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Aerial photo of the Soil Health and Agriculture Research Extension (SHARE) Farm in Mooreton, N.D., where North Dakota State University is evaluating conservation tillage practices, rotation and cover crops over non-tiled (top) and tiled (bottom) parts of the field. In the photo, the right-side of the field also has salinity issues. (Abbey Wick/NDSU Extension Soil Health Specialist)

Soil Health Minute: Multiple tools to get the job done

With soil health, it is rare that a single tool (or management approach) will help fully do the job. If we are looking to achieve on-farm goals, such as managing salinity, then using multiple tools or approaches is critical. Think of it as a "system".

With salinity, I often say, "if you manage the water, it will help you manage the salts." Soluble salts move in water, so it's when salts dissolve they become an issue and accumulate in specific parts of the field and at the surface. There are multiple ways to manage water (and I'm sure I'll miss a few): surface ditching/cleaning out road ditches, reducing surface evaporation, leaching, moving water with plants (transpiration) and tiling/drainage. These approaches are in a specific order because this is how I run through the tools in my head when I look at a field with salinity issues.

First, I look at how the surface water is managed. Is there appropriate ditching and is there compaction in the field that causes water to pond or run-off? I ask, can the farmer even ditch or drain, is it allowed? If I'm looking at salinity along the edge of the field, I look for water in the ditch and if it is upwelling into the field carrying salts. Managing surface water or getting water in the ditch to drain is the first step, or tool, that should be used if allowable.

Next, I look for tillage management or surface residue. Soluble salts move with water from deep in the soil profile that is being pulled toward the surface through evaporation. Residue can help reduce evaporation and keep the salts away from the surface. In other words: "Avoid tilling or ripping saline spots." If nothing is growing on a saline spot, sometimes the crusting from the salts will help reduce evaporation and keep it from getting worse. So rather than tilling it, leave it be and direct seed into those areas with a more salt-tolerant cash crop or cover crop such as barley.

I also look at residue to see how effectively we are capturing snow to leach salts from the soil surface into the soil profile. Leaving standing corn stalks (no chopping head) and the root balls intact (yes, this means no-till) will help capture snow evenly across the field and also give water an avenue to move down root channels into the soil. Doesn't have to be whole field, just has to be where you have salt issues.

Then I think about how we can move water through plant transpiration. This is where getting something to grow, whether it's a cash crop somewhat tolerant to salts, such as like small grains or cover crops, come into play. If leaving residue on the surface to reduce evaporation, it's good to have a plant there to use or manage water to avoid wet fields.

After all that, I look at whether it would be feasible to install tile in the field. I've been asked before if I am against tiling and the answer is no. It is a tool in the toolbox and we have a couple studies ongoing where we are evaluating tiling and salinity. I do look at using tiling in high water table situations to intercept ground water carrying salts more so than to install it to leach salts. If you want to flush salts using tile, staking other tools like reducing tillage and using plants in addition to the tile will build soil structure and increase water movement into and through the soil.

These are the steps I go through in my head when evaluating a saline area or field. A similar thought process is used when converting a non-saline field to reduced tillage. There are so many ways to come up with the multiple management approaches that will work on each farm, but consider using multiple tools for a higher success rate in achieving goals.

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