M Tech

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.