In-situ soil water dynamics under different irrigation methods at Meghalayan Plateau, North East India

Availability of in-situ soil water plays a major role in exploiting the potential yield of crops under irrigated conditions. Depending on the type of irrigation, variations of soil water is mostly observed at different soil depths within the root zone. The deviation of the soil water at the edaphic zone becomes a deciding factor in assuring optimum yield. As the availability of irrigation water is a great concern during non-rainy season, water saving irrigation techniques need to be adopted to maximize productivity under hilly terrain. An experiment was laid out with potato as a test crop under the valley region of Meghalayan plateau (sandy clayey soil) to study in-situ soil water dynamics under three different irrigation methods, viz., furrow, micro-sprinkler and gravity-fed drip. Irrigation was scheduled at every weekly basis to restore back the soil water required to achieve the field capacity. The mean value of soil water up to 15 cm depth was 21.75, 22.65 and 23.45%, however, the range (minimum to maximum) was 16.21-29.17; 15.56-29.21 and 17.84-28.97% for furrow, micro-sprinkler and gravity-fed drip irrigation, respectively. The co-efficient of variation was found to be the maximum (4.65%) for furrow over other two types of irrigations during the weekly interval. The deviation of in-situ soil water was found to vary rapidly at the upper layer (up to 30 cm soil depth) under furrow method of irrigation; but at deeper soil layer rapid variation was not observed. The water use efficiency of potato was evaluated to be 14.66, 18.78, 20.63 kg ha-1 mm-1 for furrow, micro-sprinkler and gravity-fed drip irrigation, respectively.