FIELD EVALUATION OF SITE SPECIFIC DRIP FERTIGATION USING GIS INTEGRATED NUTRIENT STATUS MAP

Abstract

A study was conducted to evaluate a site specific drip fertigation system based on the nutrient status maps prepared with help of GIS at Instructional Farm KCAET, Tavanur. Seventy soil samples were collected at a grid interval of 50×50m and different soil parameters such as pH, Electrical conductivity, Organic Carbon, Available Nitrogen, Available Phosphorous and Available Potassium in the soil were determined. The nutrient index rating of the study area indicate that, nitrogen and potassium shows “low fertility”, whereas phosphorous found to be under “high fertility” range in the study area.

Using the spatial variability maps of the nutrients, two test plots, one from high fertility zone and one from low fertility zone were identified with the help of GPS for raising the test crop tomato. The experimental plot was laid out in a Completely Randomized Design (CRD) with four treatments and four replications. The results showed increase in yield and growth parameters under site specific drip fertigation treatment in low fertility area due to the adequate fertiliser application than general recommendation, which might be inadequate for that low fertility area. In case of high fertility area, reduction of fertilizer to site specific requirement has produced almost similar result of general recommendation which indicates that site specific dose was sufficient to produce optimum yield from the crop. Moreover, a site specific drip fertigation helped to achieve a higher water and nutrient use efficiency with high economic return of agricultural produce.

From this study, it can be concluded that nutrient status map prepared using GIS for a particular area can be used as an effective tool for the better nutrient management in that area for maximum productivity. Instead of going blanket nutrient recommendation, a site specific nutrient recommendation may help the farmers who want to achieve higher profit from unit land area by using optimum inputs, thereby reducing environmental stress due to over fertilizer application.