Runoff and drainage trade-offs from cover crops exposed to freeze–thaw events

Abstract

Winter cover crops are widely promoted for multiple ecosystem services although nutrient leaching from the plant biomass and subsequent transport of those nutrients is possible after freeze–thaw events. The objective of this study was to determine the effect of freeze–thaw conditions on both runoff and drainage or leachate water quality from two common cover crops. Rainfall simulations were performed on packed columns (20 cm diam.; 56 cm length) that included triplicate combinations of cereal rye (Secale cereale L.), forage radish (Raphanus sativus L. var. longipinnatus), and bare soil and a heavy, light, and no freezing treatment. The two cover crops reduced runoff total suspended solids concentrations and nitrate leaching compared with a bare soil control, confirming many cover cropping benefits. The heavy freezing conditions (including two nights of