Plant First, Roll Later: Organic No-till Corn and Soybean Research

Penn State is participating in a multi-institution research project that seeks to address a tricky timing problem at the heart of organic no-till grain production. Typically, organic farmers who practice cover crop-based no-till grow a cover crop for mulch, flatten it with a roll-crimper, and no-till plant into the mulch. But, to effectively terminate a cover crop this way, this must happen at a specific cover crop growth stage (early pod in hairy vetch and late anthesis in cereal rye). Waiting for the cover crop to mature delays corn and soybean planting compared to tilled organic systems. Later planting often means lower yields, especially in northern regions with short growing seasons. To address this tradeoff, agricultural researchers from Cornell, the University of Wisconsin, and Penn State developed the Rolling After Crop Emergence (RACE) experiment, which experiments with planting cash crops into living cover crops prior to roll-crimping the cover crop. The project focuses on soybean no-till planted into cereal rye and corn no-till planted into hairy vetch. 

Ana Roldan, Ph.D. candidate in the Cornell Sustainable Cropping Systems Lab, is leading the RACE experiment, which is being conducted in Pennsylvania, New York, and Wisconsin in collaboration with Dr. Matthew Ryan (Cornell), Dr. John Wallace (Penn State), and Dr. Erin Silva (Univ. Wisconsin). Replicating the experiment across three states lets researchers see whether it holds up across different environments. Consistent results across locations give farmers throughout the northern U.S. more confidence that the practice will work on their own land. At each site, winter cover crops are established in the fall, followed by corn or soybean planted into the living cover crop at four consecutive weekly planting dates the following spring. The cover crop is then terminated with a roller crimper once it reaches the recommended stage: early pod set for hairy vetch and late anthesis for cereal rye. 

"Early results show different responses between the two crops. Soybean has handled the system well, with generally low injury from the roller crimper, consistent plant stands, and good yields, while the cereal rye was effectively terminated with minimal regrowth.  

Corn has been more challenging. When planted at the earliest date, it had to compete with hairy vetch that was still actively growing, which led to thinner corn stands, more injury after rolling-crimping, and reduced yields," said Ana Roldan. Despite being roll-crimped on the same day, hairy vetch in the earliest treatment showed substantial regrowth compared to hairy vetch in the last planting date, illustrating the contribution of the planter to hairy vetch termination and how the effects of planting on hairy vetch termination are impacted by timing and growth stage of the hairy vetch. 

For organic farmers interested in no-till planting into rolled-crimped cover crops, the approach allows earlier cash crop planting while giving the cover crop more time to grow and produce biomass before the right termination time. If the approach proves reliable, it could maintain good yields, reduce reliance on tillage and herbicides, and give farmers more flexibility during short growing seasons. Data from the two-year project, which began in 2024 and continues through 2026, are still being collected and analyzed, but preliminary results suggest opportunities for improved cover crop-based organic no-till production.