The depth at which impermeable layers and/or parent material are present determines soil depth. Soil with a depth of less than 500mm is generally regarded as soil of low potential. The effective depth of soil is the depth to which the crop roots can penetrate with ease.
Effective depth refers to the depth to which roots can penetrate the soil. Hard rock, a strongly structured clay horizon, a high water table, or high soil acidity, can prevent root penetration. Minimum soil depths are the following:
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