Sustainable agriculture has become increasingly supported by citizens and farmers alike. According to the United States’ 1990 Farm Bill, for agriculture to be sustainable agriculture it meets the following requirements:
- The production must satisfy the human need for food and fibers.
- The environmental quality and natural resource base that the agricultural economy depends upon must be enhanced.
- It must improve the quality of life for farmers and society as a whole.
- The economic viability of farm operations must be sustained.
- Integrated natural biological cycles and control methods must be employed.
- Non-renewable and on-farm resources must be efficiently used.
Sustainability is often associated with organic agriculture. An organic agricultural system is designed to maintain the health of the soil, ecosystems, and people. It is structured to mimic ecologic processes in order to preserve biodiversity, limit the input of non-natural resources, and adapt to local conditions. Land must be free of chemical use for three years before it can become organically certified. Organic growing generally produces lower yields, approximately 80% of those using technological inputs, although with good conditions organic crops can compete to within 5%. The discrepancy is attributed to limited nitrogen in a given system. However, productivity typically increases over time due to soil improvement and agricultural management skills. Methods used in traditionally rural settings can include, for example, crop rotation, cover crops, compost and the application of manures as fertilizer.
The employment of organic agriculture practices also requires more space as it is not dependent upon large quantities of outside inputs for its functionality (see what is the difference between intensive and extensive agricultural systems as they relate to livestock production?). Accordingly, there are typically a greater variety of activities practiced, i.e. polyculture, on a given piece of land. When employing low-intensity methods on more diversely populated plots, several benefits have been shown to emerge, including increase in forest cover, larger and fuller hedge-groves, more crop diversity and more vegetation strata. These effects have resulted in an increase in natural vegetation cycles and biodiversity levels.
Sustainability is also a major theme in alternative agriculture systems, particularly in urban spaces, where practices, such as vertical and hydroponic, are driving the competitiveness of food grown in non-traditional spaces.
However, there are obstacles to the transition from 20th-century agriculture to sustainable agriculture. For example, a study surveying sustainability practices of farmers in 12 states it was found that:
- 84% of farmers were aware of soil testing;
- 76% knew about crop rotation;
- 75% were knowledgeable about conservation tilling;
- 74% were familiar with soil cover;
- 64% had knowledge of Integrated Pest Management (IPM)
- 52% were aware of diversification.
However, researchers also noted that awareness does not necessarily transfer to use as only 18% of farmers practiced water management, 13% engaged in nutrient management and 7% employed erosion control. The top three concerns related to issues associated with sustainable agriculture are:
- Cost and fear of crop/profit loss during transitional periods;
- A lack of education on how to integrate complicated alternative options, coupled with a lack of resources and support necessary to the transition;
- Resistance to change.
It has also been noted that there is often an incompatibility between growing conditions and sustainable growing practices, such as when the climate makes growing nitrogen fixing plants difficult, if not impossible. Such fears and obstacles to sustainability have the potential to be overcome via the use of education practices and more equitable public support and financing for food production.
Rodriguez, J. M., Molnar, J. J., Fazio, R. A., Sydnor, E., & Lowe, M. J. (2009). Barriers to adoption of sustainable agriculture practices: Change agent perspectives. Renewable Agriculture and Food Systems, 24(1), 60-71.
Karp, D. S., Rominger, A. J., Zook, J., Ranganathan, J., Ehrlich, P. R., Daily, G. C., & Cornell, H. (2012, September). Intensive agriculture erodes ß-diversity at large scales. Ecology Letters, pp. 693-970.