An overview of soil loss tolerance

As the criterion for judging whether a soil has potential risks of erosion, productivity loss and whether a river has downstream over-sedimentation as well as the ultimate criterion for erosion control for the preservation of soil productivity and environmental security in the long term, the level of soil loss tolerance (T value) must be determined in a scientific manner. This overview summarized the development of T value. The factors influencing T value were then discussed, and the calculation methods for T value were also presented and evaluated. Finally, it was proposed that the evaluation of T value should be based on three criteria (referred to as T-1, T-2 and T-3, respectively) with respective definitions and research fields involved. Two key issues, which can prevent the damage by soil erosion, i.e. tolerance for agrochemicals and self-restoration capacity of ecological environments should be addressed in the near future. (C) 2009 Elsevier B. V. All rights reserved.