Contour plowing
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Contour bunding or contour farming or contour ploughing is the
Soil erosion prevention practices such as this can drastically decrease negative effects associated with soil erosion such as reduced crop productivity, worsened water quality, lower effective reservoir water levels, flooding, and habitat destruction.[4] Contour farming is considered an active form of sustainable agriculture.[5]
History
The
Modern history
This was one of the main procedures promoted by the US Soil Conservation Service (the current
The extent of the problem was such that the 1934 "Yearbook of Agriculture" noted that Approximately 35 million acres [142,000 km2] of formerly cultivated land have essentially been destroyed for crop production. . . . 100 million acres [405,000 km2] now in crops have lost all or most of the topsoil; 125 million acres [506,000 km2] of land now in crops are rapidly losing topsoil. This can lead to large scale desertification which can permanently transform a formerly productive landscape to an arid one that becomes increasingly intensive and expensive to farm.[7]
The Soil Conservation Service worked with state governments and universities with established agriculture programs such as the
Demonstrations showed that contour farming, under ideal conditions, will increase yields of row crops by up to 50%, with increases of between 5 and 10% being common. Importantly, the technique also significantly reduces soil erosion, fertilizer loss, and overall makes farming less energy and resource intensive under most circumstances.[8] Reducing fertilizer loss not only saves the farmer time and money, but it also decreases risk of harming regional freshwater systems. Soil erosion caused from heavy rain can encourage the development of rills and gullies which carry excess nutrients into freshwater systems through the process of eutrophication[9]
Contour plowing is also promoted in countries with similar rainfall patterns to the United States such as western Canada and Australia.
The practice is effective only on slopes with between 2% and 10% gradient and when rainfall does not exceed a certain amount within a certain period. On steeper slopes and areas with greater rainfall, a procedure known as
Contour bunding has been widely adopted in Burkina Faso after it was suggested by British Oxfam worker Bill Hereford in the beginning of the 1980s.
See also
References
- ^ "Contour Farming for Cropland in the Pacific." University of Hawai‘i - College of Tropical Agriculture and Human Resources. Ed. University of Hawaii at Manoa. USDA NRCS Practice (330), Web. <http://www.ctahr.hawaii.edu/wq/publications/Final_FactSheets/ContourFarmingCrop330.pdf>.
- S2CID 55929299.
- ^ Penn State College of Agricultural Sciences. "Tillage Erosion." Agronomy Guide (Penn State Extension). Penn State College of Agricultural Sciences, 2013. <http://extension.psu.edu/agronomy-guide/cm/sec1/sec11e Archived 10 March 2023 at the Wayback Machine>.
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- ^ Owuor Otieno, Mark (18 February 2018). "What Is Contour Farming". WorldAtlas.
Phoenicians ... practiced some of the earliest forms of contour farming ...(and)... helped spread contour farming throughout the Mediterranean ... however, the Romans ... preferred straight furrows. Over a period, societies who embraced irrigation farming adopted this method of plowing and planting.
- ^ Hogan, Michael C., and GreenFacts. "Desertification." Encyclopedia of Earth., 22 July 2010. Web. <http://www.eoearth.org/view/article/151708/>.
- ^ "Contour Farming." Encyclopædia Britannica. Ed. Encyclopædia Britannica., 2013. Web. <http://www.britannica.com/EBchecked/topic/135192/contour-farming>.
- ^ Hasholt, Bent; et al. (1997). "Sediment delivery to streams from adjacent slopes on agricultural land in Denmark". IAHS Publications-Series of Proceedings and Reports-Intern Assoc Hydrological Sciences. 245: 101–110.
- ^ "NRCS Conservation Practice Standard 330-Contour Farming" (PDF). Archived from the original (PDF) on 1 February 2017. Retrieved 21 March 2018.
- ^ Reinhardt, Claudia, and Bill Ganzel. "Contour Plowing & Terraces during the 1930s Depression." Living History Farm., 2003. Web. <http://www.livinghistoryfarm.org/farminginthe30s/crops_11.html>.
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External links
Media related to Contour farming at Wikimedia Commons
- NRCS Conservation Practice Standard 330-Contour Farming Archived 1 February 2017 at the Wayback Machine 4 page pdf file
- American Experience page on the dust bowl[permanent dead link]
- Encyclopædia Britannica page on contour farming
- Purdue University article on contour farming
- Natural Resources Conservation Service page on sustainable farming
- Manitoba Soil Conservation Resource Manual
- Priority One. Together We Can Beat Global Warming
- Pearce, F. (2002) Africans go back to the land as plants reclaim the desert, New Scientist 21. September, page 4.
- Looking after our land - Soil and Water Conservation in Dryland Africa - Detailed instructions for contour bund construction.
- BBC News - Sahara desert frontiers turn green
- [1]-Article on Water Erosion from Penn State College of Agricultural Sciences
- [2] Archived 10 March 2023 at the Wayback Machine-Article on Tillage Erosion from Penn State College of Agricultural Sciences