Penjadwalan Irigasi Berbasis Neraca Air pada Sistem Pemanenan Air Limpasan Permukaan untuk Pertanian Lahan Kering

Dry land farmers in Jatinangor only able to plant during the growing season twice a year. Runoff harvesting systems for agriculture is expected to answer the problems of water availability in drylands. This study aimed to explore the period of water deficit in the soil, which is used as the basis for determining the scheduling and amount of irrigation water needed for the planting pattern recommended in runoff harvesting systems for dryland agriculture. The method used in this research is descriptive method, by analyzing the water balance of dry land in order to determine the frequency of irrigation and irrigation needs. Parameters required in the analysis of soil water balance are: precipitation, evapotranspiration, soil water availability on the condition of field capacity and permanent wilting point based on the value of MAD (Maximum Allowable depletion) are permitted. The results showed a total water deficit of 217.42 mm in the cropping pattern of sweet corn - sweet corn - sweet potato, where the period of water deficit occurs during planting sweet potato in the third decade of May to the first decade of September.Irrigation scheduling is determined by the selection of fixed interval irrigation between interval 2 days, 4 days and 5 days. With an area of fields to be watered amounted to 264 meter square (57.4 metercubic water needs), 60 meter cubic of runoff that was collected in the storage pond capable to irrigate the entire of land planted with sweet potato, it indicates that the runoff water harvesting systems can increase cropping intensity dry land farming