Ecology, Environment and Conservation Paper

USING LYSIMETER TO DETERMINE WATER CONSUMPTION OF SUGARCANE

M.R. Khaledian and E. Amiri

Abstract

Crop coefficient of sugarcane is necessary for the water requirement estimation in irrigation water planning and management. This study has been initiated to determine the crop coefficient (Kc) of sugarcane (Ratoon) in Haft tappeh region. The relationships between Kc and ETc/Ep (pan evaporation) and length growth and days after cutting (DAS) and percent days after cutting (%DAS), were also investigated. The seasonal ETc for sugarcane with an 8-month growth period was 1925 mm. The mid-season and late-season Kc values were 1.45 and 1.14, respectively. These values are somewhat higher than those values that recommended by FAO. The ratio of ETc/Ep varied between 0.64-1.10 from the beginning to the end of the growing season. The maximum ratios of ETc/ET0 and ETc/Ep occurred at a length growth of 126 cm. Furthermore, second order polynomials were presented to predict the Kc values from days after cutting (DAS) and percent days after cutting (%DAS).