Soil surface compaction

Soil surface compaction refers to the compression and consolidation of the upper layer of soil, typically caused by external forces or activities. It occurs when the soil particles are pressed together, reducing the pore spaces and air-filled voids within the soil. This compaction can make the soil denser, harder, and less permeable.

Soil surface compaction is considered a form of land degradation because it can have various negative effects on soil health, ecosystem functioning, and agricultural productivity. Here are major reasons of concern:

• Reduced water infiltration: Compacted soils have reduced pore spaces, which restrict the movement of water into the soil. This leads to reduced water infiltration rates, increased surface runoff, and decreased soil moisture levels. As a result, plants may experience water stress, and the risk of erosion and flooding can increase.

•  Impaired root growth and nutrient uptake: Compacted soil can restrict root growth and penetration into the soil profile. Roots may encounter physical barriers that hinder their development and prevent access to water and nutrients deeper in the soil. This can limit plant growth, reduce crop yields, and negatively impact ecosystem productivity.

• Decreased soil aeration: Soil compaction reduces the availability of oxygen within the soil. Plants, microorganisms, and soil fauna require oxygen for respiration and metabolic processes. Insufficient soil aeration can lead to the depletion of beneficial soil organisms, reduced decomposition rates, and alterations in nutrient cycling dynamics.

• Altered soil structure: Compacted soils often exhibit poor soil structure, characterized by diminished aggregation and increased soil bulk density. This affects the arrangement of soil particles, reducing pore spaces necessary for water movement, root penetration, and gas exchange. It also results in reduced soil porosity, impeding the movement of water, nutrients, and soil organisms.

• Increased surface runoff and erosion: Compacted soils have a reduced ability to absorb and retain water. As a consequence, surface runoff increases, carrying away topsoil, nutrients, and agrochemicals. This can lead to soil erosion, loss of fertile topsoil, and degradation of water quality in nearby streams, rivers, and lakes.

• Decline in soil biological activity: Soil compaction can negatively impact soil organisms, including earthworms, beneficial bacteria, fungi, and other microorganisms. These organisms play crucial roles in nutrient cycling, organic matter decomposition, and overall soil fertility. Reduced biological activity can disrupt these processes, leading to a decline in soil health and fertility.

Overall, soil surface compaction can degrade soil quality, diminish ecosystem services, and impair agricultural productivity. It is essential to implement proper soil management practices, such as minimizing heavy machinery use, avoiding excessive tillage, and employing soil conservation measures, to prevent or mitigate the adverse effects of soil surface compaction.