Brief Summary of Minutes of Annual Meeting

Michigan:

Michigan State University (MSU) continued its commitment to cover crop research, publications and outreach in 2020. In 2020, a collaborative project between MSU and University of Michigan researchers adds another institution to the list. Activities included 26 on-going research projects, 7 scientific/society presentations, 7 peer-reviewed publications, 1 thesis, 5 Extension/outreach publications, 23 news articles, 10 in-person farmer meetings, 4 virtual farmer meetings/field days, 15 videos and 9 podcasts. Research projects include evaluation of cover crops for: 1) interseeding of cover crop into corn; 3) cover crop herbicide tolerance; 4) management across commodities including field crops, vegetables and fruit; 5) forages/feeds; 6) soil fertility; 7) soil health/science/biology; and 8) pest/disease management. MSU cover crop projects were in both conventional and organic systems. Forty-four faculty, staff and students from Plant, Soils and Microbial Sciences; Horticulture; Entomology; W.K. Kellogg Biological Station and Extension were participating in cover crop research. The MSU Michigan cover crop website (www.covercrops.msu.edu) increased to 32,095 pageviews from March 2020 – February 2021 compared to 22,073 during the same period the previous year. Of the Michigan events reporting a total of 701 participants attended in-person and virtual events. COVID restrictions reduced both events and participation in 2020 as MSU pivoted to on-line delivery methods. MSU also educated hundreds of undergraduate and graduate students through 15 different courses in the Departments of Plant, Soil, and Microbial Science, Entomology, and Horticulture that include cover crops in their curriculum.

Number of graduate students and post docs involved in cover crop work: 4 PhD, 4 MS, 2 Post Docs

Number of presentations : 45

Number of publications : 7

Iowa:

Cover crops continue to have a focus for the research, extension and teaching in Iowa. This work has and continues to be integrated both across research, teaching and extension as well as across disciplines. Current activities include economists, social scientists, plant pathologists, entomologies, plant breeders, agricultural engineers, and agronomists. Our focus has largely been on integrating cover crops into the corn and soybean centric cropping system found in Iowa. However, there are ongoing efforts exploring new cover crops and modifying existing cropping systems in a way to build a more resilient system. Researchers are looking at the role of allelochemicals, disease implications of planting green, changes to cover crop management, changes to corn management following cover crops, weed suppression from cover crops, perennial cover crop systems, and nitrogen export from cover crops systems.

Number of graduate students and post docs involved in cover crop work: MS/PHD = 3; Post doc = 2

Number of presentations : 105

Number of publications : 10

Indiana:

Cover crop interest and adoption continues to grow in Indiana (~ 950,000 adopted acres).  Therefore, the demand for training and services related to cover crops by the Conservation Partnership continues to increase. The Indiana Conservation Partnership includes NRCS, Soil and Water Conservation Districts (SWCD), Conservation Cropping Systems Initiative (CCSI), Indiana State Department of Agriculture (ISDA), State Soil Board, and Purdue Extension. Collectively in 2020, the conservation partnership provided technical training, logistical and promotional support for 38 events, reaching nearly 4650 Individuals. To further strengthen cover crop training and services to farmer and trainers, Purdue research scientist conducted approximately 13 distinct research projects related to cover crop adoption,  soil health, cropping systems climate resilience, syncrony of N and P release from cover crop residue, water quality, forage quality, weed supression, and cover crop economics. Additionally, seven cover crop related papers were accepted or published in scientific journals, eight extension and outreach publications, and 35 extension or outreach presentations that reached approximately 2,000 individuals. Ongoing research in cover crops facilitated the graduate education of 11 graduate students (5 Ph.D., 6 M.S.). 

Wisconsin:

In Wisconsin, we have several concurrent efforts in cover crop research and outreach. First, a coordinated group [Cover Crop Research and Outreach Program (CCROP)] was established and maintains active monthly meetings to organized cover crop efforts within UW-Madison, the Michael Fields Institute, and USDA-ARS (Dairy Forage Research Center). Major research efforts include involvement in the Precision Sustainable Agriculture (PSA; precisionsustainableag.org), NRCS-CIG project (cover crop use in organic agricultural systems), and multiple projects funded by the Wisconsin Fertilizer Research Council. Major extension efforts include presentations through the Wisconsin Agribusiness Classic; Soil, Water, & Nutrient Management meetings; OGrains conference; Discovery Farms webinar series; and MOSES conference.

