Research Project: Sustainable Agricultural Systems for the Northern Great Plains

Location: Northern Great Plains Research Laboratory

2023 Annual Report

Objectives
Objective 1: Develop strategies to increase production and selected non-provisioning ecosystem services while increasing socio-economic performance of grazing, crop, and integrated crop/livestock systems. Objective 2: Develop options for integrated agricultural systems that reduce production risks, and enhance economic viability and ecosystem services under extreme weather conditions. Objective 3: Assess the effects of management strategies aimed at enhancing ecosystem services on the nutrient content of crop and livestock products. This objective will be enhanced by including research on the plant physiological changes that may affect nutrient density of crops, according to the following subobjective: Subobjective 3C: Evaluate the impact of management strategies including use of phytochemical-rich cover crops and pulse crops on soil and plant function and linkages to crop and meat nutrient density and functional quality. New Subobjective 3D: Identify and quantify plant responses to soil management and abiotic and biotic stresses that affect crop and forage productivity, nutrient density, and functional quality. Objective 4: Operate and maintain the Northern Great Plains LTAR network site using technologies and practices agreed upon by the LTAR leadership. Contribute to the LTAR working groups and common experiments as resources allow. Submit relevant data with appropriate metadata to the LTAR Information Ecosystem. Objective 5: Improve the social and economic sustainability of food production systems for current and future climates in the northern states.

Approach
Agriculture not only faces the challenge of meeting growing needs for food, feed, fuel, and fiber, but also providing non-provisioning ecosystem services while adapting to variable weather conditions. This project builds upon previous research at the Northern Great Plains Research Laboratory (NGPRL), by continuing and expanding research on how management scenarios can impact ecosystem services, but also evaluating the effect of management on nutrient concentrations and providing ways to scale the research to landscape and national levels. The project will continue to develop sustainable management strategies for crops and livestock while using this knowledge to develop more efficient crop-livestock systems (Objective 1). Through collaboration with other ARS locations, NGPRL will determine how different management strategies affect nutrient concentration in crops and carcass quality in livestock (Objective 3). Modelling will be used to scale findings at the plot or field scale to landscape or regional levels and to explore potential management options for producers under variable weather conditions (Objective 2). Finally, NGPRL is involved in multiple national networks, including the National Ecological Observatory Network (NEON) and the Long Term Agroecosystem Research (LTAR) network, which allow network collaborations to leverage local expertise and scale and share research findings at a national level. The NGPRL is uniquely suited to conduct this multitier research because it has a diversity of landscapes and disciplines in which conduct these multiple approaches to sustainably intensify agriculture. We anticipate that completing this project plan will produce contributions to network databases and also guidelines for developing sustainable integrated agricultural systems. Outcomes from the project will benefit producers, the scientific community and policy makers by producing guidelines and management options.

