Abstract

A global positioning system (GPS) based soil survey was conducted during September 2011 in the sugarcane dominant tracts of Theni district, Tamil Nadu to map the soil fertility status using GIS software and link with different cane yield potentials. The soil samples were taken from 400 spatially distributed locations from a depth of 0 to 30 cm and analyzed for texture, pH, EC, organic carbon, available nitrogen, phosphorus, potassium and micronutrients viz., Fe, Mn, Zn and Cu. The ‘Asis’ survey data regarding fertilizer management practices, adoption of new technologies, irrigation practices and other crop production techniques were also collected from the farmers. The interpolated maps for the status of macro and micronutrients show a clear deficiency of available Nitrogen in 96% of the soil samples of the cane growing areas and DTPA – extractable Zn deficiency in almost 60% of the regions surveyed. However, the available phosphorus and potassium contents were reported to be moderate to high in 90% of the samples indicating the possibility to reduce the P & K fertilizer application to sugarcane in this tract of Tamil Nadu. Majority of the soils were sandy loam to sandy clay loam in texture and reported to have low organic carbon context (<0.5%). The outcome of this study has provided an insight into the unbalanced fertilization practices adopted in some of the cane dominant tracts of this district and the need to evolve a GIS based balanced fertilization model through the conduct of field experiments with graded levels of fertilizer doses and Institute (TNAU) – Industry (RSCL) recommended packages.

Key words: Geographic information system (GIS) database, sugarcane, Tamil Nadu, nutrient management.