A METHOD FOR ESTIMATING THE DIRECT AND CLIMATIC EFFECTS OF RISING ATMOSPHERIC CARBON-DIOXIDE ON GROWTH AND YIELD OF CROPS .1. MODIFICATION OF THE EPIC MODEL FOR CLIMATE CHANGE ANALYSIS

The potential impact of the global rise in atmospheric CO2 concentration and associated climatic change on agricultural productivity needs assessment. The complexity of climate-crop production interactions makes computer simulation a natural approach for such assessment. EPIC, a comprehensive mathematical cropping system model, was modified to account for the effects of change in CO2 concentration and vapor pressure deficit on the radiation-use efficiency, leaf resistance and transpiration of crops. Details of these modifications are presented in this paper. A companion paper describes an application of the modified model (this issue).