All across the American Southwest, counties and companies maintain thousands of miles of unpaved roads. They’ve got their work cut out for them: this region’s unique soil conditions make traditional soil stabilization a time-consuming, costly chore.
Thankfully, you can save time, money, and labor on unpaved road maintenance. Enzyme soil stabilizers like Perma-Zyme last longer, cost less, decrease repairs, and work better in the Southwest than traditional products. They’re also safer and more eco-friendly.
We’ll explore what makes Southwest soil so unique and why it’s hard to stabilize (we’re looking at you, clay loam!) Then, we’ll compare several soil stabilizers so you can see how they stack up to Perma-Zyme.
When most people think of the American Southwest, they think of miles and miles of desert. That’s certainly part of the region, but not all of it. To understand the local soil, we first must define “Southwest.”
The only two states that everyone agrees are in the Southwest are Arizona and New Mexico. After that, there’s some debate. Some maps include Nevada, Utah, Texas, Oklahoma, Colorado, and California, while others omit one or more of these states.
For soil stabilization, these states share many similar soil types and problems. So, we say, “The more the merrier!” If you’re in any of the states above, read on because this blog’s for you.
Most Southwestern soils are shallower than other soils nationwide. Bedrock is often only a couple of feet below the surface, and the region's many exposed rock outcroppings are actively producing new soil through wind and rain weathering.
Check out these other fast facts about regional soil conditions:
While soils tend to share these common traits, they’re not all the same. The Southwest has a mix of vibrant ecosystems—including deserts, mountains, and grasslands—that produce diverse soil types.
Southwestern soils formed over the millennia as wind, rain, tectonic activity, and bodies of water eroded tiny pieces of rock. These pieces broke down into different types of soil based on local conditions. So, in the Southwest you’ll find all the major soil types—gravel, sand, silt, clay, and loam. Of these, clay loam is one of the most widespread.
The U.S. Department of Agriculture (USDA) has also defined 12 soil orders to describe how different soil types form and behave in different climates. After all, there’s a big difference between grassland soil types and desert soil types! You can find six of the 12 orders in the Southwest.
Most Southwestern soils are aridisols, which are common in dry regions. Aridisols are characterized by little organic matter, limited ability to retain water, and low nutrient content.7 You’ll also find:
Keep in mind, each soil order may contain multiple soil types, and the exact distribution of each type may vary by location. For example, aridisol soils may contain some gravel, sand, and clay, but an aridisol in Arizona may contain more clay than an aridisol in Nevada.
As we mentioned, much of Southwestern soil is clay loam, meaning it’s mostly clay that contains a little sand, silt, or gravel. Clay often occurs in horizontal layers that can be over a foot and a half thick.9 It comes in various textures and colors, such as Oklahoma’s red clay, Utah’s blue clay, or Texas’ black clay.
Clay can make soil stabilization difficult because it’s the most plastic soil. That means it changes size and shape significantly based on its moisture level. When clay gets wet, it swells, becoming sticky and gooey. (That’s why people call highly expansive clay soil fat clay or gumbo clay). Thankfully, not all clays are the same. Some are less expansive—and therefore easier to build on—than others.
While it’s not as precise as geotechnical testing, you can often visually identify some expansive soils. Clay loam often cracks when dry and becomes sticky if you pour water on it. Its texture may look like popcorn. And if roads in your area have lots of cracks and potholes, that could be expansive soil damage.10
Expansive clay and other Southwestern soils come with unique challenges—like controlling dust, building roads, and stabilizing the soil so it won’t cause damage. Let’s take a closer look at each.
Dust is a major issue in dry climates—especially when clay loam is involved. When clay dries, it shrinks. These microscopic particles are extremely light, so the wind picks them up and blows them away, reducing visibility and carrying the dust for miles. In fact, satellite images show dust plumes from White Sands National Park in New Mexico drifting over 200 miles into Texas.11
So, in the Southwest, an ordinary windy day can quickly turn into a full-blown dust storm, causing problems for entire regions. One of those problems is bad air quality. Inhaling dust particles can cause serious health issues like silicosis, COPD, cancer, and reproductive problems.12
That’s why dust control is extremely important for unpaved roads in this region. The trouble is, many dust control solutions for gravel roads are expensive and only last a few weeks.
Dry clay loam soil is extremely hard, so it’s difficult to break through that thick outer crust and pulverize it into manageable pieces. On the flip side, clay soil swells and collapses easily when it gets wet—such as during a monsoon—which leaves dirt roads vulnerable to erosion.