Number of graduate students and post docs involved in cover crop work: 3 graduate students, 1 postdoc

Number of presentations : 12

Number of publications : 2

Nebraska:

Cover crop related efforts continued to expand in Nebraska in 2020. A highlight of Nebraska’s efforts includes collaborative work with research and extension staff through the On-Farm Research Network. The network partners with farmers to conduct on-farm research in randomized, replicated, field-scale strips. Of the 93 experiments published in the 2020 report, 25 were cover crop-related, investigating various aspects of cover crop management such as interseeding, species comparisons, grazing, and cover crops in different crop rotations. We estimate that there are eleven graduate students involved in cover crop related research across agronomy, soil science, animal science and entomology. In spite of the pandemic, we estimate 35 presentations, events and media promoted cover crop work in the state. These presentations included the first ever cover crops and soil health conference in Western Nebraska/Panhandle Research and Extension Center as well as >120 individuals attending the cover crops and soil health focused on-farm research network meeting. The 23 publications for the state included work on cover crops for weed suppression, estimating the biomass/yield impacts of varied maturity corn and soybean, cover crops and grazing, and allelopathy.

Number of graduate students and post docs involved in cover crop work: 11

Number of presentations : 35

Number of publications : 23

North Dakota:

Research on cover crops in North Dakota includes four of the objectives in this regional committee: 1) assess the impact of cover crops on  soil health, and agronomic production and profitability; 2) develop recommendations for cover crops establishment (rates, timing, application method) across production systems; and 3) evaluate cover crops for grazing

Soil erosion by wind is a serious problem in North Dakota especially in winter with little snow cover or dry springs. Cover crops are improving soil health, reducing erosion, and increasing sustainability of cropping systems. In the long-term cover crops will help reduce N fertilization and improve water quality, and provide forage for grazing. 

Research on cover crops interseeding has also increased in the last few years and many farmers are interseeding cover crops in standing corn, soybean, and sunflower either by using a interseeder drill or a broadcast system (aerial or modified sprayer).  Interseeding cover crops into standing corn or soybeans is an alternative for corn-soybean farmers, since there is no time to establish a cover crop after corn or soybean harvest.  However, most research is showing that there is not enough light under the corn or soybean canopy to support the growth of a cover crop interseeded early in the season. Thus, research now is focusing in 60” corn and sunflowers for an adequate establishment of cover crops to improve soil health and as forage for grazing.

Total area of cover crops is unknown but we believe it easily surpassed 500,000 acres in North Dakota. Cover crops adoption in North Dakota is increasing dramatically thanks to the many researchers (14) and graduate students (10) involved in cover crops research and extension in the state. Researchers were able to secure $215,610 in new funding for cover crops research in 2020, Researchers working in cover crops and soil health published 14 peer-reviewed articles, 6 extension publications, 11 presentation in conferences, workshops and symposiums, 5 field days, and 49 videos. Many webinars were organized during the season in replacement of in-person activities.

Minnesota:

Promotion of cover crops in Minnesota is very strong. State programs include 5 Board of Water and Soil Resources Cover Crop Demonstration Grants, many local cover crop cost-share programs, and a scholarship for Farm Business Management for cover crop users. Within the University of Minnesota system, researchers have presented cover crop education at statewide UMN conferences (Nutrient Management, Nitrogen, Soil Management Summit) and the Institute for Agricultural Professionals, as well as numerous local events. Researchers have pursued work on cover crops in a variety of contexts:  incorporating cover crops into corn-soybean rotations via interseeding; managing cover crops in a prevent-plant scenario; incorporating manure with cover crops; evaluating dual-use winter annual cover crops; and describing cover crop impacts on nitrogen leaching in different regions of the state. Satellite imagery has been used since 2015 to describe cover crop success across the state, and these results will inform outreach and policy around cover crop incentives. One new Midwest Cover Crop Council Cover Crop Recipe was published in 2020. Non-governmental farmer-led organizations have also offered numerous peer-to-peer learning opportunities for farmers interested in cover crops.

