Global Potential for a New Subsurface Water Retention Technology

Substantial areas of soils underfoot that require increased water-holding capacities are encountered in agricultural fields, athletic fields, golf courses, parks, home lawns, and gardens, as well as many natural ecosystems. There is a growing fundamental global imperative to convert some of these marginal droughty soils into productive agricultural lands by increasing their longer-term internal water-holding capacities. These conversions of highly permeable coarse-textured soils will contribute to food and biomass production needs associated with growing global populations and renewable energy resources. In addition, these conversions will sequester more carbon, improve soil quality, and reduce groundwater contamination. Continuous cover cropping of these improved soils will also increase water infiltration and reduce erosion of surface soil into freshwater lakes, streams, and rivers. The processes of plugging a plethora of continuously connected macropores within sandy soils have been occurring since God established sandy soils. Accumulations of thin clay-enriched layers, located at 45–65 cm depths, cause the sandy soils located above these layers to hold more water. Consequently, a few sandy soils are able to retain adequate soil water and nutrient contents, enabling them to produce more grain and biomass. Thousands of years ago, farmers in Northern Africa and Iran established additional water retention systems in irrigated soils (Stein, 1998). These attempts included burying porous clay containers below the root zones of cultivated crops. This slow leakage provided additional water for prolonged periods of excessive evaporative transpiration. Some more