Estimation of irrigation interval and soil water content distribution for drip irrigated eggplant using tensiometer under mulching condition

Abstract

An attempt was made to determine the soil water content distribution pattern and irrigation interval based on soil water potential fluctuation for eggplant (Solanum melongena L.) under plastic mulching. The layout of the experiment was conducted in three different conditions viz., black mulched drip irrigation (BM + DI), white mulched drip irrigation (WM + DI), and drip irrigation (DI) without mulching. The eggplant variety Dhruva F1 was selected for the experiment period. The observed soil water content at different horizontal and vertical depths was used to draw a contour map by the computer software “Surfer 15” of the windows version. Soil water content was found to be higher in 0−10 cm of soil layer under all mulching conditions. Drip irrigation with black coloured mulch showed higher soil water content of 26.2% just after irrigation and a lower soil water content of 18.5% after 48 hours of irrigation. The soil water content at the horizontal and vertical direction was decreasing from just after irrigation to 48 hrs after irrigation. Whereas, under drip irrigation with white coloured mulch higher soil water content was observed after two days of irrigation. Irrigation interval was decided based on soil matric potential threshold values reached 15 to 20 kPa, which was found as 1 to 3 days in drip irrigation under white and black coloured mulching condition and 1 to 2 days in drip irrigation without mulching condition. Overall, the study suggests that the irrigation interval for eggplant crops under drip irrigated mulching conditions could be 2 days interval of irrigation period.