Water balance and water use efficiency in fish-rice integrated agriculture-aquaculture

Aquaculture is dependent on water supply. This result reveals pond consumptive water use and water balance in fish-rice integrated system. Water balance variables were measured daily from meteorological station and computed following the standard procedure. Total water input and output in fish culture were 318.0923 and 26.631 m3, respectively; while in rice cultivation, they were 79.9722 and 6.5732 m3. They were measured on a daily basis with the overall presented on weekly records; the average water balance for rice paddy and fish culture was 75.1563 and 297.4433 m3, respectively. Fish growth showed the amount of water used for production (kg/m3) in integrated pond, right from fingerlings to table size fish. This shows the required amount of water used for productivity at different weeks. Rice growth showed the amount of water required for paddy in an integrated pond throughout the productive period. Water use efficiency based on rice growth showed increase weekly due to use of aquaculture effluent without fertilizer treatment. The results showed that water channels could be strongly influenced by weather and climate pattern affecting farming activities. Hence, IAA is an acceptable practice which ensures multiple and conjunctive use of scare water resources for higher productive farm outputs and future strategies for enhancing water productivity. Key words: Water use efficiency, water balance, rice plant, fish growth, rice paddy.