Measuring Soil Health in Alabama.

Almost 200 years of cropping and abuse have left many soils in the State of Alabama (USA) in poor condition with generally low quality and low productivity.  A 2001 survey of Central Alabama cotton fields indicated that 55% of fields had soil organic matter less than 0.4% and 63% had root restricting compaction within 30 cm of the surface.  Eighty-five percent of the producers were not using a cover crop which exposed the bare soil to erosion for 6 months during the year.  On the other hand, most were soil testing and doing an outstanding job of liming and fertilizing based on soil test results. Data from Alabama’s long-term “Old Rotation” experiment (circa 1896) show a significant correlation between soil organic C and crop yield potential.  Because many soil quality/soil health parameters can be measured in an existing public soil testing laboratory, we have proposed to incorporate these tests into a “Soil Quality Index” (SQI) value that producers can use to evaluate their soil health.  Our SQI was developed with objectives to: 1) make producers aware of soil quality/soil health,  2) suggest ways of improving soil quality/soil health, 3)   use existing, low-cost,  soil test methodologies,  4) use existing, routine, composite soil samples from producers and 5)  provide information in a simple, easy-to-understand manner.  Best management practices will be recommended to help producers improve their SQI value.  A draft of this index based on a scale of 0 to 100 is presented.