CHANGES IN SOIL PHYSICO-CHEMICAL PROPERTIES AND FERTILITY STATUS OF LONG-TERM CULTIVATED SOIL: A CASE STUDY IN SOUTHWESTERN BANGLADESH


Mehjabin Hossain, Md. Tareq Bin Salam

DOI: 10.26480/bda.01.2019.03.06

ABSTRACT
Sustainable soil management is essential for maintaining soil health properly for future production. A comparative study was carried out at Dumuria soil series in Khulna district to observe the current fertility and physical changes of soils over a period of time due to different land use. The soil physical (Soil Texture, Water Holding Capacity, Bulk Density and Total Porosity) and chemical (Nitrogen (N), Phosphorous (P), Potassium (K), Sulfur (S), Soil Organic Matter (SOM), Soil Organic Carbon (SOC) along with Cation Exchange Capacity (CEC), Sodium Absorption Ratio (SAR), Exchangeable Sodium Percentage (ESP), Base Saturation Percentage (BSP), %Salt) properties were determined. Except for the control, all the soils had silt loam texture. Water holding capacity varied from (33.57%±3.3 to 55.57±5.2) % and all soil indicated good porous soil (average 47±5.59)%. Soil pH (5.96 to 7.4) indicated that the soils were neutral to alkaline in nature and had an average salt content of (0.11±0.05) %. SOM was higher in natural vegetative soil (2.45±0.46) % and decreased over the period of land use for cultivation. In terms of ESP and SAR, 50 to 10 years cultivated soil showed the highest value and a significant difference was observed among the treatments (p≤0.05). In BSP, 100 to 50 years cultivated soil showed the highest value and uncultivated soil showed the lowest value and statistically insignificant among treatment (p≤0.05). Overall observation showed that long term land use reveals a significant decline of soil quality. So, sustainable soil management should be incorporated for addressing soil fertility management.

KEYWORDS
Water holding capacity, Bulk density, Porosity, CEC, SAR