Model of evapotranspirative subsurface irrigation tested with water lettuce

Providing irrigation for plants that is appropriate with the amount of the crop evapotranspiration or loss of water by plants is crucial to increase water productivity. One of the ways to increase irrigation efficiency is to apply a smart irrigation system. Intelligent automatic irrigation systems can be costly because they use a variety of microcontroller instruments. In this study, the irrigation model design utilizes automatic irrigation technology based on the evapotranspiration principle that can reduce the high cost. The objective of this study was to develop the evapotranspirative subsurface irrigation tested with water lettuce and test the performance of the model in terms of physical and economical water productivity. The evapotranspirative subsurface irrigation system used an inverted cone-shaped pots with an upper diameter of 40 cm. The pots consist of 1 pot as a supply of irrigation water, and 13 pots as planting pots. The pots are connected by a ½ in diameter pipe so that the water level at the pots is at the same level. The model yielded good results. The physical water productivity was 12.32 g liter⁻¹ and economical water productivity of IDR 9.2/kg can save IDR 22.7/kg on irrigation water costs in crop production.