سینتیک معدنی شدن نیتروژن در یک خاک تیمار شده با کمپوست، ورمی‌کمپوست و کود دامی

  Understanding nitrogen mineralization from different organic sources should be a key factor in developing efficient prediction of the need for nitrogen fertilization with minimal negative environmental impact. In order to investigate nitrogen mineralization rate in soils amended with compost, vermicompost and cattle manure, an experiment was done as factorial in a randomized complete block design in three replications. Four treatments (compost, vermicompost, cattle manure and soil alone), two temperature levels (8 and 25 0C) and two moisture levels (50% and 85% FC) were used for the 90 - day incubation study. Ammonium and nitrate were measured by spectrophotometer method. Results indicated that the mixed first-and zero-order kinetics model is the best model for our data. Cattle manure treatment had the highest Nmin at 25 0C (87.78 mgN/kg equal to 14.54% Ntotal) and the least value (23.62 mgN/kg equal to 4.62% Ntotal) was obtained for the compost treatment at 8 0C. N0k (nitrogen availability index) for treatments was in the following order: Cattle manure>Vermicompost >Compost. With increasing the temperature and moisture, N mineralization increased. Also Nmin positively correlated with N0 (r =0.583*), and N0k (r =0.834**).