Soil organic matter decline

Soil organic matter decline is indeed considered a form of land degradation. Land degradation refers to the deterioration of the physical, chemical, and biological properties of the land, leading to a decline in its productivity and functionality. Soil organic matter decline refers to the reduction in the amount and quality of organic matter present in the soil.

Here are the main concern about soil organic matter decline:

• Nutrient depletion: Organic matter is a vital source of nutrients for plants. It acts as a reservoir of essential elements like nitrogen, phosphorus, and potassium, as well as micronutrients. When soil organic matter declines, the availability of these nutrients decreases, limiting plant growth and productivity. This can lead to nutrient deficiencies and decreased crop yields.

• Soil structure degradation: Organic matter plays a crucial role in maintaining soil structure. It improves soil aggregation, which helps create pore spaces and allows for better water infiltration and root penetration. When soil organic matter declines, the soil structure can deteriorate, resulting in increased compaction, reduced water-holding capacity, and poor drainage. These changes negatively affect plant root development, nutrient uptake, and overall soil health.

• Erosion susceptibility: Soil organic matter contributes to soil stability by enhancing its resistance to erosion. It acts as a binding agent, holding soil particles together and reducing the risk of erosion by wind or water. When organic matter declines, soil becomes more susceptible to erosion, leading to the loss of valuable topsoil. Erosion can result in decreased soil fertility and productivity, as well as increased sedimentation in water bodies.

• Decreased water holding capacity: Soil organic matter has the ability to hold water, acting as a sponge that retains moisture for plant use during dry periods. As organic matter declines, the soil's water-holding capacity diminishes, leading to increased water runoff and reduced water availability for plants. This can result in drought stress, reduced crop yields, and water scarcity.

• Reduced carbon sequestration: Organic matter in soil contains carbon, and its decline contributes to the release of carbon dioxide (CO2) into the atmosphere. Soil organic matter degradation is a significant source of greenhouse gas emissions, exacerbating climate change. Maintaining or increasing soil organic matter levels helps sequester carbon from the atmosphere, mitigating the impacts of climate change.

Overall, soil organic matter decline represents a loss of vital components that support soil fertility, structure, and ecosystem functions. It compromises agricultural productivity, soil resilience, and environmental sustainability, thereby qualifying as a form of land degradation. Efforts to prevent or reverse soil organic matter decline are essential for sustainable land management and food production.