Progress Report
This is the final report for the Sustainable Agricultural Systems for the Northern Great Plains research project located in Mandan, North Dakota. The project was started on October 1, 2018 and scheduled to be completed by September 30, 2023. Project scientists have published over 90 articles including 53 peer-reviewed articles over the life of the project. Initially, the project contained 4 objectives that focused on: 1) grazing land and crop management, 2) options for resilience under weather extremes, 3) identifying potential linkages between management strategies and grain and meat quality, and 4) continuing to contribute to the location’s Long-Term Agroecosystem Research network site. In 2020, additional funding resulted in a new subobjective (Sub-objective 3c) focusing on plant secondary compounds. As part of the additional funds, the location was directed to hire a research biologist with expertise in secondary compounds. In 2021, additional new funds focused on Objective 3 resulted in an additional subobjective (Sub-objective 3d) and the hiring of a plant physiologist. Also in 2021, additional funding was given to the location for developing collaborations with the University of Alaska-Fairbanks (UAF). Half of the funds received were provided to UAF but with the rest of the funds, the location developed a new research objective (Objective 5) to improve the social and economic sustainability of food production systems in northern states. To accomplish this objective, the location hired a social scientist. In 2022, additional funding linked with Objective 3 resulted in a new analytical chemist position being hired, and funding linked to Objective 5 was used to fund a new technician to assist with soil and crop research. During the current year, all scientist positions remained filled but there were several technical positions that remained open or became open. Objective 1. Weather conditions allowed the treatments to be burned in the fall. Grazing treatments continued to include both mob and goat grazing. The late spring delayed implementation of the mob grazing slightly but all treatment paddocks were grazed. The location continues to collaborate with ARS scientists in Sidney, Montana, to collect data on grasshoppers, dung beetles, and pollinators. Treatments will be modified next year to reflect the treatment structure in the new research project. Perennial wheat failed to establish so research was redirected to provide a spot for indigenous traditional food gardens. The Integrated Crop-Livestock System experiment is still being used to investigate the genetics x environment x management (GXEXM) interaction on the location’s wheat fields. This information informs research in Objective 3. Objective 2. Sub-objective 2.A. Growth curve data on Kentucky bluegrass have been deposited with the National Agricultural Library and a paper was submitted and published. Sub-objective 2.B. The rain intercept shelters were allowed to receive ambient precipitation, and vegetation responses were recorded. Objective 3. Sub-objective 3A. Location scientists collaborated with scientists in Fargo, North Dakota, to analyze and publish results from wheat grain samples grown with and without a perennial phase. Archived soil and wheat grain samples comparing cropping systems with and without a perennial phase were analyzed to evaluate correlations between soil and plant minerals in collaboration with the scientists in Fargo, North Dakota. Spring wheat samples collected from the Integrated Crop-Livestock System experiment were sent to ARS collaborators in Fargo, North Dakota, and Beltsville, Maryland, to be evaluated for minerals, protein and phenolic compounds. Data was published from a comparison of saponins in two prominent bioenergy switchgrass cultivars ‘Liberty’ and ‘Independence’ through collaborations with ARS locations in Lincoln, Nebraska, and Logan, Utah. Research into the effects of stress on saponin fluctuations in ‘Liberty’ switchgrass is still being conducted in collaboration with the Logan, Utah, ARS location. The ARS locations in Lincoln, Nebraska, and Mandan, North Dakota, are collaborating on evaluating the effect of geographic locations on saponin concentration in ‘Liberty’ switchgrass. Silphium, a potential perennial oilseed crop, is being evaluated for saponin concentrations on two different soil types. The establishment of 5 varieties of sainfoin in spring and fall plantings on two different soil types was started in 2023. Sainfoin is a forage that contains tannins which are valuable for doing research on secondary plant compounds. A scientist at the ARS location in Mandan, North Dakota, is collaborating with researchers in Leipzig, Germany to measure ecometabolomic profiles of corn and wheat plants. Objective 4: Research on the plot-scale and field-scale cropland common experiment continued as planned. Subobjective 4A. Assessments were conducted at both plot and field scales for the Long-Term Agroecosystem Research Network Croplands Common Experiment. Relevant plant, soil, and air samples were collected along with applicable metadata. Relevant data from the first three years of the ‘business-as-usual’ treatment were uploaded to USDA Ag Data Commons. Fields included in the experiment are part of the National Wind Erosion Research Network (NWERN) and site data were collected and shared with NWERN. Objective 5: The location established collaborative agreements with Nueta-Hidatsa-Sahnish College and United Tribes Technical College to provide space for increasing seed of traditional varieties of food crops and assist with propagating plants that are culturally significant for Tribal communities. The location developed a garden space for traditional indigenous food gardens (see information in the progress report on Objective 1) that is also being used as a seed multiplication site for traditional varieties of Mandan, Hidatsa, Arikara Nation corn, beans, squash, melon and tobacco. Location scientists and representatives from Nueta Hidatsa Sahnish College identified traditional varieties through historical documents, museum collections, seed catalogs, and Mandan Hidatsa Arikara elders. In addition, a location scientist helped develop a steering committee made up of Mandan Hidatsa Arikara elders and young professionals to guide the seed soveregnity efforts of the location and the Mandan Hidatsa Arikara Nation. The location hosted a garden blessing in May for members of the Mandan Hidatsa Arikara community to celebrate the start of the garden space. One of the projected outcomes of these collaborations is the development of protocols to ensure indigenous data sovereignty and intellectual property. Location scientists are also actively involved in working with the University of Alaska – Fairbanks (UAF) to further food production systems in Alaska. Location scientists visited UAF collaborators in June to better understand the limitations of Alaskan agriculture. A location scientist has been working with UAF to identify key informants and sampling frames for data collection on food security and community well-being. A location scientist received funds for a SCInet fellow to work on developing a tool to remotely sense cloud berry locations in the state in conjunction with the Quinhagak Native Alaska community.

