Successes and Challenges of Reducing Tillage in Organic Annual Row Crop Production.

In organic agriculture, tillage is used to control weeds, prepare a seedbed, and incorporate nutrient amendments. However with increasing concern for soil health and water quality, farmers are looking for ways to reduce tillage in their operations. Continuous no-till in organic row crop production is currently not feasible, as several agronomic problems can arise, mainly related to weed control, cover crop termination, and fertility management. We initiated a cropping systems experiment at Penn State University to study several strategies for reducing tillage frequency and intensity within an organic grain/silage rotation. Four cropping systems that vary by cover crop species and termination method, manure application timing, and tillage frequency and intensity are implemented in a full entry, randomized complete block design with four replications. Two of four systems use hairy vetch plus triticale for a green manure before corn, while the other two employ red clover plus timothy. In soybean, two systems use cereal rye and two employ a mixture of annual grasses plus forage radish. One corn and two soybean entries are no-till planted while the remaining use tillage to terminate the cover crops. Cover crop biomass, weed biomass, and cash crop yield are being examined as indicators of success. Results from the past two growing seasons show that no-till in organic still has many challenges. First, if mechanical weed management is not timely in the tilled systems, summer annual weed biomass will quickly reduce cash crop yield. Second, the rolled cover crop mulch in no-till helps smother early season weeds, but high cover crop biomass production can result in poor cash crop establishment. Finding balance between no-till and tilled systems is critical for success. This project will continue to refine organic reduced tillage tactics in hopes of producing beneficial results for farmers in the mid-Atlantic region.