Effect of Applying Cattle Manure as a Potassium-containing Material for the Reclamation of Saline-sodic Soils: A Model Experiment

Sodification has developed into severe, world-wide soil problem, especially in arid region. Although the most common method for treating such sodic soils is to replace sodium (Na) with calcium (Ca) using gypsum, replacing Na with potassium (K) is also a possible solution. The present study was aimed at confirming the effectiveness of applying cattle manure as a local material in rangelands that are rich in K for remediating sodic soils in model experiments. Two saline-sodic soil samples collected from Tongliao, Inner Mongolia, China, were used. Cattle manure was applied to soils at mass ratios of 0, 1, 2, 5, 10%, and the soils were leached with water three times. The pH and electrical conductivity of the leachates and soils, cation concentrations in the leachates, and exchangeable cation contents in the soils were then measured after completion of the leaching. In both soils, Na release was increased with increasing amount of cattle manure used. The decrease in exchangeable Na and the simultaneous increase in exchangeable K indicated that the soil Na was replaced by manure K. The soil pH decreased with increasing rate of manure application, and soil infiltration was also improved, as indicated by hydraulic conductivity tests.