Accomplishments
1. No-till wheat-corn-soybean rotation is a carbon source. Corn and soybean are increasingly grown throughout the northern Great Plains. How these two crops affect the carbon balance of agricultural land in the region is not well known. Such information is important for emerging markets that aim to incentivize carbon sequestration on agricultural land. A 3-year study measured the carbon balance of a spring wheat-corn-soybean rotation under no-till management. After accounting for carbon removed in grain, the carbon balance was negative for the rotation, implying that the rotation was a carbon source since more caron was lost than taken up by plants. Data from this project was deposited with the National Agricultural Library (https://doi.org/10.15482/USDA.ADC/1528734). Practices to reduce carbon loss from this rotation may include growing cover crops, changing the types of crops grown, or extending the length of the crop rotation.

2. Perennial crops key to improving soil in integrated crop-livestock systems. Adding livestock to cropland can increase carbon sequestration and improve soil health, but outcomes are often highly variable depending on site characteristics and management practices. To better understand crop and soil responses to an integrated crop-livestock system in the northern Great Plains, a 3-yr study measured crop biomass, carbon dioxide emissions, and soil properties in grazed and ungrazed crop rotations and grass pasture. Perennial cover crops in the grazed crop rotation contributed to greater soil organic matter and carbon mineralization compared to the ungrazed crop rotation. Use of cover crops for forage in rainfed cropping systems can support livestock integration and improve soil health.

3. Switchgrass cultivars differ in their concentration of a key secondary compound. Switchgrass (Panicum virgatum L.) is a warm-season grass native to the tallgrass prairie in North America. Switchgrass can benefit agricultural systems, by increasing soil organic carbon, providing cattle forage, or harvest for biofuel. However, switchgrass also contains steroidal saponins, a plant secondary compound that may help it tolerate environmental stresses such as insects and diseases while also decreasing nitrogen loss and increasing soil water holding capacity. ARS scientists in Mandan, North Dakota, Logan, Utah, and Lincoln, Nebraska, collaborated to evaluate the steroidal saponin content of two important bioenergy switchgrass cultivars "Liberty" and "Independence". Both cultivars had three types of steroidal saponins and steroidal saponin concentrations were greater in the leaf than stem tissues in both cultivars. Steroidal saponin concentration differed between the two cultivars. This research is useful to researchers in helping to understand switchgrass effects on soil nutrient cycling, forage use, and resistance to pests and to help producers in selecting switchgrass cultivars.

4. African mustard, an invasive plant in the southwestern United States, has been identified in North Dakota and Montana. Early detection of invasive plants is critical in identifying potential threats before they occur. An ARS scientist at Mandan, North Dakota, in collaboration with a retired scientist in Sidney, Montana, reported the range expansion of African mustard [Strigosella africana (L.) Botsch] into western North Dakota. African mustard is native to northern Africa, but has invaded disturbed areas in the southwestern United States. African mustard is easily misidentified as blue musard [Chorispora tenella (Pall.) DC], which is native to the western U.S. African mustard in western North Dakota and eastern Montana have been found in undisturbed native grasslands that are leased for cattle grazing and along a popular trail in Theodore Roosevelt National Park. The high similarity between blue and African mustard will make it difficult to control the spread through public awareness efforts. However, land managers need to be aware of the sighting since cattle movement and tourists in the Northern Great Plains could increase the spread of African mustard.

