Soil erosion or degradation is a natural process. It becomes a problem when human activity causes it to occur much faster than under natural conditions.

Soil quality and abundance depends on limiting the causes and effect of the various soil degradation processes. There are a number of ways that this can be done: Wind reduction techniques Cultivation techniques Soil conditioners Efforts to stop ploughing of marginal lands These techniques are not necessarily totally successful individually but can have a greater effect when applied together.

WIND REDUCTION TECHNIQUES Wind is a major cause of soil erosion. Top soils take a very long time to form. Over a one hundred year period only a couple of millimetres of soil may be formed. This soil can then be quickly eroded by even modest winds. There are a number of ways that this can be reduced: 1.SHELTER BELTS This involves planting trees or hedges to act as a wind barrier to a crop or field. They can reduce the wind speed by up to 50% and so reduce soil movement in the protected area.

2. WIND BREAKS Wind breaks are barriers used to reduce and redirect wind. They usually consist of trees and shrubs but can also be crops, grasses, fences or other materials.

3. STRIP CULTIVATION This is the cultivation / planting of a relatively narrow strip of land. On sites where there is a steep topography and erodible soils, the method can assume the role of a soil and water conservation measure. In this case, it should consist of contour ploughing on a narrow band of sloping land. It can have the following benefits: -it increases infiltration and conservation of rain water falling prior to and immediately after planting; -it increases the amount of nutrients, especially nitrogen, by breaking down and incorporating organic matter in the soil; - it reduces weed growth which impairs the development of young planted stock by competing with them for soil moisture, nutrients and light.

CULTIVATION TECHNIQUES Human use of the land is a major contributor to soil degradation but altering the way in which the land is used can help to reduce the degradation processes. 1.TERRACING In agriculture a terrace is a levelled section of a hilly slope, often such land is formed into multiple terraces giving a stepped appearance. This is a useful method of soil conservation as it slows or prevents the rapid surface run off of water that occurs on steep slopes.

2. CONTOUR PLOUGHING Ploughing at right angles to the natural slope of the land to create a series of stepped ridges used for planting crops. It reduces the flow of water (runoff) across the land surface, thus reducing erosion. What are its benefits? Soil erosion can be reduced by as much as 50% Increased soil retention encourages root development, binding the soil and preventing erosion. Limits the release of nutrients/particulates into nearby river systems or lakes, minimising harmful effects such as eutrophication. Can disrupt wind currents, therefore reducing wind erosion. What are its restrictions? Stepped topography may hinder modern (mechanised) farming practices.

SOIL CONDITIONERS Soil conditioners are materials added to soil to improve plant growth and health. The type of conditioner added depends on the current soil composition, climate and the type of plant. Some soils lack nutrients necessary for proper plant growth and others hold too much water or too little water. A conditioner or a combination of conditioners corrects the soil’s deficiencies. E.g. LIME can be added to soil to make it less acidic. Organic materials can be added to soil to replace depleted plant nutrients.

STOPPING PLOUGHING OF MARGINAL LANDS What are marginal lands? In farming, poor-quality land that is likely to yield a poor return. If demand for land increases, marginal areas become pressured into use to grow food. Why is it not a good idea to plough this land? This is land that is poor in quality and will not support much plant life for long. As a result it is then left bare and vulnerable to increased soil erosion.