March 19, 2013
Soil Biodiversity and Conservation Ecology: U.S. Soil Degradation and the Implementation of Organic Farming Methods
Many factors contribute to the classification of healthy soil which are comprised of, but not limited to, composition, fertility, nutrients, organic matter, as well as, diversity and abundance of soil organisms. These components combine to solidify basic definitions of what can be referred to as soil biodiversity and conservation ecology.
Soil Biodiversity is the composition, heterogeneity, and abundance of soil organisms for sustained soil fertility. Examples of this are microorganisms, nutrients, and organic matter. Conservation Ecology is the study of nature and the status of biodiversity on planet Earth. This field aims at protecting species, habitats, and ecosystems through such projects as landscape preservation and the prevention of species extinction.
The United States, in its current practice, implements industrial farming methods in order to maximize efficiency and decrease expenditures. A primary example of these methods is the segregation of crop production to single cash crops. Therefore, individual farms are responsible for specific agricultural sectors which increases efficiency, but constrains soil resources. According to Diana Wall of Colorado State University, “the use of insecticides, nematicides, and herbicides for control of soil pathogens and pests rather than on biocontrol of pathogens, herbivore-resistant crop varieties, or other management strategies has furthered the impression that soil biodiversity is of little relevance to agricultural production.”
Lack of crop rotation leads to soil degradation, resulting in unforeseen effects on soil quality. In the long run, soil degradation substantially decreases crop yields and quality, further exacerbating critical food insecurities. In addition to adverse effects on human nutrition and health, soil degradation increases environmental susceptibility to droughts and elemental imbalance leading to desertification and devastating events such as the dust bowl.
A bar-graph depicting the differences in erosion rates across four different land management techniques. http://www.eatwild.com/images/Soil%20erosion.jpg
An alternative to U.S. industrial farming methods is the use of organic farming. According to a 21-year study, that was published in Science, on various farming methods in Central Europe, researchers found that organic farms produced 20% fewer yields. Fertilizer and energy use, however, was reduced by 34-53% and pesticide use was cut by 97%. This led to increased soil biodiversity and fertility for future growing seasons.
Graph depicts increased corn crop yields with the implementation of pesticides and fertilizers but yields drop in most recent years. http://www.earth-policy.org/data_highlights/2012/highlights30
Organic farming differs from industrial agriculture methods because of its focus on decomposition and nutrient management. It emphasizes maintaining nutrient levels and soil fertility with the use of crop rotation practices. Organic farms are more dependent on soil chemical content and biological processes for nutrients to sustain crop health and yield than conventional industrial U.S. agriculture.
Integrated-livestock farming is the unification of livestock and grazing land in order to negate the impacts of industrial soil degradation. This purported solution is considered an alternative to organic farming methods in that it requires no change to current crop production and claims to show an improvement in soil quality.
A study conducted in central North Dakota sought to evaluate these claims due to the lack of documentation on the subject. A Soil Quality Index (SQI) was developed using the Soil Management Assessment Framework, and was used to judge treatment effects on soil conditions over a 9 year span. Aggregated SQI values over 9 years showed no significant change in soil quality, implying no differentiation in the capacity for each system to perform critical soil functions. As a result, the study concluded that integrated-crop management systems provide limited benefit to soil quality and nutrient abundance. However, the results of this study are specific to the geographic region to which they were performed, and the climatological as well as topographical characteristics of the region likely played a role.
About the Authors:
Sara Carlson is a sophomore at the University of Southern California studying International Relations Global Business and Environmental Studies.
Jacob Leonard is a sophomore at the University of Southern California and is currently pursuing a Bachelors of Arts degree in Mathematics with a minor in Environmental Studies.
Works Cited:
J.F. Karn, et al. “Integrated Crops And Livestock In Central North Dakota, USA: Agroecosystem
Management To Buffer Soil Change.” Renewable Agriculture & Food Systems 27.2 (2012): 115-124. GreenFILE. Web. 28 Feb. 2013. http://search.ebscohost.com/login.aspx?direct=true&db=8gh&AN=75166043&site=ehost-live
Lal, Rattan. “Soil Degradation as a Reason For Inadequate Human Nutrition.” Food Security
(2009): n. pag. Springer Link. Web. 28 Feb. 2013. http://link.springer.com.libproxy.usc.edu/article/10.1007%2Fs12571-009-0009-z
Mader, Paul, Andreas Filesbach, David Dubois, Lucie Gunst, Padruot Fried, and Urs Niggili.
