Influence of different land-cover types on the changes of selected soil properties in the mountain region of Rawalakot Azad Jammu and Kashmir

摘要

The study focused on the impact of change in land-cover types on soil quality inferred by measuring the relative changes in chemical and physical properties of non-disturbed and disturbed soil system.Soil samples were collected from major land-cover types in the mountain region:natural forest,grassland and cultivated land (arable).The natural forest served as a control against which to assess changes in soil properties resulting from the removal of natural vegetation or cultivation of soil.Soil samples were collected from 0-15 and 15-30 cm depth six times during the year and examined for their nutrient status,i.e.soil organic matter (SOM);total N (TN);available P (AP);available K (AK);cation exchange capacity (CEC),pH and physical properties like particle size distribution,bulk density (BD),and porosity.Significant differences among land-cover types were found for SOM,TN,AP;AK,CEC and pH.Soil collected from the forest had the highest levels of all nutrients followed by grassland while soil from the arable site had very low nutrient status indicated an extractive effect of cultivation and agricultural practices on soil.With significantly lower clay contents (20%),texturally the soil of arable site was quite different from that of the natural forest and grassland.Similarly,a 13% more BD and 12% lower porosity showed structural deterioration of arable soil.The changes in clay contents,BD and porosity due to cultivation suggest adverse effects on environmental protection functions of soil.The correlation coefficient between OM to TN,AP,AK and CEC suggesting that within a narrow range of soil,OM may serves as a suitable indicator of soil quality.Natural vegetation appeared to be a main contributor of soil quality as it maintained the organic carbon stock and increased the nutrient status of soil and is therefore,important to sustain high-altitude ecosystems and reinstate the degraded lands in the mountain region.