EFFECTS OF SOIL DEPTH AND ALTITUDE ON SOIL TEXTURE AND SOIL QUALITY INDEX.

Healthy or good quality soils are essential for ecosystems to remain intact or recover from disturbances. Soil quality is soil- and site-specific and can vary according to controlling factors, such as inherent soil properties. The research proposal was conducted in 2015-2016 to study soil physio-chemical properties across seven elevations and the River Swat catchment area between Barikot and Topsin in Swat-district, Pakistan. The sampling date was March 11-12, 2016, to better evaluate soil classification. Soil samples were collected and analyzed for their physicochemical properties, including surface, sub-soil, and sub-strata. The data showed that silt content decreased, and clay content increased with altitude, while sand content showed inconsistent variation. Bulk density, lime content, electric conductivity, and pH decreased, while concentrations of nitrogen (N), phosphorus (P) and potassium (K), and micro-nutrients increased. Soil organic matter (SOM) content significantly increased (P<0.05) as the altitude increased. Soil samples were non-saline (EC<4 dSm^-1) and slightly calcareous (lime content 2.34% to 5.32%). Higher altitudes increase micro-nutrient content and water retention, while lower elevations decrease water retention. We found that crop available P in all selected sites along the altitude were deficient, classified as P deficient soil. All physicochemical properties were within the range of crop demands, so sustainable management practices are needed to build soil P levels that meet crop requirements. [ABSTRACT FROM AUTHOR]