| Abstrak/Abstract |
Soursop fruit is rich in health benefits. The soursop plants (Annona muricata L.) have a great potential to be cultivated in Indonesia. It requires an enough water availability in the land to optimize biomass production through photosynthesis. Soursoup farming in dry land Selopamioro Village – Bantul, Yogyakarta needs irrigation. Due to geomorphological condition, water resources for irrigation mainly from harvested rainfall in small pond (local name “rorak’). This study was aimed to determine the water balance and irrigation water requirements in Soursop farming in dry land with rainwater harvesters (rorak). The material includes the coordinates of the research location, Soursop farming land boundaries, and rainwater harvesters (rorak). Furthermore, the daily climate data in the form of rainfall, temperature, net solar radiation, wind speed, atmospheric pressure and relative humidity were used to calculate reference evapotranspiration. The reference evapotranspiration (ETo) was computed by Penman-Monteith approach. Later, it was used to determine plant evapotranspiration (ETc) using the soursop plant coefficient (Kc) from previous study. Water balance analysis was applied to assign annual irrigation water requirement in Soursop farming land. This study defined average ETo of Soursop farming land in Nawungan orchard was 5.0 mm/day, while the average ETc was 3.0 mm/day. There were three rainwater harvesters (rorak) in Soursop farming land, laid on the upper slope and two on the middle slope. Annual irrigation water requirement was 4287 m³. During this period, three “rorak” could meet the water need of plant for 84 days. So, more rainwater harvesters should be built in Soursop farming land - Nawungan orchard. |