Number of graduate students and post docs involved in cover crop work: 11

Number of presentations : 31

Number of publications : 9

Kansas:

Currently in Kansas there are 14 university researchers with active research projects ranging in topics from erosion control, water quality, N and P cycling, weed suppression, evaluation in cropping systems, effects on soil moisture, soil health, companion planting with winter wheat, control of charcoal rot in soybean, and forage production and quality. Numerous in person and virtual extension presentations featuring cover crop research were made to producers and agricultural professionals. Two Ph.D students successfully defended their dissertations on work involving cover crops. Kansas cover crop work was published in four different peer-reviewed journals as well as extension and experiment station reports. K-State faculty received grants for state and federal entities to fund cover crop research in Kansas and to support graduate education. 

Metrics:

Graduate students and Postdoctoral Researchers in Cover Crops Research:

Number of MS students: 3

Number of Ph.D. students: 4

Number of Postdoctoral Researchers:2

Number of presentations: 40

Number of publications: 11 

Michigan

• Schramski, J., Sprague, C., & Renner, K. (2020). Integrating fall-planted cereal cover crops and preplant herbicides for glyphosate-resistant horseweed (Conyza canadensis) management in soybean. Weed Technology, 1-8. doi:10.1017/wet.2020.117Acharya, J., T.B. Moorman, T.C. Kaspar, A.W. Lenssen, and A.E. Robertson. 2020.  Effect of cover crop species and rotation on corn and soybean seedling disease and yield in no-till system. Plant Disease 104:677-687. https://doi.org/10.1094/PDIS-09-19-1904-REBanik, C., C.A. Bartel, D.A. Laird, K.J. Moore, and A.W. Lenssen. 2020. Perennial cover crop influences on soil C and N and maize productivity.  Nutrient Cycling in Agroecosystems 116:135-150.
• Schramski, J., Sprague, C., & Renner, K. (2020). Effects of fall-planted cereal cover-crop termination time on glyphosate-resistant horseweed (Conyza canadensis) suppression. Weed Technology, 1-11. doi:10.1017/wet.2020.103
• Moore, V.M., Maul, J.E., Wilson, D., Curran, W.S., Brainard, D.C., Devine, T.E. and Mirsky, S.B., 2020. Registration of ‘Purple Bounty’ and ‘Purple Prosperity’ hairy vetch. Journal of Plant Registrations, 14: 340-346.
• Tarrant, AR; Brainard, DC Hayden, ZD. 2020. Cover Crop Performance between Plastic-mulched Beds: Impacts on Weeds and Soil Resources. HORTSCIENCE 55:1069-1077.  DOI: 10.21273/HORTSCI14956-20
• Nguyen T.T.L. and A.N. Kravchenko 2021. Effects of cover crops on soil CO2 and N2O production across topographically diverse agricultural landscapes in corn-soybean-wheat organic transition. European J. of Agronomy 122, article 126189.
• Mennan, H; Jabran, K; Zandstra, BH; Pala, F. 2020. Non-Chemical Weed Management in Vegetables by Using Cover Crops: A Review. Agronomy 2020, 10(2), 257; https://doi.org/10.3390/agronomy10020257
• Brooker, AP, Renner, KA; Basso, B. 2020. Interseeding cover crops in corn: Establishment, biomass, and competitiveness in on-farm trials. AGRONOMY JOURNAL 112: 3733-3743. DOI: 10.1002/agj2.20355