5. Integrating social, economic, and environmental dimensions within Long-Term Agroecosystem Research (LTAR) network. The rural landscape and agriculture are both changing, and scientists have increasing recognized that changes in ecosystems and human well-being are connected. Rangeland research has traditionally focused on livestock, grassland, environmental production, and sustainability but there has been limited focus on producer well-being and the human dimensions of agricultural production systems. To fill this gap, the USDA-led Long-Term Agroecosystem Research (LTAR) network has integrated sociological research with long-term agricultural science. The social science research has highlighted the importance of addressing humans’ role in rangeland science and management, establishing, and maintaining relationships to improve collaboration, and building trust for successful long-term collaborations. ARS scientists in Mandan, North Dakota, collaborated with scientists from the University of Idaho to develop a special issue of Rangelands (Oct 2022) to highlight these findings and refocus the LTAR network research. This special issue also provided a path for the rangeland community to normalize human well-being as a vital part of rangeland research. This research will contribute to shaping better institutions and policies and developing better management systems that incorporate diverse perspectives.

6. Kentucky bluegrass forage quantity and quality deficiencies. Grasslands in the northern Great Plains have been invaded by Kentucky bluegrass, a non-native cool-season grass. Future weather predictions estimate that growing season precipitation will decrease, and temperature will increase. These climatic patterns will negatively affect these cool-season invasive grass species' grass growth and forage quality. Livestock producers need to know if the nutritional needs of grazing cattle can be met under these changing conditions. ARS researchers in Mandan, North Dakota, estimated the nutrients offered by Kentucky bluegrass-invaded pastures and compared that to the nutritional requirements of cow-calf pairs for pasture grown in drought and non-drought years. Nutritional deficiencies occurred throughout the growing season, especially during a drought year. This study provides useful information for producers to proactively deal with an invasion of Kentucky bluegrass and expected changes in climate. The data from this project (doi: 10.17632/khksjzsbjm.2) has been deposited with the National Agricultural Library. Potential solutions include increasing forage plant diversity and adjusting management to allow adequate growth and plant cover throughout the year to ensure a more consistent forage supply.

7. Livestock grazing can be an effective conservation tool for Californian coastal grassland ecology. Grasslands cover roughly 25% of California. Across California, livestock grazing has been expanding as a land management tool for conservation and wildfire fuel reduction but attempts to investigate the impacts of grazing on California plant communities have produced mixed results, with some studies showing negative effects and others displaying neutral or positive results. In 2013, the Santa Lucia Conservancy reintroduced cattle to the Santa Lucia Preserve to test the long-term effects of grazing in California grasslands. An ARS researcher in Mandan, North Dakota, and an ARS statistician in College Station, Texas, initiated research to determine if a targeted grazing regime using cattle could achieve conservation goals tied to improved grassland conditions, including managing vegetation structure and fuels (increasing bare ground, decreasing litter and herb heights), improving native species, and reducing invasive species. Grazing successfully increased bare ground, decreased litter depth and cover, and decreased herbaceous height. Grazed plots had a greater cover of native annual forbs while decreasing invasive ripgut brome. This research suggests that targeted grazing can be an appropriate tool for grassland managers in California to accomplish conservation goals, including biomass management and canopy clearing without risk to native species. This is especially important for conservationists managing for native species and for grazingland managers working to reduce fuels as part of wildfire management.

8. Landowner perspectives and strategies for managing Kentucky bluegrass in the northern Great Plains highlight a need for more proactive intervention. Kentucky bluegrass is an invasive species that has invaded much of the northern Great Plains. This invasion has had negative ecosystem effects and has reduced the ability of these grasslands to respond to extreme weather events such as droughts. Effective management of grasslands is complicated by differences in landowner management goals, risk thresholds, attitudes, and preferences. An ARS researcher in Mandan, North Dakota, explored the potential for landowners in the northern Great Plains to control Kentucky bluegrass on their land to maintain productivity and maintain or restore ecosystem function. Results suggest that landowners tend to be more reactive than proactive when dealing with invasive species and that they view invasive grasses differently. Those with greater involvement in the management of their land rate Kentucky bluegrass as less acceptable. Because of the more reactive attitude, private landowners alone are likely ineffective at preventing invasion against new invasive grass species. This information is useful to natural resource scientists, non-governmental organizations, extension, and policymakers as they develop strategies to stop further invasion.

