STUDIES ON CHEMICAL CHARACTERISTICS AND CLASSIFICATION OF SOILS FROM SANGAMNER AREA, AHMEDNAGAR DISTRICT, MAHARASHTRA, INDIA

摘要

Studies were conducted to know the chemical characteristics of the soils and their classification from Sangamner area, Ahmednagar district, Maharashtra. For this purpose, 62 surface soil samples were analyzed for pH, EC, Ca2+ , Mg2+, Na+ , K+ , Cl, HCO3 - , SO4 2- from saturation extract. The exchangeable cations like Na+ , K+ , Ca2+ and Mg2+ by neutral ammonium acetate extract and CEC were estimated by standard procedures. pH ranged from 8 to 9.7 reflecting alkaline nature of soils. Higher EC in the downstream part reflecting low flushing rate and sluggish groundwater movement in the area. EC study showed 35.48% soils are normal and 64% soils are problematic which requires reclamation. Estimation of CaCO3 content showed 79% of the soils are strongly calcareous and remaining are having moderate CaCO3 content. The concentration of soluble cations are in the order Na+ >Ca2+>Mg2+>K+ whereas Cl is predominant followed by SO4 2- and HCO3 - in the soluble anions. 24.19% soils have SAR greater than 13 indicating shallow water table conditions and congestion of drainage. Out of the total exchangeable cations, Ca2+ is dominating over rest of the cations. The CEC values ranged from 32.14 to 82.47 C mol (P+ ) per kg indicating the soils in the area texturally classified as clay loam to clay. High CEC indicated presence of smectite in clay fraction. 35.48% soils showed ESP>15 which are located in the backwater zone of Ojhar weir. The soils from the study area are easily waterlogged during the rainy season. The problem is further aggravated due to decrease in depth of water table by injudicious irrigation and canal seepage. Therefore, there is an urgent need to focus the attention on the protection of soils particularly in the irrigation sector. Frequent awareness and training programs for farmers can be arranged to know the chemical composition and quality of soil to avoid further degradation.