Soil loss

Erosion/Deposition Impact Matrix and Map. Methods applied in this semi-quantitative assessment involved mapping depositional features using high and low altitude imagery, numerical ranking of land use activity impacts and construction of problem matrixes. The information generated in these first steps were applied to the Universal Soil Loss Equation (15-16),... 

Final top slope between 3% and 5% after settlement or subsidence. Slopes greater than 5% not to exceed 2.0 tons/acre erosion (USDA Universal Soil Loss Equation)... 

Erosion can seriously effect a landfill closure by disrupting the functioning of drainage layers and surface water and LCRSs. Heavy erosion could lead to the exposure of the waste itself. For this reason, it is important to predict the amount of erosion that will occur at a site and reinforce the facility accordingly. The Universal Soil Loss Equation shown below can be used to determine soil loss from water erosion5 ... 

Figure 26.34 can be used to find the soil loss ratio due to the slope of the site as used in the Universal Soil Loss Equation. Loss from wind erosion can be determined by the following equation ... 

Sims, R.C.C. (1990) Fate of PAH compounds in soil loss mechanisms. Environ. Toxicol. Chem. 9, 187-. 

Considerably fewer studies exist, comparing soil erosion pattern under organic and conventional systems. Soil erosion potential was measured using Universal Soil Loss Equation (USLE) model in 2,056 districts of Germany and it was noticed that... 

There are diverse indicators to measure the risk of soil erosion on different sites. The main interest of this study are the effects of the farming system, independent of site-specific risk. It focuses on the indicator agricultural measures, as expressed in the cropping factor of the Universal Soil Loss Equation (USLE). 

There was higher infiltration and lower soil loss in the treatments with stubble retained. In the integrated treatment there was less infiltration and greater soil loss (after 4 years) due to lack of disturbance of surface crust and stock trampling. There was no difference between treatments in water-stable aggregation (Penfold etal. 1995). 

Reductions in soil loss were related to the use of perennial grasses in mixed systems rather than to organic or conventional management (Eltun etal. 2002). 

Hall, G.F., R.B. Daniels, and J.E. Foss (1981). Rates of soil formation and renewal in the United States. In B.L. Schmidt, R.R. Allmaras, J.V. Mannering, and R.J. Papendick, eds., Determinants of Soil Loss Tolerance. Madison, WI American Society of Agronomy and Soil Science Society of America Special Publication. 45, pp. 23-29. 

A methodology was developed to estimate quantities of crop residues that can be removed while maintaining rain or wind erosion at less than or equal to the tolerable soil-loss level. Six com and wheat rotations in the 10 largest com-producing states were analyzed. Residue removal rates for each rotation were evaluated for conventional, mulch/reduced, and no-till field operations. The analyses indicated that potential removable maximum quantities range from nearly 5.5 million dry metric t/yr for a continuous corn rotation using conventional till in Kansas to more than 97 million dry metric t/yr for a corn-wheat rotation using no-till in Illinois. 

Index Entries Corn stover wheat straw rainfall erosion wind erosion tolerable soil loss. 

For each county in the 10 states evaluated, all cropland soil types in land capability classes (LCCs) I—VIII are identified. For each individual soil type, acres of that particular soil type, field topology characteristics (percentage low and high slopes), erodibility, and tolerable soil-loss limit are obtained from the USD A. These data are used in the rain and wind erosion equations described later. In each of the states analyzed, the following crop rotations are considered (where applicable) continuous corn, corn-soybean, corn-winter wheat, corn-spring wheat, continuous winter wheat, winter wheat-soybeans. 

To quantify the amount of residue that can be sustainably removed, quantities of residues that must be left on the field to maintain rain and/or wind erosion at or below tolerable soil-loss levels (T) must first be estimated. The revised universal soil loss equation (RUSLE) and the wind erosion equation (WEQ) are used to estimate these residue quantities (7,8). 

T, tolerable soil loss (Mg/[ha-yr]) Intercept Average Slope minimum residue remaining (dry Mg/[ha-yr])... 

---