27998 Federal Register / Vol. 61, No. 108 / Tuesday, June 4, 1996 / Rules and Regulations

Dated: May 28, 1996.

Kenneth C. Clayton,

Acting Administrator.

[FR Doc. 96–13832 Filed 6–3–96; 8:45 am]

BILLING CODE 3410–02–P

Natural Resources Conservation

Service

7 CFR Part 610

Technical Assistance

AGENCY: Natural Resources

Conservation Service, USDA.

ACTION: Final rule.

SUMMARY: Section 301(c) of the Federal

Agriculture Improvement and Reform

Act of 1996 (FAIRA) requires the

Secretary of Agriculture to publish in

the Federal Register, within 60 days of

the enactment of FAIRA, the universal

soil loss equation (USLE) and wind

erosion equation (WEQ) used by the

Department of Agriculture (the

Department) as of the date of

publication. The Natural Resources

Conservation Service (NRCS) utilizes

factors from the USLE, the revised

universal soil loss equation (RUSLE)

and the WEQ in equations to predict

soil erosion due to water and wind. The

Department was first required to use the

factors from the USLE and WEQ to make

highly erodible land (HEL)

determinations under the Food Security

Act (FSA) of 1985, Pub. L. 99–198. The

FSA defined HEL as land that has the

potential for an excessive annual rate of

erosion in relation to the soil loss

tolerance level as determined by the

Secretary through application of factors

from the USLE and WEQ.

This final rule sets forth the USLE and

WEQ used by the Department as of this

date and the circumstances under the

equations are used. Since the first

mandated use of the USLE in 1985, the

technology used to predict soil erosion

due to water has been refined. The

refinement is reflected in a revised

USLE (RUSLE) which will also be used

under the circumstances described in

this rule.

EFFECTIVE DATE: This rule is effective

June 3, 1996.

FOR FURTHER INFORMATION CONTACT:

David L. Schertz, National Agronomist,

Natural Resources Conservation Service,

P.O. Box 2890, Washington, D.C. 20013;

Fax 202–720–2646 or

Internet:dschertz@usda.gov.

SUPPLEMENTARY INFORMATION:

Rulemaking Analyses

EO 12291: Not major.

Regulatory Flexibility Act: No

significant impact.

Paperwork Reduction Act: Does not

apply.

National Environmental Policy Act:

Not applicable.

Civil Rights Impact Analysis: Not

applicable.

Federalism Assessment: Does not

have sufficient federalism implications

to warrant an assessment.

Unfunded Mandate: Not applicable.

Background And Purpose

The Natural Resources Conservation

Service (NRCS) of the United States

Department of Agriculture (the

Department), utilizes the universal soil

loss equation (USLE), the revised

universal soil loss equation (RUSLE)

and the wind erosion equation (WEQ) to

predict soil erosion due to water and

wind. Section 301(c) of the Federal

Agriculture Improvement and Reform

Act of 1996 (FAIRA), which was

enacted April 4, 1996, requires the

Secretary of Agriculture to publish in

the Federal Register by June 3, 1996, the

USLE and WEQ used by the Department

as of the date of publication. NRCS is

publishing the equations and the rules

under which the USLE, RUSLE, and

WEQ factors are used for administering

programs.

The equation for predicting soil loss

due to erosion for both the USLE and

RUSLE is A=R×K×LS×C×P. The factors

in the equation have the following

definitions:

1. A is the estimation of average

annual soil loss in tons per acre caused

by sheet and rill erosion.

2. R is the rainfall erosivity factor.

3. K is the soil erodibility factor.

4. LS is the slope length and steepness

factor.

5. C is the cover and management

factor.

6. P is the support practice factor.

A paper published by K.G. Renard, et

al., in the May–June, 1994 Journal of

Soil and Water Conservation, volume

49(3), pages 213–220, entitled, ‘‘RUSLE

revisited: Status, questions, answers,

and the future’’, describes the revision.

Primary differences between the USLE

and RUSLE include the following:

R Factor: RUSLE includes more R

values for the Western United States

than the USLE. For the eastern United

States, R values are generally the same

as those used in the USLE but includes

some revisions.

