We expect the selected combined enzyme assay will detect land management impacts either as absolute values and/or as normalized data (ratios of enzyme activity to organic C or clay content) using air dried soils. A major drawback of most soil properties is that they naturally vary as a function soil type, making interpretation of a single analysis in an ecosystem difficult unless there is a control or undisturbed site on the same soil type available for comparison (unlike soil fertility testing where results are directly interpretable). A major outcome will be a determination of the feasibility to use relative or enzyme activity normalized to clay or C content as the basis for a calibrated dynamic soil property. Secondly, we will determine if the addition of an oxidation assay as a kind of co-variate for this will improve the relationship between the index and soybean yield. The project will develop a data base that could facilitate wide adoption by both research and commercial laboratories. Soil enzymatic indicators have advantages over many other soil properties because they are simple, can be run on air-dried samples, and activity remains stable after sampling (unlike other soil biological properties), thus promoting rapid processing and assaying of soil samples for large scale adoption by commercial soil testing labs.