Studies on Effectiveness of Different Lining Materials on Rainwater Storage in Farm Pond in an Inceptisol of North Bank Plains Zone of Eastern Himalayan Region

Rainwater harvesting in agriculture is an integrated technological system designed to improve the availability of water and to provide supplementary irrigation to crops. The structures offer farmers an opportunity to improve agricultural production, especially bridging intra-seasonal dry spell. An experiment was designed during 2013–14 and 2014–15 to explore the different lining materials that can improve storage efficiency of rainwater harvesting ponds. The study was carried out in Biswanath Chariali of North Bank Plains Zone of Assam. The soils of the region are predominantly entisols, soil texture is sandy clay loam in the surface with varying amount of clay and moderately fine to fine loamy in the series control section (25–100 cm). Permeability of the soil is remarkably high (3.5 cmh⁻¹) with low water holding capacity. Based on results of analysis, it was observed that the water storage varies from Nil (Control/No lining) to 34.0m³ 200 micron Polythene sheet lining in the constructed farm ponds with different lining materials. Polythene sheet lining was found to be the best over the other lining materials viz. Cow dung + soil plaster (2:5 ratio) and Cement + soil plaster (2:10 ratio). Seepage and percolation loss was highest in no lining condition and least in polythene sheet lining material. Required data on daily variation of storage depth and rainfall data was continuously monitored throughout the experimental period. The duration of storage availability of harvested water was 41 weeks in case of polythene lining treatment for the initial year 2013–14 and throughout the year for 2014–15. Therefore, these farm ponds can be an option to harvest rainwater received during pre monsoon season which can be effectively utilized for timely sowing of crops in absence of rainfall during rabi season.