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ARS Home » Plains Area » Brookings, South Dakota » Integrated Cropping Systems Research » Research » Publications at this Location » Publication #326030

Research Project: Soil and Crop Management Systems for Improved Natural Resource Quality and Efficiency

Location: Integrated Cropping Systems Research

Title: Impact of cover crops on soil nitrate, crop yield and quality

Author
item Osborne, Shannon
item Lehman, R - Michael

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 2/29/2016
Publication Date: 3/1/2016
Citation: Osborne, S.L., Lehman, R.M. 2016. Impact of cover crops on soil nitrate, crop yield and quality. In S.L. Osborne (ed.) Proc. Great Plains Soil Fertility Conf. 16:139-146.

Interpretive Summary: Cover crops incorporated into current production systems may have multiple benefits to the production system including decreasing erosion, improving water infiltration, increasing soil organic matter and biological activity but in water limited areas caution should be utilized. A field study was conducted through the fall of 2007 until the next cash crop growing season 2008. The study was established to evaluate the impact of incorporating cover crops into a no-till crop production system in central South Dakota. Cover crops evaluated in the study included 1) cowpea, 2) lentils, 3) canola, and combinations of cover crops including 4) cowpea/canola/lentils, 5) cowpea/canola, 6) canola/lentils, 7) radish/cowpea/canola/lentil, and 8) turnip/cowpea/lentil/canola. Cover crops were allowed to grow throughout the fall and winter killed. Incorporating cover crops increased grain yield compared to the no cover crop treatment without additional nitrogen fertilizer. While when nitrogen was applied to the corn crop yields did not increase as dramatically compared to the no cover crop treatment. Fall cover crops had the ability to scavenge residual soil nitrate and make it plant available for the following crop providing a positive environmental benefit and did not have a negative impact on soil moisture.

Technical Abstract: There are multiple benefits of incorporating cover crops into current production systems including decreasing erosion, improving water infiltration, increasing soil organic matter and biological activity but in water limited areas caution should be utilized. A field study was established in the fall of 2007 to evaluate the impact of incorporating cover crops into a no-till crop production system in central South Dakota. Cover crops utilized in the experiment were: 1) cowpea (Vigna sinensis), 2) lentils (Lens culinaris), 3) canola (Brassica napus), 4) cow/can/len, 5) cow/can, 6) can/len, 7) radish (Raphanus sativus)/cow/can/len, and 8) turnip (Brassica napa)/cow/len/can combos all compared to no-cover crop. Cover crops were allowed to grow throughout the fall and winter killed. Cover crop biomass was collect prior to a killing frost. The following spring corn was planted and in-season growth and grain yield was evaluated. When cover crops were incorporated into the production practices there was a significant increase in grain yield compared to the no cover crop treatment without additional nitrogen (N). When N was applied to the corn, crop yields did not increase as significantly compared to the no cover crop treatment. Fall cover crops had the ability to scavenge residual soil nitrate and recycling it for tor the following crop providing a positive environmental benefits.