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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Dairy Forage Research » Research » Research Project #433979

Research Project: Improving Forage Genetics and Management in Integrated Dairy Systems for Enhanced Productivity, Efficiency and Resilience, and Decreased Environmental Impact

Location: Dairy Forage Research

Project Number: 5090-12210-001-000-D
Project Type: In-House Appropriated

Start Date: Mar 4, 2019
End Date: Jan 11, 2024

Objective:
1. Develop or improve annual and/or perennial forage production systems that optimize forage production for dairy farms while reducing environmental impacts. 1A. Evaluate management factors for warm-season grass species to develop forage production systems for dairy farms. 1B. Determine manure source and application rate effects on warm season grass productivity, nutritive value, and persistence, and on soil chemical and biological properties. 1C. Determine management and plant biological factors contributing to winterkill and poor persistence of alfalfa and develop strategies to reduce winterkill and improve persistence of alfalfa. 2. Develop or improve warm-season and/or cool-season grass germplasm that enhances yield, quality and resiliency of forage production for integrated dairy systems. 2A. Develop, validate, and apply genomic selection tools to be used in breeding switchgrass for improved forage/biomass yield, cold tolerance, nitrogen-use efficiency, and digestibility. 2B. Determine the role of endophytic fungi in the meadow fescue life cycle. 3. Develop or improve forage legume germplasm that enhances yield, quality and resiliency of diverse forage management systems. 3A. Develop improved red clover varieties that have greater persistence and biomass yield. 3B. Develop improved alfalfa germplasms that are genetically broad and will expand the U.S. alfalfa breeding pool. 3C. Improve underutilized forage legumes for use in forage production and as cover crops. 4. Develop or improve cover crop systems that enhance forage production while reducing nutrient losses and soil erosion in integrated dairy production systems. 4A. Refine management practices for corn grown with interseeded alfalfa. 4B. Develop or identify germplasm that is well suited for interseeding. 5: Develop ration formulation and feeding strategies that experimentally validate chemical methods designed to properly value use of alfalfa in terms of animal performance, milk production, nutrient use efficiency, and enteric methane emissions. 6: Develop cover crop strategies (and tools) for the upper Midwest that explore new plant species and overcome current soil moisture, soil temperature, crop pest and economic limitations to provide incentive to farmers to adopt cover cropping.

Approach:
Objective 1. Switchgrass, big bluestem and indiangrass cultivars will be fertilized with 0 to 80 kg/ha of fertilizer nitrogen and harvested once or twice per season to assess plant development, dry matter yield and forage quality in relation to nutrient requirements of dairy cattle. The warm season grasses will also be fertilized with 0 to 80 kg of nitrogen in the form of solid and liquid manure to assess nutrient uptake, soil chemical and biological properties, plant persistence, dry matter yield and nutritive value. Objective 2. Genomic selection tools will be developed, validated, and used in breeding switchgrass for improved forage/biomass yield, cold tolerance, nitrogen-use efficiency, and digestibility. The role of endophytic fungi in conferring drought, heat, defoliation, and traffic tolerance to meadow fescue will be assessed in greenhouse and field experiments. Objective 3. An extensive breeding program utilizing phenotypic and genotypic selection of halfsib lines grown as spaced plants and swards at multiple locations will be used to develop red clover cultivars with improved biomass production and persistence. Four alfalfa subsp. falcata syn1 germplasms developed by recurrent phenotypic selection will be harvested for multiple years in sward trials to assess persistence and dry matter yield. Two experimental birdsfoot trefoil varieties differing in tannin content and 15 experimental kura clover varieties will be compared to check varieties in sward trials to assess growth characteristics, dry matter yield, persistence, and forage quality. Objective 4. Field studies will evaluate and refine agrichemical applications as well as planting and harvesting management practices to improve the establishment and overall forage production of alfalfa interseeded into silage corn. Syn1 and hybrid alfalfa entries developed from surviving plants and various corn hybrids will be evaluated in field studies to evaluate their compatibility and dry matter yield potential in a corn silage-interseeded alfalfa production system. Objective 5. This objective will be fulfilled by conducting the following types of experiments: 1. Quantify the nutritional benefits of alfalfa and its interactions with other feed components when fed in various kinds of dairy rations and understand how protein, fiber, and other constituents in alfalfa are metabolized in the rumen and utilized for milk production vs. other less desirable outcomes such as enteric methane emissions. 2. Improve forage quality assays to more accurately predict the nutritive value of alfalfa and optimize its use in dairy rations. Objective 6. Research will focus on incorporating plants beyond alfalfa into existing crop rotations with outcomes that incentivize farmers to adopt cover cropping practices (e.g., improved crop production as mediated by soil health, water use efficiency or provision of nutrients that is more economical than application of chemical fertilizer; increased forage availability for livestock beyond that produced by conventional cropping systems; increased provision of environmental services such as pollinator habitat, soil conservation or soil carbon storage).