Salt Accumulation and Mobility in Sodic Soil as Influenced by Primary Biomethanated Spentwash

A soil column laboratory experiment was carried out in the Department of Soil Science and Agril. Chemistry, Mahatma Phule Agricultural University, Rahuri, district Ahmednagar (Maharashtra), during 2008–09 to study the salt accumulation and mobility as influenced by primary biomethanated spentwash (PBSW) in Sodic Haplusterts. The PBSW was applied in three different levels (0.5, 1.0 and 2.5 cm) and then tap water (C1S1 Class) was used to carry out leaching by four different levels of water on the basis of pore volume of soil (WPVS) (0.5, 1.0, 1.5 and 2.0). The pH of leachate decreased and EC increased with increasing levels of PBSW, whereas, pH and EC increased with increasing levels of WPVS. The highest amount of sodium and chloride was found in the leachate as compared to other cations and anions. The EC of soil increased significantly with increasing levels of PBSW, while EC decreased with increasing levels of WPVS in surface (0–15 cm) and sub-surface (15–30 cm) soil layers. The CEC of both soil layers decreased significantly with increased levels of PBSW at 0.5 and 1 WPVS level. The exchangeable sodium content decreased with increasing levels of PBSW and water in both the layers. The sodium content of saturation paste extract was increased significantly with increasing levels of PBSW and WPVS in both the layers. Application of PBSW @ 2.5 cm and then leaching with water @ 2.0 pore volume of soil showed ameliorating effect on the sodic soil.