Soils in the world degrade generally from human induced activity like logging, mining, drilling (for oil or natural gas), accidental spills or farming. However, nature can also degrade soils with changes in landscape and water levels.
Once soils are degraded, they are no longer productive. They cannot support natural vegetation or soil life. These soils can be remediated, but it takes effort, time, resources and a strategy. Soil remediation aims to reduce contaminants to levels which are suitable for reuse. This means a site can be reused without environmental risks or risks to human or other organisms that inhabit this planet.
Soil remediation is a term describing various strategies that are used to remediate and revitalize soil. Remediation deals with the removal of pollution or contaminants from the soil, groundwater, sediment, or surface water. Remediation protects the general environment and most importantly, returns it to a natural state of agricultural production. Some of the removed pollutants can be hydrocarbons (petroleum), heavy metals, salts or rocky parent material.
Soil degradation is caused by a lot different things. A host of technologies is available for correcting the problem based on the nature of the contaminant. Gypsum (calcium sulfate) can play a role for both industrial and agricultural remediation.
Soil remediation depends in part on soil biology that can do wonders to degrade carbon-based contaminants and rebuild soil structure and health. Gypsum can help improve soil structure and create a better environment for soil biological activity.
Gypsum is also an excellent choice for remediation of salinity and soils high in sodium and contaminated by salt brine. Salts and brine impact the soil by:
- Dispersing soil particles, which destroys aggregation
- Reducing the plant’s ability to take up water (osmotic potential)
- Impeding a plant’s ability to take up necessary nutrients
The Impact of Sodium on Soil Health and How Gypsum Can Help
Salts are simply ionic forms of minerals dissolved in soil water, and while many salts are essential for plant growth in trace amounts, excessive sodium can have a detrimental effect on soil health. Sodium, as a salt, is particularly troublesome because when its levels rise in soil, it leads to several significant issues that can severely impact soil structure, plant growth, and overall agricultural productivity. High concentrations of sodium in the soil cause a range of problems, including reduced water infiltration, loss of soil structure, and decreased pore space. These changes make it harder for both air and water to move through the soil, resulting in poor root development and reduced biological activity. Additionally, sodium-induced soil degradation can impair the movement of nutrients via mass flow, leaving plants with insufficient access to essential elements. Ultimately, these effects lead to increased runoff and erosion, further exacerbating soil degradation and causing long-term challenges for farmers.
The first step in alleviating the damage caused by high sodium levels is improving soil structure and functionality, which can be achieved through the use of gypsum. Gypsum (calcium sulfate dihydrate, CaSO₄ + 2H₂O) is a natural soil amendment known for its ability to help remediate sodium-affected soils. One of the main benefits of gypsum is its ability to replace sodium ions with calcium ions on the soil’s cation exchange complex. The calcium in gypsum binds to the soil particles, displacing sodium and allowing it to be flushed away with water. This process, called soil dispersion, helps break up compacted soils, improving their structure and allowing water and air to penetrate more effectively.
The effect of gypsum on soil structure goes beyond just replacing sodium with calcium. By improving soil aeration and drainage, gypsum facilitates better water infiltration, which is crucial for healthy plant root systems. With improved water movement, both surface and subsoil water can reach deeper into the root zone, promoting better plant growth and enhancing nutrient uptake. This is particularly important in areas where soils have become waterlogged or overly compacted due to high sodium levels. Furthermore, gypsum’s impact on water infiltration helps reduce surface runoff and erosion, which can carry away valuable topsoil and nutrients.
Dr. Davidson posts articles on soil management and subjects to gypsum. If you have suggestions for topics or questions, feel free to contact him at djdavidson@goodearthminerals.net or call 402-649-5919.