Restoring the farmland to forestry and grazing land at the gully and hilly area in Northern Shaanxi

aptitud de tierras aptitude des terres augmentation de rendement aumento del rendimiento china chine ciencias forestales conservation des sols economic analysis foresterie forestry grazing lands land resources land suitability manejo del suelo mise en valeur du sol plantation planting recursos de la tierra soil conservation soil management tierras de pastoreo zootechnie zootechny zootecnia