9. Repurposing old data for new uses. Many ARS locations and state experiment stations have rangeland livestock production experiments that have lasted for more than 10 years. Information from these experiments could help to understand responses to climate change, model livestock production, or help determine how vegetation changes impacts livestock production. However, this valuable information is often recorded on handwritten sheets which are stored in file cabinets making it hard to access by other scientists. ARS scientists at Mandan, North Dakota, and Fort Collins, Colorado, started a project to digitize this data and store it at the National Agricultural Library (https://data.nal.usda.gov/LTLiveProd). Currently, the team has helped digitize and store seven different long-term datasets that range from 100 years of cattle weight gains from Mandan, North Dakota, to 12 years of pregnancy rates, calf weaning rates, and sale prices form the University of Nevada Agricultural Experiment Station in Austin, Nevada. Datasets include information from ARS and state experiment stations and cattle and sheep data. The project is expanding, including more legacy datasets. These long-term livestock production experiments are rare and efforts to preserve and make them more accessible are essential so scientists can use yesterday’s data to solve tomorrow’s problems.

Review Publications
Merrill, S.D., Zobeck, T.M., Liebig, M.A. 2022. Field measurement of wind erosion flux and soil erodibility factors as affected by tillage and seasonal drought. Soil Science Society of America Journal. 86(5):1296-1311. https://doi.org/10.1002/saj2.20436.
Albanito, F., Mcbey, D., Smith, P., Ehrhardt, F., Harrison, M.T., Bhatia, A., Bellocchi, G., Brilli, L., Carozzi, M., Christie, K., Liebig, M.A. 2022. How modelers model: the overlooked social and human dimensions in model intercomparison studies. Environmental Science and Technology. https://doi.org/10.1021/acs.est.2c02023.
Menefee, D.S., Scott, R.L., Abraha, M., Alfieri, J.G., Baker, J.M., Browning, D.M., Chen, J., Gonet, J.M., Johnson, J.M., Miller, G.R., Nifong, R.L., Robertson, P., Russel, E.R., Saliendra, N.Z., Schreiner-Mcgraw, A.P., Suyker, A., Wagle, P., Wente, C.D., White Jr, P.M., Smith, D.R. 2022. Unraveling the effects of management and climate on carbon fluxes of U.S. croplands using the USDA Long-Term Agroecosystem (LTAR) network. Agricultural and Forest Meteorology. 326. Article 109154. https://doi.org/10.1016/j.agrformet.2022.109154.
Liebig, M.A., Bergh, E.L., Archer, D.W. 2023. Variation in methodology obscures clarity of cropland global warming potential estimates. Journal of Environmental Quality. 52:549-557. https://doi.org/10.1002/jeq2.20467.
Aukema, K.D., Wallau, M.O., Faust, D.R., Archer, D.W., Hendrickson, J.R., Kronberg, S.L., Liebig, M.A. 2023. Soil CO2 efflux dynamics in an integrated crop-livestock system. Soil Science Society of America Journal. 87:948-962. https://doi.org/10.1002/saj2.20546.
