borrowing and saving

• Contracting and hedging

• Off-farm income

Farm production decisions

Drought vulnerability

• Net revenue

Risks to farm safety net

• Federal outlays

• Reliability of existing programs

Community risks

• Local economies

• Food security

• Environmental services

Farm risk
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 5

insurance enrollment and conservation program participation, with budgetary implications for both programs. Enrollment in CRP illustrates such a tradeoff. Marginal 

lands that are more likely to be retired in CRP also tend to face above-average 

production risk (Lubowski et al., 2006). An implication of this tradeoff is that there 

may be high-risk, marginally productive land for which CRP rental payments are 

less than crop insurance premium subsidies, on a per-acre basis. In such areas, 

expanding CRP enrollment and reducing crop insurance enrollment could lead to 

greater environmental benefi ts and lower Federal outlays. However, such opportunities are likely rare. In the majority of counties, the average insurance premium 

subsidy is less than 80 percent of the CRP rental rate (fi g. 3). There are some counties, though, where the reverse is true and the average premium subsidy is at least 

20 percent higher than the average CRP rental rate. The extent to which costs could 

actually be reduced by encouraging CRP enrollment in some areas depends upon 

farm-level decisions—including CRP contract offers and crop insurance enrollPer-acre payments comparison

Ratio of Risk Management Agency premium 

subsidy to CRP soil rental rate

CRP is less expensive (>1.2)

Minimal difference

Insurance is less expensive (< 0.8)

Figure 3

Conservation Reserve Program rental rates and crop insurance subsidies by county, 2008

Insurance versus land retirement: Relative per-acre subsidies

Source: ERS calculations. Data on CRP rental rates are calculated from USDA/Farm Service Agency CRP contract data. These rental rates 

are the average payment per acre that farms currently enrolled in CRP receive in exchange for agreeing to retire their land from crop production and instead maintain cover crops and other practices to provide environmental benefits. Data on per-acre crop insurance subsidies are 

calculated from USDA/Risk Management Agency summary-of-business files. These subsidies are the average cost per acre per year to pay 

the federally financed portion of crop insurance premium subsidies. These payments are not made directly to the farms, so the comparison 

between programs is a partial look at Federal costs per acre and does not reflect differences in payments to farms. 
6 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

ment (e.g., buy-up) decisions. We do not attempt to model those decisions in our 

analysis since that would require joining micro data in a way not currently possible 

with acceptable accuracy.

Amid heightened drought risk, U.S. agricultural policymakers could focus on 

increasing the extent to which existing programs and policies facilitate adaptation 

(Council on Environmental Quality, 2010; Antle, 2009) or they could consider 

new adaptation policies (Easterling et al., 2004). Under either planned adaptation strategy, the role of conservation programs depends, in part, on how climate 

infl uences farmer participation in such programs. This report addresses that policy 

uncertainty by examining the role of drought risk within agricultural conservation 

programs and considering potential changes in conservation program design, such 

as adjustments in contract ranking criteria or changes in eligibility requirements. 
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 7

Defi ning Drought Risk Adaptation

This report focuses on two concepts that require careful defi nition for empirical 

research: drought risk and drought risk adaptation. To introduce these concepts, 

we begin with a history of Federal drought assistance over the past 40 years. Then 

we present a brief primer on meteorological measures of drought severity and look 

at the past century of U.S. droughts in terms of these measures. From the Palmer 

Modifi ed Drought Index (PMDI), we construct an empirical measure of drought 

risk. Last, we defi ne drought risk adaptation. There are two key fi ndings in this 

chapter: 

• Over the past decade, total drought-related crop insurance indemnities and 

disaster relief payments, which capture a portion of the cost of drought 

damages to agriculture, averaged about $4 billion annually.

• Measures of drought risk refl ect geographic differences in precipitation and 

temperature probability distributions. 

How Harmful Is Drought?

Local precipitation is an essential input for agricultural production in most regions 

of the country. Droughts result from below-normal precipitation over a sustained 

period, often in conjunction with above-normal temperatures, and can severely 

reduce agricultural productivity. In the context of agriculture, there are three types 

of drought impacts: 

• Farm-level impacts can include declines in farm income resulting from 

reduced crop yields or forage production, though these impacts may be offset 

by increases in income from higher commodity prices and Federal drought 

assistance. 

• Market-level impacts include higher commodity prices, which can greatly 

reduce the income of livestock producers who depend on purchased feed and 

can erode the purchasing power of consumers. 

• Environmental impacts include stresses on land and water resources and the 

provision of ecosystem services such as wildlife habitat and water quality. In 

some cases, as with soil erosion during the Dust Bowl, environmental impacts 

may exacerbate farm-level and market-level impacts. 

The signifi cance of drought to the Federal budget depends upon the extent to 

which USDA and other Federal agencies are tasked with alleviating the farmlevel, market-level, and environmental impacts of drought. The farm safety net in 

the United States—a combination of Federal crop insurance and ad hoc disaster 

assistance payments as well as several other farm programs—provides a partial 

buffer against the farm-level impacts of price shocks or production impacts such 

as drought. Drought-related payments are discussed here only as a proxy for farmlevel drought impacts. In many cases, farm productivity losses may not be suffi -

cient to trigger payments, or may not be fully compensated under drought payment 

programs. Market-level impacts, including shocks to food prices and secondary 
8 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

impacts on farm communities that are heavily dependent on farm income and 

production, are not directly addressed by the farm safety net. In addition, drought 

impacts outside of the agricultural sector are not included at all. Payments made 

through the farm safety net rarely refl ect total economic impacts.

Over the past four decades, drought has been the largest individual cause of U.S. 

farm production losses. Drought is responsible for 40 percent of total crop insurance 

indemnity payments made through the Federal crop insurance program. The crop 

insurance program, administered by USDA’s Risk Management Agency (RMA), 

provides enrolled farms with indemnity payments when yields and/or prices fall 

below specifi ed levels. Since the earliest years of the crop insurance program, RMA 

has tracked indemnity payments by cause of loss. Between 1948 and 2010, crop 

insurance provided $86.5 billion in indemnities for farm production losses (adjusted 

for infl ation to 2010 dollars), of which $32.5 billion resulted from drought. The 

next largest causes of loss were excess moisture ($20.5 billion), hail ($7.7 billion), 

freezes ($3.3 billion), heat ($3.2 billion), and commodity price declines ($3.2 

billion).3 The 2011 and 2012 droughts are likely to signifi cantly increase the relative importance of drought, but data on indemnities from these droughts are still 

preliminary. 

Disaster assistance payments are an equally important part of the farm safety net. 

During the 1976-77 drought, a standing disaster relief program generated billions 

of dollars in payments and considerable controversy (GAO, 1979) that led to the 

creation of the modern crop insurance program in 1980 (Dismukes and Glauber, 

2005). Since the expansion of the crop insurance program did not entirely replace 

ad hoc disaster assistance, it is helpful to examine indemnity payments and disaster 

assistance together (fi g. 4).4

Examining indemnity and disaster payments together reveals several facts about 

the farm-level impacts of drought. First, focusing only on indemnity payments 

would dramatically understate the signifi cance of drought. Second, drought impacts 

vary widely from year to year. Last, average annual payments for drought impacts 

3 Total indemnities are reported in the RMA summary of business fi le (www.rma.usda.gov/

data/sob.html), which was converted to 2010 dollars using the annual Consumer Price Index 

(CPI-U) and then aggregated by cause of loss. Total assistance for price declines represents 

a small portion of crop insurance indemnity payments, in part because most price risk was 

historically addressed through other programs such as emergency loans, loan defi ciency 

payments, and countercyclical payments. With the recent shift of many farms from yieldbased insurance to revenue insurance, price risk is gaining in signifi cance as a source of 

indemnity payments.

4 Because the RMA tracks the cause of loss for every indemnity payment, the exact 

portion of indemnity payments due to drought is reported in each crop year. In contrast, 

disaster payments are not tracked by cause of loss and so the exact portion of disaster 

payments due to drought is not known. We assume that the portion of disaster assistance 

due to drought in each year is the same as the proportion of indemnity payments due 

to drought, an assumption supported by the fact that crop insurance participation is a 

prerequisite for most disaster assistance programs. A review of the legislative actions 

authorizing disaster assistance qualitatively confi rms the relative signifi cance of drought 

within ad hoc assistance (Chite, 2006). Drought has likely played a similar role in current 

disaster assistance programs, most notably the Supplemental Revenue Assistance Payments 

(SURE) program. However, since payments through SURE lag the actual disasters, current 

data on these payments are preliminary and understate total impacts.
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 9

are clearly trending upward. The rise in total payments is due to a combination of 

expanded enrollment in crop insurance, increased liabilities due to higher yields and 

commodity prices, and a series of major droughts in recent decades. 

How Is Drought Measured?

The details underlying standard measures for drought are crucial to understanding 

the drought risk measure that we construct for this study. Droughts vary by timing, 

duration, severity, and geographic extent. Since each of these factors infl uences 

drought impacts, meteorologists and statisticians have developed drought indices 

to make comparisons across years within a given region and across regions within 

a given year. Every drought index includes some measure of precipitation. Many 

drought indices refl ect other environmental factors such as temperature, wind, and 

soil characteristics. Drought indices often differ based on differing defi nitions of 

drought and in their statistical derivations (see box, “Drought Indices”).

Meteorologists, hydrologists, and other researchers have not reached a scientifi c 

consensus on the “best” technical defi nition of drought. By common usage, drought 

Figure 4

Drought-related indemnity and disaster assistance payments, 1970-2011

Notes: Following Glauber (2004), Commodity Credit Corporation (CCC) disaster assistance payments are lagged by 1 year (i.e., FY95 

payments appear above in 1994 since losses for those payments occurred in 1994). Beyond drought, major disaster assistance payments 

reflect a variety of disasters: floods (1993), freezing (1994), low prices (1998-2000), and hurricanes (2006). While some of the indemnities 

shown here include coverage for drops in commodity prices, this figure does not include major ad hoc payments that are recorded in CCC 

tables as “market loss assistance,” including $6.6 billion in 1998, $14.8 billion in 1999, and $11.3 billion in 2000 (all nominal dollars), or other 

standing assistance programs such as marketing loans because these programs are not related primarily to yield risk. 

Sources: USDA Risk Management Agency provides “cause-of-loss” files that categorize indemnity payments by cause of loss for the (crop) 

year in which they occur. USDA provides annual (FY) reports of CCC expenditures, including a category for disaster assistance. Disaster 

assistance is categorized as either drought-related or other (non-drought-related) based on descriptions of appropriations given in Congressional Research Service Report RL31095. Disaster relief payments for 1981-85 are from Glauber (2004). More recent disaster assistance 

payments are obtained from annual CCC reports (http://www.fsa.usda.gov/FSA/webapp?area=about&subject=landing&topic=bap-bu-cc).

Billion dollars (adjusted for inflation to 2010 dollars)

0

2

4

6

8

10

12

Crop year

Drought-related indemnities

Estimated drought-related disaster assistance

Other indemnities

Other disaster assistance

1970 72 74 76 78 80 82 84 86 88 90 92 94 96 98 2000 02 04 06 08 10
10 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

is a prolonged shortage of water, usually of precipitation. Defi nitions of drought 

differ in the type of water shortage emphasized and in how shortage is defi ned. For 

example, “meteorological drought” emphasizes shortages in precipitation, “hydrological drought” emphasizes shortages in surface-water fl ows, and “agricultural 

drought” emphasizes shortages in soil moisture.5

5 Sometimes these defi nitions of drought are distinguished by the relevant time horizon 

for which they are designed. “Agricultural drought” is often more of a short-term measure 

since short-term droughts (on a weekly or monthly scale) can have large agricultural 

impacts; “meteorological drought” is a medium-term measure (on a multi-monthly or annual 

scale) since most ecological systems can “store” water locally over several months; and 

“hydrological drought” is a long-term measure (both intra- and inter-annual) since reservoirs, 

aquifers, lakes, and rivers often contain water that fell as precipitation in previous years.

Drought Indices

Index Overview Comments

Standardized Precipitation 

Index (SPI)

Measures the divergence of total 

precipitation (totaled over a given 

time scale) from the historical 

median precipitation. Negative 

values indicate below-average 

cumulative precipitation.

Only measures precipitation; rescales deviation 

to refl ect drought rarity (frequency) rather than 

drought severity. 

Available on various time scales indicated by the 

number of months over which precipitation is 

totaled (SPI-1 to SPI-60).

Has been found to be better, in a statistical 

sense, than the PDSI at making comparisons 

across months and across regions (Guttman 

1998).

Palmer Drought Severity 

Index (PDSI ) and Palmer 

Modifi ed Drought Index 

(PMDI)

Tracks the stock of soil 

moisture over time based on a 

hydrologic model of recharge 

from precipitation and losses to 

evapotranspiration, infi ltration, 

and runoff. Negative values 

indicate below-average soil 

moisture.

Incorporates key variables beyond precipitation 

that infl uence drought severity.

Usually calculated at a monthly time scale.

Has long “memory,” which requires signifi cant dry 

periods to “start” a drought and signifi cant rainy 

periods to “end” a drought.

Introduced the idea of moderate (PDSI from -2 to 

-2.99), severe (-3 to -3.99), and extreme (-4 and 

below) drought.

Palmer derivatives (PHDI, 

Palmer-Z, CMI)

These indices extend the PDSI 

to different time periods.

The Palmer Hydrologic Drought Index (PHDI) has 

longer memory than the PDSI, which makes it a 

better measure of long-term drought.

The Crop Moisture Index (CMI) is calculated on 

a shorter time scale (often weekly) and has a 

shorter memory than the PDSI, which makes it 

better at forecasting impacts on crops.

Surface Water Supply Index Tracks storage in reservoirs, 

rivers, and snowpack.

Useful to measure the severity of drought in the 

Western U.S. where surface-water supplies are a 

key focus.

Drought Monitor A compilation of PDSI, CMI, SPI, 

and other measures

A low-resolution drought index intended for 

national or regional analysis. A collaborative 

effort between USDA and the National Oceanic 

and Atmospheric Administration.

Sources: Hayes (2006) and Heim (2002).
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 11

A drought index can perform several different functions, and the choice of an appropriate index depends upon the context in which it is being used:

• In an agricultural production context, a drought index can identify the onset 

of drought, which can facilitate adoption of adaptation or mitigation practices 

at the farm level and resource-management-agency level.

• In an administrative context, a drought index can be used as a trigger for 

some action, such as distribution of disaster or indemnity payments.

• In a statistical context, a drought index can be used to compare drought 

outcomes at different points in time or across different geographic areas. 

Much of the scientifi c debate over choice of drought index is related to statistical properties of the different indices.

Average precipitation and the resulting water shortages can vary dramatically by 

region, so most drought indices measure departures from a local, longrun average. 

Negative values refl ect water shortages relative to average conditions, while positive 

values refl ect water surpluses. To allow for comparisons on a national level, drought 

indices are usually rescaled to refl ect some standardized measure of drought severity 

or drought frequency.6 Figure 5 shows how drought severity, as measured by the 

Palmer Modifi ed Drought Index (PMDI), varies over time and across regions. The 

continuous PMDI measures are mapped into four categories (minimal or no drought, 

moderate drought, severe drought, and extreme or exceptional drought), and the 

share of cropland in each category is mapped over the past century for two States—

South Dakota and Indiana—with very different histories of exposure to drought. 

