Precision management of green manure cover crops for weed and nitrogen optimization

Sasha Loewen, PhD Candidate, LRES, Montana State University

Advisor: Bruce Maxwell

Precision agriculture holds a great deal of promise for addressing many of the shortcomings of modern agriculture; organic agriculture in particular faces unique challenges of nitrogen management and weed control. On field precision experimentation (OFPE) is an adaptive management methodology of field-scale experiments which helps organic farmers understand within-field variation in crop production using precision ag tools. Precision agriculture technology is used to design, implement, and record OFPE results. The aspirations of OFPE in organic grain farm settings are to optimize nitrogen inputs from green manure cover crops, to minimize weed impacts, and maximize crop yield, quality, and profits from cash crops. Field scale experiments have been implemented on multiple sites across Montana to test seeding rates for optimum nitrogen management, weed control, and yield in organically managed pea and wheat rotations. Results from experiments using varied seeding rates, indicate that optimized variable rates outcompete farmer-chosen single field rates and can increase farmer profits.