Welikhe, P., Williams, M.R., King, K.W., Bos, J.H., Akland, M., Baffaut, C., Beck, G., Bierer, A.M., Bosch, D.D., Brooks, E., Buda, A.R., Cavigelli, M.A., Faulkner, J., Feyereisen, G.W., Fortuna, A., Gamble, J.D., Hanrahan, B.R., Hussain, M., Kovar, J.L., Lee, B., Leytem, A.B., Liebig, M.A., Line, D., Macrae, M., Moorman, T.B., Moriasi, D.N., Mumbi, R., Nelson, N., Ortega-Pieck, A., Osmond, D., Penn, C.J., Pisani, O., Reba, M.L., Smith, D.R., Unrine, J., Webb, P., White, K.E., Wilson, H., Witthaus, L.M. 2023. Uncertainty in phosphorus fluxes and budgets across the U.S. long-term agroecosystem research network. Journal of Environmental Quality. 52(4):837-885. https://doi.org/10.1002/jeq2.20485.
Ochoa-Hueso, R., Delgado-Baquerizo, M., Risch, A.C., Ashton, L., Augustine, D.J., Belanger, N., Bridgham, S., Britton, A.J., Camarero, J.J., Cornelissen, G., Liebig, M.A. 2023. Bioavailability of macro and micronutrients across global topsoils: Main drivers and global change impacts. Global Biogeochemical Cycles. 37. Article e2022GB007680. https://doi.org/10.1029/2022GB007680.
Clemensen, A.K., Lee, S.T., Mitchell, R., Schmer, M.R., Masterson, S.D. 2022. Steroidal saponin concentrations in switchgrass cultivars liberty and independence in North America. Crop, Forage & Turfgrass Management. https://doi.org/10.1002/cft2.20204.
Wanjura, J.D., Pelletier, M.G., Holt, G.A., Barnes, E.M., Wigdahl, J.S., Doron, N. 2021. An integrated plastic contamination monitoring system for cotton module feeders. AgriEngineering. 3(4):907-923.
Young, S.L., Archer, D.W., Blumenthal, D.M., Boyd, C.S., Clark, P., Clements, D.D., Davies, K.W., Derner, J.D., Gaskin, J.F., Hamerlynck, E.P., Hardegree, S.P., Jensen, K.B., Monaco, T.A., Newingham, B.A., Pierson Jr, F.B., Rector, B.G., Sheley, R.L., Toledo, D.N., Vermeire, L.T., Wonkka, C.L. 2023. Invasive annual grasses: re-envisioning approaches in a changing climate. Journal of Soil and Water Conservation. 78(2):95-103. https://doi.org/10.2489/jswc.2023.00074.
Wulfhorst, J., Bruno, J., Toledo, D.N., Wilmer, H.N., Archer, D.W., Peck, D.E., Huggins, D.R. 2022. Infusing ‘long-term’ into social science rangelands research. Rangelands. 44(5):299–305. https://doi.org/10.1016/j.rala.2022.06.001.
Namoi, N., Archer, D.W., Rosenstock, T.S., Jang, C., Lin, C., Boe, A., Lee, D. 2022. How profitable is switchgrass in Illinois, U.S.A. An economic definition of marginal land. Grassland Research. 1(2):111-122. https://doi.org/10.1002/glr2.12017.
Elias, E.H., Tsegaye, T.D., Hapeman, C.J., Mankin, K.R., Kleinman, P.J., Cosh, M.H., Peck, D.E., Coffin, A.W., Archer, D.W., Alfieri, J.G., Anderson, M.C., Baffaut, C., Baker, J.M., Bingner, R.L., Bjorneberg, D.L., Bryant, R.B., Gao, F.N., Gao, S., Heilman, P., Knipper, K.R., Kustas, W.P., Leytem, A.B., Locke, M.A., McCarty, G.W., McElrone, A.J., Moglen, G.E., Moriasi, D.N., O'Shaughnessy, S.A., Reba, M.L., Rice, P.J., Silber-Coats, N., Wang, D., White, M.J., Dobrowolski, J.P. 2023. A vision for integrated, collaborative solutions to critical water and food challenges. Journal of Soil and Water Conservation. 78(3):63A-68A. https://doi.org/10.2489/jswc.2023.1220A.
Bagnall, D.K., Morgan, C., Bean, G.M., Liptzin, D., Cappellazzi, S., Cope, M., Greub, K.L., Norris, C.E., Rieke, E.L., Tracy, P.W., Ashworth, A.J., Baumhardt, R.L., Dell, C.J., Derner, J.D., Ducey, T.F., Fortuna, A., Kautz, M.A., Kitchen, N.R., Leytem, A.B., Liebig, M.A., Moore Jr, P.A., Osborne, S.L., Owens, P.R., Sainju, U.M., Sherrod, L.A., Watts, D.B. 2022. Selecting soil hydraulic properties as indicators of soil health: Measurement response to management and site characteristics. Soil Science Society of America Journal. 86(5):1206-1226. https://doi.org/10.1002/saj2.20428.
