NATIONAL REPORT—Soil is a vital resource. Crops require it for production of the world’s food, yet the very people who are fed by those crops often do things that permit erosion of the soil. The buildup of silt in waterways and municipal storm sewers has caused flooding and damage to property, resulting in an ever-growing need to reduce soil erosion.
In the simplest terms, prevention of soil erosion comes down to two main features: Establishment of vegetation and management of water flow. Those two techniques are utilized in several different ways, including these common solutions.
Perhaps the most obvious culprit for soil erosion is construction areas. The soil that is exposed during excavation and grading can easily be washed away by even a light rainfall, clogging streams and rivers with soil.
In the last few years, construction techniques have been improved to include a more attentive eye toward handling runoff. You have probably seen the lines of black fabric staked near ditches and streams. These barriers collect soil at their base and let water push on through so that later grading can return the dirt to its original location. Bales of straw are often seen around drain grates as well, serving the same purpose.
Improved techniques for establishing vegetation have also been developed, with straw mulch and seed rolled together for quick application and more effective germination. Additionally, prefabricated concrete retaining walls help keep soil in place.
There may always be development and re-development, but the ability to improve runoff conditions and reduce soil erosion from it is growing rapidly in its own right. Innovations like those made in other consumer areas are reducing the impact of development on soil.
Urban sprawl seems to know no end. The more acres we put under asphalt, the more runoff is generated in place of what would have been dry soils and thirsty plants. All these millions of gallons must go somewhere when it rains, and storm sewers are tasked with carrying the water away.
Unfortunately, the rapid discharge of large volumes of water during a storm can prove very destructive to the area where the water is released. As a result, many cities are requiring improved water management techniques to help slow the movement of water. They also are requiring more green “islands” in parking lots and making stricter regulations on development.
While many people think of agriculture as the primary culprit in soil erosion, that is not nearly as true as it was decades ago. The advent of no-till farming has done wonders for the American farmer’s ability to reduce the amount of soil lost in the process of growing food.
But even no-till isn’t the whole contribution of agriculture to the situation. Ever-greater use of technology has made it possible for farmers to reduce erosion. As one example, many vegetables today are grown in rows covered by plastic, which conserves moisture and reduces the need for irrigation. The plastic also helps to control the runoff of surface water, slowing its movement and reducing damage to soil.
Under the plastic, there are small lines that irrigate the crops slowly and with very targeted placement of water. The reduced runoff helps cut erosion yet again.
New soil is constantly being formed, but the rate at which it is created is much slower than the rate at which it’s washed away. Keeping as much soil as possible in place requires vigilance to a lot of different areas. For the sake of agriculture, property, and commerce, it is essential that we keep soil where it belongs.