REAL WATER SAVINGS OF SIMULATED IRRIGATION METHODS AND FARM MANAGEMENTS IN SUGARCANE: CASE STUDY IN MALANG REGENCY

Water scarcity problem in East Java threatens Indonesia's sugarcane production. Various water conservation techniques are carried out to reduce water use and achieve optimal production. This study aimed to analyze the real water savings of various irrigation methods and farm managements commonly used by farmers to respond to water drought and increase crop production in Malang Regency. AquaCrop modeling software and REWAS tools were used to simulate sugarcane production under various conditions and calculate real water savings from each scenario. The results showed that irrigation methods were able to increase crop yields compared to rainfed farming. Good farm managements were also able to produce yields two times higher compared to minimum managements. Without good managements, irrigation did not show higher water productivity than rainfed agriculture. By changing the irrigation method from furrow irrigation to drip irrigation, it was only able to achieve real water savings up to 14% compared to the apparent water savings which is up to 84%. The above results do not intend to prevent drip irrigations and good farm managements use, instead to emphasize the importance of proper calculations on real water savings at the basin level in terms of water scarcity. Future study is required to acquiring a better knowledge of real water savings in sugarcane through field experiments.