Spiegal, S.A., Webb, N., Boughton, E., Boughton, R., Bentley-Brymer, A., Clark, P., Holifield Collins, C.D., Hoover, D.L., Kaplan, N.E., McCord, S.E., Meredith, G., Porensky, L.M., Toledo, D.N., Wilmer, H.N., Wulfhorst, J.D., Bestelmeyer, B.T. 2022. Measuring the social and ecological performance of agricultural innovations on rangelands: Progress and plans for an indicator framework in the LTAR network. Rangelands. 44:334-344. https://doi.org/10.1016/j.rala.2021.12.005.
Halvorson, J.J., Toledo, D.N., Hendrickson, J.R. 2022. Heterogeneity of Kentucky Bluegrass (Poa pratensis L.) seed germination after controlled burning. Rangeland Ecology and Management. 83:112-116. https://doi.org/10.1016/j.rama.2022.04.001.
Liptzin, D., Norris, C.E., Cappellazzi, S.B., Bean, G.M., Cope, M., Greub, K.L., Rieke, E.L., Tracy, P.W., Aberle, E., Ashworth, A.J., Baumhardt, R.L., Dell, C.J., Derner, J.D., Ducey, T.F., Novak, J.M., Dungan, R.S., Fortuna, A., Kautz, M.A., Kitchen, N.R., Leytem, A.B., Liebig, M.A., Moore Jr., P.A., Osborne, S.L., Owens, P.R., Sainju, U.M., Sherrod, L.A., Watts, D.B. 2022. An evaluation of carbon indicators of soil health in long-term agricultural experiments. Soil Biology and Biochemistry. 172. Article 108708. https://doi.org/10.1016/j.soilbio.2022.108708.
Bagnall, D.K., Morgan, C.L., Cope, M., Bean, G.M., Cappellazzi, S.B., Greub, K.L., Liptzin, D., Baumhardt, R.L., Dell, C.J., Derner, J.D., Ducey, T.F., Dungan, R.S., Fortuna, A., Kautz, M.A., Kitchen, N.R., Leytem, A.B., Liebig, M.A., Moore Jr, P.A., Osborne, S.L., Sainju, U.M., Sherrod, L.A., Watts, D.B., Ashworth, A.J., Owens, P.R., et al. 2022. Carbon-sensitive pedotransfer functions for plant-available water. Soil Science Society of America Journal. 86(3):612-629. https://doi.org/10.1002/saj2.20395.
Liebig, M.A., Saliendra, N.Z., Archer, D.W. 2022. Carbon fluxes from a Spring wheat-corn-soybean crop rotation under no-tillage management. Agrosystems, Geosciences & Environment. 5. Article e20291. https://doi.org/10.1002/agg2.20291.
Subhashree, S.N., Igathinathane, C., Akyuz, A., Borhan, M., Hendrickson, J.R., Archer, D.W., Liebig, M.A., Toledo, D.N., Sedivec, K., Kronberg, S.L., Halvorson, J.J. 2023. Tools for predicting forage growth in rangelands and economic analyses — A systematic review. Agriculture. 13(2). Article 455. https://doi.org/10.3390/agriculture13020455.
Pathak, H., Cannayen, I., Zhang, Z., Archer, D.W., Hendrickson, J.R. 2022. A review of unmanned aerial vehicle based methods for plant stand count evaluation in row crops. Computers and Electronics in Agriculture. 198. Article 107064. https://doi.org/10.1016/j.compag.2022.107064.
Evans, A.W., Woodward, B.D., Wyckoff, C.A., Toledo, D.N., Duke, S.E., Fischer, C., Nunez, C., Sierra-Corona, R. 2023. Livestock grazing is an effective conservation tool for Californian coastal grassland ecology: an eight-year study on vegetation dynamics. Applied Vegetation Science. 26. Article e12736. https://doi.org/10.1111/avsc.12736.
Walker, J.W., Kronberg, S.L. 2022. Nature, nurture and vegetation management: studies with sheep and goats. Animal-The International Journal of Animal Biosciences. 16. Article 100434. https://doi.org/10.1016/j.animal.2021.100434.