Degraded soil typically loses its ability to supply necessary food and habitation to other living organisms. Soil quality refers to the richness of dirt and its ability to perform its ecological functions. In contrast to degraded soils, healthy soils are rich in organic matter built out of carbon that plants pull into the soil due to photosynthesis. This carbon-rich organic matter acts as fuel to help soil organisms recycle and release mineral materials. Natural processes, such as heavy wind or rainfall, can wash away valuable topsoil and degrade soils over time. The valuable organic matter lies in the topsoil that can get washed away with the rain. However, human activity is the cause of much soil degradation. Conventional agricultural activities can degrade soil through chemical usage, which impacts soil alkalinity or salinity. Due to human farming activity, which has degraded vast quantities of agricultural lands, nutrient levels in foods have depleted from 10 to 100 percent in the past seventy years. The process of soil restoration is an ecological restoration procedure that creates new soil and regenerates degraded soils by improving the structure, increasing microbial life, retaining more carbon than is depleted to regulate carbon levels and maintain proper water and nutrient cycling. Human activity has depleted the quality of soil at an alarming rate due to increased agricultural activity to meet an ever-increasing population and demand for food and fiber.
Erosion is one of the most severe threats facing urban soil quality today. Erosion, which produces sediment, is greatly accelerated in the presence of degraded soils. Plowing and tilling from human activity and macro-agriculture has eroded the quality of soils by 10 to 100 times the natural rate. In the past ten years alone the US corn belt may have lost half of the valuable, nutrient-rich topsoil necessary for crop planting that natural processes have produced over thousands of years. Restoring the quality of soils can be an enormous task, especially for communities dominated by small, resource-poor landholders. Several different methods can be employed to restore degraded soils.
Soil remediation is the process of removing harmful contaminants such as sewage sludge, heavy metals, petroleum, liquors, and carcinogenic hydrocarbons from tarnished soil. This process is achieved through various methods — for example, by exposing the soil to extreme temperatures, the harmful contaminants are removed through thermal soil remediation. Typically, soils that have been contaminated water or hydrocarbon compounds such as oil or other petroleum products are placed in a Primary Treatment Unit (PTU), such as an oven, fed by a conveyor belt. Baking the soil allows these toxic elements to evaporate to enable the polluted plants to take root. Especially in dry areas, constant ground cover can be highly beneficial for trapping moisture in the soil that would evaporate without the organic ‘lid’ to keep it inside.
Methods of land management, namely conservation agriculture, is another salient method of soil regeneration. Certain agricultural practices are more egregious than others in depleting the soil of the carbon it needs to be fertile, such as monocropping, where one crop is harvested in a field season after season, which causes significant strain on the soil, reducing organic matter. When the same tract of land is cultivated for the same crop year-round with no breaks, the relevant nutrients in the soil become severely depleted. Monocropping also often necessitates synthetic fertilizers because of depleted soils and pesticides to control organic agents such as soil fungi, insects, and other agricultural nuisances. Instead, conservation agriculture approaches attempt to limit the “harm” these agricultural techniques inflict on the soils they till and improve it through technologies that regenerate the depleted soils. Many conservation agriculturists stress the benefits of planting ‘perennial crops’ – which differ from annual crops in that they do not need to be replanted each year because they automatically grow back. Perennial crops can live year-round, their roots living through the ground throughout winter, and therefore not requiring fertilizers and pesticides for replanting.
In contrast to remediation techniques, which aim to extract contaminants from soils to filter degrading soil contaminants, encapsulation stops contaminants from spreading further. Instead of filtering soil, encapsulation separates it. The process is somewhat akin to a soil ‘quarantine.’ Contaminated soils — that is, those containing pesticides, heavy metals, or oil products — are mixed with cement, lime, or concrete to stop them from mixing with other soils and spreading the contaminants to any different exposable soils. Encapsulation effectively ensures that contaminants do not spread to rescuable parts of the soil but treating soils with agents such as concrete or lime makes that soil unavailable for cultivation. Therefore, if you consider encapsulation, make sure that you are using it on soil that you do not intend to cultivate. When treated with an encapsulation method, the soil is not recyclable, so it should only be used as a ‘last resort’ method, especially in agricultural contexts. Remediating soil is one of the first steps humans can take to mitigate the damage we have done to our planet’s farmlands. Restoring degraded soil is achievable, and in fact, maintaining healthy soil is paramount to cultivating our well-being and life on earth. At Erosion Control, we offer soil restoration services in areas of topsoil depletion. Contact us for more information and receive detailed information on how our products can change your next project!
Bryan Hall is the managing member of EnvirolokWest, dba Erosion Control USA.