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Existing Water resources can sustain cotton production with minimal environmental impact.
Cotton has been wrongly cited as a water intensive crop, when in reality it is very drought tolerant and uses about the same amount of water as other major crops.i Cotton's global water foot print is about 2.6% of the world's water use, lower than other commodities (e.g., Soybeans 4%, Maize 9%, Wheat 12%, Rice 21%).ii Furthermore, in many regions of the world, cotton gets all of its water from rainfall – water that would be used by whatever vegetation is present. For example, about 65% of the U.S. crop is produced without irrigation, and most of the remaining 35% is just used to supplement crop needs.iii The cotton plant is drought-adapted and responds favorably to periods of water stress sufficient to slow other vegetative growth.iv
Water quality is also preserved in modern cotton productions systems.
The increase in conservation tillage practices has resulted in a reduction of runoff from agricultural lands, decreasing non-point source pollution of fertilizer and pesticides. Intensive local monitoring of surface water and sub-soils have demonstrated the benefits of no-till cotton in protecting both ground and surface water resources.v . Better nutrient management and precision technologies are insuring inputs are used by the crop and not entering ground or surface waters. The U.S. Geological Service reported Nitrate-N concentration in drainage basins north of the cotton growing region to be substantially higher than the Nitrate-N from basins planted to cotton, resulting in a Nitrate-N level of 5 ppm in the upper Mississippi River prior to entering cotton growing states, and 1.2 ppm in the lower Mississippi River upon leaving the cotton growing states and just prior to entering the Gulf of Mexico.vi
References:
- iZwart, S.J. and G.M. Bastiaanssen. 2004. Review of measured crop water productivity values for irrigated wheat, rice, cotton and maize. Agricultural Water Management 69(2):115-133.
- iiHoekstra, A. Y. and A. K. Chapagain. 2007. Water footprints of nations: Water use by people as a function of their consumption pattern. Water Resour Manage 21:35–48.
- iiiNASS, 2004. Farm and ranch irrigation survey (2003 – compiled from the 2002 Census of Agriculture). U.S. Department of Agriculture (USDA), National Agricultural Statistics Service (NASS), Volume 3, Special Studies Part 1AC-02-SS-1.
- ivGrimes, D.W., and H. Yamada. 1982. Relation of cotton growth and yield to minimum leaf water potential. Crop Sci. 22:134–139.
- vSee the "Beaver Creek Study Final Report" University of Tennessee publication AE03-63, and reference within, for the impact of no-till cotton on water quality. http://economics.ag.utk.edu/bcstudy.html
- viGoolsby, D.A., William A. Battaglin, Brent T. Aulenbach, and Richard P. Hooper. Nitrogen Flux and Sources in the Mississippi River Basin. USGS Fact Sheet 135-00. December 2000
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