Effect of varying levels of CA/MG ratios of irrigation water on dispersion and flocculation of soils

Abstract

The present laboratory investigation was carried out at Department of Soil Science and Agricultural Chemistry, Dr. PDKV, Akola. The bulk soil sample of two different soils i.e. salt affected and normal soil were collected from Ramagarh, Dist.-Amaravati and Department farm of Dr. P. D. K. V. Akola respectively in November 2017. Application of saline water in both studied soils showed decrease in the pH values and increased the EC of the soils leachates. A preferential Ca2+ holding in soil profile was only notice in salt affected soil when leaching process was performed with independent saline water. Gradual increase in Mg2+ loading in incoming solution holds more Mg2+ in soil. Clay of all the soils became more flocculated when leached with concentrated saline water as compared to dilute saline water. It was found that Ca2+ ion were more effective than Mg2+ ion flocculating in soil clays. A large dispersion percentage in salt affected soil might be due to high exchangeable Na+ content. Salt affected soil became more dispersed when leached with saline water as compared to normal soil. In this study the 2.5:1 Ca/Mg ratio with 60 meL-1TEC and SAR 5 mm1/2 L1/2 was beneficial for clay flocculation and reduce dispersion of clay particles.