[Seedbed preparation. Fine seedbed: high energy requirements and field emergence, but no higher yields in winter wheat]

analytical methods aplicaciones del ordenador application des ordinateurs computer applications crop yield cultivos de invierno culture d'hiver emergence emergencia erosion estructura del suelo fotografia labranza motte de terre perfil del suelo photographie photography profil du sol rendement des cultures rendimiento de cultivos seedbed preparation sieving soil clods soil profiles soil structure structure du sol tamisage tamizado technique analytique terrones tillage travail du sol triticum winter crops