1. Write short note on Composition of soil. 2. what is soil erosion ? How can it avoided ?
Answers
Soil erosion is the displacement of the upper layer of soil; it is a form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, air (wind), plants, animals, and humans. In accordance with these agents, erosion is sometimes divided into water erosion, glacial erosion, snow erosion, wind (aeolean) erosion, zoogenic erosion and anthropogenic erosion.[1] Soil erosion may be a slow process that continues relatively unnoticed, or it may occur at an alarming rate causing a serious loss of topsoil. The loss of soil from farmland may be reflected in reduced crop production potential, lower surface water quality and damaged drainage networks.Soil erosion could also cause sinkholes.
An ismail eroding rill on an intensively-farmed field in eastern Germany
Human activities have increased by 10–50 times the rate at which erosion is occurring globally. Excessive (or accelerated) erosion causes both "on-site" and "off-site" problems. On-site impacts include decreases in agricultural productivity and (on natural landscapes) ecological collapse, both because of loss of the nutrient-rich upper soil layers. In some cases, the eventual end result is desertification. Off-site effects include sedimentation of waterways and eutrophication of water bodies, as well as sediment-related damage to roads and houses. Water and wind erosion are the two primary causes of land degradation; combined, they are responsible for about 84% of the global extent of degraded land, making excessive erosion one of the most significant environmental problems worldwide.[2][3]
Intensive agriculture, deforestation, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion.[4] However, there are many prevention and remediation practices that can curtail or limit erosion of vulnerable soils.
ANSWER:
Soil is one of the most important elements of an ecosystem, and it contains both biotic and abiotic factors. The composition of abiotic factors is particularly important as it can impact the biotic factors, such as what kinds of plants can grow in an ecosystem.
Soil contains air, water, and minerals as well as plant and animal matter, both living and dead. These soil components fall into two categories. In the first category are biotic factors—all the living and once-living things in soil, such as plants and insects. The second category consists of abiotic factors, which include all nonliving things—for example, minerals, water, and air. The most common minerals found in soil that support plant growth are phosphorus, and potassium and also, nitrogen gas. Other, less common minerals include calcium, magnesium, and sulfur. The biotic and abiotic factors in the soil are what make up the soil’s composition.
Soil erosion can be prevented by the following steps:⬇⬇⬇
Soil erosion can be prevented by afforestation and reforestation. Reforestation is restoration of forests, which have been destroyed by deforestation, while afforestation is planting of new forests. Plants hold soil with there roots and thus prevent erosion.
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