A discussion in the Organic Grain Resource and Information Network (OGRAIN) email group started with a question about interseeeding clover into soybeans. Several no-tillers proceeded to discuss the topic and how timing of planting could dramatically affect the outcome.

For the past two years, we have been participating in a multi-regional US Soybean Board funded experiment that is investigating the effects of planting green on no-till soybean production and management of multiple-resistant waterhemp populations. Planting green is the delay of cover crop termination until after cash crop planting, which is a departure from the standard practices of terminating a cover crop 10-14 days prior to planting. Our coordinated project focused on no-till soybean (30" row spacing; Enlist system) preceded by cereal rye (60 lb/ac) that was sown after field corn.

While many herbicides have long cropping restrictions because they take a long time to break down, there are several herbicides that have a short half-life. Generally, herbicides like Sharpen (saflufenacil), 2-4D and Roundup products (glyphosate) break down fairly quickly in the soil and cause less problems with herbicide carryover.

By delaying roller-crimper termination of hairy vetch and cereal rye cover crops until they reach optimum reproductive stages, organic growers can enjoy weed suppression and avoid volunteer problems in cash crops.