Nitrogen Fertilizer Response of Maize on Some Important Soils from DSSAT Software Prediction

Abstract

To lessen the environmental impact and cost of maize production, the efficient use of nitrogen fertilization is very important. Currently, the DSSAT software has been used to predict N fertilizer requirement of maize. However, the requirement of maize be to N fertilizer in some soils have been found to be lower than the amounts predicted by DSSAT. To use the predicted N fertilizer in some important maize soils of Thailand and Laos efficiently, field experiments were conducted on 4 representative sites. Two sites were on Lop Buri (Lb) and Pak Chong (Pc) soil series in Thailand, and the other two were on Saythong (St) and Bachieng (Bc) soil series in the Lao PDR. The results indicated that grain yields of maize grown on St and Bc soil series were increased with higher rates of N fertilizer while there was no response to nitrogen applications to maize grown on Lb and Pc series soils. These effects were attributed to N mineralization or nitrate release of the soils. From this study, the nitrate (NO3^- -N) release of Pc and Lb soil series were higher than those of St and Bc soil series, especially at the first period of incubation study in the laboratory. In the case of St and Bc soil series, the nitrate release of Bc soil was higher than that released from St soil, thus, resulting in the response of maize at the lower rate of N fertilization on Bc soil series.