Location: Dairy Forage Research
2023 Annual Report
Accomplishments
1. Measuring the balance between greenhouse gas emission and carbon mitigating processes on a model dairy farm. The dairy industry has set an ambitious target of “net zero” dairy by 2050. Achieving this target will require simultaneous reductions in greenhouse gas emissions from the field, herd, and manure management while increasing carbon storage in farm soils and vegetation. ARS and University of Wisconsin-Madison researchers in Madison, Wisconsin, evaluated the effects of farm vegetation and management practices on carbon balance and ecosystem services. Greenhouse gas emissions and carbon storage were assessed using the Prairie du Sac Agricultural Research Station as a model system and found that 60% of all farm emissions were offset by the 40% of the farm in permanent perennial cover, including pasture, grassland, and woodland vegetation. Net zero production will require strategies to reduce emissions and increase carbon mitigation, and these findings create clues to changes in both parameters that result in reduced emissions, greater carbon conservation and storage in soils and plants, and reaching the goal of net zero production.
2. Breeding alfalfa for successful establishment when it is interseeded with corn. Alfalfa can be established for long-term forage production by planting it with a corn silage companion crop. This intercropping system has the potential to increase forage yields and farm profitability while reducing the risk of nutrient and soil loss from cropland. Unfortunately, excessive loss of alfalfa seedlings under corn during wet growing conditions hampers adoption of this practice by farmers. Field studies by ARS researchers in Madison, Wisconsin, in collaboration with commercial seed companies demonstrated that alfalfa seedlings that survive under corn can be intermated to produced progeny with 35% greater survival in the intercropping system. Further breeding efforts for improved varieties of alfalfa, other forages, and cover crops that can be reliably, profitably, and sustainably be intercropped with corn on farms will have great benefits to production efficiency and nutrient loss in corn production.
3. Discovering genes associated with seed dormancy of hairy vetch for use as targets to improve its utility on the farm. Hairy vetch is a winter hardy annual legume that can be planted in late summer, grown in the fall and early spring, and then killed to provide soil protecting ground cover, supply nitrogen, and boost yields of subsequent row crops such as corn. Unfortunately, hairy vetch produces a high proportion of dormant seed that limits germination, discouraging its use. ARS researchers in Madison, Wisconsin, in collaboration with the Noble Research Institute conducted a study that identified over 24,000 gene products (RNA transcripts) associated with seed dormancy in hairy vetch by comparing RNA transcript samples from seed of hairy vetch plants that produced a high and low proportion of dormant seed. This work will ultimately help scientists develop new varieties of hairy vetch whose seed will germinate quickly and vigorously create ground cover while minimizing the risk of hard seeding lying dormant in the soil risking a contribution to future weed issues on farms.
Review Publications
Osterholz, W.R., Ruark, M.D., Renz, M.J., Grabber, J.H. 2023. Interseeded alfalfa N fixation and transfer to maize are reduced by N fertilizer. Nutrient Cycling in Agroecosystems. 126:67-79. https://doi.org/10.1007/s10705-023-10276-y.
Casler, M.D. 2023. Impact of ploidy on biomass yield of upland switchgrass (Panicum virgatum L.): A meta-analysis. Genetic Resources and Crop Evolution. 70:1115-1122. https://doi.org/10.1007/s10722-022-01489-1.
Casler, M.D., Lee, D. 2023. Registration of 'Cedar Creek' Switchgrass. Journal of Plant Registrations. 17(3):483-487. https://doi.org/10.1002/plr2.20294.
Casler, M.D., Lee, D. 2023. Registration of 'Empire' big bluestem. Journal of Plant Registrations. 17(2):223-227. https://doi.org/10.1002/plr2.20280.
Tilhou, N., Casler, M.D. 2021. Subsampling and DNA pooling can increase gains through genomic selection in switchgrass. The Plant Genome. 14(3). Article e20149. https://doi.org/10.1002/tpg2.20149.
Tilhou, N., Casler, M.D. 2022. Surveying Grassland Islands: The genetics and performance of Appalachian Switchgrass (Panicum virgatum L.). Genetic Resources and Crop Evolution. 69:1039-1055. https://doi.org/10.1007/s10722-021-01282-6.
Barre, P., Asp, T., Byrne, S., Casler, M.D., Faville, M., Rognli, O., Roldan-Ruiz, I., Skot, L., Ghesquiere, M. 2022. Genomic prediction of complex traits in forage plants species: Perennial grasses case. Ahmadi, N., Bartholomé, J., editors. Methods in Molecular Biology. Vol 2467. Humana, New York, NY. p. 521-541. https://doi.org/10.1007/978-1-0716-2205-6_19.
Poudel, H., Tilhou, N., Sanciangco, M., Vaillancourt, B., Kaeppler, S., Buell, C., Casler, M.D. 2021. Genetic loci associated with winter survivorship in diverse lowland switchgrass populations. The Plant Genome. 14(3). Article e20159. https://doi.org/10.1002/tpg2.20159.
Grabber, J.H., Riday, H., Enjalbert, N., Wagner, S., Mickelson, D. 2023. Establishment of alfalfa interseeded into corn in response to one cycle of selection and hybridization. Crop Science. 63(3):1139-1147. https://doi.org/10.1002/csc2.20923.
Kucek, L.K., Dawson, J., Darby, H., Mallory, E., Davis, M., Sorrells, M. 2021. Breeding wheat for weed-competitive ability: II. Measuring gains from selection and local adaptation. Euphytica. 217. Article e203. https://doi.org/10.1007/s10681-021-02905-w.
Kucek, L.K., Mallory, E., Darby, H., Dawson, J., Sorrells, M. 2021. Breeding wheat for weed-competitive ability: I. Correlated traits. Euphytica. 217. Article e202. https://doi.org/10.1007/s10681-021-02930-9.
Ali, S., Kucek, L.K., Riday, H., Krom, N., Krogman, S., Cooper, K., Jacobs, L., Mehta, P., Trammell, M., Bhamidimarri, S., Butler, T., Saha, M.C., Monteros, M.J. 2023. Transcript profiling of hairy vetch (Vicia villosa Roth) identified interesting genes for seed dormancy. The Plant Genome. 16(2). Article e20330. https://doi.org/10.1002/tpg2.20330.