“Soil Fertility and Biodiversity in Organic Farming.” Science 296 (2002): 1694-697. JSTOR. Web. 28 Feb. 2013.
http://www.jstor.org.libproxy.usc.edu/stable/3076892
Stockdale, E. A., and C. A. Watson. “Biological Indicators of Soil Quality in Organic Farming
Systems.” Renewable Agriculture and Food Systems 24.4 (2009): 308-18. ProQuest
Research Library. Web. 28 Feb. 2013.
http://search.proquest.com.libproxy.usc.edu/docview/220383136
Wall, Diana H. “Chapter 10: Making Soil Biodiversity Matter For Agriculture.” Microbial
Ecology in Sustainable Agroecosystems. By Tanya E. Cheeke and David C. Coleman. Boca Raton: CRC, 2013. 267. Print. http://books.google.com/books?hl=en&lr=&id=92fbRsUSWTgC&oi=fnd&pg=PA267&dq=definition+of+soil+biodiversity&ots=-OyVeDJUoW&sig=-2klu3oSseuuhhaS7YXDFEx7RA8#v=onepage&q=definition%20of%20soil%20biodiversity&f=false
September 25, 2011
Sustainable Agriculture: the new face of agriculture in America
Agriculture is an important multi-billion dollar industry in the United States that plays an important economic and social role. In recent years, the concept of sustainable agriculture has emerged out of the increasing concern for long-term farm productivity and the effect of agricultural practices on the environment. Sustainable agriculture is an alternative approach to agriculture that incorporates integrated farming systems to produce environmental goods while protecting resources and enhancing future environmental quality. The key to creating sustainable agriculture is improving and maintaining soil biodiversity, but this cannot be done until the economic and social issues related to farming are addressed.
Soil biodiversity is a central component of sustainable agriculture since without it the availability of arable soil would decrease, therefore making soil management techniques crucial in sustainable farming. Soil is the home for a myriad of organisms, bacteria, fungi, and microbes, which all play key roles in soil quality and health, in turn affecting agriculture. The function of these soil biota are “central to the decomposition processes and nutrient cycling” and therefore “affect plant growth and productivity, as well as the release of pollutants in the environment.” Soil biodiversity is key in sustainable agriculture’s goal of producing adequate amounts of nutritious food while maintaining environmental quality and conserving natural resources.
Sustainable farming is extremely intertwined with three variables: environment, economy, and society. Environmental factors sustainable farmers must take into account are biodiversity, recycling of nutrients, waste, and avoidance of pollution, to name a few. Although most attention is usually places on the environmental facet of sustainable agriculture, the economic and social influences play increasingly crucial roles in its success. Economically, concerns of profitability, especially compared to other farms, and maintenance agricultural raw materials are important for farmers to take into consideration. The social dimension includes the “retention of an optimum level of farm population, the maintenance of an acceptable quality of farm life, and the equitable distribution of material benefits from economic growth.” The struggle for many sustainable farms is that environmental, economic, and social factors do not always coincide and therefore priority must be given to certain interests over others. For example, sustainable agriculture techniques such as crop rotation, conservation tillage, cover cropping, nutrient management, and multicrop farming can become costly and do not necessarily yield the biggest profit margin. Conversely, due to competition from other farms, sustainable or not, in order to stay in business farms must have a maximum output of crops.
Organic farming is a type of sustainable farming that prohibits the use of synthetic products, including fertilizers and pesticides, and stresses maintaining soil productivity and quality. In 1995, the National Organic Standards Board defined it as “an ecological production management system that promotes and enhances biodiversity, biological cycles and soil biological activity.” Since organic farms do not use unnatural pesticides and fertilizers, they tend to rely more on natural nutrient cycles than do conventional farms. These types of farms must be creative in the ways they replace chemical fertilizers and frequently practice crop rotation, maturing, cultivation, and mineral fertilizers. Since many of these practices are more time consuming and costly than traditional chemical fertilizers, organic farms rely on higher prices for their produce in order to ensure profitability. By increasing their prices, organic farmers do not have to choose between being environmentally sustainable and making an economic profit.
Due to the increasing global population rate and more demand on agricultural resources, sustainable agriculture is becoming more important and necessary, however it is crucial to remember the role of soil biodiversity in its success and how economic and social factors play an important role in its effectiveness and implementation.
About the authors: Ariana Verdu and Lily Phillips are working towards their bachelor degrees in the USC Dornsife College of Letters, Arts and Sciences.