Nitrogen leaching and residual effect of barley/field bean intercropping

Abstract

Cereal/legume intercropping may improve resource use efficiency in agroecosystems and increase yield per unit surface area and yield stability. Two field bean ( Vicia faba L.) and four barley ( Hordeum vulgare L.) cultivars were mono- and intercropped (additive design) in a 2-year lysimeter experiment on a sandy loam soil. The aim was to test the effect of the cropping system on dry matter and N yield of forage, the residual effect on the subsequent ryegrass crop ( Lolium multiflorum Lam. westerwoldicum ), and NO 3 -N leaching in the rotation. Land equivalent ratios were 1.65 for dry matter and 1.67 for N yield, indicating a clear advantage of the intercrop over sole crops. Both species suffered from competition, especially in terms of N resources, but barley was less affected. Nitrate leaching was the lowest from intercrop. Preceding crop significantly affected dry matter, N content and NO 3 -N leaching of ryegrass. Field bean sole crop gave the highest benefits to ryegrass in terms of forage dry matter and N content, but also the highest NO 3 -N leaching, followed by the intercrop and the barley sole crop. Barley/field bean intercropping may be an effective strategy to reduce land requirements, N leaching losses and fertilizer inputs, thereby increasing the sustainability of farming systems.