Soil management strategies to sustain continuous crop production between vegetative contour strips on humid tropical hillsides

arbre contour cultivation crops cultivo en curvas de nivel cultivos culture en courbe de niveau erosion fertilidad del suelo fixation de l'azote hedging plants humid tropics nitrogen fixation plantas para cercas vivas plante de culture plante de haie sloping land soil degradation soil fertility terre en pente terreno en declive trees tropiques humides