K Factor: Values used in RUSLE are

similar to the USLE values but are

adjusted to account for changes, such as

freezing and thawing, and soil moisture.

These adjustments are calculated at onehalf month intervals for use in RUSLE

and are applicable in the northern and

southern plains, midwest, southern, and

eastern United States.

LS Factor: USLE uses one LS table;

RUSLE uses four LS tables, as

determined by the relationship of rill to

interrill erosion. Although both the

USLE and RUSLE can account for the

effects of complex slopes, RUSLE

simplifies this LS determination

through the use of computer technology.

C Factor: USLE provides estimates of

soil changes for 4–5 crop stage periods

throughout the year. RUSLE provides

estimates of cover and soil changes on

one-half month intervals, especially in

relation to canopy, surface residue,

residue just under the surface, and the

effects of climate on residue

decomposition, roughness, roots, and

soil consolidation.

P Factor: USLE uses P factors for

contouring, contour stripcropping, and

terracing from table values established

for field slope ranges; and for terraces,

the P factor is also based on channel

gradients. RUSLE uses P factors for

farming across the slope and includes

new process-based routines to

determine the effect of stripcropping

and buffer strips. Values for farming

across the slope are based on slope

length and steepness, row grade, ridge

height, storm severity, soil infiltration,

and the cover and roughness conditions.

The stripcropping P factor is based on

the amount and location of soil

deposition.

The equation for predicting soil loss

due to wind erosion is E=f(IKCLV). The

factors in the equation have the

following definitions:

1. E is the estimation of average

annual soil loss in tons per acre.

2. f indicates the equation includes

functional relationships that are not

straight-line mathematical calculations.

3. I is the soil erodibility index.

4. K is the ridge roughness factor.

5. C is the climatic factor. All climatic

factor values are expressed as a

percentage of the value established at

Garden City, Kansas. Garden City,

Kansas was the location of early

research in the WEQ and established the

standard for climatic factors against

which the other locations are measured.

6. L is the unsheltered distance across

an erodible field, measured along the

prevailing wind erosion direction.

7. V is the vegetative cover factor.

The Department was first statutorily

required to use the factors from the

USLE and WEQ to make highly erodible

land (HEL) determinations under the

Food Security Act (FSA) of 1985, Pub.

L. 99–198. The Department published

the equations used to determine HEL

during promulgation of the regulations
Federal Register / Vol. 61, No. 108 / Tuesday, June 4, 1996 / Rules and Regulations 27999

implementing the HEL and wetland

conservation provisions of the FSA, 7

CFR Part 12 (see Federal Register, Vol.

52, No. 180, page 35194, September 17,

1987). Section 12.21 provides that land

in a soil map unit will be considered to

be highly erodible if the quotient of

either the RKLS/T or the CI/T equals or

exceeds 8. The factors, R, K, and LS are

from the USLE. The USLE factors are

explained in the U.S. Department of

Agriculture Handbook 537. The factors

C and I are from the WEQ. The WEQ

factors are explained in a paper by N.P.

Woodruff and F.H. Siddaway, 1965. The

soil loss tolerance (T) value represents

the average annual rate of soil erosion

that could occur without causing a

decline in long term productivity. The

specific factors values which are used

for determining whether soil map units

are considered to be highly erodible are

published in the local Field Office

Technical Guide (FOTG) which is

maintained in each NRCS field office.

The values published as of January 1,

1990, in the FOTG are the basis for all

HEL determinations. The FOTG is

available for review in each NRCS field

office. The values vary across the

country to correspond to differences in

climate, soil types, and topography.

Since the publication of the USLE in

1985, additional research on erosion

processes has resulted in refined

technology for determining the factor

values in the USLE. RUSLE represents

a revision of the USLE technology in

how the factor values in the equation

are determined. RUSLE is explained in

the U.S. Department of Agriculture

Handbook 703, ‘‘Predicting Soil Erosion

by Water: A Guide to Conservation

Planning with the Revised Universal

Soil Loss Equation (RUSLE).’’

