Infiltration discussion, soil-water

The industrial fatty acid-DETA derivatives were evaluated for application to soil. Water infiltrated soil coated with the BETA derivative of tallow more rapidly than the controls. This was due to the high unsaturation content and also in part to the glycerine retained in the product as discussed below. We were unable to find a solvent system which would readily separate the glycerine, formed from the triglyceride, from the BETA reaction product. If the glycerine were removed, the infiltration rates for the tallow-DETA derivative should be identical with the rates obtained for tallow fatty acid-DETA reaction product. 

Although water is not destroyed on Earth, the hydrosphere can certainly suffer damage by human activities as discussed in Chapters 4 and 5. One of the main human activities detrimental to the hydrosphere is excessive utilization of water in regions deficient in rainfall. Withdrawal of irrigation water from rivers in arid regions has reduced some once-mighty rivers to trickles by the time they reach the ocean. The water is not destroyed, but it evaporates and in some cases infiltrates the soil. 

Percolation and Infiltration—We shall now consider the flow of water through soils at very low heads. The more general problem of packing behavior with high heads and pressures is discussed in Chapter 13. 

Mulches are used primarily to increase water infiltration, reduce evaporation, modify soil temperatures, control weeds, prevent evaporation, and increase crop yields. They also increase the biological activities in the soil, modify the level of available nutrients, and help to maintain or increase the level of soil organic matter. Under conditions of no tillage, or minimum tillage of fine-textured soils, there is also likely to be a favorable effect on the physical conditions in the soil. These effects are discussed in the following pages. 

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