Studies on soil physico-chemical and biological properties and evaluation of nutrient index for soil fertility along rural-urban interface of southern transect of Bengaluru

Abstract

The expansion of urbanization and industrialization has an adverse effect on the physical, chemical, and biological properties of soils with this our objective was to study the soil quality and evaluation of nutrient index for soil properties along rural-urban interface of southern transect of Bengaluru. The results of the analysis of variance with unequal number of observations showed that rural soils were recorded significantly higher mean values of SOC (0.70%), N (323.01 kg ha-1), P2O5 (28.98 kg ha-1), K2O (246.16 kg ha-1), S (19.32 kg ha-1), Zn (0.73 ppm), B (0.84 ppm) and DHA activity (14.59 µg TPF g-1 soil 24 h-1) whereas, urban soils were characterized by higher mean values of soil pH (7.93), EC (1.33 dS m-1), exchangeable Ca (12.03 c mol (p+) kg-1) and Mg (7.70 c mol (p+) kg-1) and heavy metals such as Cd (0.088 ppm), Cr (0.086 ppm), Pb (0.065 ppm) and Ni (0.056 ppm).The results of nutrient index revealed that available nitrogen (1.61 and 1.42) and zinc (1.65 and 1.57) were belongs to low category of nutrient index in rural and peri-urban, respectively. Urban soils were characterized by low nutrient index category w.r.t. SOC (1.44), available N (1.25), P2O5 (1.52), K2O (1.50), S (1.56), Fe (1.50), Mn (1.40), Zn (1.25) and B (1.42). Conclusively, rural soils were recorded higher available nutrients and microbial activity, followed by peri-urban and lowest were recorded in urban soils, this clearly suggests that the process of urbanization has adversely affected the soil quality along rural-urban interface.