Spatial distribution of organic carbon in selected arecanut gardens of Karnataka

Spatial distribution of organic carbon was studied in different ecosystems such as traditional, tank-fed, bore well-fed and canal irrigation in Shivamoga, Chickamagaluru and Davanagere districts of Karnataka. The chosen gardens were 15–18 years old with medium management. The standard grid technique with a spacing of 50 x 50 m was employed to draw soil samples from the selected study areas at 0–30 cm depth with global positioning system (GPS) identity. The data were analysed for pH, salts and organic carbon. Among the areas studied Humcha and Konandur soils were acidic and Agaradhalli soils were neutral to slightly acidic while others were tending towards basisity in soil reaction. Kabbala (mean value of 0.81 dS/m) and Kerehosahalli (mean value of 0.59 dS/m) soils showed little higher salt accumulation than rest of the soils. Status of organic carbon remained high to medium for Chikkingala, Agaradahalli, Kabbala and Kerehosahalli whereas Humcha, Konandur and Banoor soils remained of medium to low status. Utilizing variable value of this data the study areas were mapped in geographic information system (GIS) environment. For each location depending on its site specific variations nutrient application approaches for future are advised to the farmers.