Water requirement and crop coefficient of sugarcane cultivated in Nicaragua

Sugarcane is one of the main agro-industrial crops in Nicaragua and Central America and one of the crops with the highest evapotranspiration rates. The lack of information related to sugarcane evapotranspiration as well as the crop coefficient (Kc) has limited productivity and water resources in Nicaragua. The knowledge of crop coefficient and water requirement for sugarcane, developed locally, will guide companies, farmers, and technicians for better irrigation management. In this context, this study aimed to determine the crop evapotranspiration and Kc for sugarcane in Nicaragua and to compare the results with those suggested by FAO. The study was performed in a field experiment at the Casur Sugarcane mill in Nicaragua, where the sugarcane was cultivated in a vertisol with a furrow irrigation method. The reference evapotranspiration was estimated using the Penman-Monteith FAO approach, and the crop evapotranspiration (ETc) was determined using the field water balance method. During the crop season, the total ETc was 1346.6 mm, resulting in a 0.90 average of Kc. The determined Kc for initial, tillering, grand growth and maturity was 0.37, 0.91, 1.11, and 0.71, respectively. The Kc proposed by FAO showed values 11.11% higher than that obtained in this study. These results highlight the importance of determining the Kc values at a local scale, parameters that guide irrigation management to use the water resources efficiently.