Production of the Norfolk crop rotation and of the monoculture of spring barley in relation to fertilizing and soil cultivation

application rates cero-labranza crop yield cultivos de primavera culture de printemps dose d'application essai fertilisation fertilizer application hordeum vulgare labranza monocultivo monoculture pruebas rendement des cultures rendimiento de cultivos rotation culturale rotational cropping spring crops tillage travail du sol trials variedades varieties zero tillage