The Role of Ecosystem Transformation and Agricultural Expansion and Its Effect on Some Soil Properties in Shingra and Birganj National Forests, Dinajpur, Bangladesh

Soil quality has critical implications for ecosystem health and agricultural productivity, particularly in regions where land-use practices have transformed natural habitats to a large extent. The paper studied two national forests of Dinajpur, Bangladesh, the Shingra and Birganj National Forests soils, in which their adjacent soils were samples, and their physical and chemical properties were compared of forest soils (FS) with adjacent agricultural soils (AS) to evaluate the physicochemical changes occurred due to ecosystem transformation from forest to agricultural in these two forest areas. Analysis of soil pH, electrical conductivity (EC), organic matter (OM), total nitrogen (TN), available phosphorus (P), exchangeable potassium (K), available sulfur (S), and cadmium (Cd). Agricultural soils had significantly lower OM, TN, and plant nutrients than forest soils (p < 0.001). For instance, organic matter (OM) content was 1.74% (in forest soils) and 1.26% (in agricultural soils) in Shingra whereas 1.53% (in forest soils) and 1.12 (in agricultural soils) in Birganj. Available phosphorus was 15.1 g kg-1 (in forest soils) and 69.9 g kg-1 (in agricultural soils) in Shingra whereas 15.5 g kg-1 (in forest soils) and 51.0.9 g kg-1 (in agricultural soils) in Birganj. On the other hand, cadmium content was 0.61 mg kg-1 (in forest soils) and 3.68 m kg-1 (in agricultural soils) in Shingra whereas 0.53 mg kg-1 (in forest soils) and 2.35 m kg-1 (in agricultural soils) in Birganj. These results suggest that beside changes of other physic-chemical properties, significant increase of Ca contamination occurs due to high application of phosphorus fertilizers.