Syllabus
GS Paper 3 – Conservation, environmental pollution and degradation, environmental impact assessment.
Context
At a recent conference, UNESCO issued a warning that up to 90% of Earth’s land could face degradation by 2050.
Soil Degradation
Introduction
Soil degradation is a critical environmental issue, exacerbated by unsustainable agricultural practices, deforestation, and climate change. Recent reports highlight alarming trends, such as the FAO’s warning that 90% of Earth’s topsoil could be at risk by 20501. In the U.S. Midwest, soil erosion rates have become unsustainable, threatening future crop production2. These developments underscore the urgent need for global action to protect and restore soil health, ensuring food security and environmental sustainability for future generations.
Soil and Soil Degradation
Soil is a material composed of minerals, living organisms, soil organic matter, gas, and water. Soil degradation refers to the loss of the intrinsic physical, chemical, and/or biological qualities of soil due to natural or anthropogenic processes, leading to the reduction or elimination of important ecosystem functions. Currently, a third of the world’s soils are degraded, and in India, approximately 29.7% of land is degraded.
Importance of Soil
- Nutrient Supply: Soil provides essential nutrition for plants to grow and offers a foothold for their roots.
- Water Filtration: It filters rainwater and helps in recharging groundwater.
- Water Regulation: Soil regulates the discharge of excess rainwater, preventing flooding.
- Carbon Storage: It can store large amounts of organic carbon.
- Greenhouse Gas Regulation: Soil helps regulate the emissions of carbon dioxide and other greenhouse gases.
Causes of Soil Degradation
The leading causes of soil deterioration include wind and water erosion, deforestation, and urbanization.
- Soil Erosion: Soil erosion involves the displacement of the top layer of soil, primarily due to wind and water forces. While these are natural processes, excessive erosion can lead to significant soil depletion.
- Deforestation and Overgrazing: Deforestation and overgrazing are major human activities contributing to soil depletion. These practices remove vegetation cover, making soil more vulnerable to erosion. These activities disrupt the biological balance of soil, reducing microbial activity and organic matter content.
- Urbanization: Urbanization results in high levels of pollution and reduced agricultural productivity, indirectly causing soil deterioration.
- Wind and Water Erosion: Physical forces like wind and water displace soil particles, leading to erosion and loss of soil structure.
- Pollution: Urbanization introduces pollutants that alter soil chemistry, reducing its fertility and productivity.
Impacts of soil degradation
- Loss of Fertile Soil: Degradation reduces the soil’s ability to supply essential nutrients to plants, leading to decreased agricultural productivity.
- Global Soil Degradation: According to the World Atlas of Desertification, 75% of soils are already degraded, directly affecting 3.2 billion people.
- Soil Compaction: Heavy machinery, overgrazing, and deforestation can compact the soil, reducing its ability to hold water and air. Compacted soils have poor drainage and root penetration, negatively impacting plant growth.
- Health of Living Organisms: The use of pesticides, herbicides, and industrial pollutants can contaminate the soil, affecting its health and the health of plants, animals, and humans that rely on it.
- Loss of Soil Inorganic Carbon: Depletion of soil inorganic carbon can hurt the soil’s ability to regulate nutrient levels, foster plant growth, and store carbon. In India, soil acidification might lead to the loss of 3.3 billion tonnes of soil inorganic carbon from the top 0.3 meters of soil over the next 30 years.
- Decreased Productivity: Acidic soils affect crop growth and productivity by reducing the availability of plant nutrients. Low pH levels dissolve solid carbonate, releasing it as carbon dioxide gas or directly into the water, and predispose plants to other biotic and abiotic stress factors.
- Threat to Food Security: Soil erosion and land degradation pose a major threat to global food security and the achievement of the UN-mandated SDGs, compromising the well-being of at least 3.2 billion people worldwide. The loss of a few inches of topsoil can lower crop yields by 50%.
Measures by UNESCO for Conserving Soil
- World Soil Health Index:
- UNESCO has pledged to support its member states by establishing a World Soil Health Index.
- This index will help to standardize measures for analyzing and comparing soil quality in different regions and ecosystems.
- Long-term Soil and Landscape Management:
- Planned as a pilot project in ten natural sites, this initiative is supported by UNESCO’s Biosphere Reserves Programme.
- It will assist in assessing the management methods used on these sites and ensure that best practices are developed and implemented in other parts of the world.
Way forward
- Practice conservation tillage: Reducing the frequency and intensity of tillage helps preserve soil structure, reduces erosion, and maintains organic matter. Techniques such as no-till or minimum-till farming can be adopted.
- Cover crops: Planting cover crops during off-season periods helps protect the soil from erosion, improves soil structure, adds organic matter, and enhances nutrient cycling.
- Promote Agroforestry: Integrating trees and shrubs into agricultural landscapes provides multiple benefits, including improved soil structure, increased organic matter, reduced erosion, and enhanced biodiversity.
- Follow terracing and contour farming: On sloped land, terracing and contour farming can reduce soil erosion by slowing down water runoff and promoting water infiltration.
- Enhance soil testing: Regular soil testing helps determine nutrient needs and prevent over-application of fertilizers.
- Control usage of fertilizers: Using balanced fertilization practices maintains soil fertility without causing pollution.
- Create awareness: The United Nations Food and Agricultural Organization (FAO) declared December 5 as ‘World Soil Day’.
Conclusion
Soil degradation is a critical issue that poses significant threats to agricultural productivity, environmental health, and global food security. The loss of fertile soil, compaction, contamination, and depletion of essential nutrients all contribute to the decline in soil quality. This degradation affects not only plant growth but also the health of animals and humans who depend on these ecosystems. Efforts to combat soil degradation, such as conservation tillage, cover cropping, agroforestry, and balanced fertilization, are essential for maintaining soil health and ensuring sustainable agricultural practices. By raising awareness and implementing effective soil management strategies, we can work towards preserving this vital resource for future generations.
Source: Down to Earth
Related PYQ
What are the impediments disposing the huge quantities of discarded solid waste which are continuously being generated? How do we remove safely the toxic wastes that have been accumulated in our habitable environment? [UPSC Civil Services Exam – 2018 Mains]
Practice Question
Discuss the major causes of soil degradation and suggest effective soil management measures to combat this issue. (150 words)