Impact of coal mining on soil characteristics around Ib river coalfield, Orissa, India.

The present article deals with soil analysis around five opencast coal projects of Ib river coalfield during pre-monsoon (March), monsoon (July) and post monsoon (November) periods of successive three years (i.e., 2006, 2007 and 2008). Sampling of soil has been done from the vertical surface of the overburden at successive depths of 0-5 ft, 5-10 ft and at 10-15 ft. The different physical (soil texture, soil moisture, particle density, bulk density and porosity) and chemical (pH, organic carbon, nitrogen, phosphorus and potassium) parameters have been analysed. The soil textures of the study area are found to be loamy sand to loam, loam to silty loam and clay loam to silty clay loam in the depth of 0-5 ft, 5-10 ftand at 10-15 ft, respectively. The moisture content (7.297 at 0-5ft, 5.25 at 5-10 ft and 4.134% at 10-15 ft) and porosity (43.994 at 0-5 ft, 40.682 at 5-10 ft and 35.85% at 10-15 ft) of the soil in the study area decreased gradually from the surface to greater depth. However, the particle density (2.639 at 0-5 ft, 3.11 at 5-10 ft and 3.523 g cc(-1) at 10-15 ft) and the bulk density (1.478 at 0-5ft, 1.839 at 5-10 ft and 2.269 g cc(-1) at 10-15 ft) in this region increased from surface to the deeper region of the soil. The organic carbon (1.367 at 0-5 ft, 0.9 at 5-10 ft and 0.396 kg ha(-1) at 10-15 ft), nitrogen (2.845 at 0-5 ft, 1.059 at 5-10 ft and 0.48 kg ha(-1) at 10-15 ft) and phosphorus level (1.11 at 0-5 ft, 0.715 at 5-10 ft and 0.679 kg ha(-1) at 10-15 ft) of the soil decreased with increasing depth of the soil. However, the content of potassium (2.636 at 0-5 ft, 4.374 at 5-10 ft and 5.82 kg ha(-1) at 10-15 ft) increased gradually from the surface to the greater depth. Analysis of variance is computed to infer the variation in the concentration of parameters in different open cast coal projects and in various depths of the study area.