Tillage and Cover Crop Effects on Potato Yield and Quality.
Timothy Griffin, USDA-ARS, USDA-ARS-NEPSWL, Orono, ME 04469-5753
Delayed tillage and the inclusion of cover crops can substantially reduce erosion in intensively tilled potato systems. Both of these practices can potentially impact potato yield and quality via changes in soil temperature and soil water status. Research was conducted over seven rotation cycles at two Maine locations to evaluate the effects of timing of primary tillage (fall vs. spring) and cover crop (none, red clover, ryegrass, or winter rapeseed) on tuber yield and quality in 2-yr barley-potato rotations. Delaying primary tillage until spring, immediately before planting potato, resulted in higher soil water content early in the growing season (30 d after planting) in some rotation cycles, and also provided nearly complete ground cover during potentially erosive periods in fall and early spring. The inclusion of clover or ryegrass cover crops also had small, positive effects on ground cover. Effects on total and marketable tuber yield were small and inconsistent. Tillage did not effect tuber diseases, but black scurf (Rhizoctonia solani) was significantly increased by ryegrass in some rotation cycles. This research shows that conservation practices can be implemented while maintaining potato yield.