The constant cycle of swelling and shrinking means any structure you build on expansive clay soil may shift and incur damage. That’s one reason why so many roads in the Southwest have cracks, potholes, and other problems. All that to say, building unpaved roads on clay can be exceptionally difficult.
Most traditional soil stabilization products don’t work well on Southwestern soils—or if they do, they don’t last long. The costs of finding a suitable method can stack up fast. Here are some examples of how soil stabilizers do (or don’t) work in this region.
Chlorides are salts that draw moisture from the environment into the soil to prevent dust. Chlorides also form a crust over the soil’s surface to stabilize it. However, both magnesium chloride and calcium chloride have drawbacks like adverse environmental effects and recurring application costs. But the biggest problem is that chlorides are ineffective in much of the Southwest. In these dry climates, they can’t draw enough moisture from the air to work effectively.
Lime and cement soil stabilization won’t help much either, especially for unpaved roads. These methods both bind soil particles together, but they’re often cost-prohibitive and time-consuming, as they require extensive soil testing to ensure that you use the right type and amount of lime or cement. Lime also poses health hazards to the crews who apply it, while cement is prone to become brittle and crack.
Topical and injectable polymers are like glue that holds soil together. They’re most effective on large soil particles, which is good if your area has lots of sand and rocks. But clay particles are microscopic. Using polymers on clay is like trying to glue glitter together; it’s messy and ineffective. (Think about your kid’s kindergarten art class—and how long it took to clean the glitter off their clothes, hair, carpet, the dog… you get the idea.)
Even if your soil has large particles, polymers may still not be the best choice. They’re expensive, and since they tend to wear off after a year or two, you’ll need to replace them regularly.
Traditionally, some states in the Southwest—like Texas—spray emulsions on roads to keep dust down. These emulsions combine water and petroleum products, such as bitumen or base oil (the main ingredient in engine oil).
Now, dumping engine oil on the ground is illegal in most states because of the environmental hazards, so it doesn’t take a rocket scientist to figure out that spraying petroleum-based emulsions onto roads is also dangerous. That’s why some companies are inventing new, eco-friendly dust control emulsions made from ingredients like soybean oil. As with any new technology, we’re still learning how these products will impact the environment over time. (For example, does soybean oil contain residual pesticides that could harm local wildlife or waterways?)
While emulsions may control dust, most won’t stabilize unpaved roads or prevent potholes. You need a more permanent solution.
As in other communities, people in the Southwest are considering how they can increase their quality of life by adopting sustainable practices that will make their towns and homes great places to live and work for years to come. One of the best ways to do that is by using a green soil stabilization solution like Perma-Zyme to stabilize unpaved, rural roads.
Perma-Zyme is an all-natural, eco-friendly enzyme soil stabilizer. We manufacture it right here in Nevada, where our team lives and works. So, we know firsthand the difficulties you face when managing unpaved roads in the Southwest, and we’ve created Perma-Zyme to overcome those challenges.
Unlike traditional products that struggle to stabilize clay, Perma-Zyme works with clay in the soil by binding its particles together into a hard, concrete-like surface. Geotechnical testing shows that Perma-Zyme can strengthen soil up to 13 times. In Nevada, treated soil became nearly as strong as steel and outperformed traditional Type II aggregate on strength tests.
Thus, Perma-Zyme creates a durable, resilient road that’s capable of supporting all types of traffic—including heavy trucks and equipment. The surface lasts 10+ years for unpaved county roads and up to five years for heavy industrial roads, with little to no maintenance.
With Perma-Zyme, you’ll also notice much less dust. That’s because the clay in the soil has bonded and hardened, so it’s far less likely to drift into the atmosphere.
You only need one Perma-Zyme application to achieve results that last for years—no costly reapplications needed! That’s a huge advantage over other soil stabilizers that only last a few weeks or months.
Because Perma-Zyme treated roads require minimal maintenance, many of our customers report that their yearly maintenance costs drop to $0. Perma-Zyme customers can also save as much as 80% on road construction because the enzyme formula reduces or eliminates the need for hauling and aggregate.
With the money you save, you can now fund other important projects and feel more financially secure, even through economic downturns and rising labor costs. Speaking of labor, your crews will save hundreds of hours on maintenance, freeing them up to handle other essential projects.
Finally, Perma-Zyme is a sustainable solution. It’s all-natural, non-toxic, and safe for crews and the environment. With Perma-Zyme, you save money and get sustainable soil stabilization that lasts. So, why wait? Take the next step to stabilize your road, stabilize your budget, and stabilize your future.