Spatial Assessment and Variation of Soil Physicochemical Properties and Water Quality in the Tungi Watershed of Maharashtra, India

Aims: To thoroughly evaluate the spatial variability of soil physicochemical properties and groundwater quality of the study area by systematic collection and analysis of geo-referenced soil and groundwater samples to quantify the physical, chemical and biological attributes of the soil. The objective is to gain a comprehensive understanding of soil and water quality in the Tungi watershed, providing valuable insights to guide sustainable land and water management practices in the region.

Place and Duration of Study: Department of Soil Science and Agricultural Chemistry, College of Agriculture, Latur between 2020 and 2021.

Methodology: A total of one hundred geo-referenced surface soil samples (0-30 cm) and ten groundwater samples were methodically collected from the surrounding area of soil profiles in the Tungi watershed, situated in Latur, Maharashtra. Physical, chemical and biological properties of soil evaluated using recommended standard methods.

Results: Bulk density varied from 1.13 to 1.93 Mg m-3, particle density from 2.48 to 2.94 Mg m-3 and porosity from 22 to 58 percent. Soil pH ranged from 7.05 to 8.96 and electrical conductivity was within the permissible range. Organic carbon content of soils ranged from 0.15 to 1.05 percent, with some soils having a calcareous character (0.6 to 22.2 percent). The analysis of nutrient content revealed variable quantities with available nitrogen ranging from 53.31 to 250.88 kg ha-1, available phosphorus from 12.51 to 27.49 kg ha-1, available potassium from 106.9 to 851.5 kg ha-1 and available sulphur from 4.37 to 66.65 mg kg-1. Exchangeable calcium and magnesium quantities revealed ranges of 14.60 to 42.40 cmol(p+) kg-1 and 5.40 to 21.60 cmol(p+) kg-1, respectively. Furthermore, DTPA extractable iron varied from 4.24 to 16.38 mg kg-1, manganese from 4.76 to 25.84 mg kg-1, zinc and copper from 0.5 to 6.56 mg kg-1 and 0.72 to 15.56 mg kg-1, respectively and boron from 0.1 to 3.56 mg kg-1. Microbial population estimates revealed the dominance of bacteria over fungi and actinomycetes in the studied area. Groundwater carbonate and bicarbonate ranged from 0.01 to 0.62 m mol-1 and 6.35 to 10.24 mmol-1 respectively. The dug well, bore well and tube well water RSC ranged from 0.70 to 1.25 mmol-1.

Conclusion: This extensive study provides helpful insights into the regional variability of physical and chemical properties in both soil and water with help of soil fertility maps, providing better understanding of soil fertilizer input and environmental conditions in the Tungi watershed.