Agroecological bases for raising the productivity of degraded soils in Khorasan province of Iran

Agroecological principles and approaches for the assessment of the soil water supply in Khorasan province of the Islamic Republic of Iran are suggested. The soil water supply is the crucial factor controlling the productivity of local pastures. The agroclimatic division of the province is suggested and the seasonal dynamics of the soil water and surface runoff on experimental plots are analyzed. Experimental materials that are used in semiempirical models and calculations of the potential productivity of pastures are discussed.