Soil Water and Nitrogen Balance Study of Maize Using CERES Maize Model in DSSAT

摘要

Simulated studies indicated that early sowing i.e 15th April (D1) predicted highest grain yield during all the years from 1986-2013. Under irrigated conditions increasing levels of N predicted increased grain and stover yield from N levels up to 90 kg N ha-1. Under irrigated and mulched conditions increased level of N predicted increase in maize grain and stover yield upto 120 kg N ha-1. Whereas under un-irrigated mulched conditions highest grain and stover yield was predicted at 60 kg N ha-1. Maize yield was also simulated at different sowing dates and in combination with variable spacings and it was predicted that under irrigated condition closer spacing 40 cm × 20 cm at 15th April sowing recorded highest grain and stover yield of maize. Under un-irrigated mulched conditions highest grain yield was predicted at 30th April sowing with spacing 65 cm × 20 cm. Soil water balance under simulation studies indicated that potential ET was recorded comparatively higher with early sowing date than late sowing date under both irrigated un-irrigated mulched conditions. Similar trend was recorded with respect to transpiration under both irrigated and un-irrigated mulched conditions. Simulated soil evaporation was more in wider spacing than closer spacing. Similar trend was recorded with regard to simulated run-off. Predicted nitrate content (final) of irrigated soil decreased where under un-irrigated mulched conditions 15th April (D1) sowing predicted lowest NO3 leaching than later sowing dates. Under un-irrigated mulched conditions leached nitrate was nominal. Nitrogen denitrification was comparatively more under un-irrigated mulched conditions than irrigated condition. It is concluded that DSSAT v 4.5CERES-Maize model is very robust in predicting the growth and yield of maize as influenced by agrotechniques and could be used in wider perspective.