The location and geographic extent of a drought are key determinants of its impact 

on agricultural markets. During the Dust Bowl in 1934, about 55 percent of U.S. 

agricultural land was affected by severe or extreme drought (as measured by the 

Palmer Drought Severity Index). The 1954 and 2012 droughts were almost as severe 

and extensive as the 1934 drought. In contrast, at the height of two other major 

droughts in the past 50 years (1988 and 2002), about 20 percent of agricultural land 

was under severe to extreme drought (Gollehon and Buckholtz, 2007). The marketlevel effects of drought depend on the severity and the spatial extent of the drought, 

as well as the coincidence of drought area with major commodity production areas.

The duration and timing of drought are often key determinants of drought impacts. 

Major droughts are typically both widespread and prolonged (often spanning 1 to 10 

years).7 In agricultural production, though, even short-term droughts (ranging from 

6 Deviations in absolute levels of precipitation would not capture the signifi cance of 

meteorological drought. For example, a shortfall of a few inches in annual precipitation is 

probably not signifi cant in Birmingham, Alabama, which has an average annual precipitation 

of 54 inches, while such a shortfall could have major impacts in Casper, Wyoming, which has 

an average annual precipitation of about 13 inches. 

7 The major droughts of the past century may not represent the worst that can occur. 

Drought measures for the past 2,000 years, reconstructed from tree ring observations, 

suggest that some historical droughts far exceeded the Dust Bowl drought in duration and 

severity (Wodehouse and Overpeck, 1998).
12 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

Figure 5

Drought severity in South Dakota and Indiana, 1912-2008 

Sources: ERS calculations based on county-level cropland acreage from the 2007 Agricultural Census and weather-station-level Palmer 

Modified Drought Index (PMDI) data from the National Oceanic and Atmospheric Administration. The weather station-level data were 

interpolated to county centroid for the July PMDI. (http://www.ncdc.noaa.gov/temp-and-precip/drought/nadm/indices.php?mdf=data&divstn=

stn&indicator=palmer). 

Share of cropland

0

20

40

60

80

100

1912191619201924192819321936194019441948195219561960196419681972197619801984198819921996200020042008

South Dakota 

Moderate drought Severe drought Extreme or exceptional drought

0

20

40

60

80

100

1912191619201924192819321936194019441948195219561960196419681972197619801984198819921996200020042008

Indiana

Share of cropland
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 13

a few weeks to a few months) can have major impacts because soil moisture during 

key stages of plant development is a critical determinant of crop yield. 

What Is Drought Risk?

Drought severity, as captured by drought indices, is a measure taken at a given 

point in time. Climatologists refer to such measurements as weather and distinguish weather from climate. Measures of climate (such as average temperature in 

June) refl ect longrun patterns at a given location. In contrast to drought severity 

and duration, which refl ect prevailing weather conditions at a point in time, drought 

risk is a measure of climate. Drought risk captures differences across regions in 

the likelihood of periodic water shortages. The semi-arid Western regions of the 

United States generally face greater drought risk because their average soil moisture 

content is lower than in more humid regions, causing extreme droughts to occur 

more frequently.8 When farmers make long-term decisions about how to prepare 

for potential drought—including decisions about retiring cropland or investing in 

major conservation practices—they are adapting to drought risk, not current weather 

conditions.

Efforts to measure drought risk, or the related concepts of drought proneness and 

drought vulnerability, are less common than efforts to develop drought indices. 

Wilhelmi and Wilhite (2002) and Banik et al. (2002) both attempt to develop localized measures of drought risk for agricultural land in Nebraska and Maharashtra 

(India), respectively. In general, drought experts recognize that drought risk refl ects 

several climate-related factors, including variance in precipitation, the correlation 

between high temperatures and precipitation shortages, and soil’s capacity to store 

water. Measures of drought risk can either be constructed directly from these variables or from drought indices. 

Since severe droughts are rare events, good measures of drought risk require 

decades of weather data. Instrumental weather data are available in most U.S. 

locations for about 100 years, although data on some weather variables (such 

as humidity, evapotranspiration, and wind) are only available for the past few 

decades. While some meteorological studies suggest that drought risk can change 

over decades in response to changing sea-surface temperatures, detecting changes 

in drought risk as they occur is exceptionally diffi cult (Cook et al., 2007).9 Under 

several major climate change scenarios, drought risk is projected to increase for 

most of North America, in part because increases in average temperatures will lead 

to lower soil moisture levels, even in those regions of the country where annual 

precipitation is projected to increase (Hirabayashi et al., 2008; Strzebek et al.,

2010). 

This study relies on a measure of drought risk constructed from the PMDI. For our 

drought-risk measure, we estimate the variance in the June PMDI, calculated at the 

8 See Appendix A for a discussion of spatial differences in factors that contribute to 

drought risk.

9 Given that we are examining regional difference in drought risk and participation in 

conservation programs, we assume that drought risk is fi xed over our timeframe within 

regions. 
14 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

weather-station level from over 100 years of data and interpolated to the county 

level. We selected the June-based measure because early to midsummer is a critical 

period for crop development for most major crops (Prasad et al., 2008; USDA/

NASS, 2010). In addition, within a given area (a county or a weather station), 

drought risk measures are very similar across growing season months.10 Variance 

of PMDI is roughly equivalent to measures of drought risk based on the frequency 

of a severe or extreme drought per decade or per century, but the variance-based 

measure is better at capturing minor variations in drought risk.11 Figure 6 maps this 

measure of drought risk. Appendix A discusses these calculations in greater detail. 

What Is Drought Risk Adaptation?

Drought vulnerability is closely related to and often confused with drought risk, but 

drought vulnerability invokes choices. Drought risk is a climatic characteristic that 

is static and does not vary with the choices made by individuals and governments. 

In contrast, drought vulnerability is the probability of experiencing drought-related 

damage, which depends upon a variety of production decisions, policy choices, 

and site-specifi c resources. For example, two irrigators in the same county would 

face the same drought risk, but the farm with access to a more reliable source of 

water would be less likely to experience negative impacts from a drought and so 

would have lower drought vulnerability. Economic modeling can help us understand how farmers make choices that may either reduce or exacerbate their drought 

vulnerability. 

Drought preparedness is the state of having planned and taken actions in advance 

that reduce drought vulnerability. Agricultural drought preparedness is not a very 

precise policy goal because farmers and resource managers are rarely willing or 

able to totally eliminate drought vulnerability.12 Proposals to increase drought 

preparedness often operate on two assumptions: (1) farmers can take certain 

actions to be more prepared for drought and to reduce drought vulnerability; and 

(2) farmers are not taking these actions to a suffi cient degree, with implications 

for regional economic costs and Federal budgetary liabilities. The degree and 

suffi ciency of drought preparedness is determined by particular actions, including 

production decisions (crop choices, irrigation, and conservation practices) and 

revenue risk management strategies (insurance, contracting, savings, off-farm 

10 At the weather-station level, the correlation coeffi cient for June and July PMDI 

variances is 0.95, for July and August it is 0.96, and for June and August it is 0.90. In other 

words, regions that are more prone to experience June drought are almost equally prone 

to experience July drought and so on. Not surprisingly, the lowest correlation is between 

January- and July-based drought risk measures, but even those two variances have a 

correlation coeffi cient of 0.51.

11 For example, 2 counties with 10 severe or extreme droughts over the past century 

would have the same drought risk measure under a frequency-based calculation but would 

probably have different drought risk measures under a variance-based calculation since the 

PMDI values are not likely to be identical for both boundaries. In this sense, frequency-based 

measures of drought risk are “throwing away information” by categorizing droughts into 

discrete (but overly broad) categories of severity. 

12 In contrast, many drinking water-supply systems maintain suffi cient capacity to nearly 

eliminate the risk of drought restrictions.
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 15

income). It is also important to consider why relative inaction by some farmers 

might occur.13

Drought risk adaptation is the process of selecting the appropriate level of drought 

preparedness conditional on drought risk. Farmers facing high levels of drought risk 

13 There are a number of reasons why farmers might not exhibit maximum drought 

preparedness in their production decisions: (1) farmer preferences (i.e., risk aversion); (2) 

costs (i.e., even for highly risk-averse farmers the opportunity costs of drought preparedness 

may be too high); (3) perverse incentives or moral hazard (i.e., farmers may assume riskier 

choices if risk-mitigating policies are in place); or (4) market failure (e.g., a failure to properly 

price risk-reducing or risk-increasing inputs/practices).

Figure 6

Variation in drought risk as measured by the Palmer Modified Drought Index (PMDI) 

Notes: Drought risk is calculated as the standard deviation in natural soil moisture over the past century as captured in the PMDI in June of 

each year. Drought risk is calculated at weather stations and then interpolated to county centroids using the seven nearest weather stations to 

each centroid (http://www.ncdc.noaa.gov/temp-and-precip/drought/nadm/indices.php). The variance categories can be converted into ranges 

of the expected number of severe or extreme droughts per century as follows:

• Highest risk: 12.2-19.3 per century

• Moderate risk: 9.0-12.1

• Average risk: 7.4-8.9

• Low risk: 6.6-7.3 

• Lowest risk: 1.8 -6.5

Source: ERS calculations based on National Oceanic and Atmospheric Administration station-level data. Spatial patterns are reflective of the 

underlying spatial patterns in temperature and precipitation. Corrections were not made for the few outliers that result from outliers within the 

original weather station data. 

Standard deviation in June PMDI

Drought risk

Highest risk

Moderate risk

Average risk

Low risk

Lowest risk
16 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

have a higher incentive to invest in drought preparedness. However, these same 

farmers may also face higher costs of investing in drought preparedness. Drought 

risk is one of several drivers of farmers’ production decisions, and conservation 

choices are among the many production decisions that farmers must make. While 

this report focuses on conservation program decisions, many production decisions 

are a part of drought adaptation. 
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 17

The Conservation Reserve Program and Drought 

Risk Adaptation

The Conservation Reserve Program (CRP), introduced in 1985 and reauthorized 

under subsequent farm acts, is the primary USDA program for retiring environmentally sensitive land from crop production. Landowners participating in CRP agree 

to remove farmland from agricultural production and maintain specifi ed cover crops 

and conservation practices on that land under long-term (10-15 year) contracts. 

In return, participants receive an annual rental payment plus additional fi nancial 

assistance to establish and maintain vegetative cover that enhances environmental 

benefi ts. Eligible land includes highly erodible cropland and other environmentally 

sensitive land with an established cropping history. An estimated 212 million acres, 

or 23 percent of U.S. farmland, are eligible to participate in CRP; as of June 2012, 

about 29.6 million acres were enrolled. 

Enrolling Land in CRP

Farmers and farmland owners have two options for enrolling land in the CRP. 

Under the general signup, parcels are offered for enrollment during designated 

signup periods that typically last only a few weeks.14 Under the continuous signup, 

which tends to involve more intensive conservation practices on smaller parcels of 

land, parcels within special project areas may be offered for enrollment at any time 

during a year. This report focuses on farmer participation in the general signup, 

which accounts for 24.3 million of the 29.6 million acres in CRP. 

In the general signup, owners of eligible land submit an offer to enroll a specifi c 

parcel. To meet eligibility requirements, a land parcel must have an established 

cropping history (i.e., have been in crop production for 4 of the 6 years prior to the 

most recent authorizing (2008) Farm Act) or be currently enrolled in CRP under a 

contract that is expiring. In addition, a land parcel must either be highly erodible 

land (as determined by an erodibility index calculated by NRCS) or located within 

conservation priority areas designated by USDA’s Farm Service Agency (FSA) in 

cooperation with each State or subject to an expiring contract. 

For each parcel, an offer to enroll in CRP consists of a bid with a proposed annual 

rental payment (the “bid rate”), a proposed set of conserving practices, and a decision whether to accept fi nancial assistance that offsets the installation costs for 

conservation practices (fi g. 7). Annual rental payments are subject to bid caps 

(maximum bid rates), which vary by county and by soil type. Offers are ranked 

nationally by FSA using an Environmental Benefi ts Index (EBI) that assigns points 

based on fi eld characteristics (such as erodibility), proposed conservation practices, 

and the bid rate. Prior to 2010, offers were also awarded points based on the acceptance or rejection of fi nancial assistance. 

14 In most cases, there is one general signup period per year, but not all years have had 

general signups due to regulatory review requirements and an extended re-enrollment and 

extension (REX) process that occurred during 2006.
18 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

Figure 7

Enrollment process for general signup Conservation Reserve Program

Decisionmaker Decision Economic

Analysis

Congress

+

USDA (FSA)

Is land eligible to enroll?

(Eligibility is determined by requirements 

set in each Farm Act and by designiation 

of conservation priority areas established 

by FSA and the States.) Yes No

Landowner/

Farmer

Is an offer made?

Yes No

Yes No

Offer rates *

(Likelihood to bid)

Decision Tree

What is the offer?

(Farms make a bid that 

specifies the practices

to be installed on the

land and an annual 

rental rate that is 

limited by a 

county-specific,

soil-type-adjusted

bid cap)

Rental rate bid

+

Practices applied

+

Field

characteristics

=

EBI score

USDA (FSA)

Is the offer accepted?

(FSA chooses an

EBI cut-off subject

to county enrollment 

caps and a national

enrollment cap)

Contract is signed and

parcel is enrolled in CRP

Bid premiums

and conservation

practice selection **

Enrollment rates ***

* This report is the first study to econometrically examine offer rates.

** A handful of studies examine bid premiums and practice selection (Kirwan et al., 2005; Roberts and Lubowski, 2007; Vukina et al., 2008).

*** Many CRP participation studies look at enrollment outcomes at either the field level or the county level (Wu, 2000; Sullivan et al., 2006; 

 Wu and Lin, 2010).

USDA’s Farm Service Agency (FSA) begins the process by announcing the date for a general signup and establishing 

the formula for calculating the Environmental Benefits Index (EBI), which is used to rank offers.

ELIGIBILTY OFFERS ENROLLMENT
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 19

Environmental benefi ts considered under the EBI have evolved from an initial focus 

in the early 1990s on soil erosion control on highly erodible land. At the time of 

preparing this report, the EBI is based on six factor scores, including fi ve environmental factors: wildlife habitat, onfarm soil erosion, water quality, air quality, and 

enduring benefi ts beyond the contract period. Wildlife habitat, soil erosion, and 

water quality benefi ts receive the greatest weight, followed by enduring benefi ts and 

air quality benefi ts.15

At the end of a general signup, FSA selects a cutoff EBI score and enrolls those 

parcels with an EBI score at or above the cutoff. When submitting an offer, landowners know their own EBI score but not the fi nal EBI cutoff. Landowners can 

increase their EBI score and thus the probability that their offer will be accepted by 

either lowering their bid rate or selecting conservation practices with higher EBI 

points. Several studies confi rm that landowners choose bid rates and practices strategically (Kirwan et al., 2005; Roberts and Lubowski, 2007; Vukina et al., 2008).

