A couple weeks ago we went over the saline problem with some hints at a solution and some perceived solutions. Today I want to talk more about the solution and discuss more of the perceived solutions.
Tiling comes across as the best perceived solution. Salt affected areas is a water usage issue, so what better way to use up the water than to have tile carry it away. Sound in theory, not so sound in science. We went over it last week but it’s hard for water to penetrate concrete to carry the salt down to the tile.
“If it, the salt, can’t get to the tile then I just need to deep rip it to fix my water infiltration, right?” I know many of you have been involved in the FFA soils contest at least once when you were in high school. With this you covered the soil’s structure. Tillage can sure screw up soil structure, but it can’t make it better. Every time we make a pass with tillage, we make our soil particles tighter and tighter together. Will a deep ripper make openings in the ground? Sure, but that doesn’t improve water infiltration. That trait lies in the soil structure and the only way to improve that is with roots and time. Side note: this relates to regular soil compaction as well. Deep ripping might be a perceived solution, but it’s not a real one.
For sodic (still salt) soils, the application of gypsum is offered up as a solution by replacing sodium ions with calcium ions. Sounds great, until you realize you can spend a lot of money to barely move the needle. Yes, gypsum can do what it’s touted to do. However, the extent to which it does it isn’t enough to justify the cost. This is just another extremely expensive perceived solution that doesn’t work in the practical world.
“I’ll just clean out my cow lot and apply it there, that’ll fix it!” There is a little to the whole bury it manure thought, for a short period. Yes, it will alleviate for a year or two, but that salt will make it back to the surface rather quickly. To wrap our minds around why this and other perceived solutions don’t work is that we have to get the enormous volume of salt that is in play here. Now, do I think you could use manure as part of a solution? Sure, it still involves planting it back to perennial plants though. Some areas have such a high salt content that even wheat grasses won’t germinate. The perennial plants will over time come from the outside of and shrink these areas as the salt gets drawn down from the outside and allows the plants to creep inward. Much easier to do with your rhizomatous native Western and Slender Wheatgrass than your bunch Tall Wheatgrass. I’m sorry I can never miss a moment to question the use of introduced species when we have better native ones. Ok back to the bull $%!^ point. Manure application may allow our seeded plants a chance to get started in these worst salt affected areas and speed up the time it takes to get something established on them.
“Getting back to small grains will fix my problem.” I have seen this tried half-heartedly where we will plant small grains for a year or two and then go right back to the beans. Small grains will not reduce the amount of salt. They are still just a crop that only grows for a few months, there isn’t anywhere near the amount of root growth it takes to reduce the salt volume. Small grains are more salt tolerant and if you are going to keep farming saline areas, they should definitely be part of or a significant part of the crop rotation. They aren’t going to be a solution to the problem.
“What’s the solution then?” Glad you asked. Not sure if I mention this enough, it’s perennial native plants! If you could take a cross section of soil with all of our crops, alfalfa, introduced grasses, and a healthy native plant community, you would see what I mean when I say it’s about the roots. Since you probably don’t have those in front of you, maybe use your imagination. Imagine just how the volume of roots in the crop cross section pales in comparison to the perennial native one. I’m not just talking about the depth, which is stark on its own, but just the shear tangled mess of roots that perennial plants have by growing most of the year — year in, year out. Crops germinate and mature in a few short months; they just can’t produce that kind of root volume. If you can imagine that difference in roots, then you won’t have to imagine why perennial native plants are the solution to salty soils.