 Indiana

• Nichols, V., R. Martinez-Feria, D. Weisberger, S. Carlson, B. Basso, and A. Basche. 2020. Cover crops and weed suppression in the US Midwest: A meta-analysis and modeling study. AriXiv. doi: 10.31220/osf.io/43b9n.
• Nichols, V., L. English, S. Carlson, S. Gailans, and M. Liebman. 2020. Effects of Long-Term Cover Cropping on Weed Seedbanks. Front. Agron. 2:591091. doi: 10.3389/fagro.2020.591091.
• Muhammed, Y.A., S. Patel, H.L. Matthees, A.W. Lenssen, B.L. Johnson, M.S. Wells, F. Forcella, M.T. Berti, and R.W. Gesch. 2020. Biomass and soil N dynamics in response to interseeded oilseed cover crops in a maize-soybean system. Agronomy 10, 1439; doi:10.3390/agronomy10091439 
• Muhammed, Y.A., H.L. Matthees, R.W. Gesch, S. Patel, F. Forcella, K. Aasand, N. Steffl, B.L. Johnson, M.S. Wells, and A.W. Lenssen. 2020. Establishing winter annual cover crops in the upper Midwest, USA: Interseeding into maize and soybean. Agronomy Journal 112:719-732. doi: 10.2134/agronj2019.06.0415
• Moore, K.J., C.L. Kling, and D.R. Raman. 2020. A Midwest USA Perspective on Von Cossel et al.’s Prospects of Bioenergy Cropping Systems for A More Social-Ecologically Sound Bioeconomy.  Agronomy 10:1658; doi:10.3390/agronomy10111658
• Forcella, F., S. Patel, A.W. Lenssen, C. Hoerning, M.S. Wells, R.W. Gesch, and M.T. Berti. 2021. Pollinator visitation of flowering winter oilseeds (field pennycress and winter camelina). Journal of Entomology. doi:10.111/jen.12854.
• Casler, M.D., K.P. Vogel, D.K. Lee, R.B. Mitchell, P.R. Adler, R.M. Sulc, K.D. Johnson, R.L. Kallenbach, A.R. Boe, R.D. Mathison, K.A. Cassida, D.H. Min, and K.J. Moore. 2020. Nitrogen demand associated with increased biomass yield of switchgrass and big bluestem. BioEnergy Research 13:120-131; doi.org/10.1007/s12155-019-10081-y
• Bartel, C.A., S.V. Archontoulis, A.W. Lenssen, K.J. Moore, I.L. Huber, D.A. Laird, S. Fei, and P.M. Dixon.  2020.  Modeling perennial groundcover effects on annual maize grain crop growth with the Agricultural Production Systems sIMulator. Agronomy Journal 112:1895–1910.
• Banik, C., C.A. Bartel, D.A. Laird, K.J. Moore, and A.W. Lenssen. 2020. Perennial cover crop influences on soil C and N and maize productivity.  Nutrient Cycling in Agroecosystems 116:135-150.
• Acharya, J., T.B. Moorman, T.C. Kaspar, A.W. Lenssen, and A.E. Robertson. 2020.  Effect of cover crop species and rotation on corn and soybean seedling disease and yield in no-till system. Plant Disease 104:677-687. https://doi.org/10.1094/PDIS-09-19-1904-RE
• Nevins, C., Lacey, C. L., & Armstrong, S. D. 2021. Cover crop enzyme activities and resultant soil ammonium concentrations under different tillage systems. European Journal of Agronomy. (Accepted)
• Sadeghpour, A., Adeymi, O., Hunter, D., Lua, Y., & Armstrong, S. D. (2021). Precision planting impacts on winter cereal rye growth, nutrient uptake, spring soil temperature and adoption cost. Renewable Agriculture and Food Systems. https://doi.org/https://doi.org/10.1017/S1742170520000411
• Thompson, N. M., Armstrong, S. D., Roth, R. T., Ruffatti, M. D., & Reeling, C. J. (2020). Short-Run Net Returns to a Cereal Rye Cover Crop Mix in a Midwest Corn-Soybean Rotation. Agronomy Journal, 112, 1068–1083.
• Lacey, C., Nevins, C. J., Camberato, J. J., Kladivko, E. J., Sadeghpour, A., & Armstrong, S. D. (2020). Carbon and nitrogen release from cover crop residues and implications for cropping systems management. Journal of Soil and Water Conservation, 75(4), 505–514.
• Hodgskiss, C. L., Young, B. G., Armstrong, S. D., & Johnson, W. G. (2021). Evaluating cereal rye and crimson clover for weed suppression within buffer areas in dicamba-resistant soybean. Weed Technology, 1–29.
• DeSimini, S. A., Gibson, K. D., Armstrong, S. D., Zimmer, M., Maia, Lucas O. R., & Johnson, W. G. (2020). Effect of cereal rye and canola on winter and summer annual weed emergence in corn. Weed Technology, 34(6), 787–793. https://doi.org/10.1017/wet.2020.51
• Thompson, N. M., Reeling, C. J., Michelle Fleckenstein, Prokopy, L. S., & Armstrong, S.D. (2020). Examining Intensity of Conservation Practice Adoption: Evidence from Cover Crop Use on U.S. Midwest Farms. Food Policy. (Accepted)

