|NICHOLS, KRISTINE - Rodale Institute|
|TANAKA, DONALD - Retired ARS Employee|
Submitted to: Renewable Agriculture and Food Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/16/2021
Publication Date: 5/20/2021
Citation: Hendrickson, J.R., Liebig, M.A., Archer, D.W., Schmer, M.R., West, M.S., Nichols, K.A., Tanaka, D.L. 2021. Late-seeded cover crops in a semiarid environment: Overyielding, dominance, and subsequent crop yield. Renewable Agriculture and Food Systems. 1-12. https://doi.org/10.1017/S174217052100020X.
Interpretive Summary: There is increasing interest in using cover crops in the northern Great Plains but little information on how to manage them in diverse rotations. The Northern Great Plains Research Laboratory evaluated late-seeded cover crops to determine 1) whether they could be incorporated after harvest of short-season crops, 2) how cover crops may impact subsequent crop yields and 3) whether cover crop mixtures provide more benefits than cover crop monocultures. The study found that cover crops could be successfully established following short-season crops but timely rainfall was critical. Cover crops did not have a negative effect on subsequent crop yields and cover crop mixtures had limited benefits compared to cover crop monocultures. This information can help producers in the northern Great Plains design a cover crop program that fits their needs.
Technical Abstract: There is increased interest in cover crops but limited information on how to incorporate them into crop rotations especially in the relatively short growing season on the northern Great Plains. A research project, near Mandan, North Dakota, USA, evaluated 1) whether late seeded cover crops could be incorporated after harvest of short season crops; 2) what impact cover crops may have on subsequent crops yields and 3) whether cover crop mixtures are more productive and provide more benefits than cover crop monocultures. The three year study was initiated in 2009 and evaluated 18 different cover crop monocultures and mixtures that were seeded in August following field pea (Pisum sativum L.). The following year, spring wheat (Triticum aestivum L.), corn (Zea mays L.), soybean (Glycine max L.) and field pea were seeded into the different cover crop treatments and a non-treated control. Cool-season monocultures were more productive than warm-season monocultures and some mixtures in 2008 and 2010. A lack of timely precipitation in 2009 resulted in a maximum cover crop productivity of 17 g m2 compared to 100 and 77 g m2 in 2008 and 2010, respectively. Late-seeded cover crops did not reduce yields in the subsequent crops in any year. Compared to monocultures, cover crop mixtures did not provide significant yield advantages. Four of the 11 mixtures yielded more than the average monoculture but none yielded more than the most productive monoculture. Late-seeded cover crops can be used in the northern Great Plains but species selection is critical.