Effects of Cereal Rye Management Prior to Organic Soybean on Soil Health, Weed Suppression, and Yield.

Cover crops can cycle nutrients, enhance soil health, and suppress weeds, thereby reducing the need for inputs and decreasing environmental problems associated with nutrient losses, soil erosion, and non-target herbicide effects. This research aimed to compare three cereal rye (Secale cereale L.) management strategies prior to organic soybean (Glycine max (L.) Merr) production in terms of their agronomic performance and impact on soil health. In 2014-2015 and again in 2015-2016 in central New York, we compared: 1) roller-crimping cereal rye, 2) harvesting cereal rye at boot stage for fodder, followed by moldboard plowing, 3) terminating cereal rye with a moldboard plow at jointing phase, and 4) a no cover crop control treatment that was moldboard plowed. Results from the 2014-2015 experiment show that average weed biomass ranged from 522 kg/ha in the roller-crimped cereal rye treatment to 38 kg/ha in the no cover crop control treatment. Soybean yield did not differ significantly in the roller-crimped cereal rye treatment compared to the no cover crop treatment, but yield in the two treatments in which cereal rye was harvested or terminated with tillage was 10 and 11% greater than in the no cover treatment, respectively. Although we did not observe a yield advantage with roller-crimping cereal rye, it did lead to significant improvements in soil health, including 19% greater soil respiration and 17% greater soil moisture than the no cover treatment. Preliminary results also show that harvesting cereal rye and using tillage prior to planting soybean has potential to overcome the tradeoff between crop yield and soil health.