Soil erosion

            
            
             Soil quality is one of the most basic and perhaps least understood indicators of land health. Soil supports plant growth and represents the living reservoir that buffers the flows of water, nutrients, and energy through an ecosystem. The ongoing degradation of the earth's soils by human activity, particularly agriculture, threatens human potential to feed a growing population. The annual global erosion amounts to about 36 billion tons, of which 10 billion are due to natural causes and 26 billion are the result of human activity (Crosson et al. 1995). The soil or runoff that has been eroded ends up in groundwater, lakes, streams, and rivers. The deposits of excess soil and the contaminates in it, cause further ecological complications. Bodies of water need to be dredged and monitored for contamination. Water levels are lowered with the increasing soil eroded into them, making our world's water supply a concern directly related to the erosion of soil. The process of soil renewing itself is largely unknown. However, there is consensus on the need for conservation. Evaluating the scope of the problem or predicting the effects that various solutions might have on agriculture and the environment is very difficult. Degradation is gauged for all soil in terms of compaction, erosion, nutrient loss and loss of organic matter. Soil quality refers to the capacity of a soil to perform these beneficial functions. Its texture, structure, water-holding capacity, porosity, organic matter content, and depth, among other properties determine a soil's quality. Because soils naturally vary in their capacity to perform these functions, we must tie our understanding of soil quality to landscapes and land use. We must understand soil quality for two important reasons: First, we must match our use and management of land to soil capability. Second, we must establish understanding about soil quality so we can recognize ongoing trends.