COMPARISON OF PEDOTRANSFER FUNCTIONS TO PREDICT NITROGEN-MINERALIZATION PARAMETERS OF 1-POOL AND 2-POOL MODELS

Information on nitrogen (N)-mineralization is required to model effici ent N nutrition managment options for crop production and to reduce th e risk of N contamination of water bodies. Experimental determination of N-mineralization for different soils is laboreous and expensive. Th e objectives of this study were to develop, using the pedotransfer fun ction, PTF, approach, and compare predictive equations for N-minerliza tion parameters of the one- and two-pool models. Published information from five sources was used in this excercise. Four data sets containe d information on N-mineralization parameters of the one-pool model and the information for the two-pool model was available in only one data set. The R(2) of the PTF developed for the potentially mineralisable- N parameter of the one-pool model ranged from 0.58 to 0.89 and that fo r the rate constant from 0 to 0.29. The R(2) of PTF's developed for th e two potentially mineralizable-N parameters of the two-pool model ran ged from 0.68 to 0.94 and that for the rate constants from 0.67 to 0.7 2. The results show that more accurate predictions, using the PTF, of the N-mineralization parameters can be obtained for the two-pool model than the one-pool model.