Modeling spatial variability of major soil nutrient status in rice - fallow system of Madpal watershed in Bastar district of Eastern Ghat region using geo-spatial techniques

Abstract

The present investigation entitled “Modeling spatial variability of major soil nutrient status in rice - fallow system of Madpal watershed in Bastar district of Eastern Ghat region using geo-spatial techniques” was conducted in the Madpal watershed in Jagdalpur block of Bastar district, by analyzing 221 surface soil samples (0-15 cm) on 500 grid intervals. Soil fertility parameters like, soil reaction, electrical conductivity, organic carbon and available nitrogen, phosphorus and potassium were evaluated and mapped using geo-spatial techniques based on the readings and analysis. Soil reaction of the study area ranged from 4.22 to 7.78 with a mean value of 5.79 indicating acidic in reaction. The electrical conductivity of the soil water suspension were found to be extremely non-saline category with average value of 0.03 dSm-1 and medium status of soil organic carbon with average value of 0.53 per cent. Overall, physico-chemical properties of the soils of study area are slightly acidic, non-saline with medium organic carbon. The study area showed low available nitrogen and phosphorus and medium to high potassium status in soil with a median fee of 222.71 kg ha-1, 13.23 kg ha-1 and 322.67 kg ha-1, respectively. All the farming situations of the study area showed uniform non-saline and low status of available N. Medium to strongly acidic soil reaction recorded at elevated farming situations like Marhan, Tikra and part of Mal whereas, slightly acidic to neutral soils observed at low lying areas like Gabhar and part of Mal soils. Soil organic carbon status showed uniform medium in all farming situations except some patches of low at eroded Marhan and Tikra and some patches of high level nearer to forest and uncultivated scrublands. Available P was found to be medium in low lying Gabhar and part of Mal whereas, low status at Marhan and Tikra undulating uplands. Similarly available K was high at whole Gabhar, Mal and part of Tikra and found medium at Marhan farming situations.