Measuring Soil Quality.

Soil Quality is defined by how well the soil does what we want it to do. Soil is responsible for many ecological functions such as water supply and purification, nutrient recycling, and sustaining plant and animal life. Alabama agricultural soils are considered poor quality due to compaction, excessive runoff, a history of severe erosion, low soil organic matter content, and lack of cover crops. Routine soil testing does a good job of evaluating the status of plant nutrients, but not all important components of soil quality are measured in the lab. Most of the available soil quality determination methods require in situ determination of some of the soil quality parameters.  Our objective was to determine a Soil Quality Index (SQI) that involves measurement of soil parameters that are inherently associated with soil quality in a soil testing lab and make such service available for clienteles. Paired samples, two samples from fields with similar soils and landscapes, but different yields, were taken from farms throughout the state of Alabama. The samples were then analyzed for C and N mineralization, organic matter, pH, N, P, K, Ca, Mg and micronutrients, electrical conductivity, CEC, wet aggregate, and respiration.  Each of the parameters were assigned a predetermined weight and rate accordingly.  Products of weight and rate for each parameter were summed up to determine SQI of each soil.  The SQI was related to soil health and productivity.