Soil Conservation - 1 | Agriculture Optional Notes for UPSC PDF Download

Soil Conservation

Soil conservation involves implementing strategies to halt the erosion of the uppermost layer of soil or to protect the soil from losing its fertility due to soil pollution. In simpler terms, soil conservation aims to counteract or at least alleviate the consequences of soil pollution.

Soils are the result of extensive processes, including chemical, physical, and biological processes acting on regoliths over millions of years. They consist of minerals, organic matter, air, and water. The organic matter in soil is the residue of decaying plant material that decomposes through the activities of microorganisms.

Soil conservation is crucial because the formation of the topmost soil layer has taken tens of thousands of years. Even a mere inch of soil requires more than a millennium to develop. Given the limited availability of soil, it is essential to take measures to prevent soil loss due to erosion. Furthermore, soil serves as the foundation of life; it supports plant growth, provides habitats for numerous insects and animals, and facilitates water percolation to maintain groundwater levels.

Types of Soil Conservation Methods

Here are some of the major soil conservation methods that will help us in preventing the loss of the top layer of soil: 

Salinity Management 

Unscientific irrigation practices can significantly raise soil salinity levels. Excessive fertilizer use can also contribute to soil salinity. This occurs because salt remains in the soil when water evaporates in the sunlight. Consequently, the salt content in the soil surpasses acceptable levels, potentially leading to soil degradation and desertification by disrupting the soil structure. Excessive irrigation exacerbates the issue by causing salt to accumulate on the soil surface through water infiltration.

To address soil salinity, it is possible to manage and maintain the salt levels within permissible limits. Humic acids are effective in preventing salinity issues, particularly in cases of over-irrigation. Humic acid helps regulate anions and cations, eventually relocating them away from the root zones. This approach reduces the water table and diminishes the process of surface salt accumulation through evaporation. Additionally, planting species that can tolerate saline conditions is another viable solution.

Afforestation

Afforestation, which involves planting more trees, is a straightforward and effective method of soil conservation. This age-old practice helps prevent soil erosion by firmly anchoring the soil to the ground through the roots of plants and trees, thus preventing erosion caused by agents such as wind and water runoff.

Studies have shown that regions with a high density of trees experience less erosion compared to areas with fewer trees. Certain tree species offer substantial protection to the soil, even in the face of strong winds and floods, while others provide more moderate protection. The 2018 draft forest policy underscored the importance of maintaining forest cover over 33% of India's geographical area.

Controlling Overgrazing

Overgrazing is an unsustainable farming practice in which a large number of cattle graze intensively on a limited area of land. This activity disrupts the soil's stability and exposes the topsoil to erosion agents like wind, rain, and water runoff. The rate of plant regrowth cannot keep pace with grazing, leading to land exposure and severe erosion.

To address the problem of overgrazing, it is essential to closely monitor grasslands and forests. Farmers should be prohibited from grazing their cattle in areas where the soil is exposed. Grazing activities should be regulated and restricted to designated areas.

Utilizing Natural Fertilizers

Chemical fertilizers contain high levels of salt and chemicals, posing a risk of land acidification and desertification. Consequently, it is advisable to opt for natural fertilizers in agriculture instead of chemical alternatives. Natural fertilizers are not only less polluting but also enhance crop productivity to a greater extent.

They replenish the soil with essential nutrients like phosphorus, potassium, and nitrogen, while also providing organic matter to improve soil health. Examples of natural fertilizers include livestock manure, municipal sludge, mulch, and legume plants.

Changing Agricultural Practices 

Traditional farming methods have been found to strain the soil and expose it to erosion risks. Scientific studies show that practices like mono-cropping, excessive fertilizer use, and tillage have exacerbated soil erosion globally. In light of these findings, it is crucial to reconsider our agricultural practices.
Here are various soil conservation methods related to agriculture:

• Strip Cropping: In strip cropping, crops are grown in narrow parallel strips. The key benefit is that farmers can harvest crops at different times. Once one strip is harvested, the next one is ready for harvesting. This approach minimizes the fallow periods, reducing the vulnerability of the land to soil erosion.
• Crop Rotation: Crop rotation involves cultivating different types of crops each year. Instead of growing the same crop repeatedly, farmers switch to various crops annually. This practice maintains soil nutrient levels and can enhance soil health. Leguminous plants, in particular, contribute nitrogen to the soil, improving its productivity.
• Contour Ploughing: This technique is used on sloping terrain to reduce soil erosion. Furrows are designed to follow the contour lines of the land, preventing excessive surface runoff by maintaining a consistent altitude. Ploughing is done at right angles to the natural hill contours. Furrows and ridges break the momentum of downhill water flow, protecting the soil from erosion and boosting crop yield through improved moisture retention and water absorption.
• No Till Farming: Traditional tillage practices can harm the soil. No-till farming involves planting crop seeds directly into the residue of the previous crop, eliminating the need for tilling the soil. This method reduces the risk of soil erosion since the soil is exposed only during planting.
• Addressing Shifting Cultivation: Shifting cultivation, mainly practiced by tribal communities, involves clearing dense vegetation for farming. This practice contributes to deforestation. Encouraging settled agriculture among tribal communities, providing modern farming tools, equipment, and training on natural fertilizers, can help maintain soil fertility while protecting forests.
• Windbreaks: Planting rows of trees, especially on the windward side of agricultural fields, acts as a barrier to protect against strong winds that can lead to soil erosion. Trees can also generate additional income for farmers by selling their products.
• Terrace Farming: Terrace farming involves creating a series of stepped levels on hill slopes, each higher than the previous one. Soil barriers are installed on every terrace to prevent soil erosion. This method is popular in hilly regions with high runoff potential, effectively conserving soil, especially on smaller farms.