GIS integrated site-specific fertigation recommendations for Instructional farm, KCAET, Tavanur

Abstract

Excessive application of fertilizers can cause wastage of fertilizer which increases input cost and environmental pollution. Implementation of Precision Agriculture through site specific nutrient management is the best suitable solution to increase nutrient application efficiency and thereby increase crop productivity. Site Specific Nutrient Management (SSNM) is the real time feeding of crops with nutrients while recognizing the spatial variability within the fields. In this context a study on “GIS Integrated Site-Specific Fertigation Recommendations for Instructional Farm, KCAET, Tavanur” was conducted. Delineation of the study area was done with the help of cadastral map of KCAET campus and coordinates of the corner of the study which were found using hand held GPS during the study. Sampling points were located by using gridding tool. The soil samples were collected at the 40 sampling points and analysed for the soil chemical properties such as pH, Electric Conductivity, Available Nitrogen, Available Phosphorous, Available Potassium, Boron and Sulphur by using standard methods. Spatial variability maps of soil chemical properties were prepared by using Inverse Distance Weighing method of interpolation tool in spatial analyst tool of Arc tool box in ArcGIS. Based on soil analytical values, site specific nutrient recommendations were calculated to each grid for Coconut, Banana and different vegetables by Site Specific Soil Nutrient Calculator (SSSNC). It is a winForm Windows application created with the help of Objective-C using Visual studio 2019. Based on nutrient index rating given by Meena et al., (2006), potassium and phosphorous were found in the range of ‘medium fertility’ (1.67-2.33), nitrogen and sulphur were under ‘low fertility’ (<1.67) and boron was found to be under high fertility range (>2.33) in the study area. According to the criteria given by Wilding et al., (1985), pH was found to be least variable whereas nitrogen and boron were moderately variable and the remaining parameters such as organic carbon, phosphorous, potassium and sulphur were found to be most variable parameters in the study area. The maps and the Site-Specific Soil Nutrient (SSSN) App which were developed during the study will help farmers to make better site-specific nutrient recommendations. From this study, it can be concluded that implementation of site-specific fertigation recommendations can eliminate the excessive application of fertilizers and a significant amount of fertilizer can be saved when compared to Package of Practice/ adhoc recommendation.