The Cavalier County Soil Health tour, which was held on October 8, had a structured message for those dealing with soil salinity and sodicity problems.
Posted on 10/18/14
The tour started at the Krahn Farm, where the results of different cover crop practices were compared by Craig Brumbaugh and Dustin Brodina on the saline and sodic soils and the soil salinity and sodicity level comparisons between 2012 and 2014.
The group then went to the Langdon Research Extension Center where Naeem Kalwar, the Area Extension Specialist on Soil Health, presented a lecture on how locals can improve their soil health.
Craig Brumbaugh showed the growth and vigor of three different cover crop mixes on a saline-sodic gradient. Chris Augustine and John Lukach then gave talks in two different soil pits and briefed the audience about the soil difference. The tour ended with the NRCS rainfall simulator demonstration.
The following is a condensed version of the lecture given by Naeem Kalwar.
If we look at the root cause of soil salinity and sodicity problems then it comes down to the management of soil water and cover crops can greatly benefit us in that regard.
Since the parent materials of our soils is rich in soluble salts along with having the sodium rich shale, whenever soil water comes too close to the surface it causes soil salinity and sodicity to rise.
If we carefully manage soil water then we can also manage saline areas. A low water-table depth can not only help leach out the excessive salts and sodium out of the plant root zone but it will also result in reducing the capillary rise of the soil water.
Different weather cycles bring different challenges; wet weather brings the water-table close to the top of the soil whereas dry weather promotes capillary rise of the soil water towards the surface due to excessive evaporation.
Our landscape is generally rolling type where water in the soil moves readily from high grounds to low grounds. High grounds are the discharge areas.
In case of heavy rainfall, the amount of water received will generally exceed the soil water infiltration capacity of the recharge area and this excess water will enter the discharge area under natural subsoil flow and that low ground may not further any drainage.
That is why the high grounds most often won’t have any excessive salts (in the wet cycle) due to lower water-table and good salt leaching process.
Higher ground will lose the topsoil and soil organic matter due to excessive surface run off. When this excessive water gets dumped in the low grounds it raises the soil water table and that will lead to the buildup of excessive of amounts of either salts or sodium or even both.
There are different options to reduce the water table level, one example is installing a drainage system. Another method to manage excess soil water is by planting water-use efficient crops.
The best strategy would be to plant a high water use crop on the high ground to intercept that excessive soil moisture before it reaches the low ground as well as to establish salt-tolerant grasses or crops on the low ground.
These grasses will use up some of the moisture, provide soils a vegetative cover and biomass which will improve soil structure and drainage.
Leaving the saline areas bare will only make the problem worse. Chisel plowing in the fall also worsens the problem by causing the top soil to dry out leaving behind salts and causing the water table to rise, bringing more salts to the surface.
The Cavalier County 2014 Soil Health Tour was organized by the North Dakota State Langdon Research Extension Center, Cavalier County Extension, Cavalier County Soil Conservation District, and NRCS. Thank you to the Cavalier County Soil Conservation District for providing refreshments and lunch.
For more information or if you have questions concerning soil health please contact Naeem Kalwar at 701-256-2582.