Boron Leaching and Regeneration Capacity in Saline Sodic Soils

Mobility and leaching of boron in two soil columns containing saline sodic soils viz, Kotli Duman silt loam (Natric Camborthld) and Ghabdan loam (Salic Natraqualf) soils from Punjab were studied. Calcium sulphate, magnesium sulphate and ferrous sulphate å 9 me/100 g in Kotli Duman and 20 me/l00 g in Ghabdan soil were mixed with 0–10 cm section of soil column. These columns were subjected to leaching till 12, 24 and 36 cm leachate was collected. All the amendements were equally effective in reducing boron with leachates. Per cent decrease in soluble boron was less as compared to that of salt content. A major portion of decrease (62–87%) could be attributed to the washing out of soluble boron in the leachate and the remaining 13–38% to conversion to some insoluble forms. Boron was reduced to safe limit after collecting 36 cm leachate in both soils. Leached soil on incubation for 30 days regenerated boron and there was a quadratic relation between soluble boron content and regeneration capacity of the soil.