T Value 

T is soil loss tolerance expressed in tons per acre per year.

The T value is not directly used in RUSLE. However, it is important in the use of the soil loss equation for conservation planning. Soil loss tolerance is the maximum amount of soil loss in tons per acre per year, that can be tolerated and still permit a high level of crop productivity to be sustained economically and indefinitely.

Soil loss tolerance values of 1 through 5 are used. These values represent the tolerable tons of soil loss per acre per year where food, feed and fiber plants are to be grown. T values are not applicable to construction sites or other non-farm uses of the erosion equation.

From Technical Guide to RUSLE use in Michigan, NRCS-USDA State Office of Michigan.

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