U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Dairy Forage Research: Madison, WI
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Midwest Area Madison, Wisconsin U.S. Dairy Forage Research Center Dairy Forage Research Research





- Duff, Alison
- Food Animal Production (101)
- Grass, Forage, and Rangeland Agroecosystems (215)

Research Project: **Location:
                            Dairy Forage Research** Project Number: 5090-21500-002-028-R
                        
                        Project Type: Reimbursable Cooperative Agreement Start Date: Apr 1, 2023
                        
                        End Date: Dec 31, 2025 **Objective:**
                        
                        The goals of this project are 1) to evaluate and demonstrate innovative establishment and termination strategies for alfalfa to improve soil health and field carbon (C) balances
Project objectives are to:
1). Evaluate the impacts of tillage, nurse crops, and alfalfa-grass mixtures on field-scale carbon dioxide (CO2) fluxes, mineralizable carbon, and soil organic carbon during the establishment and termination periods using on-farm alfalfa stands (ARS objective). Management practices to evaluate include: Cover or nurse crops for alfalfa establishment (e.g. oat, barley, triticale, Italian ryegrass)
Tillage management for alfalfa establishment and termination (no-till/herbicide, chisel till, undercutting, strip tillage). **Approach:**
                        
                        ARS scientists in St. Paul, MN, and Madison, WI, will lead research on Objective 1. Research will be conducted at two on-farm locations in Minnesota and Wisconsin.  At each measurement site, two adjacent fields with at least 200 m fetch (~40 acres) in the prevailing wind direction will be identified for establishment of the experiment.  One field will be managed with a “business as usual” (BAU) approach that represents standard approaches to establishment or termination of alfalfa with respect to tillage, grass mixtures, and cover/nurse cropping.  As a contrast to the BAU field, a second field at each site will be managed as the “treatment” field where alternative approaches to establishment and termination are employed with a goal of improving the field C balance relative to the BAU approach.  Practices that may be evaluated include no-till or strip-till seeding and herbicide/no-till termination of alfalfa; cover or nurse crops for alfalfa establishment such as oat, barley, tritcale, or Italian ryegrass; alfalfa-grass mixtures (e.g, seeded in biculture with meadow fescue).  The specific management practices chosen for the treatment field will be selected based on each producer’s ability to implement the selected practices at the field scale.   Treatments may be combined for an individual field (e.g. no-till + cover crop).  In this case, the impacts of individual management practices may be confounded, so the treatments will be considered as a “system” for comparison with the BAU approach.  All other management practices will be held consistent between fields to the extent possible.  This “paired-field” design will allow for a treatment vs BAU contrast at each farm.

Eddy covariance towers will be installed in both fields at each measurement site and monitored for a two year period (2023 - 2024).  Year-round, field-scale eddy covariance flux measurements will allow for continuous monitoring of CO2, water, and energy exchange of each alfalfa management system throughout the duration of this project. Additional meteorological data will be collected including incident photosynthetically active and net radiation; air temperature and relative humidity; precipitation; soil moisture and temperature. We will also work with producers at each site to record any additions of C to each field via manure application (manure C) and removals of C in harvested forage (crop harvest C). From these data we will calculate the net ecosystem production (NEP, or the net CO2-C flux in each field),  and the net ecosystem C balances (NECB) for each management system, where NECB = NEP + manure C – crop harvest C.  The NECB accounts for all major C flows from the field, both gaseous and non-gaseous, and represents the implied change in soil organic carbon (SOC).  Soil samples will also be collected at each measurement site at the beginning and end of the experiment and analyzed for total, inorganic, and organic C for comparison with NECB estimates.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov