A rotation design to reduce weed density in organic farming

Abstract

Weeds are a major obstacle to successful crop production in organic farming. Producers may be able to reduce inputs for weed management by designing rotations to disrupt population dynamics of weeds. Population-based management in conventional farming has reduced herbicide use by 50% because weed density declines in cropland across time. In this paper, we suggest a 9-year rotation comprised of perennial forages and annual crops that will disrupt weed population growth and reduce weed density in organic systems. Lower weed density will also improve effectiveness of weed control tactics used for an individual crop. The rotation includes 3-year intervals of no-till, which will improve both weed population management and soil health. Even though this rotation has not been field tested, it provides an example of designing rotations to disrupt population dynamics of weeds. Also, producers may gain additional benefits of higher crop yield and increased nitrogen supply with this rotation design.