Pulin B. Chakraborty
Dept. of Soil & Water Conservation
Bidhan Chandra Krishi Viswa Vidyalaya
Regional Research Station (CSZ), Kakdwip 743 347, West Bengal e-mail: email@example.com
The study was undertaken in the micro watershed located in Kakdwip Block in saline eco-system of Sundarban. Composite soils from 0-15 cm depth of double and mono-cropped paddy fields as well as grassed and barren lands were analyzed for different physical (particle size distribution, bulk density, aggregate stability, water holding capacity, moisture evaporation, plasticity) and chemical(organic carbon, SAR, ESP, CEC, , pH, EC as well as total N, available phosphate P2O5 and K2O) propertiesResult reveals that low land contains 49.8% clay and it was more than 50% in both double and mono-cropped paddy fields, which resulted 99% aggregation in these land uses. All the physical and hydrological parameters were found to be highly correlated with both clay and organic matter content of the soil. The result further revealed that pH of the soils under cultivated double and mono-cropped land uses shows acidic reaction varying from 5.3 to 4.6; whereas it was alkaline in nature in rest of the land uses. ECe shows > 2.0 dSm-1 in both the land situations. Other chemical indicators viz. SAR, ESP, CEC were found to be relatively higher in lowland situations due to higher clay and organic matter content of the soil. Total nitrogen content although did not show any variation with respect to land uses and land situations, but, considerably higher content of available P2O5 and K2O in either double cropped or mono-cropped lands in lowland situation was found to be associated with high clay content. Finally it was revealed that both double and mono-cropped paddy land under medium land situation proved to have highest productivity. In lowland situation, productivity of cropped lands was marginally lower than those under medium land situation.
Key words: Sundarban, land uses, physical properties, chemical properties, productivity
Soil serves as a medium for plant growth by providing physical support and acts as a source of water, essential nutrients and oxygen for the plants. Suitability of soil for sustenance of plant growth and related biological activities is a function of physical properties like porosity, water-holding capacity, structure and tilth as well as chemical properties like nutrient supplying capacity, pH and salt concentration. In fact, a large number of physical, chemical and biological properties of soil are function of soil organic matter content. The quality of soil determines land use, sustainability and productivity and plays an important role not only in production of food, fuel and fiber but also in maintenance of regional, national and international environmental quality. Further, improper soil management for enhancing crop production too leads to severe soil degradation through soil and nutrient loss, which thereby reduces soil productivity. In fact, a sustainable land management system helps in maintaining or improving resource quality. Identifying and characterizing changes in the dynamic component of soil quality is essential in evaluating sustainability of any soil management system (Pierce and Larson, 1993). The necessity for development of a soil health index was stimulated by the perception that human health and welfare is associated with the quality and health of the soil (Haberern, 1992). Soil quality investigations are, therefore, essentially needed to provide information for resource management and regulatory decisions on land use system.
No information on the quality and health of coastal saline soil of Sundarban delta is available. But it is pre-requisite for developing and planning any land and soil management system. The present study was, therefore, been considered...