Since the passage of the FSA in 1985,

USLE and WEQ have been used to

compile the highly erodible soils list

and to make highly erodible field

determinations. USLE has been used to

develop conservation plans and

revisions and to conduct status reviews.

As new understanding is gained through

research on erosion processes, updates

of erosion prediction equations can

occur. Changing the highly erodible

soils list and field determinations each

time these technologies are updated

would be disruptive to farmers and

impractical for long range planning.

Therefore, no changes to the existing

highly erodible soils list or field

determinations will be made as a result

of the implementation of RUSLE.

However, as technology is improved,

such as with RUSLE, NRCS will use it

to develop new conservation plans, plan

revisions, and to conduct status reviews.

NRCS will not require producers to

meet more restrictive levels of erosion

reduction that might result from using

RUSLE instead of USLE while carrying

out existing conservation plans.

Therefore, all existing conservation

plans developed using USLE, that have

been implemented, will remain

acceptable plans for purposes of the

HEL conservation provisions of the

FSA.

List of Subjects in 7 CFR Part 610

Soil conservation, Technical

assistance, Water resources.

For the reasons set forth above, 7 CFR

Part 610 is amended as follows:

PART 610—TECHNICAL ASSISTANCE

1. The authority for Part 610 is revised

to read as follows:

Authority: 16 U.S.C. 590a–590f, 590q,

3801(a)(9).

§§ 610.1–610.5. [Designated as Subpart A]

2. Sections 610.1 through 610.5 are

designated as subpart A—Conservation

Operations.

3. Section 610.1 is revised to read as

follows:

§ 610.1 Purpose.

This subpart sets forth Natural

Resource Conservation Service (NRCS)

policies and procedures for furnishing

technical assistance in conservation

operations.

4. Subpart B—Soil Erosion Prediction

Equations containing §§ 610.11 through

610.14 is added to read as follows:

Subpart B—Soil Erosion Prediction

Equations

Sec.

610.11 Purpose and scope.

610.12 Equations for predicting soil loss

due to water erosion.

610.13 Equations for predicting soil loss

due to wind erosion.

610.14 Use of USLE, RUSLE, and WEQ.

Subpart B—Soil Erosion Prediction

Equations

§ 610.11 Purpose and scope.

This subpart sets forth the equations

and rules for utilizing the equations that

are used by the Natural Resources

Conservation Service (NRCS) to predict

soil erosion due to water and wind.

Section 301 of the Federal Agriculture

Improvement and Reform Act of 1996

(FAIRA) and the Food Security Act, as

amended, 16 U.S.C. 3801–3813

specified that the Secretary would

publish the universal soil loss equation

(USLE) and wind erosion equation

(WEQ) used by the Department within

60 days of the enactment of FAIRA. This

subpart sets forth the equations,

definition of factors, and provides the

rules under which NRCS will utilize the

USLE, the revised universal soil loss

equation (RUSLE), and the WEQ.

§ 610.12 Equations for predicting soil loss

due to water erosion.

(a) The equation for predicting soil

loss due to erosion for both the USLE

and the RUSLE is A=R×K×LS×C×P. (For

further information about USLE see the

U.S. Department of Agriculture

Handbook 537, ‘‘Predicting Rainfall

Erosion Losses—A Guide to

Conservation Planning,’’ dated 1978.

Copies of this document are available

from the Natural Resources

Conservation Service, P.O. Box 2890,

Washington, DC 20013. For further

information about RUSLE see the U.S.

Department of Agriculture Handbook

703, ‘‘Predicting Soil Erosion by Water:

A Guide to Conservation Planning with

the Revised Universal Soil Loss

Equation (RUSLE).’’ Copies may be

purchased from the National Technical

Information Service, 5285 Port Royal

Road, Springfield, VA 22161.)

(b) The factors in the USLE equation

are:

(1) A is the estimation of average

annual soil loss in tons per acre caused

by sheet and rill erosion.

(2) R is the rainfall erosivity factor.

