TY - JOUR T1 - Effect of Land Use Shifting and Overgrazing on Loss of Selected Soil Phosphorus Forms in Two Regions of Vanak Watershed TT - اثر تغییر کاربری و چرای مفرط بر هدررفت برخی از شکل‌های فسفر خاک در دو منطقه از زیر حوزه آبخیز ونک JF - JCPP JO - JCPP VL - 12 IS - 46 UR - http://jcpp.iut.ac.ir/article-1-1146-en.html Y1 - 2009 SP - 595 EP - 606 KW - Land use changing KW - Soil degradation KW - Phosphorus forms KW - Phosphorus loss. N2 - The forms and dynamics of soil phosphorus can be greatly affected by land use changes, which often involve changes in vegetation cover, biomass production and nutrient cycling in the ecosystem. Present research evaluates the impact of land use change on the amount of total organic and inorganic P, labile, moderately labile and nonlabile P pools in semiarid soils of central Zagros. Samples were collected from surface soils (0-10 cm) of i) of moderately degraded pasture (20-25% plant cover), ii) highly degraded pasture (5-10 % plant cover), and iii) cultivated field (10 years) in Soolegan sub watershed and i) moderately degraded pasture (25-30 % plant cover) and ii) highly degraded pasture (5-10 % plant cover) in Sadat Abad sub-watershed. Significantly (P M3 ER -