Ploughless tillage in large-scale trials. Part 1. Yields, grain quality and couch grass [also incl Elymus repens]

aradura avenas avoine barley cebada cero-labranza contenido de materia seca crop yield drilling dry matter content elymus fertilizers grain granos harrowing herbicidas herbicide herbicides hersage labour loam soils monocultivo monoculture oats orge paille paja papa ploughing pomme de terre potatoes rastreo rendement des cultures rendimiento de cultivos sol sablolimoneux straw suelo franco trigo tubercule tubers variedades varieties wheats zero tillage