Optimizing the clipping frequency and nitrogen topdressing in a dual-purpose oat used for fodder and cover cropping

Abstract

Summary Management strategies such as nitrogen (N) topdressing and clipping can be used to optimize a cover crop for the dual purpose of soil cover and forage. The present study tested oat (Avena sativa) for a holistic provision of soil cover and forage under various levels of clipping frequency and N topdressing. Effects on root and above-ground biomass, acid detergent fiber, neutral detergent fiber, and crude protein (CP) were evaluated. Clipping frequency had four levels, namely clipped only at termination (C1), clipped at 28 days after emergence (DAE) and termination (C2), clipped at 28, 42 DAE, and termination (C3), and clipped at 28, 42, 56 DAE, and termination (C4). Nitrogen topdressing had two levels, namely with (N1) and without (N0) the recommended N topdressing. Increasing clipping frequency reduced the root and aerial biomass and did not affect the forage quality harvested before termination. However, N topdressing increased biomass and CP content across the clipping frequencies. Results suggest clipping thrice combined with N topdressing (C4 + N1) provides the best option to satisfy both soil cover and livestock demands. The treatment (C4 + N1) gave > 2 t ha−1 of biomass during the growing period and 6 t ha−1 at termination which can be used for livestock forage and soil cover, respectively. Clipping thrice without N topdressing (C4 + N0) was the best option for resource-constrained farmers.