A simple new crop model based on water balance for agrometeorological crop monitoring

Abstract

A simple new crop model based on water balance concept for crop monitoring is developed. The main distinctive features of the model are use of two layer soil water balance, effectivity of precipitation, weekly assessment of water fulfillment of the crop and an index value in percentage accumulated during a season expressing performance of the crop. The maximum cumulative seasonal index value of 100 is apportioned equally into weeks required by a crop to complete the growth. Actual weekly contribution is evaluated on the basis of deficits and surplus experienced by a crop and value accumulated during a season is reached. The model is tested against actual observations in shifting sowing date experiment conducted on sorghum on the vertisols of Nagpur under monsoon conditions. The model has exhibited excellent correlation ship between yield and the total seasonal index value. The linear relationship between the two can be used to predict yields. The model can give better results in arid, semi-arid, and dry sub humid regions in rainfed agriculture under monsoon.