|Lyon, Drew - Washington State University|
|Hergert, Gary - University Of Nebraska|
|Higgins, Robert - University Of Nebraska|
|Holman, Johnathan - Kansas State University|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/28/2015
Publication Date: 9/1/2015
Citation: Nielsen, D.C., Lyon, D.J., Hergert, G.W., Higgins, R.K., Holman, J.D. 2015. Cover crop biomass production and water use in the central great plains under varying water availability. Proceedings of the Agronomy Meetings, November 15-18, 2015, Minneapolis, Minnesota.
Interpretive Summary: Cover crops grown in mixtures are reported to produce more biomass with greater water use efficiency than cover crops grown in monocultures. This finding needs to be verified for the water-limited environment of the central Great Plains. A 2-yr study was conducted in Akron, CO, Sidney, NE, and Garden City, KS to measure biomass production, water use efficiency, and residue cover of flax, oat, pea, rapeseed, and a 10-species mixture. The mixture did not produce greater biomass nor show greater water use efficiency or residue cover than the single-species plantings. There appears to be no reason to use a cover crop mixture over a less costly single-species cover crop unless a certain cover crop forage quality is required for grazing or haying.
Technical Abstract: The water-limited environment of the semi-arid central Great Plains may not have potential to produce enough cover crop biomass to generate benefits associated with cover crop use in more humid regions. There have been reports that cover crops grown in mixtures produce more biomass with greater water use efficiency than single-species plantings. This study was conducted to determine differences in cover crop biomass production, water use efficiency, and residue cover between a mixture and single-species plantings. The study was conducted at Akron, CO, Sidney, NE, and Garden City, KS during the 2012 and 2013 growing seasons under both rainfed and irrigated conditions. Water use, biomass, and residue cover were measured and water use efficiency was calculated for four single-species cover crops (flax (Linum usitatissimum L.), oat (Avena sativa L.), pea (Pisum sativum ssp. arvense L. Poir), rapeseed (Brassica napus L.)) and a 10-species mixture. The mixture did not produce greater biomass nor exhibit greater water use efficiency than the single-species plantings. The slope of the water-limited yield relationship was not significantly greater for the mixture than for single-species plantings. Relative ranking of the water-limited yield relationship slopes were in the order of rapeseed