Abstract:A spring-wheat field trial (2001~2002)was carried out to investigate the effects of different organic or inorganic fertilizer applying manner on the physical, chemical or biological characteristics of the degraded soil and the interactions among the soil fertility factors in central Tibet. A 4×4 split-plot design was employed. Organic fertilizer (sheep manure containing 7 g/kg N, 4.9 g/kg P_2O_5, 2.8 g/kg K_2O and 267g/kg O.M respectively) was the main treatment which included four (0、7.50、26.25、45.00 t/(hm...