 |  Environmental Science: A Global Concern, 7/e William P. Cunningham,
University of Minnesota
Mary Ann Cunningham,
Vassar College
Barbara Woodworth Saigo,
St. Cloud State University
Food and Agriculture
BE ALERT FOR: Nature of Soil
Take time to understand that soil is not simply dirt, any loose, fine-grained mineralized covering of earth. Your text describes soil as a rich, complex mixture of mineral particles obtained from weathered rock, organic substances in various stages of decay, and an interactive web of living organisms. In fact, soil could be considered an ecosystem unto itself.
Thanks to the actions of diverse fungi, the absorption of minerals is enhanced. Animals, from worms to mites to insects, move through the soil, aerating it and helping to give it a structure hospitable to the penetration of plant roots. Decomposers, of course, move materials from the bodies of dead organisms back into soil compartments from which they can be recycled into new growth. The result of all this activity is a slowly renewable resource, perpetually available if it is managed properly.
A number of specific farming practices lead directly to increased soil loss. You are learning about others that do not, whose adoption is crucial if agriculture is to become truly sustainable.
BE ALERT FOR: Erosion
The United States is widely acclaimed for its tremendous agricultural production. Our high-yield and intensive-input agriculture are exacting a hefty price, however. Read carefully the text pages about erosion in our country. The facts are astounding. The total amount of soil lost to erosion in the U.S. appears to be the highest in the world. We are now losing as much soil per year to erosion as we were during the Dust Bowl of the 1930s. In a century of farming, we have lost half of our topsoil on average. That is not sustainable agriculture.
BE ALERT FOR: Sustainability
We encounter the words sustainable and sustainability often: sustainable worldview, sustainable society, sustainable forestry, sustainable agriculture, sustainable development. The basic meaning is an action or practice conducted in such a way as to be repeatable forever. Conceptually, it’s akin to living off the interest produced by an investment rather than off the principle.
In essence, environmental science is the search for ways to conduct all human affairs sustainably—a necessity imposed on us by the finiteness of the earth and the magnitude of our exploding numbers and environmental impacts.
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2003 McGraw-Hill Higher Education