Yielding of cereals and physical properties of soil under different systems of tillage

agua del suelo analytical methods compactage du sol contenido de agua en el suelo crop rotation crop yield crops cultivos cultivos de invierno cultivos de primavera culture d'hiver culture de printemps direct sowing eau du sol field experimentation hordeum vulgare labranza plante de culture poland pologne polonia rendement des cultures rendimiento de cultivos rotation culturale sampling semis direct siembra directa soil soil compaction soil texture soil water soil water content sol spring crops statistical methods suelo technique analytique teneur en eau du sol textura del suelo texture du sol tillage travail du sol triticum aestivum variedades varieties winter crops zea mays