 Wisconsin

• West, J.R., M.D. Ruark, and K.B. Shelley. 2020. Sustainable intensification of corn silage cropping systems with winter rye. Agron. Sustain. Devel. 40:11.
• West, J.R., A.M. Cates, M.D. Ruark, L. Deiss, T. Whitman, and Y. Rui. 2020. Winter rye does not increase necromass contributions to soil organic carbon in continuous corn silage in North Central US. Soil Biol. Biochem. 148:107899

 Nebraska

• Blanco-Canqui, H., and S, Ruis. 2020. Cover crops and soil physical properties: A review. Soil Sci. Soc. Am. J. 1527-1576. 
• Blanco-Canqui, H., M. Drewnoski, D. Redfearn. J. Parsons, G. Lesoing, and W. Tyler. 2020. Does cover crop grazing damage soils and reduce crop yields?. Agrosystems, Geosciences & Environment 3: e20102.
• Blanco-Canqui, H., S, Ruis, C. Proctor, C. Creech, M. Drewnoski, and D. Redfearn. 2020. Harvesting cover crops for biofuel and livestock production: Another ecosystem service? A review. Agron J. 112:2373-2400.
• Chatterjee, N., Archontoulis S., Bastidas A., Proctor C., Elmore R, and Basche, A. Simulating alternative corn management for earlier cover crop introduction in corn-soybean rotation. Agronomy Journal. https://doi.org/10.1002/agj2.20377
• Koehler-Cole, K., R.W. Elmore, H. Blanco-Canqui, C.A. Francis, C.A. Shapiro, C.A. Proctor, D.M. Heeren, S. Ruis, S. Irmak, and R.B. Ferguson. 2020. Cover crop productivity and subsequent soybean yield in the western Corn Belt. Agron. J. 112:2649-2663.
• Koehler-Cole, K., S. Everhart, Yan Gu, C. Proctor, M. Marroquin Guzman, D. Redfearn, and R. Elmore. 2020. Is allelopathy from winter cover crops affecting row crops? Agricultural and Environmental Letters. doi:1031002/ael2.20015.
• Koehler-Cole, K., C.A. Proctor, R.W. Elmore, D.A. Wedin. Spring-planted cover crops for weed control in organic soybean. Renewable Agriculture and Food Systems. In Press.
•  
• Koehler-Cole, K., and R.W. Elmore. 2020. Seeding Rates and Productivity of Broadcast Interseeded Cover Crops. Agronomy 10:1723. doi: 10.3390/agronomy10111723. 
• Nichols, V., Martinez-Feria, R., Weisberger, D., Carlson, S., Basso, B., Basche, A. 2020. Cover crops and weed suppression in the US Midwest: a meta-analysis and modeling study. Agricultural and Environmental Letters.5:e20022. https://doi.org/10.1002/ael2.20022
• Ruis, S.J., H. Blanco-Canqui, K. Koehler-Cole, P. Jasa, G. Slater, R.W. Elmore, and R.B. Ferguson 2020. Winter cover crop root biomass yield in corn and soybean systems. Agrosystems, Geosciences & Environment 3: e20101.
• Ruis, S.J., H. Blanco-Canqui, K. R.W. Elmore, C. Proctor, K. Koehler-Cole, C.A. Shapiro, C.A. Francis, and R.B. Ferguson. 2020. Impacts of cover crop planting dates on soils after four years. Agron. J. 112:1649-1665.

