The Environment Series: Part 1 Soil Erosion

You buy organic because you know the chemical free fruits and vegetables are better for your health. But buying organic also has the greater impact of promoting environmental sustainability and ecosystem preservation. Over the next few posts we'll talk about different environmental issues and how organic farming is doing its part to address them.

Soil Erosion

According to article in The Ecologist, almost half of the agricultural land in India is now degraded due to erosion from over use of chemicals. Why should we all be worried about topsoil erosion? If there is less fertile land, we will not be able to grow enough food to feed a continuously growing population. Soil erosion is a natural process where the top layer of soil is worn off by either wind or water. It is a form of soil degradation because of the loss of topsoil. This is especially important to agriculture because it drastically decreases soil fertility and lowers ability of soil to retain water, therefore reducing the productivity of the land. The soil's nutrients are mainly in the topsoil, and heavy erosion leads to infertility, making once productive land completely barren.

There are several modern agricultural practices that lead to rapid soil erosion. High use of agrochemicals is one. Pesticide and herbicide use lowers the amount of organic matter in the soil, causing the soil to absorb significantly less water. It also decimates helpful “weeds” like clover which create a protective cover for the soil. The excess water runs, taking topsoil with it and shunting agrochemicals into streams and other bodies of water. Soil with high organic matter absorbs water more effectively, retaining nutrients because of the soil binding microorganisms. Another cause of erosion is the use of tractors to till the soil. Tractors break up soil particles, creating a fine dust that is susceptible to wind and water erosion. Finally, monoculture, or planting just one crop in a specific area also contributes to erosion because the crop is harvested at once, leaving the fields completely bare and susceptible to the elements. Organic farming seeks to address these problems by engaging in practices that preserve soil quality.

Organic agricultural practices halt soil erosion in a few specific ways. Because of the use of materials like cow dug and vermicompost, soil on organic farms have a significantly higher organic matter content, available potassium, and polysaccharide content than soil on a conventional farm. It also has more active microflora, better soil structure, and significantly more fertile topsoil. All of this means that when heavy rains come water stays in the earth, instead of the topsoil running off with the water flow, and the soil is more resistant to being lifted away by the wind. Other practices include crop rotation, which gives the Earth a chance to recover from the the growing season and replenish nutrients, and encouraging the growth of helpful plants to provide coverage and mulch when uprooted.

Soil erosion is a serious issue, though it doesn't get as much attention as it deserves. The importance of the health of the soil is downplayed, and farmers continuously use more and more chemicals every year to attempt to maintain their yields. With India's arable (farmable) land diminishing at extremely high rates, one has to wonder to the country will continue to feed itself.

Use your demand for organic to create impact and change. By eating organic you are providing farmers for reasons to protect the soil, protect the Earth, and protect our future. 

Sources and Further Reading:

http://www.theecologist.org/News/news_round_up/304237/half_indias_land_degraded_agrochemicals_partly_to_blame.html

http://www.sciencedaily.com/releases/2006/03/060322141021.htm

http://www.omafra.gov.on.ca/english/engineer/facts/87-040.htm#Conservation%20Measures

http://farmlandforecast.colvin-co.com/2009/12/08/soil-erosion-the-silent-killer.aspx

http://www.cartage.org.lb/en/themes/sciences/earthscience/geology/soils/SoilUse/ErosionSoilDegradation/Erosionsoildegradation.htm