Studies on covering and furrowing techniques and increase mechanism in yields in the semiarid region of Loess Plateau, Shanxi Province [China]

cobertura seca contenido de agua en el suelo crecimiento croissance crop yield culture multiple dry mulches gossypium hirsutum growth labranza mulch sec multiple cropping rendement des cultures rendimiento de cultivos semiarid zones shanxi soil water content teneur en eau du sol tillage travail du sol triticum aestivum