Enrollment in CRP is potentially constrained by national and county acreage enrollment caps, although the signifi cance of enrollment caps varies among counties and 

over signups. A national cap on CRP acreage enrollment has been modifi ed under 

successive farm acts; the 2008 Farm Act set the current national enrollment cap 

at 32 million acres.16 The county enrollment cap stipulates that no more than 25 

percent of a county’s cropland may be enrolled in the program.17 Many U.S. counties are at or near this cap, while other counties (with less than 25 percent of cropland eligible for CRP) are not impacted at all. Landowners in counties that are at or 

near the cap are likely to be more reluctant to offer their land in the general signup 

since the likelihood of acceptance is diminished. 

Modeling Drought Risk Adaptation and the CRP

This report illustrates the challenge of using existing conservation programs to facilitate climate adaptation, specifi cally to drought risk. If landowners consider drought 

risk when deciding whether to offer eligible land for CRP contracts, then CRP is 

already facilitating climate adaptation, albeit indirectly. Changes to the design of 

CRP, even if those changes are designed to address the conservation goals of the 

program, could therefore either facilitate or hinder participation in CRP by landowners who are purposely adapting to drought risk.

How might an offer to enroll land in CRP be a response to higher levels of drought 

risk? The bid caps are designed to set the maximum CRP rental rate equal to the 

expected cash rental rate for cropland given a parcel’s county and soil type, so most 

15 Additional points are assigned to offers that accept below-average rental payments, a 

feature of the EBI that is designed to improve the cost-effectiveness of the CRP.

16 See the ERS topic page on Conservation Programs for more information on enrollment 

caps and other program details (www.ers.usda.gov/topics/natural-resources-environment/

conservation-programs.aspx). 

17 The 2008 Farm Act only applies the county enrollment cap to acres enrolled through the 

general signup, so acres enrolled through the continuous signup no longer count against the 

cap. In some instances, counties have applied for and received waivers for (small adjustments 

to) the enrollment cap.
20 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

landowners should be fairly indifferent between putting land into CRP and leaving 

land in crop production. However, a number of considerations, such as risk aversion 

or dynamic production decisions in water-scarce environments, provide plausible 

reasons for why landowners facing greater drought risk might prefer CRP. 

Over the life of a CRP contract, a farmer receives a fi xed annual rental payment 

for enrolled acreage, thereby lessening farm income variability attributable to price 

and yield variation. Since CRP payments are fi xed, retiring land through CRP 

may enable farmers to diversify their income stream and reduce their exposure to 

revenue risk. Several studies fi nd that risk is an important factor in CRP participation. Lubowski et al. (2006) fi nd that environmentally sensitive land enrolled in 

CRP also tends to be higher risk land, where risk is measured as an acre-weighted 

average of returns to crop insurance premiums. Chang et al. (2008) fi nd that farmers 

accept reduced levels of income with CRP enrollment, which supports the idea that 

risk aversion drives participation decisions. Williams et al. (2010) demonstrate that 

risk-averse farmers are likely to prefer CRP enrollment to standard cropping rotations in western Kansas. 

Even if farmers are not risk averse, CRP may have added benefi ts in more droughtprone regions. Idling cropland can be an important way to replenish soil moisture 

and recharge aquifers, which could provide benefi ts to cropland adjacent to parcels 

enrolled in CRP (Rao and Yang, 2010). Also, special grazing provisions under the 

CRP may be attractive to livestock producers with eligible cropland enrolled in the 

program, and livestock production is generally more prevalent in regions of the 

country facing higher drought risk. 

Much of the CRP enrolled acreage is concentrated in the Plains States, refl ecting 

the program’s historical emphasis on erosion control on highly erodible soils (fi g. 

8). The biggest challenge in evaluating the effect of drought risk on farmer behavior 

is that the EBI may favor enrollment of marginal soils in transitional agricultural 

zones (corn/wheat, wheat/grasslands), which are also apt to be more vulnerable to 

drought. Since enrollment rates are likely to be higher in high-risk counties, county 

caps are more likely to be binding in those counties. Failing to control for county 

caps likely understates the impact of drought risk on CRP offer rates because offers 

are less likely when county caps are binding.18 

Some facets of the CRP may actually discourage farmers from using the program 

for drought risk adaptation. Bid caps refl ect local rents for dryland production, 

so limits on rental payment rates may drive down enrollment in irrigated areas 

of the West where higher returns to irrigated production are capitalized into the 

value of the land. However, increased fi nancial assistance for irrigated enrollment may be available through Federal/State partnerships under the Conservation 

Reserve Enhancement Program (CREP). In several CREP project areas where 

fi nancial assistance is available, retirement of irrigated lands improves water supply 

reliability—a de facto response to drought risk—for remaining irrigators and for 

18 A similar issue arises for irrigation adoption rates. Since irrigation adoption is likely 

greater in areas with higher drought risk and since irrigated land is much less likely to accept 

dryland rental rates for crop retirement, failing to control for irrigation would likely understate 

the impact of drought risk on CRP offer rates.
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 21

environmental fl ows.19 County-level enrollment ceilings that restrict enrollment to 

not more than 25 percent of cropland may also be limiting in drought-affected areas. 

Since binding county caps and extensive irrigation adoption are (potentially) positively correlated with drought risk and negatively correlated with CRP enrollment 

decisions, failing to control for the effects of these factors could lead to a downwardly biased estimate of the effect of drought risk on offer rates. 

19 Today, four CREP projects in Western river basins target irrigated land retirement 

to achieve reductions in consumptive water use and restoration of hydrologic fl ows and 

groundwater systems. The projects are intended to lessen the effect of water-supply shortfalls 

on agricultural producers and natural systems during periods of drought. Through these 

projects, FSA offers higher payments tied to irrigated rental rates for projects that create 

water savings, while State, tribal, and private partners may provide funding for additional 

expenses, including permanent easements and retirement of water rights. The partnership 

also acknowledges the primacy of State law in water-supply management, helping ensure 

that water withdrawals are restricted in project areas and that resulting water savings are 

allocated to desired uses. 

Figure 8

Conservation Reserve Program enrollment by county, 2011

Source: USDA Farm Service Agency data on county-level CRP enrollment. 

Total acres enrolled

Enrollment as of October 1, 2011

0 - 500

501- 5,000

5,001 - 25,000

25,001 - 50,000

50,001 - 274,281
22 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

Data and Methods 

This study is the fi rst to econometrically estimate the likelihood that cropland is 

offered for enrollment in CRP. Conceptually, we build on earlier efforts that evaluated the probability that farmland is enrolled in CRP (e.g., Wu, 2000; Sullivan et 

al., 2004; Lubowski et al., 2006; Wu and Lin, 2010).20 While assessing CRP participation in terms of the probability of being enrolled rather than making an offer 

may be necessary given traditional data sources, there is a downside: enrollment 

refl ects both the landowner’s decision and FSA’s ranking of offers using the EBI. 

Moreover, when working with observations of enrollment rather than offers, it is 

diffi cult to correctly control for the infl uence of county enrollment caps.

For this report, our analysis uses a combination of data on CRP offers and data on 

land eligibility and availability. The offer data are traditionally used to evaluate 

how landowners formulate their offers to enroll land in CRP (Kirwan et al., 2005; 

Roberts and Lubowski, 2007; Vukina et al., 2008). The offer data do not include 

any information on landowners who did not make a bid, so the data are insuffi cient 

for analyzing factors that infl uence landowner decisions to bid or not. Our analysis 

was made possible by the construction of a careful measure of land eligible for 

CRP enrollment within each county. To compute, for every county, the number of 

acres “eligible” for the program, we use data on soil erodibility, cropping history, 

and conservation priority area delineations. To compute the number of eligible 

acres that are “available” to be offered in a signup, we subtract enrolled acres from 

eligible acres.21

Our strategy is thus to model the farm-level decision of whether to make an offer 

in a CRP signup. We incorporate nonparticipants into the model by aggregating 

offered acreage and eligible acreage at the county level. We model offer rates as 

the share of eligible acres (not already in the program) that are offered. For our 

offer data, we use the offer rates that occurred during the eight most recent general 

signups: 1997, 1998, 1999, 2000, 2003, 2004, 2006, and 2010. Participation probabilities are estimated using a grouped logit model, the results of which are detailed 

in Appendix B.

To determine how the CRP may be used for drought risk adaptation, we estimate 

the effect of drought risk on the probability of eligible land being offered to the 

program. Spatial variation in drought risk is captured by calculating, at the county 

level, the long run variance in the Palmer Modifi ed Drought Index (PMDI). Other 

variables, also measured as county averages, are included to control for attributes 

that may be correlated with drought risk. 

20 Those studies that model the participation decision usually compare participants to 

non-participants by either sampling parcels of land or aggregating contract data to the county 

level. Samples of parcels identifying CRP enrollment status can be obtained from either the 

Natural Resources Inventory (NRI) data or from the Agricultural Resource Management 

Survey (ARMS) data. Data on contracts (acres enrolled) at the county level can be obtained 

from FSA and combined with Agricultural Census data to generate an estimate of the share 

of cropland enrolled in CRP.

21 Acres enrolled in an expiring CRP contract are not subtracted from eligible acres since 

they are eligible to re-enroll.
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 23

Results: Base Case and Policy Scenarios

The model results indicate that drought risk is a strong predictor of the likelihood 

that eligible land is offered for enrollment into CRP.22 Our analysis of offer rates 

therefore suggests that landowners use the CRP as a tool for drought risk adaptation. We also fi nd that nearly binding county enrollment caps reduce the probability 

that eligible land is offered for enrollment. A higher average EBI score—looking 

only at the (environmental) portion of the EBI score that is not directly affected by 

the bids—leads to a higher probability that eligible land is offered. We also fi nd 

that higher average soil rental rates lead to a lower probability of eligible land being 

offered. Details on the magnitude of these effects and on the likely reasons for such 

farmer behavior are discussed in Appendix B. 

Given the potential for increased drought risk under projected climate change 

scenarios, CRP design options, such as eligibility and enrollment rules, may be 

able to enhance the program’s usefulness for drought adaptation. We evaluate 

three program design provisions—the EBI, county enrollment caps, and eligibility 

criteria—in that regard. To implement these drought adaptation scenarios, we categorize counties as having either low, medium, or high drought risk.23 The specifi c 

scenarios are as follows:

1. An EBI adjustment that adds a “drought risk factor” (DRF). The EBI-DRF

scenario creates a factor that assigns an additional 10 or 20 EBI points to 

counties with medium or high drought risk, respectively. Thus, if having a 

higher EBI score increases the attractiveness of offering a parcel to the CRP, 

incorporating drought risk will increase offers in drought-prone counties and 

reduce offers in less drought-prone counties.

2. A county cap adjustment (CC) that increases the share of total cropland that 

can be enrolled in a county. The CC-35 variant of this scenario models an 

increase in the cap from the current level of 25 percent of county cropland 

to 35 percent. The CC-70 variant models an increase to 70 percent of county 

cropland. The CC-70-HDR variant models an increase in the county cap for 

only those counties with the highest levels of drought risk.

3. An eligibility adjustment (EA) that increases land eligible for enrollment 

in high-drought-risk counties. As with conservation priority areas, the EA

scenario assumes that all land in high-drought-risk regions with an appropriate cropping history would be eligible for enrollment. In other words, to be 

eligible for CRP enrollment, farmland would either have to be highly erodible, within a conservation priority area, or located in a county with a high 

level of drought risk. 

The fi rst scenario we consider is the revision of the EBI to assign points for land in 

counties facing higher drought risk. Changing the EBI to refl ect drought risk in the 

22 See tables B3 and B4 in Appendix B for details on model estimation.

23 Based on the PMDI drought risk measure defi ned in Appendix A, the low-, medium-, 

and high-drought-risk counties represent 85 percent, 7.5 percent, and 7.5 percent of counties, 

respectively. Since drought-prone counties in the West tend to be larger, the 85 percent of 

counties that are low drought risk represent only 75 percent of CRP-eligible acreage.
24 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

EBI-DRF scenario leads to a small increase in offer rates and a 1.4-percent increase 

in total acres offered (table 1).24 Raising the EBI in high-risk counties effectively 

lowers the normalized (relative) EBI in other counties. In other words, the increase 

in offer rates in high-drought-risk (HDR) counties is offset by the decrease in offer 

rates in other counties. This suggests that a moderate increase in EBI points, granted 

to medium- and high-drought-risk counties, would have a limited impact nationally 

(increasing total acres offered by less than 2 percent) but a more pronounced impact 

within drought-prone counties (fi g. 9). 

The CC scenarios, in which the county cap is increased, show more substantive 

changes in expected offer rates (fi g. 10). For example, the CC-70 scenario yields an 

almost 28-percent increase in offered acres (when compared to the baseline), over 

a third of which come from the high-drought-risk counties. (Of an average increase 

of 588 acres per county, 207 come from the 13 percent of counties that are medium 

or high drought risk. In general, HDR counties have higher offer rates and larger 

percentage point changes in offer rates in all scenarios (table 1). This large increase 

in rates, combined with the larger size of HDR counties, explains why HDR counties comprise such a disproportionate share of the increase in offered acres. 

24 Due to aggregation of data and uncertainty regarding unobserved characteristics on 

nonparticipating eligible lands, scenario results should be taken as indicative of the type of 

possible responses to changes in CRP policies. 

Table 1

Offer rates under alternative program design scenarios

Percent of eligible 

acres that are offered

Percentage change 

in total acres offered 

compared to baseline

Percent of eligible 

acres that are offered

Percentage change 

in total acres offered 

compared to baseline

All counties Drought-prone counties1

Observed 7.08 9.66

Baseline prediction 7.08 10.04

Program design scenarios

Changing the EBI

1) EBI-DRF2 7.12 1.4 10.29 4.1 

Changing county caps

2a) CC-353 7.26 7.2 10.39 6.9 

2b) CC-704 7.59 27.6 11.08 27.7 

2c) CC-70-HDR5 7.23 9.9 11.08 27.7 

Changing eligibility

3) EA6 7.08 38.0 10.04 106.4 

1Drought-prone counties are those in the top 15th percentile of drought risk (those with a drought risk score above 2.65). 

2Increases the Environmental Benefi ts Index score (drought risk factor) for land in medium- and high-drought-risk counties. 

3Increases the county enrollment cap to 35 percent of cropland acres for all counties.

4Increases the county cap to 70 percent for all counties. 

5Increases the county cap to 70 percent for high-drought-risk counties only. In the CC-70-HDR scenario, counties that are not highly 

drought prone have no change in county caps and therefore are not affected by the program design change. Thus, changes in the “all 

counties” column for the CC-70-HDR scenario are entirely due to changes in the 13 percent of counties that are HDR. 

6Eligibility adjustment; eliminates the crop history requirement for eligibility within high-drought-risk counties.
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 25

In the EA scenario a dramatic expansion in CRP eligibility in drought-prone counties has a large impact on total acres offered into CRP (fi g. 11). Offer rates remain 

essentially identical to the baseline as both acres offered and eligible acres increase 

proportionately. However, total acres offered increase by almost 40 percent for 

all counties, and over 100 percent for HDR counties (table 1). These calculations 

assume that landowners with currently ineligible acres in HDR counties will have 

the same propensity to offer land to the CRP as landowners with currently eligible 

acres, which may lead to an overestimation.

