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Soil loss tolerance. Soil loss tolerance for a specific soil, also known as the T value, which can be calculated with [1] formula, is the maximum average annual soil loss expressed as tons per acre per year that will permit current production levels to be maintained economically and indefinitely. T values range from 1 to 5 tons per acre per ...
The Universal Soil Loss Equation (USLE) is a widely used mathematical model that describes soil erosion processes. [1]Erosion models play critical roles in soil and water resource conservation and nonpoint source pollution assessments, including: sediment load assessment and inventory, conservation planning and design for sediment control, and for the advancement of scientific understanding.
The United States loses almost 3 tons of topsoil per acre per year. [16] 1 inch (2.5 cm) of topsoil can take between 500 [17] and 1,000 years [18] to form naturally, making the rate of topsoil erosion a serious ecological concern. Based on 2014 trends, the world has about 60 years of topsoil left.
Soil conservation. Contour plowing in Pennsylvania in 1938. The rows formed slow surface water run-off during rainstorms to prevent soil erosion and allow the water time to infiltrate into the soil. Soil conservation is the prevention of loss of the topmost layer of the soil from erosion or prevention of reduced fertility caused by over usage ...
Soil retrogression and degradation are two regressive evolution processes associated with the loss of equilibrium of a stable soil. Retrogression is primarily due to soil erosion and corresponds to a phenomenon where succession reverts the land to its natural physical state. Degradation is an evolution, different from natural evolution, related ...
Crop rotation is the practice of growing a series of different types of crops in the same area across a sequence of growing seasons. This practice reduces the reliance of crops on one set of nutrients, pest and weed pressure, along with the probability of developing resistant pests and weeds. Growing the same crop in the same place for many ...
The runoff curve number (also called a curve number or simply CN) is an empirical parameter used in hydrology for predicting direct runoff or infiltration from rainfall excess. [1] The curve number method was developed by the USDA Natural Resources Conservation Service, which was formerly called the Soil Conservation Service or SCS — the ...
It estimates the average annual soil loss A on a plot-sized area as: [98] A = RKLSCP. where R is the rainfall erosivity factor, [99] [100] K is the soil erodibility factor, [101] L and S are topographic factors [102] representing length and slope, [103] C is the cover and management factor [104] and P is the support practices factor. [105]