Abstract

Increasing agricultural water use efficiency is of prime importance owing to the decrease in availability of fresh water for agriculture. In these circumstances, drip irrigation is considered so far as the most efficient irrigation systems and can be utilized correctly with the knowledge of dimension of the soil wetted volume which is the main factors in determining the spacing of drippers. Therefore, the present study was conducted at the Instructional Farm, Faculty of Agricultural Engineering, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal during 2019–20 to examine the vertical (Z) and horizontal (W) water fronts advance within the soil profile at the dripper in a clay loam soil. Same volume of water (50 litre) was applied at the rate of 2.3 and 4.9 lph at each irrigation. By observing the soil on the tips of the auger, the depth of wetting was determined and noted down for different points on the line of the wetted area. It was found that there is little variation in the theoretical width and depth with the actual width and depth of wetting of the soil in case of 4.9 lph discharge rate. For the given discharge rate, the inaccuracy was less for the wetted depth than the wetted diameter. So, the information obtained from this investigation, about soil wetting pattern of drip irrigation system can be helpful to decide emitter, lateral spacing and system pressure for delivering required amount of water to the plant root zone. Thus, this investigation can be instrumental in design and management of drip system, which is slowly becoming a promising agricultural water management practice to tackle the huge food productivity problem and environmental issues of developing and under-developed countries.