 North Dakota

• Delavarpour, N., S. Eshkabilov, T. Bon, J. Nowatzki, and S. Bajwa. 2020. The Tractor-Cart System Controller with Fuzzy Logic Rules. Appl. Sci. 2020, 10, 5223; doi:10.3390/app10155223
• Teuber, O., D. Samarappuli, and M.T. Berti. 2020. Nitrogen and sulfur fertilization in kale and swede for grazing. Agronomy 10(5), 619; doi:10.3390/agronomy10050619
• Acharya, K., Yan, G. P., and Plaisance, A. 2020. Effects of cover crops on population reduction of soybean cyst nematode, Heterodera glycines. Plant Disease 104. https://doi.org/10.1094/PDIS-08-20-1778-RE
• Podder, S., D. Samarappuli, James V. Anderson, and M.T. Berti*. 2020. Phenotyping a diverse collection of forage sorghum genotypes for chilling tolerance. Agronomy, 10:1074 doi:10.3390/agronomy10081074
• Mohammed, Y.A., S. Patel, H. Matthees, A.W. Lenssen, B.L. Johnson, M.S. Wells, F. Forcella, M.T. Berti, R.W. Gesch. 2020 Soil nitrogen in response to interseeded cover crops in maize–soybean Production Systems. Agronomy 10, 1439; doi:10.3390/agronomy10091439
• Forcella, F., S. Patel, A.W. Lenssen, C. Hoening, J. Eckberg, M.S. Wells, R.W. Gesch, and M.T. Berti. 2020. Pollinator visitation of flowering winter oilseeds (field pennycress and winter camelina). J. Applied Entomology 00:1-9 doi: 10.1111/jen.12854
• Wittenberg, A., J.V. Anderson, M.T. Berti. 2020. Crop growth and productivity of winter camelina in response to sowing date. Ind. Crops Prod. 158:113036 doi.org/10.1016/j.indcrop.2020.113036
• Patel, S., A.W. Lenssen, K.J. Moore, Y.A. Mohammed, R.W. Gesch, M.S. Wells, B.L. Johnson, M.T. Berti, and H.L. Matthees. 2021. Interseeded pennycress and camelina yield and their influence on row crops. Agronomy J. Accepted 
• Cecchin, A., Pourhashem, G., R.W. Gesch, A.W. Lenssen, S. Patel, and M.T. Berti. 2021. Environmental trade-offs of relay-cropping winter cover crops within maize and soybean. Agric. Systems 189:103062
• Cecchin, A., Pourhashem, G., R.W. Gesch, A.W. Lenssen, S. Patel, and M.T. Berti. 2021. The environmental impact of ecological intensification of a cropping system in the U.S. Upper Midwest. Sustainability 13: 1696. https://doi.org/10.3390/su13041696
• Sigdel, S., A. Chaterjee, M.T. Berti, C. Gasch, and A. Wick. 2021.  Interseeding cover crops in sugarbeet. Field Crops Res. 263: 1080709, doi.org/10.1016/j.fcr.2021.108079
• Johnson, K., H. Kandel, D.P. Samarappuli, and M.T. Berti. 2021. Interseeding camelina and rye in soybean with varying maturity provides soil cover without affecting soybean yield. Agronomy 11, 353. https://doi.org/10.3390/agronomy11020353
• Lukaschewsky, J., D.P. Samarappuli, and M.T. Berti. 2021. Intercropping alfalfa into silage maize can be more profitable than maize silage followed by spring-seeded alfalfa. Agronomy Accepted
• Schmitt, M. M.T. Berti, D. Samarappuli, and J. Ransom. 2021. Factors affecting the establishment and growth of cover crops intersown into maize (Zea mays L.). Agronomy Accepted
• Sciarresi, C., C. Proctor, E. Haramoto, L. Lindsey, G. Carmona, R. Elmore, S. Everhart, W. Looker, M. Marroquin-Guzman, J. McMechan, J. Wehrbein, R. Werle, M. Salmeron. 2020. Evaluating short-season soybean management adaptions for cover crop rotations with a crop simulation model. Field Crop Research. 250:107734. doi: 10.1016/j.fcr.2020.107734.

