Desert Soil: Oxymoron?
Those two words seem like opposites when you think about it. A desert doesn’t have soil really, does it? Living in a dry climate doesn’t necessarily mean you’re in the desert. Your home could be situated in a semi-arid “Mediterranean” zone that gets far less water than many places but still supports a variety of plants. Whatever the ground is composed of, that’s your growing medium. I firmly believe most “soils” can be recovered, but you may be starting with more of a dirt than a soil. And that’s okay. If your goal is to create or improve a landscape with little rainfall (clouds occasionally hovering but not always releasing their magic for the ground to soak up), you can focus on improving your soil’s capacity to hold what water does fall onto it. This is one step toward moving it up the scale in terms of how well it will grow plants.
I recently tried to find information about how specifically to improve a special type of clay soil but didn’t find much at all. Most people familiar with what I was looking for were adding it to their existing non-clay soil. I wanted to know what to add to it in the case where a property’s soil was made of it. The soil type in question? Bentonite.
Desert Clay – What It Needs
When working with this special situation, I knew that clay soils benefit from the addition of organic matter. But what specifically to add to bentonite soil to take advantage of its water-holding capacity while increasing its porosity and nutrient content?
I decided to focus on cover crops as a way to add nitrogen, increase nutrient levels, and add other benefits such as enhanced structure, surface cooling, and habitat. In the context of farming, cover crops are turned under before cash crops are planted. While I think this is a fast way to add organic matter to a soil with low nutrient levels, it also kills me to kill all those wondrous and beneficial plants. Plants doing amazing work while living. And after they do their thing, any dead parts mean you don’t have to mulch.
Allow Plants to Repair Your Desert or Dry Land Soil
So if you have a clay soil and live in a dry or semi-arid region, try planting cover crops suited to your zone – and leaving them in place instead of turning them under. (You might also try turning your first cover crops under and then letting the second cover crops you plant stay rooted. That way you get both buried organics and precious soil cover, habitat, and mulch all in one.)
If you would like to experiment alongside me, I recommend trying out this mixture of seed that includes a variety of cover crop plants. To plant in dry land soil, use a tiller (I know it says “no-till” but a little indentation and roughness on the surface of the dirt allows the seeds to find a spot and not be blown away) like this one. I prefer to do it by hand because, well, I am off the grid and enjoy my relative independence from gasoline whenever I can achieve it. I use a hand-crank seed scattering tool very similar to this one. I like to weave in among the shrubs and perennial plants already growing on my land, and this type allows me to do that without running over any existing plants. A permaculture trick is to create lateral lines across the landscape and seed those rather than try to cover every square inch of a large space. If you’re working on an urban or suburban single lot (about 50’x100′) this is less of an issue.
Next, I prefer to add a moisture-holding or other amendment to help the seeds get established. This can benefit your project especially if it’s your first time around planting cover crops on your property. I used “humic dg” the first time around and was pleased by it. Since I own 5 acres, I wanted an amendment that covers a lot of square footage, and this one does. I spread the granules using the seed scattering tool I used to evenly cover my ground with the seeds.
When you have spread your seeds after lightly disturbing the compacted surface layer of your dirt, you can wait for the rains to come or start irrigating. I prefer to work with the natural rain regime in my region, which has its benefits and drawbacks. The main benefit is having time to get the seeds scattered. The drawback is that, especially in a dryer area, they are vulnerable to being blown away before then. My solution was to ferment my compost (which also kept a large amount of material out of the landfill or from polluting my property) and then apply it using a sprayer to my cover crop seeds. This is the one I used, and I am happy with it. I also used the precious liquid, diluted after harvest from the fermenters, as a foliar spray in my greenhouse and on my new trees.
I’m having a lot of fun with my project, and it’s wondrous to witness the land transform before my eyes. I hope this helps you do something similar where you live.