Accounts for the energy and intensity of

rainstorms.

(3) K is the soil erodibility factor.

Measures the susceptibility of a soil to

erode under a standard condition.

(4) LS is the slope length and

steepness factor. Accounts for the effect

of length and steepness of slope on

erosion.

(5) C is the cover and management

factor. Estimates the soil loss ratio for

each of 4 or 5 crop stage periods

throughout the year, accounting for the

combined effect of all the interrelated

cover and management variables.

(6) P is the support practice factor.

Accounts for the effect of conservation

support practices, such as contouring,

contour stripcropping, and terraces on

soil erosion.

(c) The factors in the RUSLE equation

are defined as follows:

(1) A is the estimation of average

annual soil loss in tons per acre caused

by sheet and rill erosion.

(2) R is the rainfall erosivity factor.

Accounts for the energy and intensity of

rainstorms.

(3) K is the soil erodibility factor.

Measures the susceptibility of a soil to

erode under a standard condition and

adjusts it bi-monthly for the effects of

freezing and thawing, and soil moisture.

(4) LS is the slope length and

steepness factor. Accounts for the effect

of length and steepness of slope on
28000 Federal Register / Vol. 61, No. 108 / Tuesday, June 4, 1996 / Rules and Regulations

erosion based on 4 tables reflecting the

relationship of rill to interrill erosion.

(5) C is the cover and management

factor. Estimates the soil loss ratio at

one-half month intervals throughout the

year, accounting for the individual

effects of prior land use, crop canopy,

surface cover, surface roughness, and

soil moisture.

(6) P is the support practice factor.

Accounts for the effect of conservation

support practices, such as cross-slope

farming, stripcropping, buffer strips,

and terraces on soil erosion.

§ 610.13 Equations For Predicting Soil

Loss Due To Wind Erosion.

(a) The equation for predicting soil

loss due to wind in the Wind Erosion

Equation (WEQ) is E=f(IKCLV). (For

further information on WEQ see the

paper by N.P. Woodruff and F.H.

Siddaway, 1965. ‘‘A Wind Erosion

Equation,’’ Soil Science Society of

America Proceedings, Vol. 29, No. 5,

pages 602–608, which is available from

the American Society of Agronomy,

Madison, Wisconsin. In addition, the

use of the WEQ in NRCS is explained

in the Natural Resources Conservation

Service (NRCS) National Agronomy

Manual, 190–V–NAM, second ed., Part

502, March, 1988, which is available

from the NRCS, P.O. Box 2890,

Washington, DC 20013.)

(c) The factors in the WEQ equation

are defined as follows:

(1) E is the estimation of the average

annual soil loss in tons per acre.

(2) f indicates the equation includes

functional relationships that are not

straight-line mathematical calculations.

(3) I is the soil erodibility index. It is

the potential for soil loss from a wide,

level, unsheltered, isolated field with a

bare, smooth, loose and uncrusted

surface. Soil erodibility is based on soil

surface texture, calcium carbonate

content, and percent day.

(4) K is the ridge roughness factor. It

is a measure of the effect of ridges

formed by tillage and planting

implements on wind erosion. The ridge

roughness is based on ridge spacing,

height, and erosive wind directions in

relation to the ridge direction

(5) C is the climatic factor. It is a

measure of the erosive potential of the

wind speed and surface moisture at a

given location compared with the same

factors at Garden City, Kansas. The

annual climatic factor at Garden City is

arbitrarily set at 100. All climatic factor

values are expressed as a percentage of

that at Garden City.

(6) L is the unsheltered distance. It is

the unsheltered distance across an

erodible field, measured along the

prevailing wind erosion direction. This

distance is measured beginning at a

stable border on the upwind side and

continuing downward to the

nonerodible or stable area, or to the

downwind edge of the area being

evaluated.

(7) V is the vegetative cover factor. It

accounts for the kind, amount, and

orientation of growing plants or plant

residue on the soil surface.

§ 610.14 Use of USLE, RUSLE, and WEQ.

