Real-time irrigation scheduling for upland crop based on soil and climate characteristics of tidal lowland area in South Sumatera

Abstract

The research aims to determine the water requirement of plants based on soil and climate characteristics in the lowland area of South Sumatra. The study was conducted at the Soil Physics Laboratory, Soil Department, Faculty of Agriculture, Sriwijaya University. Soil samples were taken from lowland areas at Tidal Lowland Reclamation in Telang I Banyuasin. Field research was conducted from March to November 2019. Climatic data were differentiated into rainfall conditions below 2,500 mm/year and more than 2,500 mm/year. The BUDGET model was used for simulations to determine real-time irrigation scheduling. The indicator crop is tomatoes, with a scenario arranged at the dry season planting period. The results showed that in the condition of annual rainfall < 2,500 mm, farmers need more irrigation frequencies compared to rainfall > 2,500 mm. Irrigation is not required under normal climatic conditions. Farmers only need to maintain the groundwater table under 40 cm using gate operation in the tertiary canal. Rainfall was sufficient to fulfill crop evapotranspiration. However, the irrigation scheduling was done every week during the initial growing stage and every ten days in the vegetative up to generative stages in the dry climatic condition.