What are the challenges of using the soil test for crop production vs. nutrient management?
For routine soil fertility evaluation and recommendations, it generally is recommended that soil samples be collected to “plow depth” or the zone of greatest root concentration, which is usually 6 to 8 inches deep. When soil testing is used to estimate P loss, it is the surface inch or two of soil that comes in direct contact with runoff that is important. A different sampling procedure may be necessary for a soil test that is used to estimate the potential for P loss in surface runoff.
