Naeem Kalwar is an extension Soil Health Specialist in the Langdon Research Extension Center. His expertise is shared today in facing sodicity and salinity issues in your soils.
The term salinity refers to the potential for high salt levels in the soil which can decrease water absorption at the root-level resulting in drought stressed crops. Fortunately salinity does not affect soil structure allowing for the smooth movement of water and air through the soil despite the increased salt content. Good drainage and improved soil water infiltration can help manage salinity concerns.
Sodicity, on the other hand, creates an issue that is not as easy to correct. With sodicity, a bond between the sodium molecules and the clay is formed. This directly affects the ability of the water to move through the soil as it will settle in dense layers. With an increase in sodicity you will also have a higher retention of salt resulting in increased salinity. Amendments like gypsum are required to increase the aggregation and good structure of the soil in order to compensate for the structural changes caused by sodicity.
“Our groundwater has very high salt levels, plus sodium. And this sodium i’m talking about is not presented as salt. This sodium gets attracted to the negative charges of clay and humus soil particles, and causes sodicity or the breakdown of soil aggregates…so we have two different problems: salt and sodicity.” – Naeem Kalwar