One caveat to these results is that it is not possible to model the corresponding 

impact of increased offers leading to increasingly binding county caps. We cannot 

model this because we do not model which offers will be accepted. The geographic 

distribution of enrollment, as well as the net environmental impacts, depends not 

only on offer rates, which we model, but upon the structure of the offers (i.e., the 

portion of EBI score determined by conservation practice decisions), which we 

do not model. Future research is needed, along with parcel-specifi c data, to accurately predict the enrollment and environmental outcomes of these program design 

options.

Figure 9

Scenario map for changes in Environmental Benefits Index (EBI) 

Drought risk EBI factor

Change in offered acres

-9 - 0

0 - 300

301 - 600

601 - 1,000

> 1,000

Source: USDA Economic Research Service simulations based on model of Conservation Reserve Program offer rate.
26 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

Figure 10

Scenario map for increases in county caps

35-percent enrollment cap

Change in offered acres

0 - 300

301 - 600

601 - 1,000

1,001 - 5,000

> 5,000

70-percent enrollment cap

Change in offered acres

0 - 300

301 - 600

601 - 1,000

1,001 - 5,000

> 5,000

Source: USDA Economic Research Service simulations based on model of Conservation Reserve Program offer rate. 
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 27

Conclusion

We fi nd that drought risk currently infl uences CRP offer rates, which likely occurs 

because the revenue certainty associated with CRP payments is more important 

to landowners in higher risk regions. This fi nding implies that the CRP is already 

implicitly serving as a tool for drought risk adaptation. Landowners in higher 

drought-risk (HDR) regions are more likely to offer eligible land for enrollment in 

CRP, which increases competition for enrollment in these regions and makes county 

enrollment caps more likely to be binding. 

Changes in CRP provisions could infl uence how producers rely on the CRP for 

drought risk adaptation. These program design provisions include changes that 

explicitly focus on drought-prone counties, such as adding points to the EBI or 

relaxing eligibility requirements in HDR counties, as well as changes that may be 

applied nationally, such as relaxing county enrollment caps. However, changes in 

Figure 11

Scenario map for changes in CRP eligibility 

Expanded eligibility in high-risk counties

Change in offered acres

0

1 - 300

301 -600

601 - 1,000

1,001 - 5,000

5,001 - 20,000

Source: USDA Economic Research Service simulations based on model of Conservation Reserve Program offer rate.
28 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

CRP enrollment to address drought risk may affect regional enrollment patterns, 

with implications for environmental benefi ts, rural economies, and program 

cost-effectiveness. 
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 29

The Environmental Quality Incentives Program and 

Drought Risk Adaptation

The Environmental Quality Incentives Program (EQIP), introduced in 1996 and 

extended under the 2002 and 2008 Farm Acts, is the Nation’s primary conservation program for working farms and ranches. Administered by USDA’s Natural 

Resources Conservation Service (NRCS), EQIP provides technical and fi nancial 

assistance for the adoption of conservation practices under contracts ranging from 1 

to 10 years. 

EQIP is a complex program that addresses many different resource concerns. In the 

enabling regulations for EQIP, NRCS identifi ed fi ve national environmental priorities for the program: (1) reduction of nonpoint-source pollution in impaired watersheds, (2) conservation of ground and surface water, (3) reduction of emissions that 

contribute to air quality impairment, (4) reduction in soil erosion and sedimentation, and (5) conservation of wildlife habitat for at-risk species (USDA/NRCS and 

CCC, 2009). NRCS developed a list of 80 resource concerns that fall within these 5 

categories. EQIP provides payments for over 150 different types of practices, each 

of which addresses one or more of these resource concerns. State and county NRCS 

offi ces, given their knowledge of local conditions, have considerable fl exibility in 

identifying which combinations of resource concerns and practices represent the 

most appropriate use of EQIP funds. However, EQIP is a voluntary program, so the 

willingness of farmers to enter into contracts for the desired practices is also key to 

program outcomes. 

Enrolling in EQIP

As with CRP, farmers voluntarily apply for EQIP. Farmers must submit an EQIP 

application, with an associated conservation plan, to their local NRCS fi eld offi ce.25

The conservation plan specifi es a set of practices, the fi elds or parcels on which 

those practices will be implemented, the schedule of implementation, and the 

resource concerns that will be addressed by those practices. Enrollment is open to 

all crop and livestock producers.

Many of the conservation practices covered by EQIP result in both offsite environmental benefi ts and onfarm production benefi ts. For example, conservation tillage 

may reduce soil loss and associated off-farm pollution while also helping farmers 

conserve soil moisture for improved productivity. Other conservation practices are 

implemented primarily for their environmental benefi ts. For example, stream buffer 

strips provide both water quality and wildlife benefi ts but do not generally enhance 

returns to crop or livestock production. EQIP is intended primarily to encourage, 

through fi nancial assistance, the adoption of conserving practices that provide environmental benefi ts. Financial assistance for installation of structural and vegetative 

practices ranges from 50 to 75 percent of typical installation costs as established 

at the county level. Annual payments for up to 3 contract years are also offered for 

25 While conservation plans are a prerequisite for EQIP enrollment, a number of other 

programs and policies within USDA also encourage or require conservation plans.
30 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

implementation of management practices relating to nutrient and pesticide use, irrigation water application, and wildlife habitat.

The process for selecting which contracts to fund is an important determinant of 

enrollment rates. Within this process, any practices that farmers favor for drought 

risk adaptation must compete with other practices that may more effectively address 

local environmental resource concerns. The contract selection process for EQIP can 

be divided into two major components: funding allocation and contract ranking. 

Funding allocations infl uence both the spatial distribution of EQIP contracts and the 

types of farms that receive contracts. Contract ranking infl uences which practices 

are funded within a given region.

Funding Allocation

At the national level, EQIP must meet certain congressional mandates for funding 

allocations across agricultural sectors and States. At least 60 percent of funding 

must go toward livestock-related practices. In addition, the EQIP budget is apportioned across States by the NRCS national offi ce. Roughly two-thirds of the 

national EQIP budget appropriation is allocated based on a “general fi nancial assistance” formula, which considers indicators of natural resource endowments and 

priority environmental concerns by State (GAO, 2006). A total of 31 individual 

factors are included in the formula, with corresponding weights that determine how 

much of the total national EQIP budget is allocated by factor. This amount is then 

apportioned across States based on the relative importance of individual factors 

(i.e., measured by number of farms in various categories, highly erodible acres, 

animal units, and miles of impaired streams) in each State. 

The remaining portion of national EQIP funds is allocated across States for conservation technical assistance, performance bonus funds, conservation grants, and 

other special programs. These special programs often target specifi c resource 

concerns and regions. Other funding appropriations made for a number of regional 

programs administered under EQIP rules have included the Colorado Salinity 

Program, the Agricultural Water Enhancement Program (formerly the Ground 

and Surface Water Conservation Program) and the Klamath River Basin Program, 

(GAO, 2006).26 In contrast to CRP acreage enrollment, EQIP funding has been 

fairly evenly distributed across producing areas, refl ecting the wide array of eligible 

practices, the broadly defi ned targeting provisions based on national resource priorities (particularly after 2002), and regional equity considerations (SWCS and EDF, 

2008).

26 Klamath River Basin funds were divided evenly between California and Oregon. 

Funding for the Colorado Salinity Program was divided among Colorado, Utah, and Arizona, 

based on acreage requiring salinity-control treatment. Funding criteria varied by State 

groupings under the Ground and Surface Water Conservation (GSWC) Program. For eight 

Plains States, GSWC funds were tied to acreage overlying the High Plains aquifer. For nine 

Western “drought” States, funding refl ected extent of irrigated acreage. For other States with 

agricultural water needs, distributions were based on proportion of total water diversions 

used for agriculture.
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 31

Contract Ranking

While funding allocations under the general fi nancial assistance formula and 

the special programs effectively determine each State’s EQIP budget, States 

have considerable leeway in allocating funds across resource concerns and locations within the State. Unlike the CRP, States are given wide discretion in setting 

resource priorities, defi ning priority practices and payment rates within legislated 

limits, and establishing State enrollment procedures. In approximately half of the 

States, all funding and enrollment decisions are made at the State level. In the 

remaining States, one or more of these responsibilities is handled at a county or subwatershed level (Nickerson and Ribaudo, 2008). A number of newer national and 

regional EQIP initiatives provide States with greater guidance on choosing which 

contracts to fund, refl ecting the complex partnership between the national and local 

offi ces in administering the program.

Contracts are ranked similarly to the CRP’s EBI, with practices rated according to 

the degree to which they address key resource concerns. Most conservation practices address multiple resource concerns. NRCS captures the relationship between 

practices and resource concerns using a set of metrics known as the Conservation 

Practice Physical Effects (CPPE). The CPPE metrics give each practice a “score” 

for each of the 80 resource concerns. While there is a national CPPE table, the 

effects of each practice depend upon the regional context in which it is implemented, and so State CPPE tables play a more prominent role in contract ranking. 

Other factors beyond the CPPE also enter into contract ranking. 

“Drought vulnerability” is not explicitly identifi ed as a priority resource concern 

under EQIP, but funding provisions focus on resource concerns that are often 

exacerbated by droughtand therefore likely to receive more funding in higher 

drought-risk regions. Generally, the drought-related resource concerns are ancillary 

to other resource concerns such as water quantity, soil quality, soil erosion, and 

water quality. 

Modeling Drought Risk Adaptation and EQIP: Irrigation 

and Tillage Practices

When deciding what practices to include on their EQIP application, farmers are 

likely to consider two key factors: the net onfarm benefi ts of practice adoption and 

the likelihood that NRCS will agree to fund those practices. Drought risk is potentially an important consideration in projecting net onfarm benefi ts of some EQIPeligible practices, particularly those related to water and soil conservation. We focus 

on practices likely to have signifi cant private benefi ts in drought-prone regions—

irrigation and tillage-related practices—by helping crop farmers manage soil moisture levels.27 

27 Other soil-moisture retention practices supported by EQIP may also mitigate drought. 

Windbreaks composed of planted or manufactured materials help slow surface velocity of 

winds that dry the soil. Snow fences capture snowfall that increases moisture infi ltration on 

portions of the fi eld. Terraces and other land forming measures can help capture and route 

storm runoff to maximize soil-moisture infi ltration. Rotation-fallowing with crop stubble or 

cover crops may help replenish subsoil moisture.
32 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

Despite the variation in priority resource concerns across regions and the large 

number of practices available for producers to include in their conservation plans, 

most EQIP funding goes to a small number of practices. The 10 most prevalent 

practices account for more than half of total funding, while 20 practices account 

for three-quarters of funding (table 2). Irrigation and tillage practices represent a 

substantial portion of EQIP fi nancial assistance expenditures.28 Since the program’s 

inception in 1996, EQIP has contributed more than $250 million toward the adoption of conservation tillage practices. More than $1 billion has been allocated to 

irrigation-related practices under the program, with the most prevalent system 

upgrades involving low-pressure sprinkler systems, conveyance pipelines, and 

micro-irrigation systems.

The responsiveness of EQIP enrollment to drought risk depends upon how 

producers respond to drought risk. We expect that farmers facing greater drought 

risk will be more likely to adopt practices that lessen soil-moisture variability and 

28 Prior to the 2008 Farm Act, fi nancial assistance was referred to as cost-share.

Table 2

Obligated Environmental Quality Incentives Program funds for the 20 most prevalent 

practices, 1997-2010

Rank in 

funding

NRCS

practice

code Practice name

Total funding

($ million, 

nominal)

Share of 

funding

(Percent)

Cumulative 

share

(Percent)

1 313 [Animal] Waste Storage Facility 610.84 10.1

2 382 Fence 455.31 7.6 17.7

3 442 Irrigation System, Sprinkler 433.30 7.2 24.9

4 430 Irrigation Water Conveyance Pipeline 333.41 5.5 30.4

5 314 Brush Management 304.53 5.1 35.5

6 * [Reduced] Tillage (*329, 345, 346) 258.88 4.3 39.8

7 516 Pipeline 246.19 4.1 43.9

8 590 Nutrient Management 233.72 3.9 47.8

9 441 Irrigation System, Microirrigation 201.86 3.4 51.1

10 512 Pasture and Hay Planting 189.96 3.2 54.3

11 561 Heavy Use Area Protection 177.57 2.9 57.2

12 595 Pest Management 174.77 2.9 60.1

13 614 Watering Facility 154.75 2.6 62.7

14 528 Prescribed Grazing 153.46 2.5 65.2

15 410 Grade Stabilization Structure 116.15 1.9 67.2

16 378 Pond 99.39 1.7 68.8

17 642 Water Well 99.10 1.6 70.5

18 464 Irrigation Land Leveling 98.69 1.6 72.1

19 600 Terrace 97.88 1.6 73.7

20 533 Pumping Plant 92.15 1.5 75.2

Source: Data from 1997 to 2001 were compiled from the Farm Service Agency EQIP data, which preceded the USDA Natural 

Resources Conservation Service (NRCS) ProTracts database. Data from 2002 to 2010 were compiled from ProTracts. Only 

active or completed contracts were used to compile funding totals. EQIP expenditures (or contract counts or other appropriate 

variables) are ERS estimates using NRCS data and are not offi cial NRCS values.
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 33

to seek EQIP funding for such practices.29 However, the extent to which conservation practice adoption decreases drought vulnerability is complex and depends on 

many factors. The ability of a particular practice to alleviate moisture defi cits during 

drought may differ across enterprises, climatic conditions, and resource settings. 

Practice adoption and related input adjustments typically involve costs and may also 

involve changes in average yield. 

The responsiveness of EQIP to drought risk also depends on program funding 

criteria. While drought is not an explicit resource concern used in funding allocations, EQIP enrollment decisions at the State or sub-State level are potentially 

more responsive to the incidence of drought than national weighting criteria might 

suggest. NRCS State offi ces, State technical committees, and local conservation 

districts provide input in defi ning priority resource concerns and practices, setting 

payment rates by eligible practice, and establishing program enrollment criteria. 

Producers, in turn, infl uence payment distributions through contract proposals that 

identify resource concerns and practices to be adopted. Consequently, local funding 

for drought adaptation may diverge from Federal allocations. According to an 

analysis of EQIP practice expenditures, funding rates for water conservation practices exceeded the weighting assigned to water conservation at the national level for 

purposes of State budget apportionment; the effect was largest where State ranking 

and enrollment decisions were made at a sub-State level (Nickerson and Ribaudo, 

2008).

Irrigation-Related Practices

Irrigation has been widely used to ensure adequate soil moisture for crop growth. 

Irrigation is often required in arid regions with limited growing-season precipitation, and may be used in humid regions to enhance crop yield and minimize yield 

variability. While Western irrigated acreage has expanded since the mid-1980s, a 

decline in aggregate regional water use refl ects continued improvements in wateruse effi ciency as well as changes in cropping patterns (Schaible and Aillery, 2012). 

Drought risk is likely an important factor in irrigation investment decisions. 

