Subsurface Water Retention for Sandy Soils
Competition for limited water supplies necessary for the production of crops on sandy soils is becoming more intense in the US and globally, particularly with the increasing need for biomass produced as renewable energy sources. Subsurface water retention technologies (SWRT) are designed to increase water use efficiencies by as much as 20 times. SWRT technologies have the potential to impact strategic water and nutrient conservation and improve food, fiber, and livestock productivity. Although supplemental irrigation and additional fertilization do increase plant production on most sandy soils, farming such soils is not sustainable due to the elevated leaching losses of nutrients and other chemicals into groundwater.
Description of Technology
Michigan State University's technology resolves the depleted water and nutrient deficits in the plant root zone while reducing groundwater pollution and the leaching losses of nutrients and other chemicals into groundwater. Polyethylene (PE) water barrier films that can be shaped to maximize soil water retention are installed at appropriate depths in sandy soils with a specially designed barrier installation device (BID). The technology enables double and triple water retention capacities in plant root zones via interruption of natural percolation rates within the upper 70-100 centimeter of the soil column. Although large pores within sandy soils absorb large quantities of rainfall, less than 20 percent of the water is retained in the root zone between the soil surface and 60-70 cm depths by the coarse-textured soils.
The SWRT approach incorporates water barriers at prescribed depths and configurations within coarse textured and sandy soil profiles in a pattern that alters the hydropedological water regimes and improves water use efficiencies by up to 20 times for food and cellulosic biomass crops on sandy soils. SWRT barriers are designed to bring marginal sandy soils into highly productive natural landscapes with substantial savings of water and fertilizer costs. SWRT processes can also be used to confine and reduce the deep leaching and groundwater contamination by agricultural chemicals and/or remove toxic chemical and biological wastes from municipal waste disposal and industrial sites to locations better suited for long-term sorption and bioremediation.
- Durable and easier to install than asphalt barriers: Polyethylene barriers can last at least 40 years and can be installed more quickly and with less labor than asphalt barriers.
- Enhanced plant and food crop production: The technology could potentially have an immediate impact in areas where marginal lands are the only option for production of food crops.
- Better water resource usage: Subsoil water retention technology has the potential for increasing water use efficiencies.
- Better chemical utilization: Just as better water resource efficiencies could potentially be derived, so could better utilization of fertilizers and other agricultural chemicals.
- Agriculture industry: Any crops (food, biofuel, and biomass) that are being grown in marginal regions would potentially benefit from the CEPEM and BID technologies.
- Waste management: Potential for use in landfills as a method for reducing toxic leaching exists.
For Information, Contact:
Michigan State University