Study of Irrigation Water Requirement to Increase Rice Planting Index in Rainfed Paddy Field

Abstract

Achieving food self-sufficiency can be supported by expanding cultivated areas and optimizing land use. One effective strategy for land optimization is increasing the cropping index (CI) from 100 to 200 allowing two rice harvests per year. Rainfed paddy fields in Jambi Province, particularly in Muaro Jambi Regency, have significant potential for such improvement. However, limited water availability during the dry season restricts farmers to a single annual planting. The purposes of this study to analyze water availability in rainfed rice fields and assess the feasibility of increasing the cropping index from 100 to 200. Sungai Duren Village was selected as a representative area with potential for CI enhancement. Crop water requirements were calculated using the CROPWAT 8.0 model, based on data on rainfall, climate, soil texture, and percolation. The analysis indicates that rice planting in Sungai Duren Village can begin in early February based on available rainfall. A second planting season is feasible start in early July, provided supplemental irrigation is supplied using well pumps that lift water from the groundwater or water pools located around the rice fields during the dry season.