Research on technology adoption rates among irrigators has generally shown that 

drought risk is associated with greater adoption of irrigation (Negri et al., 2005) and 

irrigation effi ciency improvements (Peterson and Ding, 2005), although there may 

be exceptions or limits to this relationship (Green and Sunding, 1997; Schoengold 

and Sunding, 2011). In very high-risk regions, concerns over water supply reliability 

may inhibit investment in effi ciency improvement, making the relationship between 

drought risk and investment decisions nonlinear. A number of studies suggest that it 

29 There are two alternatives to this behavioral hypothesis. First, farms may be able to 

purchase crop insurance, which, if providing high enough coverage, would mean that farms 

would not have any additional net benefi ts from reducing soil moisture variability. This is 

compatible with our null statistical hypothesis that there is no relationship between drought 

risk and EQIP participation for these practices. A second hypothesis is that these practices 

are used primarily because they are yield increasing, and therefore revenue increasing, thus 

making any relationship to risk spurious. However, irrigation effi ciency and conservation 

tillage often increase average yields precisely by increasing yields in the lower tail of the yield 

distribution, which is a form of risk reduction. Ultimately distinguishing between the yield and 

yield-risk benefi ts/costs of particular production practices is very diffi cult in most contexts and 

requires data that permit stochastic dominance tests.
34 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

may be drought occurrence and the associated water-supply shortfalls, rather than 

simply drought risk, that have spurred increased adoption of more effi cient irrigation practices (Carey and Zilberman, 2002; Schuck et al., 2005). Over time, this 

observation would still imply that higher drought-risk regions have greater investment in irrigation effi ciency.30

Conservation Tillage Practices

Conservation tillage refers to various methods of soil cultivation—including no-till, 

ridge-till, and mulch-till—intended to reduce soil erosion and runoff. Under conservation tillage systems, 30 percent or more of the prior year’s crop residue (eg., 

corn stalks or wheat stubble) is maintained on the fi eld after planting. Adoption of 

conservation tillage systems involves specialized equipment and management adaptations, and yield effects may vary with local soils and climate or weather factors. 

Potential benefi ts include both public gains for water and air quality, as well as 

farm-level benefi ts involving soil moisture retention, labor and energy savings, and 

long-term soil productivity.

Conservation tillage may be an important drought adaptation response in many 

areas.31 Reduced soil disturbance limits moisture loss from the soil profi le, as less 

soil surface is exposed to drying. Soil compaction and crusting are also reduced, 

enhancing water infi ltration. Increased residue cover that lowers soil temperatures 

further lessens moisture loss while contributing organic material that enhances 

water infi ltration and soil moisture-holding capacity (Bruce and Steiner, 1995). 

However, conservation tillage may delay planting and seed germination under cool 

and wet spring conditions, particularly on heavier soils with limited drainage. 

The use of conservation tillage has expanded over time, with notable variation in 

adoption rates observed across crops. Nationally, the estimated 2009 acreage share 

in no-till was highest for soybeans (45.3 percent), with lesser shares for corn (23.5 

percent), wheat (21.9 percent), and rice (11.8 percent) (Horowitz et al., 2010).32

Ding et al. (2009) fi nd that adoption of conservation tillage is positively correlated 

with the incidence of abnormally dry conditions in preceding crop years, while wet 

conditions at planting time generally restrict the use of conservation tillage. 

30 While irrigation investments may reduce drought vulnerability at the farm level, the 

potential expansion of regional consumptive water use with widespread irrigation adoption 

may decrease water supply reliability at a basin level, particularly in surface-water systems 

since drought is more likely to lead to withdrawal restrictions in those systems.

31 Conservation tillage may be especially benefi cial as a drought response in rainfed 

production areas. Cropping systems that rely on natural precipitation may be particularly 

susceptible to yield loss due to soil-moisture defi cits. While moderate drought of short 

duration may have relatively little impact on crop growth, sustained moisture stress during 

critical phases of the growing season can result in signifi cant declines in crop yield and 

quality. 

32 Based on acreage in no-till observed in the most recent ARMS crop survey years 

(2003-07), with an estimated annual acreage expansion rate of 1.5 percent through 2009.
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 35

Data and Methods

Data on EQIP contracts are obtained from the NRCS ProTracts database. The database includes all EQIP contracts for which funds were obligated between fi scal 

years 2002 and 2010. For this analysis, we developed county-level counts of all 

contracts with obligated funds for the relevant practices. We identify irrigationrelated contracts and tillage-related contracts based on the practice codes that appear 

in the contract data (see Appendix C).

We are interested in modeling the likelihood of EQIP participation conditional on 

drought risk and other variables. However, unlike the CRP case, the EQIP dataset 

does not include data on offers that were not accepted by NRCS. Instead, we model 

enrollment by looking at participation in terms of the number of active (i.e., funded) 

contracts in a county. Since we are interested in establishing longrun relationships 

between climate and program participation, we use the average number of contracts 

per year over 2002-10.

To express the number of contracts as a participation rate, we rely on agricultural 

census data to determine potentially eligible farms in each county. For irrigationrelated practices, this is represented by operations with harvested irrigated cropland 

in a county. For tillage-related practices, this is the number of operations with crop 

sales in a county. To allow for fl uctuation in the number of crop farms and the 

number of irrigators, both of which may vary from year to year due to price and 

weather shocks, we take the maximum number of operations over the past three 

censuses (1997, 2002, and 2007). 

Using these two variables (the number of contracts and the number of eligible 

operations in each county), we use a conditional grouped logit model to estimate the 

likelihood of program participation. Our primary concern is in identifying the effect 

of drought risk on EQIP enrollment. The data refl ect enrollment, and not offers, 

so there is a greater risk in this analysis of confounding farmer decisions with the 

NRCS offer selection process. To control for the NRCS selection process, we rely 

upon two types of variables: the Erodibility Index (EI), which was also used in the 

CRP analysis, and State-level dummy variables, which capture differences in Statelevel ranking criteria such as the Conservation Practice Physical Effects (CPPE). 

We also run versions of the model that incorporate measures of CPPE directly 

(Appendix C).

For irrigators, a number of other variables could infl uence the likelihood that farms 

rely on EQIP for irrigation-related capital improvements. The value of the land, for 

example, may affect the ability of farmers to borrow for capital improvements. If 

that value increases the likelihood of making irrigation investments, counties with 

higher land values may also be more likely to rely on EQIP. Alternatively, if NRCS 

is able to identify farms that are less likely to invest in irrigation improvements in 

the absence of fi nancial assistance, then land values may be negatively correlated 

with enrollment rates. The type of water source used for irrigation may also infl uence investment and participation decisions. As a measure of land values, we use 

the soil rental rate variable from the CRP analysis. These rental rates are for dryland 

crop production, which is more likely than irrigated cropland rents to be correlated with drought risk. As a measure of water source, we use the share of irrigated 
36 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

acreage that is supplied by groundwater, a statistic available at the county level 

from the U.S. Geological Survey. 

For crop producers, a similar set of control variables (soil rental rates, State fi xed 

effects, EI values, and CPPE values) potentially infl uences the likelihood of 

enrolling in EQIP tillage-related contracts. Since conservation tillage is directly 

related to crop choice, we also use the share of cropland in soybeans as a control 

variable. The share of cropland in soybeans is calculated as the maximum share 

of planted soybean acres to total cropland over the 2002 and 2007 agricultural 

censuses. For counties that grow no soybeans in any year, this variable is zero. 

Since conservation tillage is applied to soybeans much more than to other crops 

such as corn, wheat, and cotton (Horowitz et al., 2010), the share of crop farms with 

tillage-related EQIP contracts will likely be higher in counties with a greater share 

of soybeans.

Potential EQIP Design Responses to Drought Risk

For both irrigation-related practices and tillage-related practices, counties with 

higher drought risk tend to have higher EQIP participation rates (Appendix C, 

table C1). For irrigation-related practices, this effect diminishes as drought risk 

increases, likely because the benefi t of capital investments in irrigation is attenuated 

when there is increased risk that water supplies will be interrupted during droughts, 

a concern in many high-risk counties where surface water is the primary water 

source. Counties with higher erodibility and greater groundwater dependence also 

have higher EQIP participation rates among irrigators. 

For tillage practices, counties with higher concentrations of soybeans have higher 

participation rates, which is consistent with higher conservation tillage adoption 

rates for soybeans relative to other crops. In contrast, counties with higher erodibility have lower participation rates in conservation tillage contracts. One of the 

only other studies to examine tillage contract participation found that the relationship between highly erodible land (HEL) and EQIP participation is small and not 

statistically signifi cant (Cooper, 1997). One reason that we might fi nd a negative 

relationship is that farmers may have been more likely to have adopted conservation 

tillage on HEL fi elds prior to our study period due to both conservation compliance provisions, which were initiated by the 1985 Farm Act, and the larger private 

benefi ts of conservation tillage on erodible land. Having already adopted conservation tillage, these fi elds would not have been eligible for EQIP payments on tillage 

practices during the years over which we observe program participation.

The view that EQIP is currently facilitating drought risk adaptation by farmers is 

consistent with these results. We are only able to examine EQIP enrollment data 

(not offer data), so we structured our analysis in an effort to control for administrative decisions. Without any control variables, it could be that irrigation and tillage 

practices are more common in more drought-prone counties because these practices 

receive higher contract ranking scores where drought risk is higher. For example, 

we know that contract ranking scores vary considerably across States.33 We are able 

33 See, for example, the contract ranking scores within Nebraska (www.ne.nrcs.usda.gov/

programs/EQIP/eqip_NRD.html) and Illinois (www.il.nrcs.usda.gov/programs/eqip/index.html).
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 37

to control for administrative decisions made at the State level through either State 

fi xed effects or our CPPE variables. However, if there are more local decisions, such 

as at the county level, we are not able to control for those given currently available 

data.

The program design implications of farm-level drought risk adaptation are less 

apparent for EQIP than for CRP. Unlike CRP, EQIP does not include county caps or 

strict eligibility requirements that can steer participation toward higher risk areas. In 

addition, while the CPPE scores are incorporated into contract rankings, the decentralized nature of EQIP means that States and counties have fl exibility in how those 

CPPE scores are set. In addition, our simple models do not fi nd a strong positive 

relationship between CPPE scores and participation rates. Setting the CPPE matrix 

at a national level could infl uence the local planning process but would not necessarily target certain practices.

The importance of State-level infl uence is particularly pronounced in the EQIP data 

and can be seen in maps of participation rates. The number of irrigation-related 

contracts, shown for counties with at least 5 percent of harvested cropland irrigated, 

shows that participation rates vary signifi cantly by State (fi g. 12). Often there are 

noticeable differences in participation across jurisdictional boundaries in locations 

where the climatological and hydrological conditions are very similar. For example, 

in the Central Plains, where there is a great deal of irrigation based on withdrawals 

from the High Plains Aquifer (mostly coincident with the Ogallala Aquifer) and 

relatively high drought risk, both western Nebraska and northern Texas have relatively high EQIP participation rates while western Oklahoma and western Kansas 

have lower participation rates. Similarly, participation rates vary by State within the 

Mississippi Alluvial Aquifer region (where drought risk is relatively low); Alabama 

and Louisiana have high participation rates while southeastern Arkansas has much 

lower participation rates. The cross-jurisdiction differences within regions of similar 

drought risk indicate that local planning is a critical determinant of participation 

rates. In general, though, drought risk does seem to infl uence EQIP participation.

The number of tillage-related EQIP contracts similarly shows that participation 

rates vary by State (fi g. 13). The contrast is most notable in the Northern Plains. 

Participation in conservation tillage contracts is relatively high in North Dakota and 

Minnesota but nearly zero in neighboring counties in South Dakota. 

Given the great deal of local fl exibility in ranking and selecting EQIP contracts, it 

may be that national concerns about drought adaptation can be addressed through 

EQIP using special project designations. Similar to previous efforts in the Klamath 

River Basin or the Colorado Salinity Project, drought adaptation could be targeted 

using set-aside funding for areas identifi ed as being at high risk of drought or 

projected to have increased drought risk in the future. The tradeoff of this approach, 

however, is that it implies a de facto reduction in local fl exibility to determine 

the optimal mix of practice funding. If we assume fl at budgets for national EQIP 

funding, adding set-aside funding for a special project would reduce the share of 

funding going to practices that are unrelated to drought, and to geographic areas that 

are unlikely to face high drought risk.
38 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

Conclusion

Counties with higher drought risk have higher EQIP participation rates for irrigation and tillage practices. As with CRP, this result suggests that climate adaptation 

is likely to include changes in conservation program participation. The tools for 

USDA to encourage or enhance such adaptation are more limited in the case of 

EQIP, in part because of the extent to which contract ranking is determined at local 

levels. Since EQIP involves practices on working lands, the role of drought risk in 

program participation may also have important implications for how drought risk 

affects the farm safety net. Investment in drought-mitigating practices, for example, 

may lessen reliance on crop insurance. It is also conceivable that such investments 

may favor expansion of cultivated land in areas more prone to drought. Improving 

our understanding of the connections between EQIP participation and farmers’ 

Figure 12

Irrigation-related Environmental Quality Incentives Program participation rates by county, 2002-10 

*Contract data are obtained from the USDA’s Natural Resources Conservation Service (NRCS) ProTracts database and totaled within the 

county in which the practices are located. The number of irrigators in the county is maximum value within each county of the number of 

operations with harvested irrigated cropland in each Agricultural Census (1997, 2002, and 2007). 

Source: Data on irrigation-related contracts were compiled from the NRCS ProTracts database. Data on the number of farms with irrigated 

cropland were compiled from the 1997, 2002, and 2007 Agricultural Censuses. Note that the set of practices used by ERS to identify 

irrigation-related contracts differs with respect to a handful of practices when compared to NRCS designations of irrigation practices. EQIP 

expenditures (or contract counts or other appropriate variable) are Economic Research Service estimates using NRCS data and are not 

official NRCS values.

Irrigation contracts per year per 100 irrigators*

Counties (cropland)

0 to 1.2

1.2 to 2.9

2.9 to 5.1

5.1 to 10.1

10.1 to 71.7
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 39

exposure to production risks, however, will require better EQIP data, most notably 

improved data on EQIP offers and not just EQIP contracts.

Figure 13

Conservation tillage-related Environmental Quality Incentives Program participation rates 

by county, 2002-10

Contracts per year per 100 crop farms*

Counties (cropland)

0 

0.00 to 0.1

0.1 to 0.3

0.3 to 0.9

0.9 to 13.6

*Contract data are obtained from the USDA’s Natural Resources Conservation Service (NRCS) ProTracts database and totaled within the 

county in which the practices are located. The number of farms in the county is maximum value within each county of the number of 

operations with crop sales in each Agricultural Census (1997, 2002, and 2007). 

Source: Data on tillage-related contracts were compiled from the NRCS ProTracts database. Data on the number of farms with crop sales 

was compiled from the 1997, 2002, and 2007 Agricultural Censuses. EQIP expenditures (or contract counts or other appropriate variable) 

are Economic Research Service estimates using NRCS data and are not official NRCS values.
40 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

Drought Risk Adaptation in the Animal Sector

While this report focuses primarily on drought adaptation in the U.S. crop sector, 

drought is also an important concern for livestock producers, especially those 

who use grazing land for forage needs. Prolonged drought can have signifi cant 

effects on regional economies where livestock grazing is an important land use. 

