Potassium, which constitutes about 33% of the cation equivalent capacity of langbeinite, will also help to displace exchangeable sodium because its selectivity coefficient is higher than that of sodium for most soils.
The study was conducted to investigate the response of a soil that was not naturally sodic but had a sodicity characteristic due to exchangeable Na accumulation with a long period of extensive irrigation using sodic municipal water to different rates of gypsum and langbeinite applications.
A column leaching experiment was conducted using a sodic soil amended with gypsum and langbeinite (K-Mag) and leached with sodic water.