Modeling Record Corn Yields, Water Use and Transpiration Efficiency.

Irrigated corn yields of over 500 bu/acre have been recorded for the past 3 years in Georgia and Virginia. The SALUS model was successfully used to simulate the phasic development, biomass and yields, given the weather, genetic and management input. The model also simulates soil evaporation and transpiration. Transpiration for the record yields averaged approximately 450 mm. Using the measured yields assuming a harvest index of 0.55 and simulated transpiration, the transpiration efficiency was found to be about 0.092 t/ha/mm. The transpiration for the record crops was approximately the same as reported for other crops growing in humid and sub-humid climates, demonstrating the water demands for higher yielding crops with the same length of season is the same as for much lower yielding crops growing without soil water limitations.