Soil Quality
Soil is a renewable resource, but only on a very long time scale, as it takes hundreds or thousands of years for the natural processes of erosion, organic decay, and accumulation to create soils. Soil quality and the potential to produce crops can vary enormously from region to region and among various soil types.
One important factor affecting the productivity of soils over time is agriculture. Top- quality lands are brought into production earlier because of their higher potential to produce food. As more and more land has been brought under agricultural production, the average quality of land has decreased, reducing potentialproductivity per hectare. Crops deplete soil fertility by consuming nutrients, and this eventually reduces crop yields. Poor management practices lead to soil compaction and soil pollution as well as loss of soil cover. Without proper management and the constant addition of nutrients and energy in the form of fertilizers and irrigation, crop production falls over time.
Within the scientific community, there is little doubt that soil quality is diminishing in many areas around the world. Scientists have found that the quality of one quarter of the world’s soils has experienced some degradation, and the pace of degradation has accelerated over the past 50 years. The loss of soil fertility has caused a slowing in the growth of agricultural productivity. Annual crops tend to degrade soils more than perennial crops, and common property lands generally suffer more degradation than private lands.
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