Resulting degradation of land and water resources can reduce returns to livestock 

grazing systems, both through declining animal productivity and greater reliance 

on purchased feed and emergency water supplies. Local market effects—such as 

higher costs for supplemental hay and silage and reduced prices of animals sold at 

lower weights—may exacerbate income losses for both confi ned and non-confi ned 

production. In this section, we describe how USDA conservation programs, historically focused on the crop sector, have broadened in scope to provide livestock 

production with tools for adapting to drought risk.34

Grazing Land Resources and Drought Prevalence

Land resources available for livestock grazing covered roughly 779 million acres 

in 2007, or roughly two-thirds of the U.S. agricultural land base. Grassland pasture 

and rangeland accounted for 614 million acres, with an additional 36 million acres 

in cropland pasture and 129 million acres in forested rangeland (Nickerson et 

al., 2011). While private grazing lands are located in all States, grazing lands are 

concentrated in the Mountain and Plains regions of the West. Much of the Nation’s 

grazing land is in areas prone to drought, according to the Palmer Modifi ed Drought 

Index (PMDI) (see fi g. 6. p. 15). Moreover, a large share of the Nation’s rangeland 

is characterized by poorer soils with low moisture-holding capacity, making the 

land particularly vulnerable to drought (Wilhelmi and Wilhite, 2002). 

A related concern for livestock grazing systems is the compounding effect of rising 

temperatures during drought. The coincidence of low precipitation and higher 

temperatures is evident across the Mountain States, Plains, and Southeast regions—

an expanse encompassing much of the Nation’s private grazing land resources (see 

Appendix A, fi g. A3). Lack of precipitation during drought, in combination with 

higher temperatures, can weaken grazing animals and deplete the land and water 

resources upon which they depend. 

Drought Impacts and Adaptation 

Drought management is an important element of livestock grazing systems. Various 

farm practices—augmenting water supply and shade, maintaining forage by land 

grading or brush removal, and regulating animal stocking rates—may be implemented prior to, during, and after drought to mitigate drought-related losses. 

34 Unlike for CRP and EQIP, we do not empirically evaluate the role of drought risk in 

program participation rates.
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 41

Livestock Water Supply 

Livestock production depends on an adequate and reliable supply of high-quality 

water. Water-supply shortages and poor water quality due to sustained drought are 

especially important concerns for livestock grazing operations. Ponds, streams, 

and shallow wells that normally serve as water sources may dry up or become 

undrinkable. Higher temperatures often associated with drought generally increase 

livestock water requirements for animal growth and thermal control, further exacerbating water-supply concerns. Limited water supplies may affect animal health 

and productivity via reduced feed intake and effi ciency, reduced weight gain, and 

increased susceptibility to disease. 

Small-scale water-supply augmentation, through a variety of off-stream livestock 

watering systems and catchments, can provide critical supplies during drought. 

Constructed ponds, or “dugouts,” may be developed from springs, seeps, and high 

groundwater tables. Water obtained from wells or rural water sources, or hauled 

from elsewhere, may be stored in tanks and piped to livestock troughs. Ensuring 

shade for livestock is also important; constructed shade structures and planted shelterbelts can reduce heat exposure while helping to disperse herds. 

Forage Productivity and Quality 

While rangeland vegetation and perennial forage and hay crops may be relatively 

resistant to moderate drought stress over short periods, more severe drought—often 

in combination with higher temperatures—may result in declining productivity. 

This is particularly true for the more marginal soils characteristic of many grazing 

lands. Drought may also reduce the nutritional quality of forage production; 

dormant pasture and native range forage during drought is often lower in protein, 

vitamins, and minerals. Dry forage crops may be harder to digest, while concentrations of salts, nitrates, and acid levels can increase to harmful levels. The risk of 

weed poisoning may also increase as some rangeland plants accumulate toxins when 

subject to drought stress. Livestock are more apt to graze on toxic weeds in drought 

years when desirable forage is limited, and drought-stressed animals may be more 

susceptible to toxins.

Land treatments for pasture and rangeland may help to maintain forage productivity 

under drought conditions. Brush removal to reduce non-crop water use, mechanical 

treatments to enhance soil permeability, and land grading to create runoff catchments can all increase soil moisture for forage production. Planting of perennial and 

self-sustaining vegetation may improve the drought tolerance of forage cover. Weed 

infestations that can be especially hazardous during drought may be treated through 

herbicides or mechanical means. 

Stocking Rates 

Balancing animal stocking rates with the forage capacity of land is a critical element 

of managed grazing systems.35 Sustainable stocking rates contribute to healthy 

35 Stocking rate is defi ned as the number of animals on a given amount of land over a 

certain period of time. Stocking rate is generally expressed as animal units per unit of land 

area. Car rying capacity is the stocking rate that is sustainable over time per unit of land area.
42 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

grazing systems that are better able to withstand the onset of drought. Reduced 

stocking levels during prolonged drought can help alleviate grazing pressure on 

pasture and rangeland, lessening plant stress while providing additional forage for 

remaining animals. 

To minimize reductions in herd size and productivity, supplemental feeding is often 

necessary to offset the loss of forage and fodder supplies. Alternative onfarm feed 

sources may include forage harvested and stored in advance; drought-damaged 

crops that are grazed or harvested for silage; crop residues such as small grain 

straw and corn stover; or short-season forage crops such as buckwheat or millet 

planted to offset early crop losses. Alternative commercial feeds—such as corn 

gluten, soybean meal, and distillers’ grains—may also help to stretch limited forage 

supplies. Renting additional pastureland can increase access to forage and water, 

although drought may restrict the local supply and quality of available grazing land. 

Temporary feeding in off-farm feedlots may be an option for some animal types. In 

many instances, however, sustained drought will require producers to reduce herd 

size through selective culling.

Conservation Programs and Livestock Grazing 

USDA has provided technical assistance for grazing systems since the 1930s. 

However, the stewardship of private grazing land resources has emerged as an 

important conservation priority in recent years, with expanded policy emphasis 

and program funding. Support for improved management of private grazing land 

comes from both working lands programs such as EQIP and from land retirement 

programs such as CRP.

Under the 2008 Farm Act, 60 percent of EQIP conservation expenditures are 

targeted to livestock production. Grazing land practices generally address multiple 

resource concerns, with adaptation to drought often secondary to grazing land 

productivity and water-quality control. Prescribed grazing plans, for example, 

typically include a drought contingency plan that identifi es mitigation actions to 

minimize drought-related damages. For this report, we identifi ed a select group of 

practices that clearly provide some private benefi ts in coping with drought risk: 

forage management, prescribed or planned grazing, and livestock water supply 

augmentation. Since 1997, these practices have accounted for more than 13 percent 

of total EQIP funding (table 3). Contracts containing one or more of these practices 

are heavily concentrated in the more drought-prone regions of the country (fi g. 14).

Other USDA programs also provide funding for grazing land conservation practices that support drought preparedness and recovery. Under the Conservation 

Stewardship Program (CSP), administered by NRCS, pasture and rangeland have 

accounted for a signifi cant share of acres approved for contracts. The Grassland 

Reserve Program (GRP), administered jointly by NRCS and FSA, is designed to 

preserve grasslands for livestock grazing and other uses under long-term easements and rental agreements; an approved grassland resource management plan is 

required for enrollment, with fi nancial support available for approved practices. The 

Emergency Conservation Program (ECP), administered by FSA, provides funding 

and technical assistance for farm and ranchland damaged by drought, as well as 

emergency livestock water supplies. NRCS technical assistance is funded primarily 
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 43

through the Conservation Technical Assistance program. Non-Federal grazing lands 

constitute about half of the total land for which NRCS provides technical assistance 

(USDA/NRCS, 2003). 

CRP enrollment can be a potential drought risk-management strategy for crop 

producers with environmentally sensitive cropland. Enrollment may also lessen 

drought-related income risk for livestock producers with eligible cropland. Much 

of the CRP enrolled acreage is concentrated in the Plains States, where marginal 

soils in transitional cropland/grassland agricultural zones—favored under CRP 

contract ranking criteria—coincide with concentrations of livestock production. For 

CRP participants who maintain livestock operations, haying and grazing access on 

enrolled acreage in exchange for a reduction in CRP rental payments can provide 

additional fl exibility in managing livestock feed requirements. In the Texas High 

Plains, the presence of a livestock enterprise on a CRP participant’s farm operation signifi cantly increased the probability of re-enrollment (Johnson et al., 1997), 

underscoring the importance of CRP land as a forage source for many livestock 

producers. 

Two separate provisions for haying and grazing are authorized under the CRP. 

Managed haying and grazing may be permitted during specifi c time intervals (eg., 

in accordance with the nesting season for grassland birds) for no more than 1 out of 

every 3 years after the CRP cover is fully established, depending on site conditions 

and conservation objectives. While managed haying and grazing allows for diversifi cation of returns from CRP enrolled acreage, the primary purpose of acreage 

enrollment is to maintain or enhance wildlife habitat, minimize soil erosion, and 

protect water quality. However, CRP lands may provide an important source of livestock forage, especially during dry years. 

Emergency haying or grazing may be authorized to provide emergency relief to 

livestock producers in designated areas affected by severe drought or other natural 

Table 3

Drought-related livestock practices in Environmental Quality Incentives Program, 1997-2010

NRCS 

practice code Practice name

Total funding

($ million, nominal)

Percent of total 

EQIP funding

(Percent)

512 Pasture and hay planting 189.96 2.96

516 Pipeline 246.19 3.83

528 Prescribed grazing 153.46 2.39

550 Range planting 2.35 0.04

574 Spring development 15.11 0.24

614 Watering facility 154.75 2.41

642 Water well 99.10 1.54

708 Cistern 0.08 < 0.01

762 Planned grazing system 0.61 0.01

Note: Detailed practice descriptions are available on the USDA, Natural Resources Conservation Service (NRCS) website: 

http://www.nrcs.usda.gov/technical/Standards/nhcp.html

Practice 642 (water well) also appears under irrigation practices because it can be used for both livestock and irrigation. 

Practice 516 (pipeline) appears only as a livestock-related practice because it may not be used for irrigation purposes. EQIP 

expenditures (or contract counts or other appropriate variables) are ERS estimates using NRCS data and are not offi cial 

NRCS values.
44 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

disaster.36 During periods of prolonged drought when local hay supplies are often 

limited and hay prices are high, CRP acreage in grasses and other vegetative cover 

can provide an important reserve for livestock grazing and haying. Managed and 

emergency haying and grazing are subject to conservation plan provisions that 

protect environmental benefi ts achieved under the program. CRP participants are 

assessed a reduction in rental payments under managed haying and grazing and a 

reduction under emergency conditions, a loss in payments that is presumably offset 

by revenues from livestock production since activation of these provisions is voluntary.37 The size of the payment reductions has varied over time. In addition, in some 

36 To be approved for drought-related emergency haying or grazing on CRP land, a 

county must be suffering from either extreme drought conditions (D3 on the Palmer Drought 

Index or worse) or 40 percent less precipitation than average over a 4-month period. 

37 Producer participation incentives refl ect the quantity and quality of available CRP hay 

and forage, the reduction in annual rental payments, and the costs of harvest and hauling as 

well as the costs of alternative feed sources.

Figure 14

Environmental Quality Incentives Program contracts with drought-related livestock practices, 2008-10

Number of contracts 

County

*Contract data are obtained from the USDA’s Natural Resources Conservation Service (NRCS) ProTracts database and totaled within the 

county in which the practices are located. 

Source: NRCS ProTracts database, active and completed contracts only. EQIP expenditures (or contract counts or other appropriate 

variable) are Economic Research Service estimates using NRCS data and are not official NRCS values. 

0 - 4

5 - 8

9 - 12

13 - 16

17 -80
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 45

regions farmers may not invoke hay and grazing provisions on CRP land until after 

the completion of primary nesting season, which is in the summer for most bird 

species.

Over the 2003-11 period, U.S. acreage approved for managed haying ranged from 

less than 500,000 acres to more than 1 million acres annually, representing roughly 

2 to 3 percent of all CRP contracts nationwide (fi g. 15). Smaller CRP acreages have 

been used for managed grazing than for emergency grazing, generally representing 

less than 1 percent of CRP contracts (USDA/FSA, 2012). Managed haying on 

CRP-enrolled land occurs throughout the United States, particularly in the droughtprone Northern Plains and northern Mountain regions. Managed grazing on CRP 

land occurs predominantly in the West, with the largest acreages concentrated in the 

Southern and Northern Plains and northern Mountain regions. 

While participation in managed haying and grazing has held fairly constant, the 

use of CRP emergency haying and grazing provisions has been more variable 

across years and regions, refl ecting the uncertain nature of extreme weather events. 

National participation peaked in the summer of 2006, when moderate, severe, or 

extreme drought conditions extended across much of the Mountain West, Plains 

States, and Central-Southeastern United States. Emergency haying was authorized on an estimated 875,000 acres nationwide in 2006, including more than 15 

percent of active CRP contracts in North and South Dakota; emergency grazing was 

authorized on an estimated 877,000 acres, including more than 8 percent of CRP 

contracts in Wyoming, Colorado, and Texas (USDA-FSA, 2012). Under prolonged 

drought conditions in 2011, 845,000 acres were enrolled in CRP emergency grazing 

across Texas, Oklahoma, Kansas, New Mexico, and Colorado. The large increase in 

Figure 15

Conservation Reserve Program managed/emergency haying and grazing allotments, 2003-11

0.0 0.5 1.0 1.5 2.0 2.5 3.0

2003

2004

2005

2006

2007

2008

2009

2010

2011

Managed haying and grazing Emergency haying and grazing

Source: USDA Farm Service Agency data on CRP contract utilization of haying and grazing provisions.
46 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

national CRP acreage in managed haying and grazing in 2007 and 2009, following 

years with higher enrollment in CRP emergency provisions, suggests its use by 

some CRP participants as a hedge against multi-year drought effects on livestock 

forage supply. 

Conclusion

Multiple conservation programs encourage practices that help livestock producers 

adapt to drought risk. In some cases, program provisions for livestock producers 

may be explicitly designed to address drought impacts—as in the case of emergency grazing provisions on CRP land. Conservation programs, therefore, already 

serve a role in facilitating drought risk adaptation for livestock producers. To the 

extent that climate change increases drought risk in some regions, producer demand 

for these programs is likely to increase. 
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 47

Conclusion

Drought risk, a key measure of climate, is shown to infl uence conservation program 

participation. For both EQIP and CRP, this implies that these programs are currently 

serving as de facto drought risk adaptation tools. Crop producers in higher droughtrisk regions are more likely to offer land for retirement in CRP or to enroll in 

EQIP contracts that fund irrigation and conservation tillage practices. For livestock 

producers using emergency haying and grazing provisions, the link between drought 

and program design is generally more explicit.

Climate change, to the extent that it alters drought risk, is likely to affect the ability 

of conservation programs to achieve USDA goals. It may be possible to adjust 

program provisions to encourage drought-risk adaptation, although this may involve 

tradeoffs with the conservation goals of the programs.

