Soil Erosion Threatens Long-Term Agricultural Productivity
Definition
Soil erosion
Soil erosion is a gradual process of movement and transport of the upper layer of soil (topsoil) by different agents – particularly water, wind, and mass movement – causing its deterioration in the long term
- As the nutrient-rich topsoil essential for plant growth is removed, this reduces crop yields and increases dependency on fertilizers.
Causes of Soil Erosion
- Deforestation and Overgrazing: Exposing soil to wind and water.
- Intensive Tillage: Weakening soil structure through frequent plowing.
- Poor Water Management: Uncontrolled irrigation washes soil away.
Solutions to Combat Soil Erosion
- Contour Farming: Planting along land contours reduces runoff.
- Cover Crops: Protect soil between harvests, improving structure.
- Terracing: Stepped fields slow water flow, reducing erosion.
Terracing in China’s Loess Plateau reduced soil erosion by 60%, restoring fertility and boosting crop yields.
Leaching Depletes Nutrients Critical for Fertile Soil
Definition
Leaching
Leaching refers to the loss of water soluble plant nutrients from the soil due to rain and irrigation.
- This occurs when water washes away nutrients like nitrates and phosphates, leaving soil infertile.
Causes of Leaching
- Excessive Rainfall or Irrigation: Nutrients are carried beyond plant roots.
- Monoculture Farming: Repeatedly growing the same crop depletes specific nutrients.
Solutions to Minimize Leaching
- Crop Rotation: Alternating crops balances nutrient use.
- Organic Matter Addition: Compost improves soil structure, reducing leaching.
- Precision Irrigation: Targeted watering minimizes nutrient loss.
Leaching increases fertilizer dependency, driving up costs and environmental risks.
Fertilizers Must Be Used Sustainably to Avoid Harm
Definition
Fertilizers
Fertilizers refer to natural or artificial substance containing the chemical elements that improve growth and productiveness of plants
- Overuse of fertilizers harms ecosystems and raises costs for farmers.
Challenges of Fertilizer Overuse
- Eutrophication: Excess nutrients in water bodies cause algal blooms, depleting oxygen.
- Soil Acidification: Long-term synthetic fertilizer use lowers soil pH.
- Dependency: Farmers rely on fertilizers instead of sustainable practices like crop rotation.
More on eutrophication and leaching in the next section.
