The study was conducted by the United Soybean Board (USB) to understand the potential for cover crops to perform in a corn and soybean rotation, and to collect data on the performance of cover crops in those rotations in relation to the timing of termination.
The research showed winter cereal rye that grew an extra three weeks prior to soybeans produced about 300-400% more biomass with a 100% increase in nitrogen retention, when compared with early terminated cover crops. This study results showed no difference in soybean yield following a cover crop killed three weeks prior to soybean planting compared to a cover crop that was killed one day before soybean planting.
This study consisted of three major experiments that included corn and soybean systems with and without the cover crop, winter cereal rye. Despite letting the cover crop grow an extra three weeks, the data showed no negative effect on soybean yields. By increasing biomass production and retaining nitrogen, the system will build soil health and have a positive impact on water quality challenges.
In this study, leaving cover crops in the ground three weeks longer resulted in a 300-400% increase in biomass production. This extra growth should improve soil health by leading to lower compaction, greater aeration, more organic matter, increased water-holding capacity, and nutrient retention.