Crop water use module The main function of the Crop water use module is to calculate the water usage per  crop between two specified dates for all the planted crops on a scheme based on the  plant date, the area planted and the crop water use curve.  The crop yield (ton/ha) can  be captured at the end of a growing season which is used to calculate the total yield  (ton) and the yield in (g/m³).  A summary of water used for a specified period can easily  be generated per crop type.