Soil Fertility Affected by Human Activities

Factors Affecting Soil Fertility

Deforestation

The removal of trees in mass quantities can lead to significant soil erosion; deep tree roots bind the soil together and control water flow.
Without vegetation, soil fertility can decrease due to nutrient loss and increased water runoff, leaving the soil highly vulnerable to erosional processes.
Deforestation also disrupts natural nutrient recycling from decayed vegetation, compromising soil’s nutrient composition.

Agricultural Practices

Excessive use of fertilisers can lead to nutrient overload in soil, causing imbalanced soil health and increased run-off of nutrients. This contributes to problems like eutrophication.
Over-cultivation and intensive farming practices disturb and degrade soil structure, accelerating erosion and lowering fertility.
Rotation of crops can increase soil fertility by optimising the nutrition uptake from the soil and disrupting pest and disease cycles.
Inappropriate irrigation methods can lead to build-up of salts in the soil (salinisation), causing fertility loss over time.

Industrialisation

Industrial pollutants such as heavy metals and chemical waste can contaminate soils and degrade soil health and fertility.
Emissions of sulphur and nitrogen oxides increase soil acidity, reducing availability of essential nutrients and eradicating beneficial soil organisms.

Urbanisation

Land development and construction compact the soil, reducing its permeability, and hence its ability to retain water and other vital nutrients.
Sealing of the soil by impervious surfaces disrupts the natural soil processes and nutrient cycling, affecting soil fertility.

Climate Change

Changes in climate patterns and severe weather events can significantly affect soil fertility. Increased temperature accelerates organic matter decomposition, increasing nutrient turnover, while extreme rain events can wash away surface soil and nutrients.
Long periods of drought can lead to degradation of soil structure and fertility, primarily through the loss of organic matter and breakdown in soil structure.

Waste Disposal

Unregulated dumping of waste, especially in developing countries, can lead to soil degradation. Certain hazardous wastes can also contaminate the soil with toxic substances, making it infertile.
Conversely, well-managed composting of organic waste can improve soil fertility by adding beneficial organisms and essential nutrients.