(a) All Highly Erodible Land (HEL)

determinations are based on the

formulas set forth in 7 CFR § 12.21 using

some of the factors from the USLE and

WEQ and the factor values that were

contained in the local Field Office

Technical Guide (FOTG) as of January 1,

1990. In addition, this includes the soil

loss tolerance values used in those

formulas for determining HEL. The soil

loss tolerance value is used as one of the

criteria for planning soil conservation

systems. These values are available in

the FOTG in the local field office of the

Natural Resources Conservation Service.

(b) RUSLE will be used to:

(1)(i) Evaluate the soil loss estimates

of conservation systems contained in

the FOTG.

(ii) Evaluate the soil loss estimates of

systems actually applied, where those

systems were applied differently than

specified in the conservation plan

adopted by the producer or where a

conservation plan was not developed, in

determining whether a producer has

complied with the HEL conservation

provisions of the Food Security Act of

1985, as amended, 16 U.S.C. § 3801 et

seq., set forth in 7 CFR Part 12; and

(2) Develop new or revised

conservation plans.

Dated: May 30, 1996.

Paul W. Johnson,

Chief, Natural Resources Conservation

Service.

[FR Doc. 96–13920 Filed 5–31–96; 11:33 am]

BILLING CODE 3410–16–M

Agricultural Marketing Service

7 CFR Part 928

[Docket No. FV96–928–1–IFR]

Papayas Grown in Hawaii; Assessment

Rate

AGENCY: Agricultural Marketing Service,

USDA.

ACTION: Interim final rule with request

for comments.

SUMMARY: This interim final rule

establishes an assessment rate for the

Papaya Administrative Committee

(Committee) under Marketing Order No.

928 for the 1996–97 and subsequent

fiscal periods. The Committee is

responsible for local administration of

the marketing order which regulates the

handling of papayas grown in Hawaii.

Authorization to assess papaya handlers

enables the Committee to incur

expenses that are reasonable and

necessary to administer the program.

DATES: Effective on July 1, 1996.

Comments received by July 5, 1996, will

be considered prior to issuance of a final

rule.

ADDRESSES: Interested persons are

invited to submit written comments

concerning this rule. Comments must be

sent in triplicate to the Docket Clerk,

Fruit and Vegetable Division, AMS,

USDA, P.O. Box 96456, room 2523–S,

Washington, DC 20090–6456, FAX (202)

720–5698. Comments should reference

the docket number and the date and

page number of this issue of the Federal

Register and will be available for public

inspection in the Office of the Docket

Clerk during regular business hours.

FOR FURTHER INFORMATION CONTACT:

Mary Kate Nelson, Marketing Assistant,

California Marketing Field Office, Fruit

and Vegetable Division, AMS, USDA,

2202 Monterey Street, suite 102B,

Fresno, California 93721, telephone

(209) 487–5901, FAX (209) 487–5901, or

Charles L. Rush, Marketing Specialist,

Marketing Order Administration

Branch, Fruit and Vegetable Division,

AMS, USDA, P.O. Box 96456, room

2523–S, Washington, DC 20090–6456,

telephone (202) 720–5127, FAX (202)

720–5698.

SUPPLEMENTARY INFORMATION: This rule

is issued under Marketing Agreement

No. 928 and Order No. 928, both as

amended (7 CFR part 928), regulating

the handling of papayas grown in

Hawaii, hereinafter referred to as the

‘‘order.’’ The marketing agreement and

order are effective under the

Agricultural Marketing Agreement Act

of 1937, as amended (7 U.S.C. 601–674),

hereinafter referred to as the ‘‘Act.’’

The Department of Agriculture

(Department) is issuing this rule in

conformance with Executive Order

12866.

This rule has been reviewed under

Executive Order 12778, Civil Justice

Reform. Under the marketing order now

in effect, handlers of papayas grown in

Hawaii are subject to assessments.

Funds to administer the order are

derived from such assessments. It is

intended that the assessment rate as

issued herein will be applicable to all

assessable papayas beginning July 1,

1996, and continuing until amended,

suspended, or terminated. This rule will

not preempt any State or local laws,