EFFECTS OF LAND USE ON PHYSICAL, CHEMICAL AND BIOLOGICAL PROPERTIES OF SOIL

The study's objective was to evaluate the distribution of physical, chemical and biological properties of soil in Batiaghata upazilla, Khulna, Bangladesh as influenced by land use and soil depth. For the study, two different land uses were used such as mono-cropping (Rice field, Banana field, Orchard of Mango and Orchard of Teak) and multi-cropping (Rice -green gram -Melon-pumpkin, Potato -Bitter gourd- Green bean, Bottle gourd- Eggplant –pumpkin and Spinach- Tomato -Cucumber). Soil samples were taken from soil at depth of 0 – 15 cm, 15-30 cm and 30-45cm from each field. There were 10 to 15 sampling point based on the heterogeneity of land unit in a zigzag manner and they underwent laboratory testing. To ascertain the difference between the land-uses and soil depth, the obtained data were statistically examined using analysis of variance (ANOVA), and mean comparisons were done using the least significant difference. Results revealed more variation in soil pH, EC,TN, TP, OC, CEC, MBC, soil respiration and less variation were found in  soil texture, soil K, Na, Ca and Mg among land uses and soil depth, that was statistically significant (p<0.05). Most of the soil properties increased or decreased irregularly with soil depth. Soil physical and biological properties were found within maximum ranges in mono-cropping and the highest values of chemical properties were found in both mono-cropping and multi-cropping. The highest values of Bulk density, porosity, EC, Ca, CEC, MBC were found in 0-15 cm soil depth. The values of soil TN, TP, OC and Mg were highest at 15- 30cm depth and the values of pH, K, Na and soil respiration were highest at 30-45cm.

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