Low-Residue Cover Crops for Organic No-till.

Most organic no-till systems research has relied on high-residue cover crops to provide a weed suppressing mulch, but high residue systems are limited in their applicability because of timing of cover crop termination and changes to the soil environment that are not conducive to early season crops. Our research in Maryland has shown that forage radish (Raphanus sativus L.), a low-residue, winterkilled, and weed suppressing cover crop, facilitates no-till early spinach (Spinacea oleracea L.) production without herbicides. Further field trials in Maine have shown this system produces competitive yields even in colder climates and for small-seeded root vegetables like carrot (Daucus carota L.). Farmer collaborators have also adopted this system for beets (Beta vulgaris L.) and peas (Pisum sativum L.). We propose that in regions with cold winter temperatures and cool springs, low-residue winterkilled cover crops may fill an important niche for organic no-till production not currently addressed by high-residue cover crop systems.