Contamination in Soil and Groundwater in Sangrampur Taluka of Buldhana District, Maharashtra

Abstract Soil and groundwater are the principal natural resources supporting agriculture and drinking-water supply in Sangrampur taluka of Buldhana district, Maharashtra, where cotton, soybean and pulses are cultivated with substantial use of agrochemicals. This study evaluated the physico-chemical quality of fifteen soil samples, each analysed in two series of determinations (Series I and Series II) for pH, electrical conductivity (EC), potassium, water holding capacity, available phosphorus, organic carbon, organic matter and available nitrogen, and of fifteen groundwater samples analysed for pH, EC, turbidity, total dissolved solids (TDS), acidity, alkalinity, chloride and total hardness. Soil pH was neutral to slightly alkaline (Series I: 6.74–7.90; Series II: 7.18–7.82). EC differed significantly between the series (mean 0.48 versus 1.12 dS/m, p < 0.001), and nine of fifteen Series II soils reached the 1.0–2.0 dS/m range considered critical for salt-sensitive crops. Organic carbon was high in 14 of 15 Series I soils but low or medium in 14 of 15 Series II soils, and available nitrogen was low in nine Series II soils. In groundwater, pH (7.04–7.32) and chloride (120.7–248.5 mg/L) complied with BIS IS 10500:2012, whereas alkalinity (400–750 mg/L) exceeded the acceptable limit of 200 mg/L in all samples and the permissible limit of 600 mg/L in one sample. Hardness exceeded the acceptable limit in 14 samples, TDS exceeded 500 mg/L in six samples, and turbidity exceeded 1 NTU in twelve samples, with one sample (20 NTU) above the permissible limit of 5 NTU. Alkalinity was higher than total hardness in every sample, which points to a sodium-bicarbonate contribution and warrants further study of irrigation suitability. The results show that groundwater in the study area is chemically stable in pH and chloride but is affected by high alkalinity, hardness and localised turbidity, and that the soils show marked spatial and between-series variability in salinity and organic-matter status.