The goal of this project was to develop cover crop based no-till systems for small to mid-scale organic vegetable producers. Four systems were evaluated:
(1) Cereal rye + hairy vetch terminated by mowing, roller-crimper, or occultation under black plastic; middle 12” of bed planted with tillage radish, winterkilled.
(2) White clover living mulch maintained by mowing; middle 12” planted with tillage radish (winterkilled) or strip-tilled.
(3) Sorghum-sudangrass + cowpea planted in May, frost-killed in fall. Different rates of compost in planting row to speed cover crop breakdown.
(4) Tillage radish over entire bed, winterkilled.

Summer squash was transplanted into the first three systems, and beet was sown directly in the fourth. Control treatments consisted of cover crop tilled followed by black plastic mulch (both crops) or bare soil (beet only) or no cover crop. Treatment effects on soil health, arthropod communities, weeds, plant pathogens, and yields of summer squash (transplanted) and beets (direct-sown) were measured.

Different cover crop termination methods had different effects on soil enzyme levels. Flail-mowing cover crops boosted soil microbial biomass, active soil organic matter (SOM), potentially mineralizable nitrogen (N) and plant-available phosphorus (P). All cover crop treatments greatly reduced weed populations compared to no-cover controls. In the first year, yields were highest with cover crops terminated by tillage or occultation, followed by the no-cover plastic mulched controls. In the last two years, hot dry summer conditions reduced yields, with all cover crop treatments maintaining higher yields than no-cover controls.