Cubiertas vegetales en viñedos: Comportamiento de mezclas de leguminosas forrajeras anuales y efectos sobre la fertilidad del suelo

Abstract

With the objective of evaluating and selecting cover crops to improve soil management in vineyards (Vitis vinifera L.) cv. Cabernet Sauvignon, five cover pastures were evaluated: a) control without vegetation; b) control with spontaneous vegetation; c) legume mixture of early maturing cultivars of subterranean clover (Trifolium subterraneum L.) and burr medic (Medicago polymorpha L.); d) legumes mixture of late maturing cultivars of subterranean clover and balansa clover (T. michelianum Savi); and e) legumes mixture of late maturing cultivars and annual ryegrass (Lolium rigidum Gaud.). The study was conducted at Cauquenes Experimental Center, Agriculture Research Institute (INIA), over two seasons, 2005-2006 and 2006-2007. The experimental design was randomized blocks with four replicates. The three pasture mixtures had a good establishment and achieved high populations. Biomass production was significantly higher (P ≤ 0.05) in the mixtures with late maturing cultivars of subterranean clover and balansa clover, compared to the mixture of early maturing cultivars of subterranean clover and burr medic (2.3 to 4 t DM ha -1 yr-1 and 5.3 to 6.2 t DM ha-1 yr -1 in the first and second year, respectively). The contents of N, P and K in the biomass of the cover crops were higher (P ≤ 0.05) than those covers with spontaneous species, which increased the content of available N in the soil. Higher contents of K and P were detected in the soil. The cover crops had an important detrimental effect on the population of the spontaneous species that grow in the inter-rows of the vineyard.