 Minnesota

• Ginakes, P.., Grossman, J., Baker, J., & Sooka-sanguan, T. (2020). Living mulch management spatially localizes nutrient cycling in organic corn production. MDPI Agriculture, 10(6), 243. 
• Ginakes, P., Grossman, J., Baker, J., & Sooksa-nguan, T. (2020). Tillage intensity influences nitrogen cycling in organic kura clover living mulch. Nutrient Cycling in Agroecosystems, 116(1), 71-82. 
• Liu, R, MS Wells, and A Garcia y Garcia. 2019. Cover crop potential of winter oilseed crops in the Northern U.S. Corn Belt. Arch. Agron. Soil Sci., 65(13): 1845-1859.
  doi: 10.1080/03650340.2019.1578960 
• Moore, S.A., Wells, M.S., Gesch, R.W., Becker, R.L., Rosen, C.J., & Wilson, M.L. (2020). Pennycress as a Cash Cover-Crop: Improving the Sustainability of Sweet Corn Production Systems. Agronomy, 10(5), 614. https://doi.org/10.3390/agronomy10050614
• Yesuf Assen Mohammed, Swetabh Patel, Heather L. Matthees, Andrew W. Lenssen, Burton L. Johnson, M. Scott Wells, Frank Forcella, Marisol T. Berti and Russ W. Gesch. 2020. Soil nitrogen in response to interseeded cover crops in maize–soybean production systems. Agronomy 2020, 10(9), 1439; https://doi.org/10.3390/agronomy10091439
• Yesuf Assen Mohammed, Heather L. Matthees, Russ W. Gesch, Swetabh Patel, Frank Forcella, Kyle Aasand, Nicholas Steffl, Burton L. Johnson,  M. Scott Wells and Andrew W. Lenssen. 2020. Establishing winter annual cover crops by interseeding into Maize and Soybean. Agronomy Journal. https://doi.org/10.1002/agj2.20062
• Perrone, S., Grossman, J., Liebman, A., Sooksa-ngua, T., & Gutknecht, J. (2020). Nitrogen fixation and productivity of winter annual legume cover crops in Upper Midwest organic cropping systems. Nutrient Cycling in Agroecosystems, 117, 61–76. 
• Rusch, HL, JA Coulter, JM Grossman, GA Johnson, PM Porter, and A Garcia y Garcia. 2020. Towards sustainable maize production in the U.S. upper Midwest with interseeded cover crops. PLOS ONE 15(4): e0231032. doi: 10.1371/journal.pone.0231032
• West, J. R., Cates, A. M., Ruark, M. D., Deiss, L., Whitman, T., & Rui, Y. (2020). Winter rye does not increase microbial necromass contributions to soil organic carbon in continuous corn silage in North Central US. SOIL BIOLOGY & BIOCHEMISTRY, 148. doi: 10.1016/j.soilbio.2020.107899

Kansas

• Fontes GP, Tomlinson PJ, Roozeboom KL, Warren J, Diaz DR. 2020. Nitrogen fertilization offsets the N2O mitigating effects of cover-crops and double-crop soybean in a wheat-sorghum system. Agron J. 112 (2) 772-785. https://doi.org/10.1002/agj2.20095
• Carr, P., J. Bell, D. Boss, P. DeLaune, J. Eberly, L. Edwards, H. Fryer, C. Graham, J. Holman, M. Islam, M. Liebig, P. Miller, A. Obour, and Q. Xue. Annual forage impacts on dryland wheat farming in the Great Plains. Agronomy Journal. 113:1, 1-25. https://doi.org/10.1002/agj2.20513
• Holman, JD, A. Obour, and Y. Assefa. 2020. Cover-crop water use and productivity in the High Plains wheat-fallow crop rotation. Crop Science. 1-12. https://doi.org/10.1002/csc2.20365
• Holman, JD, Y. Assefa, M. Stamm, and A. Obour. 2020. Canola yield, forage accumulation, and nutritive value in dual-purpose and companion cropping. Holman, Yared, Stamm, and Augustine. Crop Science. 63:1, 814-824. https://doi.org/10.1002/csc2.20291
• Holman, JD, Schlegel A, Obour AK, and Y. Assefa. 2020. Dryland cropping system impact on forage accumulation, nutritive value, and rainfall use efficiency. Crop Science. 60:6, 3395-3409. https://doi.org/10.1002/csc2.20251
• Obour AK, JD Holman, and AJ Schlegel. 2020. Spring triticale forage responses to seeding rate and nitrogen application. Agrosyst Geosci Environ. 2020;3:e20053. https://doi.org/10.1002/agg2.20053
• Kumar V, A. Obour, P. Jha, R. Liu, M.R. Manuchehri, J.A. Dille, J. Holman, and P.W. Stahlman. 2020. Integrating cover crops for weed management in the semiarid U.S. Great Plains: Opportunities and challenges. Weed Sci. doi:10.1017/wsc.2020.29