Cover crop and early nitrogen management for common bean in a tropical no‐till system

Abstract

Common bean (Phaseolus vulgaris L.) has been grown under no‐till (NT), but nitrogen (N) management remains unclear when a previous cover crop is part of the farming system. In this study, we hypothesized that N applied to living cover crops, preceding the main grain crop of the rotation, can increase productivity and N‐use efficiency of the grain crop. Common bean was grown after palisade grass [Urochloa brizantha (Hochst. Ex A. Rich.) R.D. Webster] and ruzigrass [Urochloa ruziziensis (R. Germ. and C.M. Evrard) Crins] cover crops combined with N management [application to living cover crops 35 days before common bean seeding (DBS), 1 DBS, conventional, and control (zero‐N application)] in four experiment‐years. Dry matter (DM) and N content for palisade grass was consistently greater at termination relative to ruzigrass. Nitrogen application 35 DBS increased cover crop DM, N content, and the decomposition rate relative to the other N treatments. Greater common bean yield occurred following palisade grass than ruzigrass, and N application 35 DBS increased common bean yield compared to 1 DBS and conventional in one out of four experiment‐years. Only minor differences in the agronomic efficiency (AE) of applied N to cover crops were detected between 35 DBS and 1 DBS, and only for one experiment‐year, when palisade grass resulted in greater AE than ruzigrass. Applying N early to living crops such as palisade grass is an alternative N management strategy to the traditional approach for N fertilization in common bean.

Combined legume and non-legume residues management improve soil organic matter on an Oxisol in Brazil

“…Currently, the high demand for food, fiber and bioenergy has required more sustainable production systems as an alternative to land-use change (Molotoks et al, 2021;Lap et al, 2022). Cover crops have been widely used as a strategy within more sustainable systems alternating crops of commercial interest, which can commonly reach two to three annual harvests in tropical regions (Momesso et al, 2021). Benefits of using cover crops include preventing soil erosion, promoting nutrient cycling, improving weed control, and influencing C stocks dynamics in the soil (Garcia-Franco et al, 2015;Momesso et al, 2021).…”