Variability of soil properties in Sikhe village under Lower Subansiri district, Arunachal Pradesh

Abstract

The study was conducted under three land uses, viz., terrace, jhum and forest to assess the variability of soil properties in Sikhe village under Lower Subansiri district, Arunachal Pradesh. The soil pH was strong to moderate acidic in reaction (pH 4.6 to 6.1). Organic carbon ranged from 10.7 to 46.0 g kg-1 which was found to be highest in forest ecosystem among the land uses. Cation exchange capacity (CEC) ranged between 7.9 and 22.8 cmol (p+) kg -1 and had significant positive correlation with organic carbon (r=0.68**). Bulk density varied from 1.10 to 1.56 Mg m-3, and showed significant negative correlation with organic carbon(r= -0.61*). Bulk density of forest was recorded to be the lowest. Water holding capacity (WHC) varied from 37.0 to 64.2 %, and was found higher under forest land use. WHC had significant positive correlation with organic carbon (r=0.55*) and significant negative one with sand (r=-0.62*). Hydraulic conductivity varied from 0.21 to 1.86 cm hr-1, and was found lowest under terrace land uses. Water stable aggregates (WSA > 0.25) ranged from 83.0 to 96.8 %. Mean weight diameter of the soil varied from 0.52 to 0.88 mm. The textural classes of various soils under different land use systems were loam, sandy loam and silt loam. The dispersion ratio varied from 30.2 to 47.9, which was very high in all the land uses. It had significant positive correlation with sand (r=0.76**) and significant negative correlation with organic carbon (r= -0.74**) and clay (r=-0.56**). Erosion index ranged from 48.1 to 89.9, and the highest was observed under terrace land use and lowest under forest land use. Erosion index had significant positive correlation with sand (r=0.72**) and dispersion ratio (r=0.74**) and significant negative one with organic carbon (r=-0.69**) and clay (r=-0.68**). The dispersion ratio and erosion index of all the land uses were very high indicating that the soils are highly erodible.