Identification of soil nutrient constraints by geographic information system (GIS) technique and response of crops to identified nutrient constraints in southern dry zone of Karnataka

The selected micro watershed belongs to Kollegal taluk of Chamarajanagar district. Composite soil samples (0–30 cm) at random were collected during 21–25^th July 2013. The exact sample location was recorded using GPS Collected and analyzed for physical and chemical properties. Upland soils was slightly acidic to neutral, lowlands soil reaction was neutral to slightly alkaline. The electrical conductivity of all the fertility points was negligible, The organic carbon content vary between low to medium, The cation exchange capacity of the soil varied from low to medium. The available nitrogen, phosphorus and potassium were low, low to medium and medium respectively.