Balancing weed suppression, beneficial insect conservation, soil quality and profitability is challenging in organic cropping systems due to reliance on soil disturbance for weed control. We hypothesized that the benefits of tillage can be retained while mitigating adverse impacts on soil quality by alternating tillage with practices that can build soil organic matter. We conducted a four-year experiment in central Pennsylvania, USA, to compare four organic feed and forage cropping systems, each differing in tillage, manure management, and cropping strategies. Each system was designed to address baseline soil quality and weed pressure conditions arising from practices implemented during the previous three-year transition period. To assess cumulative system effects, we established a soybean (Glycine max) uniformity trial across all systems in year four. Systems that were in perennial forage for 2 years outperformed annual crop-based systems in weed control and beneficial insect conservation, while maintaining overall profitability over the four-year study period. Soybean yields during the uniformity trial were more than 30% greater in systems that had included perennial forages than in systems with only annual crops. Labile soil carbon pools, an indicator of soil quality, were maintained over time in all systems. Our results indicate that soil quality, weed management, beneficial insect conservation, and profitability can be maintained in organic systems when periodic tillage is coupled with perennial forage crops in rotation.
All Science Journal Classification (ASJC) codes
- Animal Science and Zoology
- Agronomy and Crop Science