اثر كمپوست قارچ، گوگرد و كودهاي نيتروژن بر روي قابليت جذب فسفر خاك در زراعت ذرت

Effect of spent mushroom compost, Sulfur and N- fertilizers on Soil Phosphorus Availability

During a two years field experiment, the effects of Spent Mushroom Compost (SMC), Sulfur(S) and three kinds of N- fertilizers on Soil Olsen-P was investigated. The treatments consisted of 4 levels of S (0-8-16 and 32 t/ha), 3 levels of SMC (0-20 and 40 tons/ha) and 3 kinds of N-fertilizers (Urea, Am. Sulfate and Am. Nitrate).These amendments were added to each plot separately at the first year .Corn; Zea maize Var 704,was used as test plant. More than 110 t/ha yield were harvested at each year. After each harvest, soil samples were taken from each of 144 plots and were used for chemical analysis. Wet weights, TOC, TN, pH, EC, available K and Olsen-P were measured and the results were used for the statistical calculations. Original Olsen-P was 2.15 mg/kg. At the end of first and second year, this parameter varied between 6.58-16.08 and 5.65-13.17 mg/kg respectively, which are much greater than the original Olsen-P. So, it may be concluded that the treatments were well chosen and effective.