Salinity is rearing its ugly head this spring as a result of a relatively high water table from all the rain last fall, limited flushing of salts as a result of low snow cover/melting and high evaporation from fall tillage and lack of soil residue since most of it blew across fields this winter. A high water table brings the water that carries the salts closer to the surface, less snow cover means less flushing of salts in the spring and high evaporation drives a process called capillary action that moves the water from the water table up towards the surface. Additionally, with as much soil erosion as there was this winter, the soluble salts below the surface now have less soil to move up through to reach the rooting zone of crops.
Tillage seems like a good option to make a salt-affected, “white” soil turn “black” again and get rid of the problem. But, this practice actually accelerates salt movement towards the surface by increasing evaporation while the water table remains constant. When we talk about actively managing salinity, we often say, “dry the soils down.” To do this, you need to reduce evaporation and lower the water table.
Two things I recommend you do this spring:
- Collect soil samples – you need to “get your number” so you have a starting point to develop a long-term management plan. Do this from a saline area that you are concerned about and also a productive area from your field. Keep the samples separate and send them off to a soil testing lab to be run for Electrical Conductivity (aka Soluble Salts). You cannot begin to effectively manage an area until you know what your salt levels are. And having a comparison from a salt-affected area versus a highly productive area will help you understand what good and bad salt levels are.
- Avoid tilling saline areas – this is something you can do even without “getting your number”. Tilling increases evaporation and will bring more salts to the surface. Chances are good that nothing is growing in those saline areas anyways, so you can plant directly into them without the tillage. I have had conversations with a few producers who are doing this and it is working well for them.
Do these two things in the short-term and then work on developing a long-term plan.