Grade 8 Notes CBC Junior Secondary 2024
SOIL CONSERVATION:
INTRODUCTION
Soil provides the nutrients essential for plant growth, animal life, and millions of microorganisms. However, if soil becomes unhealthy, unstable, or polluted, the life cycle stops.
Soil conservation refers to the protection and management of soil resources to prevent their degradation and promote sustainable land use practices. aef
It is an important field of study and practice aimed at preserving the productivity, fertility, and health of soils for future generations.
Soil is a vital natural resource that plays a crucial role in supporting plant growth, water filtration, carbon storage, and providing a habitat for various organisms.
Threats to soil conservation
The primary threats to soil conservation are
Chemical contamination
The use of pesticides can contaminate the soil, as well as nearby vegetation and water sources, with harmful chemicals. In addition to contamination, chemicals used on crops can be toxic to important beneficial insects, such as bees, as well as fish and bird populations. A Good example `is the growing use of pesticides, herbicides and toxic fertilizers.
Slash and burn
Slash-and-burn farming is the practice of burning and clearing forests to make way for farmland. This method kills plant species and displaces wildlife from their natural habitats. Land cleared using slash and burn is only used while it’s productive for farming. Once it loses its fertility, another patch of forest is identified for clearing. This unsustainable process repeats endlessly, preventing soil from recovering sufficiently to support healthy ecosystems.
Land overuse, overgrazing, etc.
Overuse of land can limit soil’s ability to play its part in the global climate cycle. For example, overcutting forests and woodlands for timber and overgrazing pastures can far outpace the natural regrowth of vegetation, subjecting soil to increased exposure to erosion
Grade 8 Notes CBC Junior Secondary 2024
Importance of Soil Conservation
Soil conservation is of paramount importance due to the following reasons:
Preserving Agricultural Productivity: Healthy and fertile soil is essential for sustaining agricultural productivity. Soil conservation practices help prevent soil erosion, nutrient depletion, and degradation, ensuring that the land remains productive for farming. By conserving soil, we can maintain high yields, improve food security, and support sustainable agriculture.
Protecting Ecosystems and Biodiversity: Soil is a crucial component of terrestrial ecosystems, supporting diverse plant and animal life. Soil conservation helps preserve natural habitats, including forests, grasslands, and wetlands, which are home to a variety of species. By protecting soil, we maintain the balance of ecosystems and safeguard biodiversity.
Water Quality and Quantity: Healthy soil acts as a natural filter, purifying water as it infiltrates through the soil layers. Soil conservation practices reduce runoff and erosion, preventing sediment and pollutants from reaching water bodies. By preserving soil, we maintain water quality, prevent contamination, and ensure the availability of clean water resources.
Climate Change Mitigation: Soils play a significant role in mitigating climate change through carbon sequestration. Healthy soils store organic carbon, helping to reduce greenhouse gas emissions in the atmosphere. By practising soil conservation, such as promoting organic matter content and reducing soil disturbance, we enhance carbon storage and contribute to climate change mitigation efforts.
Mitigating Soil Erosion: Soil erosion is a natural process, but human activities can accelerate it to alarming levels. Erosion leads to the loss of topsoil, which contains essential nutrients for plant growth. Soil conservation practices, such as contour ploughing, terracing, and cover cropping, help control erosion and preserve valuable topsoil, ensuring long-term land productivity.
Methods of Soil Conservation
There are several effective methods and techniques for soil conservation. Here are some commonly used methods: Grassed waterways
gr (sometimes also called grass waterways) are wide, shallow channels that are installed where water runoff usually concentrates in an agricultural field. They are planted with permanent vegetation, meaning they might be mowed, but the plants are never plowed or killed intentionally
Stone lines are constructed along the contours to slow down the speed of runoff, reduce soil erosion, and enhance water infiltration. In addition, the stone barrier blocks and settles down the sediments transported from the upper slopes. Stone constructions are often used to rehabilitate eroded and abandoned land
Trash lines are ideally 0.5m to 1.0m wide and 0.5m high. Advantages of using trash lines They conserve top soil by trapping or reducing the speed of run-off. When they compose they turn into manure and boost soil fertility. Trash lines increase soil water infiltration since they tend to hold the water longer
Bund is an engineering measure of soil conservation, used for creating obstruction across the path of surface runoff to reduce the velocity of flowing water. It retains the running off water in the watershed and thus to helps to control soil erosion. Bunds are simply embankment like structures, constructed across the land slope
Grade 8 Agriculture Notes For Junior Secondary(JSS)- CBC
Crop rotation
Instead of planting the same crop year after year on the same plot of land, crop rotation involves planning out growing seasons for different crops. This method of sustainable agricultureExternal link:open_in_new requires long-term planning, with crops changed every season. In addition to improving soil health and organic matter, crop rotationExternal link:open_in_new reduces the need for fertilizer and pesticides, lowering costs. It also helps prevent excess chemicals from entering water supplies, improving water quality.
Contour Plowing: Plowing along the contour lines of the land helps to slow down water runoff, reduce erosion, and retain moisture in the soil. This technique involves creating furrows or ridges that follow the natural contours of the land.
Terracing: Terracing is the construction of broad, level platforms on steep slopes. By creating terraces, water runoff is slowed down, allowing it to infiltrate the soil and reducing erosion. Terraces also help to retain moisture and provide flat areas for planting crops.
Windbreaks: Windbreaks are rows of trees or shrubs planted along the edges of fields or across wind-exposed areas. They help to reduce wind speed, minimise wind erosion and protect the soil. Windbreaks also provide habitat for wildlife and contribute to biodiversity
Strip Cropping: Strip cropping involves planting different crops in alternating strips or bands across a field. This method helps to break up the flow of water and reduce erosion. The alternating strips of different crops also help to improve nutrient uptake and reduce pest and disease problems.
Conservation Tillage: Conservation tillage practices involve reducing or eliminating the amount of soil disturbance during planting and cultivation. This includes techniques such as no-till, where seeds are planted directly into untilled soil, and reduced tillage, where minimal soil disturbance occurs. Conservation tillage helps to maintain soil structure, reduce erosion, and conserve moisture.
Cover Crops: Planting cover crops, such as legumes or grasses, during fallow periods or between cash crops, helps to protect the soil from erosion, improve soil fertility, and increase organic matter content. Cover crops also capture nutrients, prevent weed growth, and enhance soil microbial activity.
Grade 8 Notes CBC Junior Secondary 2024
Mulching: Applying a layer of organic or inorganic material, such as straw, wood chips, or plastic, on the soil surface is known as mulching. Mulch helps to conserve soil moisture, reduce erosion, regulate soil temperature, suppress weed growth, and improve soil structure.
Conservation Buffer Strips: Buffer strips are areas of vegetation, such as grass or trees, established along the edges of fields, water bodies, or sensitive areas. These strips act as barriers, filtering runoff, reducing erosion, and preventing the movement of pollutants into water bodies.
Nutrient Management: Proper nutrient management is essential for soil conservation. It involves applying fertilizers based on soil nutrient testing and crop requirements to avoid over-application, which can lead to nutrient runoff and pollution. Balanced nutrient management helps maintain soil fertility, minimize nutrient losses, and protect water quality.
