Influence of crop growth on ionic equilibria, selectivity and diffusion of cations in soil

The rate and temporal pattern of N mineralization from decomposing residues of hairy vetch (Vicia villosa Roth) and rye (Secale cereale L.) were compared with the pattern of N uptake by corn (Zeamays L.) planted under no-tillage into these cover crops in the field. In a second field study where no corn crop was grown, the pattern of N mineralization from killed fescue sod was compared with the pattern from killed hairy vetch plus sod. Hairy vetch was far more effective than rye in supplying corn N requirements. In both experiments, the majority of N mineralized during the corn growing season became available only after a period corresponding to corn silking. The results suggest poor synchronization between N release via cover crop mineralization and corn N uptake in the no-till system.