Chemical properties of soil and runoff water under different land uses in Abbottabad, Pakistan

This study examined properties of soil and runoff water under different land uses: forestry, pasture, cropping and fallow. The moisture level was found higher in the forest soil, while fallow and pasture soils showed a similar level of moisture. In top soil, the water holding capacity of pasture and forest soils was higher than other soils, especially that under cropping; the sub-soil held more water (12.1 %) than the top soil (10.3 %). The lower moisture level in cultivated or fallow lands could be attributed to the lower soil organic matter. Carbon concentration in the soils varied in the order forest > pasture > fallow > crop land. Across land uses, the concentrations of cations differed in the order: Ca > Mg > Na > K. Relatively higher concentrations of nutrients and lower pH were obtained in the top soil and sub-soil of the forest land. Forest and pasture catchments showed lower Na in soil. Regression analysis showed higher correlation between soil carbon and soil moisture, water holding capacity and nutrients. The nutrients concentrations were higher in forest soil and lowest in the soils of fallow and agricultural lands. The cations in the runoff water varied in the order Ca > Mg > Na > K, being highly consistent with that in the soil in each land use. Calcium concentrations in the runoff varied in the order forest > pasture > crop > fallow. Magnesium concentration was higher in forest runoff than other land uses, whereas higher K concentration was in pasture runoff. Higher total solids in the runoff of fallow land indicate soil erosion. The study highlights the value of plantation as a measure for land management.