Effect of forecrop, ploughing date, and depth on the changes of hydrophysical soil properties and on the grain yield of winter wheat (Pt.1)

air temperature contenido de agua en el suelo cultivos de invierno date grain granos labranza lluvia pluie rain rendement rendimiento soil chemicophysical properties soil water content statistical analysis temperatura del aire teneur en eau du sol tillage timing travail du sol winter crops yields