The extent to which conservation programs can actually reduce drought vulnerability is an important area for future research. Given that producers in areas with 

higher production risk due to drought are more likely to participate in USDA 

conservation programs, there may be important interactions between conservation 

programs and the farm safety net. As the science of climate change improves to 

provide more precise predictions about regional changes in drought risk, USDA 

programs would benefi t from greater consideration of how voluntary adaptation by 

farmers is likely to affect participation. 
48 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

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54 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

APPENDIX A: Constructing a Measure of Drought Risk

Our drought risk measure is a variant of the Palmer Modifi ed Drought Index 

(PMDI) for the month of June, calculated at the weather-station level from over 100 

years of data and interpolated to the county level (see fi g. 6). In this appendix, we 

explain our choice of this measure for drought risk and compare it with a number of 

biophysical characteristics that are thought to be associated with drought risk, such 

as available soil water storage, the variance of precipitation, and the covariance 

between precipitation and temperature.

From previous literature, there is no standard measure of drought risk. Some studies 

measure drought risk as the frequency of severe and extreme droughts over the 

previous century. Other studies generate an index based on Geographic Information 

Systems (GIS) data of variables that infl uence drought vulnerability, such as soil 

moisture holding capacity, but none of these indices are available at the national 

level. Due to the national scope of our study, we needed to develop a unique 

measure of drought risk that varied at the county level and captured fi ne-grained 

differences in risk. Five factors infl uenced our choice of a drought risk measure:

1. PMDI measures variance in soil moisture, which is more relevant for most 

agricultural production than simple measures of precipitation.

2. PMDI is not normalized with respect to variance (unlike the Standardized 

Precipitation Index, SPI), which allows a measure of variance to indicate the 

relative frequency of severe and extreme droughts.

3. Measures of variance provide a more refi ned (i.e., continuous) measure of 

drought risk than counts of severe and extreme droughts.

4. June PMDI is a reasonable measure of drought risk since most spring crops 

are most sensitive to drought during the month of June.

5. Our measure of drought risk is roughly compatible with biophysical 

measures of drought vulnerability such as soil moisture availability, precipitation variance, and precipitation and maximum temperature covariance.

Some measures of drought intensity focus only on precipitation, and many others 

focus on measures of water availability, either in hydrological systems or as soil 

moisture. The widely used Palmer Drought Severity Index (PDSI) translates 

measures of precipitation and temperature into an index of estimated soil moisture 

availability. Despite some criticisms of the PDSI on statistical grounds (Guttman, 

1998), the PDSI has been found to be a good estimator of actual soil moisture 

(Mika et al., 2005). Since we are focused primarily on national conservation 

programs designed for crop and livestock producers, the focus on soil moisture 

makes the PDSI (and the related PMDI) a natural starting point for our measure of 

drought risk.

The PMDI is structured to provide a measure of soil moisture variability that allows 

for spatial comparisons. Like the popular standardized precipitation index (SPI), 

the PDSI and PMDI are locally standardized (demeaned) so that a value of zero 

represents the average conditions at a given location. However, unlike the SPI, the 

PDSI and PMDI are not normalized with respect to variance, which means that 
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 55

both the PDSI and PMDI measure drought severity according to a common scale.38

Tellingly, when mapping variance in the SPI, there is little spatial pattern. 

In contrast to some other drought indices, such as the crop moisture index (CMI), 

the PDSI and PMDI are available for a long period of time at the weather-station 

level. That availability of data (more than 100 years) reduces the noise when estimating the local variability of drought severity. We chose June PMDI because for 

many crops the sensitivity to drought is greatest in the early portion of the growing 

season. We calculated the variance of June PMDI at individual weather stations 

and then interpolated that measure to county centroids based on the nearest seven 

stations to each centroid.

Drought risk, when defi ned as the variability of soil moisture availability, is actually 

a complex characteristic of climate that refl ects both more basic climatic variables 

and local environmental characteristics, most notably soil characteristics. To ensure 

that our measure of drought risk conforms to key biophysical characteristics that 

infl uence drought risk, we also examined a number of other “factors” of drought 

risk. Three of those factors are presented here graphically: available soil water 

storage (fi g. A1), the variance of precipitation (fi g. A2), and the covariance between 

precipitation and temperature (fi g. A3).

Since the PMDI models deviations in soil moisture, any measure of drought risk 

should refl ect spatial variation in soil moisture holding capacity. There is some 

east-to-west variation in soil water storage (fi g. A1) that corresponds to our measure 

of drought risk. However, soil moisture capacity is more refl ective of underlying 

geology that accounts for the extremely deep soils in the Corn Belt (with large soil 

moisture capacity) and the extremely shallow soils along the Appalachians (with 

very little soil moisture capacity). Future research on drought risk would likely 

benefi t from a more detailed examination of the extent to which PMDI calculations 

adequately capture local biophysical characteristics.

The variance of precipitation is a major driver of our measure of drought risk, as 

evidenced by the close correspondence between our measure of drought risk (fi g. 

6) and the coeffi cient of variation (CV) of June precipitation (fi g. A2). Mapping 

the CV of precipitation normalizes variance with respect to mean precipitation, not 

unlike the local normalization of PMDI, although the two are not mathematically 

equivalent.

Since PMDI incorporates both precipitation and temperature, drought risk is also a 

function of temperature patterns. The interaction of precipitation and temperature 

is particularly important because extremely hot weather increases crop evapotranspiration, thus exacerbating precipitation shortfalls that occur simultaneously 

with high temperature. From the perspective of drought risk, then, the important 

climatic variable is the extent to which high temperatures and low rainfall are likely 

to occur in the same season. The spatial pattern of this covariance reveals that the 

Southern Plains, the Intermountain West, and the Lower Mississippi Valley are the 

most vulnerable regions in this regard (fi g. A3). However, precipitation levels in the 

38 In contrast, since the SPI is normalized in both mean and variance, the SPI measures 

drought rarity or frequency rather than drought severity.
56 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

Lower Mississippi Valley (fi g. A2) are seemingly high enough to offset the impact 

of this covariance on drought risk. 

Figure A-1

Median water storage capacity in the top 150 centimeters of the soil profile, by county

Source: ERS calculations based on USDA Natural Resources Conservation Service Soil Survey Geographic (SSURGO) database.

Soil moisture capacity (cm)

Median in county

1.5-15.3

15.3-19.3

19.3-21.9

21.9-25.4

25.4-32.7
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 57

Figure A-2

Variability of precipitation by county, 1950-2009

Source: ERS calculations based on 1950-2009 PRISM data. Coefficient of variation calculations are based on annual values of total Juneto-August precipitation from 1950 to 2009. Monthly county-level precipitation totals are the averages within counties masked to cropland 

based on the latest National Land Cover Dataset (NLCD) coverage.

Summer precipitation

0.36 - 2.35

0.30 - 0.36

0.27 - 0.30

0.25 - 0.27

0.17 - 0.25

Coefficient of variation
58 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

Figure A-3

Correlation between June precipitation and average maximum temperature by county, 1950-2009

Source: ERS calculations based on 1950-2009 PRISM data. Correlation coefficient calculations are based on June average daily maximum 

temperature and total precipitation values from 1950 to 2009. County-level values are the averages within counties masked to cropland 

based on the latest National Land Cover Dataset (NLCD) coverage.

June temperature and precipitation

-0.84 - -0.62

-0.62 - -0.52

-0.52 - -0.31

-0.31 - 0.01

0.01 - 0.23

Correlation coefficient
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 59

APPENDIX B: Modeling CRP Participation

This appendix presents additional detail on the econometric model of farmer 

participation in the CRP, the variables used in that analysis, and the results of that 

analysis.

Variable Discussion

Table B1 presents the variables used in the econometric analysis, as well as a 

number of variables used to construct the measures of cropland acres eligible for 

enrollment and share of eligible acres that are acceptable, based on the county 

acreage cap. 

The dependent variable, a measure of CRP participation, is modeled as the offer 

rate, pctOffer, or the share of eligible acres in a county that are offered in a general 

signup. The variable Offered is the numerator in that share and is calculated from 

data on individual offers. Data are aggregated to the county in which the property 

being offered for enrollment is located, which in most cases is the same as the 

administrative county in which the offer is submitted. The denominator is based on 

ERS estimates of the number of acres available for enrollment in each county; the 

variable availableAcres is the estimate of total eligible acres in a county minus total 

acres that are enrolled (and not expiring) prior to each general signup. As a proxy 

for parcel-level data on cropping history, we identifi ed cropped lands based on the 

National Land Cover Dataset (NLCD) classifi cations. Erodibility index calculations for eligible land were developed by ERS from the SSURGO (Soil Survey 

Geographic) soil characteristics database. Conservation Priority Area (CPA) boundaries and erodibility index estimates were overlaid on the NLCD cropland surface 

to estimate the total acres in each county that met enrollment criteria. The variable 

dRisk is the drought risk variable developed by ERS and described in Appendix A. 

Table B2 highlights the expected impacts of dRisk and the other regressors in the 

model.

County caps are refl ected in the variable %Acceptable, which is the ratio of acres 

that can be accepted (canAccept: the county cap (0.25 * total cropland) minus total 

currently enrolled acres) to the variable availableAcres. When this ratio is zero, 

there is no room within the cap to accept additional acres. When this ratio is greater 

than 1, the variable %Acceptable is set to 1. 

The variables on soil rental rates (SRR) and EBI scores (eEBInorm) are developed 

from CRP offer data. The eEBInorm variable is based on USDA’s Environmental 

Benefi ts Index (EBI), which is used to rank parcels offered for CRP enrollment. To 

address the endogeneity of portions of the EBI that are jointly determined with the 

decision to make an offer, we rely only on the environmental components of the 

EBI, or those portions of the score that are exogenous (i.e., determined entirely by 

land characteristics and therefore unaltered by the details of the offer). The EBI has 

fi ve factors (N1-N5) that measure various environmental and conservation services 

provided by retired land. Since the factor values change over time, we normalize 

the EBI score such that the variables we use (avgN1 to avgN5) represent the “fraction of the maximum score achievable” (averaged over all offers from a county in a 
60 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

given year). Note that eEBInorm refl ects the qualities of the acres actually offered to 

the program. This is likely an overstatement of environmental attributes of all land 

in the county, since higher EBI land is more likely to be offered to the program.

We also include in our model the variable %Irrigated, the maximum share of cropland in each county that is irrigated over the past 3 agricultural census survey years. 

Enrollments in general signups are limited by bid caps based on the average dryland 

soil rental rate, so CRP enrollment may be less attractive to producers in counties 

where irrigation is more prevalent. Table B2 includes a brief explanation of the 

predicted coeffi cient signs for model variables.

Appendix table B-1

Variables used in CRP analysis

Variable Description

Level of 

measurement Mean 

Standard 

deviation

Offered Acres offered, including re-enrollments

by county and 

year 2,563.22 9,581.34 

Retained

Acres retained in the program: currently enrolled 

acres minus expiring acres

by county and 

year 9,000 22,580

canAccept

Maximum number of acres that can be accepted: 

county cap minus Retained acres

by county and 

year 27,870 28,960

availableAcres

Eligible acres minus retained acres. Note that 

availableAcres may be greater than, or less than, 

canAccept acres

by county and 

year 77,403.7 121,030 

pctOffer Percent of acres offered: offered/availableAcres 

by county and 

year 0.0708734 0.193757 

dRisk

Drought risk; larger values represent higher 

drought risk by county 2.24798 0.302072 

%Acceptable

Share of available acres that can be accepted, 

accounting for county cap: equal to canAccept/

availableAcres. Values >1.0 are set to 1.0

by county and 

year 0.663018 0.350890 

SRR The average dryland cropland rental rate.

average by 

county and year 

(FSA data) 55.1121 37.6734 

eEBInorm

Normalized average “environmental EBI score”: 

sum of EBI factors that cannot be infl uenced 

by the structure of the bid (exact set of factors 

varies by signup), which is then divided by the 

maximum number of points that can be awarded 

for the N1-N5 factors.

by county and 

year 0.41 0.10

%Expire

Expiring acres divided by the number of acres 

that can be accepted (canAccept)

by county and 

year (FSA data) 0 .07 0.22

%Irrigated

Percent of cropland irrigated (max % of cropland 

irrigated in 1997, 2002, and 2007)

by county (Ag 

Census) 15.195026.3899 
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 61

Appendix table B-2

Expected responsiveness of offer rates to key variables

Variable

Expected 

sign Discussion

dRisk + We assume that landowners in more drought-prone counties (i.e., counties where 

the variance of returns is high) will be more interested in enrolling land in the CRP.

%Acceptable + This is a measure of competitiveness, ranging from 0 to 1, that captures the 

effects of county enrollment caps. A value of 1 indicates that if 100 percent of 

eligible land were offered, all of it could be accepted into the program. For these 

counties, the county cap is nonbinding and the only constraint on enrollment is 

the selection of the national EBI cutoff. A value of 0 indicates that a county is at 

its enrollment cap and cannot accept any additional acres. These values can vary 

from year to year within a county as new contracts are signed and other contracts 

expire without being re-enrolled. Since a higher value implies less competition, 

we expect %Acceptable to be positively correlated with offer rates. With less 

competition, any individual offer has a greater likelihood of being accepted, which 

will lead to greater interest in the program. One caveat to this prediction is that, 

since being close to the cap is a sign that a large share of a county’s eligible 

land is already enrolled, small values of %Acceptable may also refl ect some 

unobserved characteristic that leads to increased popularity of CRP within a given 

county. If there is a major factor affecting CRP enrollment incentives for which we 

are not controlling, a lack of local competition may simply refl ect a lack of local 

interest in the program and the coeffi cient on this variable may be negative. 

SRR - The SRR is a county average of dryland cropland rental rates. There are two 

considerations about how variation in SRR across counties may impact CRP participation: 

the role of SRR as a proxy for opportunity cost and the role of SRR in the EBI. 

First, as an average dryland rental rate, SRR approximates the opportunity cost 

of enrolling land in CRP under the assumption that the land could otherwise be 

rented out for crop production. Since FSA uses SRR to set the maximum bid 

rate, SRR is the expected value for the maximum annual rental payment that CRP 

contracts can specify in each county. We expect that, in this regard, since farms 

can bid up to their opportunity cost, the marginal effect of SRR on the probability 

of offering land is zero. This implies that SRR refl ects both the expected value and 

variance of profi t from the land.

A second consideration is that the EBI includes a cost factor. Bids with a higher SRR 

will tend to have higher rental rates, and therefore will tend to receive a lower EBI 

score. Thus, counties with a higher SRR are slightly less competitive in the CRP 

ranking process and are therefore expected to be less likely to offer land to CRP.

Outside of the impact on EBI, there are two other reasons to include SRR as 

a control variable. If SRR (and therefore maximum bids) are systematically 

mismeasured in higher risk counties, or if heterogeneity in risk aversion is greater 

in higher drought-risk counties, then estimation of the participation without SRR 

included would lead to biased estimates of the impact of drought risk. There is 

no clear reason to suspect that systematic errors occur since counties use soil 

productivity information to tailor parcel-specifi c maximum bid rates based on the 

county SRR. Any risk premia incorporated into local agricultural land rents will be 

an equilibrium phenomenon, so that prices clear for some marginal (“equilibrium”) 

participants. For landowners with a more risk-averse profi le, guaranteed longterm rental payments (from the CRP) will be more attractive than either growing 

crops or renting yearly to neighboring farmers.

