Do the Soil's Physiochemical Properties Fluctuate with Season and Soil Depth in the Ecological Critical Areas (ECA) of Sundarbans, Bangladesh?

Abstract

The Ecological Critical Areas (ECA) of Sundarbans is located outside of Sundarbans Reserved Forest at 10 km extended landward, which is threatened to reach a critical state due to human activities. Aquaculture is the dominant land use in the ECA and the tree coverage is going to deplete at an alarming rate due to the deterioration of site conditions, which significantly influence the productivity of aquaculture and the establishment of the plantations on the dikes of the fishpond. The present study aimed to assess some static and dynamic soil physiochemical properties of the fishpond dikes located in the ECA of Sundarbans. Soil samples were collected from the western part (Satkhira district) of ECA of Sundarbans during the pre-monsoon and post-monsoon seasons. The bulk density, pH, and electrical conductivity of the studied areas varied from 1.05-1.18 g/cm3, 7.30-8.54, and 1.05-2.13 ms/cm respectively. However, the concentration of available form of Nitrogen, Phosphorus, Potassium and Sodium were 0.5-0.72 mg/g, 0.03-0.06 mg/g, 10.5-12.88 mg/g and 16.89-20.53 mg/g respectively. Some of these parameters showed significant variation among the zones, seasons, and soil layers. However, the stock of available nitrogen, phosphorus, potassium, sodium and organic carbon varied from 52.5- 84.96 kg/ha, 3.15-7.08 kg/ha, 1.10-1.52 t/ha, 1.77-2.42 t/ha and 173.47-199.43 t/ha respectively. As pond soil provides all the important nutrients with water, the findings of this study will help to take proper management interventions for the dike greening initiatives and productivity of fishponds in the ECA of Sundarbans.