Soil Quality Index for Different Land Use Systems in Northwestern Hilly Region of India

Unsuitable land use has led to environmental degradation especially in hilly regions. This study investigated the impact of different land use systems on soil quality in tropical north-western hilly region of India using a systematic framework. The assessment framework used comprises of a minimum data set, linear scoring functions and weighted additive indices. Soil quality was evaluated according to seven identified soil attributes. With respect to the forest soil, bulk density increased by as much as 8.0% (1.6 to 8.0%), organic carbon declined by as much as 39.5% (19.7 to 39.5%) and hydraulic conductivity declined by as much as 46.9% (41.9 to 46.9%) in scrub and terraced agricultural lands. Although, streambed had maximum value of hydraulic conductivity, all other attributes were very less. Substantial losses of total N (6.25 to 87.5%), and available K (21 to 69.9%) were also observed. However, extractable P exhibited the increasing trend (101%) in agricultural land. When the attributes were combined to assess the performance of soil functionality, the forest land use system showed higher overall soil quality. Streambed areas had the lowest score (0.32) and forest woodlands had maximum score (0.68). Present study showed that land use has a great influence on many soil quality attributes, mostly through its effect on soil organic matter, total N and saturated hydraulic conductivity. The study further revealed that cultivation on the hill slopes has resulted in a significant deterioration of soil quality as described by different physical and chemical soil attributes.