[Effect of different tillage systems on the behaviour of sunflowers (Helianthus annuus)]

contenido de agua en el suelo costra del suelo crop yield croute du sol dry season evaluation field experimentation genetic soil types girasol helianthus annuus hybride hybrids labranza oil crops plantas oleaginosas portuguesa rendement des cultures rendimiento de cultivos soil crusts soil texture soil water content soil water deficit teneur en eau du sol textura del suelo texture du sol tillage travail du sol