Continued—
62 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

Model Discussion

Table B3 shows the coeffi cient estimates from our primary model, while table B4 

shows those estimates expressed as elasticities. We apply a grouped logit model 

using pctOffer as the dependent variable.39 Thus, rather than use a 0/1 dependent 

variable, we use a proportion (ranging between 0.0 and 1.0).

The modeling results are mostly in line with expectations, especially for the variables of greatest interest. In particular, the coeffi cient on drought risk is positive 

and highly signifi cant – counties more prone to drought are likely to have greater 

interest in the CRP. Acres with lower potential competition, as measured by values 

of %Acceptable close to 1.0, also have greater offer rates; we consider this more 

closely in our policy scenario simulations. A greater number of just-expired acres 

increases the offer rate. Increasing soil rental rates decrease offer rates, as does 

higher percentage of land in irrigation. Not surprisingly, the positive coeffi cient on 

eEBInorm indicates that counties with relatively high, increasing environmental 

scores have higher offer rates.40 Model fi t is reasonable, with a 75-percent correlation between predicted acres offered and actual acres offered (by county). 

Given the nonlinearity of the logit model, it may be more informative to consider 

elasticity estimates rather than coeffi cient values. Interestingly, drought risk (dRisk) 

has the largest, most highly signifi cant (different from zero) elasticity of all the independent variables. SRR, %Acceptable, and eEBInorm also have moderately sized, 

and statistically signifi cant, elasticities.

39 We also estimated a Tobit model and several Poisson models. The Tobit performed 

less well, in terms of goodness of fi t and coeffi cient signifi cance. The Poisson models yielded 

results that were similar to the logit (i.e., 93 percent correlation in predicted offer rates 

between the grouped logit and the Poisson), with slightly worse goodness of fi t. Therefore, in 

this analysis we focus on the grouped logit results.

40 We also ran other variants, using a fuller set of variables (such as individual EBI factor 

scores). Results were similar for the more important variables, such as drought risk. Since the 

coeffi cients on these other factors were less than robust (for example, sign switches occur as 

variables are dropped and added), in this analysis we focus on this “sparse” model.

Appendix table B-2

Expected responsiveness of offer rates to key variables—Continued

Variable

Expected 

sign Discussion

SRR

—continued

- The impacts of these infl uences are ambiguous, and may vary by county. For example, if a 

county’s average rental rate is too high, this may encourage more participation in the CRP.

eEBInorm + Parcels with higher EBI scores are more likely to be selected and hence, have a 

competitive advantage. However, these measures may suffer from endogeneity, 

since they are based on offers rather than eligible acres.

%Expire + We expect that a large share of expiring acres will be reoffered to the program – 

which suggests that offer rates will be larger when the share of expiring acres is 

large.

%Irrigated - Since irrigation represents an alternative risk-mitigation strategy, high levels of 

irrigation are likely to reduce interest in the CRP.
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 63

Policy Simulation Discussion

Given the nonlinearities of our models, both in terms of functional form and in 

the use of aggregate data, we run policy scenarios based on a more disaggregated 

prediction. Using actual offers from the most recent CRP signups (2004, 2006, and 

2010), we predict a probability of making an offer for each of these signups, using 

the offer-specifi c variables commensurate with the variables used in the county/year 

Appendix table B-3

Grouped logit model results: coeffi cients

 coeffi cient t-stat coeff. var. (*100)

Constant -6.576 -16.7 -35.5

dRisk 1.16 8.6 16.6

%Acceptable 0.533 4.4 12.2

SRR -0.00617 -5.33 -14/2

eEBInorm 1.18 3 1 6.3

%Expire 4.78 48.7 74.3

%Irrigated -0.00656 -4.4 -8.4

Log likelihood -34,785

Notes:

• Dependent variable: pctOffer

• In all models, N=21,466 (up to 8 years for 2,783 counties).

• The coeff_var values (sd/mean of coeffi cient estimates) are generated from 100 bootstrap estimates; each estimate uses 

a randomly chosen 60% sample of observations.

Appendix table B-4

Logit model results: elasticities

Estimates Bootstrap results

Average stdDev

10% of CI

(% of median)

90% of CI

(% of median)

dRisk 2.44 0.531 7.5 7.9

%Acceptable 0.322 0.182 10.2 9.8

SRR -0.320 0.232 9.9 8.6

eEBInorm 0.449 0.134 21.6 21.5

%Expire 0.147 0.337 1.98 1.94

%Irrigated -0.0918 0.163 15.6 17.2

Notes:

• Elasticities are based on the average across all observations, computed for each variable using a 1% change in own 

values. 

• The bootstrap results are based on 100 coeffi cient estimates, where each estimate comes from a separate model run 

that uses a randomly drawn 60% sample for each observation.

 100 elasticity measures are computed. 

 A median value, and 10% and 90% quantile measures, are drawn from these 100 estimates.

 The 10% column (90% column) uses the observation-specifi c difference between the median and this 10% (90%) 

quantile, as a fraction of the median. Thus, small values of these measures indicate more precise measures of that 

observation’s elasticity.

The reported values are the averages, across 21,466 observations.
64 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

grouped logit model. Some of these measures (such as SRR and EBI factor scores) 

are offer-specifi c, while others (such as dRisk and %Acceptable) are county-specifi c.

The goal is to predict changes in overall offer rates as policy changes. Offer data are 

used to capture within-county variation in land attributes—variations that may be 

washed out when county-level measures are used. However, the use of offers means 

that we have no implicit information on parcels not offered to the program. 

Thus, we use weightings that treat offers as representative of a large pool of parcels. 

We treat changes in probabilities as indicative of what other parcels that were not 

offered might do. In particular, a baseline probability of participating (PPb) is 

computed for each offer.

 For example, a PPb value of 8 percent may be computed for a given parcel. This 

implies that “8 percent of parcels that look like this were offered to the program.”

Then, we predict a new probability of participation, under a policy scenario (PPs). 

This is then normalized by the baseline probability (PPb) to provide a parcelspecifi c weight. This weight is used to scale up (or down) the offer’s actual acreage. 

This scaled “offered acres” is used to predict total acres offered in the scenario.

For example, if the given parcel’s PPs=10 percent and PPb=8 percent, the weight 

would be 1.25. This implies that, under this scenario, 25 percent more acres would 

be offered (relative to the baseline) – or that this parcel’s acreage contribution to the 

CRP is increased by 25 percent.

In addition to scenario-specifi c weights for each offer, a county-specifi c “correction” weight (CCW) is computed. The CCW is used to scale up the 6.5 million acres 

of accepted offers (in the 3 years of data used) with a goal of generating a program 

size of 25.8 million “general signup” acres. Applying these CCW weights to all 

offered acres yields a prediction of 36.4 million acres of offered land, which implies 

a 70-percent (25.8/36.4) acceptance rate on offered acres.

To develop policy scenarios based on these variables, we create a categorical variable to differentiate counties with higher drought risk from those with lower drought 

risk. Within the EBI scenarios, this categorization provides a basis for awarding EBI 

points based on a drought risk factor (DRF), which is scored as follows: 

• All counties with a dRisk value < 2.65 are assigned 0 DRF points: this represents 76 percent of eligible acres and 85 percent of all counties.

• For 2.65 < dRisk < 2.78, DRF = 10 (representing 7.5 percent of counties and 13 

percent of acreage). In addition, the county is identifi ed as a medium-droughtrisk county.

• For dRisk > 2.78, DRF = 20 (representing 7.5 percent of counties and 11 percent 

of acreage). In addition, the county is identifi ed as a high-drought-risk county.

There are 2,859 observations (out of 21,466) that classify as high-drought-risk 

(HDR) counties (for example, of the 2,732 counties with observations in the 2010 
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 65

signup, 374 are high-drought-risk counties). Not surprisingly, the dRisk elasticity in 

these counties is higher than average, as is the percent irrigated elasticity.

To model these scenarios, several variables are modifi ed:

• The fi rst policy scenario requires some means of simulating the impacts of 

modifi cations to the EBI. The eEBInorm variable is used to simulate the 

impacts of DRF points. 

• The second scenario uses the %Acceptable variable—increasing eligibility will 

increase the share of eligible acres that can be accepted. This has two impacts: 

the acreage that can be accepted in a county is increased, and more landowners 

are encouraged to submit offers.

• The third scenario involves no changes in the model’s independent variable, but 

does increase the number of eligible acres. Thus, while the predicted offer rate 

is constant, the number of acres that may be offered may vary.

Modeling these scenarios requires several assumptions:

• Scenario one: the “normalized” EBI is recomputed, adding the DRF points to 

the numerator and adjusting the denominator. This assumes that DRF points 

will have the same impacts as all other points (that may appear in the EBI 

measure).

• Scenario two: the use of %Acceptable assumes that relaxing county caps will 

encourage participation in newly “uncapped counties” as it would in counties 

currently below the cap. 

• Scenario three assumes that ineligible acres are similar to eligible acres, in 

terms of their owners’ interest in participating in the CRP. 
66 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

APPENDIX C: Modeling EQIP Participation

In this appendix, we present several aspects of our model of EQIP participation: the 

dependent variable of participation levels; the measure of CPPE ranking scores; and 

the results of the regression.

Participation Levels

Our modeling strategy was to focus primarily on only those EQIP practices likely to 

be related to drought risk. To do this, we needed to determine reasonable categories 

of practices for which we could identify both participation levels and some population of eligible participants. We grouped practices into the two fairly broad categories—tillage-related practices and irrigation-related practices. 

The practices (and NRCS practice codes) that we use to identify tillage-related 

contracts are residue and tillage management (329 (A,B, and C)), seasonal residue 

management (344), mulch tillage (345), ridge tillage (346), mulching (484), residue 

management by direct seeding (777), and long-term no-till (778). 

The practices (and practice codes) that we use to identify irrigation-related contracts 

are irrigation canal or lateral (320), irrigation fi eld ditch (388), diversion dams 

(348), multipurpose dams (349), well decommissioning (351), well water testing 

(355), diversion (362), dam (402), irrigation water conveyance ditch (428 (A, B, 

and C)), irrigation water conveyance pipeline (430 (AA, CC, DD, EE, FF, GG, and 

HH)), above-ground multi-outlet pipeline (431), irrigation storage reservoir (436), 

microirrigation (441), irrigation sprinklers (442), surface and subsurface irrigation 

systems (443), tailwater recovery (447), irrigation water management (449), irrigation land leveling (464), pond sealing or lining (521), pumping plant (533), irrigation regulating reservoir (552 (A and B)), structure for water control (587), surface 

drainage fi eld ditch (607), surface drainage main or lateral (608), toxic salt reduction (610), water harvesting catchment (636), water spreading (640), water well 

(642), soil salinity control (738), pond sealing and lining with soil cement (740), 

and improved water application (743). Most of the funding and contracts within this 

category are focused on a few practices consisting primarily of sprinklers, micro 

irrigation, and land leveling.

CPPE Ranking Scores

Applications for EQIP funding are ranked at the State or county level. Several 

factors infl uence ranking, including CPPE scores. The precise formula for incorporating CPPE scores into ranking involves calculations that are often performed at 

the county level and rely on data that are not available at the national level. To overcome this limitation, we developed a method for collapsing CPPE scores based on 

the practice categories described above.

The CPPE scores are assembled in tables with the 80 conservation resource 

concerns listed by column and the practice codes listed by row. Every practice 

receives a score between -5 and 5 for each resource concern. Negative values indicate that a practice exacerbates a particular resource concern and positive values 
Economic Research Service, USDA The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 67

indicate that a practice alleviates a particular concern. While there is a national 

CPPE table that serves as a template, contract ranking is based on the State CPPE 

tables. 

NRCS provided ERS with State-level matrices of CPPE scores for 2008 and 2009. 

For each practice we calculated a simple total of CPPE scores across all resource 

concerns. We then calculated the maximum total score for all practices in a State 

and the maximum and average total scores for the two practice categories described 

above. This provided us with a normalized measure of how tillage and irrigation 

practices rank within each State according to the CPPE.

Results 

Table C1 presents the regression results of our grouped logit model. The fi rst two 

columns present the irrigation-related participation rates and the last two columns 

present the tillage-related participation rates.

For the model of participation in irrigation-related practices, we are only interested 

in measuring participation within counties for which irrigation is a viable production practice. We estimate our model on counties for which at least 5 percent 

of cropland is irrigated in at least one census year (1997, 2002, and 2007). The 

preferred model for irrigation participation is the fi rst column of coeffi cients, which 

includes State-level fi xed effects and should therefore be interpreted as a model of 

the average difference in participation rates across the drought risk gradient within a 

State. As expected, drought risk is positively correlated with EQIP participation by 

irrigators. Irrigators in areas with higher erodibility and higher use of groundwater 

are also slightly more likely to have an EQIP contract containing irrigation-related 

practices. Irrigators in counties with higher land values are less likely to rely on 

EQIP contracts for irrigation-related practices, perhaps refl ecting that our measure 

of land values captures dryland rental rates or that EQIP is most attractive to farms 

that face credit constraints due to lower land values. 

The second column presents a similar model with qualitatively similar results that 

are obtained by replacing the State-level fi xed effects with our CPPE metric. This 

model results in a surprising negative correlation between our CPPE metric and 

participation rates, suggesting that participation rates are lower in States where 

irrigation practices are ranked higher. This could refl ect measurement error in our 

CPPE index or could refl ect the greater prevalence of negative CPPE values for 

some resource concerns in areas where irrigation is more widespread and therefore 

more associated with both positive and negative physical effects.
68 The Role of Conservation Programs in Drought Risk Adaptation, ERR-148 Economic Research Service, USDA

Appendix table C-1

Coeffi cient estimates for Environmental Quality Incentives Program participation

(1) (2) (3) (4)

Variables

Irrigation contracts 

per year 

per irrigator

Irrigation contracts 

per year 

per irrigator

Tillage contracts 

per year 

per crop farm

Tillage contracts 

per year 

per crop farm

risk

4.420*** 2.715** 0.526*** 0.563***

(1.490) (1.263) (0.200) (0.118)

risk2

-0.843*** -0.567**

(0.289) (0.257)

eimax

0.00754* 0.0200*** -0.0196*** -0.0281***

(0.00406) (0.00423) (0.00510) (0.00542)

ShareGW 0.00655*** 0.00631***

(0.000853) (0.000791)

SRR2008 -0.00854*** -0.0116*** -0.00340** -0.00723***

(0.00138) (0.00121) (0.00134) (0.00123)

CPPE_IRR -0.0106**

(0.00435)

SHARE_SOY 0.874*** 0.638**

(0.305) (0.301)

CPPE_TILL -0.00180

(0.00386)

Constant -7.751*** -6.273*** -5.979*** -6.548***

(1.835) (1.551) (0.439) (0.344)

State fi xed effects Y N Y N

Observations 1,155 1,155 1,695 1,695

R-squared 0.439 0.152 0.341 0.059

Standard errors in parentheses

*** p<0.01, ** p<0.05, * p<0.1

Note: statistical models using EQIP expenditures (or contract counts or other appropriate variable) are ERS estimates using 

USDA Natural Resources Conservation Service data and are not offi cial NRCS values.