Common chemical halts soil erosion
MetadataShow full item record
CTA. 1994. Common chemical halts soil erosion. Spore 51. CTA, Wageningen, The Netherlands.
Permanent link to this item: http://hdl.handle.net/10568/49395
In the eastern part of the USA, in Magic Valley, farmers can be seen throwing handfuls of white crystals into their irrigation water. Almost immediately the water turns from murky brown to crystal clear. The crystals are the latest way to stop soil...
In the eastern part of the USA, in Magic Valley, farmers can be seen throwing handfuls of white crystals into their irrigation water. Almost immediately the water turns from murky brown to crystal clear. The crystals are the latest way to stop soil being washed down the valley by irrigation water. So much top-soil has been lost in Magic Valley that some farmers foresee only a few more years of cropping ahead. The Agricultural Services of the United States Department of Agriculture (USDA) have found that by adding a handful of a common polymer to the water soil erosion is reduced by 90%. The polymer, a polyacrylamide, is commonly used to treat waste water. he polymer strands make the fine solid particles in the water flocculate so that they sink to the bottom. The same thing happens when the polymer is dissolved in irrigation water. The polymer strands adhere to the soil and to each other and form a kind of net over the surface as the water sinks into the soil This binds the soil particles together so that they resist the eroding force of the flowing water. Researchers feel that the first three irrigations are the most important as soil is at its most vulnerable when irrigation first starts. The amount of polymer required is small, just 10 parts per million. That is about a handful in 120,000 litres of water. Research in Kenya is showing that the polymer has a role in preventing soils from 'capping' or forming a hard crust after heavy rain. Once soils have capped very little water soaks in and they are more prone to erosion. In a trial where soils were sprayed with the polymer, no capping occurred and there was greater infiltration. Agricultural Research Service, USDA 3793 North 3600 East, Kimberly, Idaho 83341, USA