The effect of different ways of basic soil cultivation on the winter wheat grain yield

air temperature cero-labranza clay soils clima climat climate crop yield cultivos de invierno culture d'hiver date de semis essai fecha de siembra fertilisation fertilizer application gleysol gleysoles gleysols grain granos labranza meteorological observations pisum sativum pruebas rendement des cultures rendimiento de cultivos slovak republic sol argileux sowing date suelo arcilloso temperatura del aire tillage travail du sol trials triticum aestivum winter crops zero tillage