Cover crop-based rotational no-till enables organic farmers to reduce labor and build soil health. In these systems, cover crops are terminated with a roller-crimper and cash crops are direct-seeded into the resulting mulch. A systems experiment was conducted at three Mid- Atlantic locations to test how cover crop termination timing affects cover crop biomass production, control, and volunteers in subsequent crops during the transition to organic production. The annual crop rotation was hairy vetch (Vicia villosa Roth) plus triticale (x Triticosecale Wittm.)–corn (Zea mays L.)–cereal rye (Secale cereale L.)– soybean [(Glycine max (L.) Merr.]–winter wheat (Triticum aestivum L.) using a full-entry design. Cover crops were terminated based on growth stages designated Early, Intermediate, or Late. Hairy vetch– triticale and cereal rye biomass production exceeded 5000 kg ha−1 by Late termination in all site- years. Although hairy vetch–triticale biomass production peaked at early flowering of hairy vetch, control increased as termination was delayed. Hairy vetch regrowth and volunteer hairy vetch in subsequent soybean and winter wheat crops was lower in Late compared to Early termination treatments. Cereal rye biomass increased as termination was delayed but optimal control was achieved with Intermediate termination. Rolling cereal rye Early resulted in tillering and seed production whereas rolling Late allowed kernels to mature. Wheat grain contamination by volunteer hairy vetch ranged from 11 to 29% and by volunteer cereal rye from 3 to 11% at Maryland and Pennsylvania, respectively, demonstrating that minimizing cover crop seed production with strategic termination is critical in rotational no-till.
All Science Journal Classification (ASJC) codes
- Agronomy and Crop Science