Water Productivity of Newly Developed Lowland Rice Field

Abstract

. Newly developed wetland rice fields require more water because plough pan layer are not developed. Plough pan is established several years after the field development and its formation depends on the intensity of rice cultivation and the soil properties. Plot scale study was conducted on newly developed wetland rice field originated from upland in Pati village, North Kalimantan Province, Indonesia in 2013. The aim of this experiment was to study the water productivity of the newly developed wet land rice fields. Different water ponding treatments including water ponding layer of 5 cm as control (T0), ponding layer of 3 cm (T1) intermittent with two weeks wetting and one week drying (T2), and saturated condition with water layer of 0.5 cm (T3) were tested. Rice growth, rice grains yield and water productivity were evaluated. Water productivity was computed according to the ratio between rice grains yield and water input. Water input was predicted based on the difference between incoming and outgoing water. In this study water balance was not taken into account in calculating the water input. The results indicated that under saturated condition (T3), plant height and tiller number were significantly lower than the 5 cm ponding and also significantly lower than other treatments. Water productivity between 0.78 and 0.40 gram liter-1 were recorded under ponding water depth of 0.5 cm and intermittent ponding of 5 cm in the wet period