Spatial variability of soil nutrients and GIS-based nutrient management in upland of Tamil Nadu: A case study from Valapadi Block, Salem district

Abstract

Spatial distribution of soil nutrients is not normally considered for small holder farms in Tamil Nadu resulting in blanket fertilizer application which leads to low efficiency of some applied nutrients. This study focuses on applying geospatial analyses to map from 39 revenue villages of Valapadi block of Salem district, Tamil Nadu to identify nutrient distribution. Soil samples were taken from these 640locations and analysed soil reaction, EC, OC, major nutrients viz. nitrogen (N), phosphorus (P) and potassium (K) and micro nutrients (Fe, Mn, Cu and Zn). Spatial models of the contents were generated through geo statistical analysis to map the status of N, Pand K nutrients across the locations. Study results indicated that proportion of area of soils are neutral (56.1%) and non saline. Low OC was distributed in 68.2% area and low in available N (91.5%), P (39%) and K (52.8%) respectively. The soils are deficient in Zn (37.3%) and sufficient in Fe (75.6%), Cu (80.7%) and Mn (97.0%).Distribution pattern for P, K, Cu and Mn were rated of low to high and mapped. Outcome of this study could enhance site-specific nutrient recommendation in upland of Tamil Nadu.