Submitted to: Renewable Agriculture and Food Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/8/2009
Publication Date: 9/18/2009
Citation: Wienhold, B.J., Karlen, D.L., Andrews, S.S., Stott, D.E. 2009. Protocol for indicator scoring in the soil management assessment framework (SMAF). Renewable Agriculture and Food System. 24(4):260-266.
Interpretive Summary: Soils provide a number of essential functions such as serving as a growth medium for plants, filtering and storing of water, and exchanging gases with the atmosphere. Management affects these soil functions and assessment tools for monitoring management impacts are needed. The Soil Management Assessment Framework (SMAF) is being developed to meet that need. The current version of the SMAF uses scoring curves for eleven soil properties to generate an index that can be used to compare among management practices or monitor management over time. Additional scoring curves are needed to improve the utility of the SMAF. This paper presents a step-by-step description of how scoring curves are developed. In addition, scoring curves for a physical (water-filled pore space), chemical (soil test potassium), and biological (ß-glucosidase activity) soil property are developed as examples for use by others interested in developing scoring curves for the SMAF.
Technical Abstract: Assessment tools are needed to evaluate management effects on critical soil functions. These tools will need to be flexible in terms of selection of soil functions to be assessed and indicators to be measured to insure that assessments are appropriate for the management goals. The Soil Management Assessment Framework (SMAF) is being developed to meet this need. The SMAF uses measured soil indicator data (physical, chemical, and biological) to assess management effects on soil function using the three step process of indicator selection, indicator interpretation, and integration into an index. While the SMAF is functional in its present format, it is intended to be malleable so that user needs are met. Development of additional indicator interpretation scoring curves is one way that this framework can be expanded. Scoring curve development is a multi-step process of identifying an indicator, determining the nature of the relationship of the indicator to a soil function, programming the curve describing that relationship, and validating the scoring curve. This paper describes the steps involved in developing a SMAF scoring curve. Scoring curves for percentage water-filled pore space (%WFPS), soil test potassium (K) concentration, and ß-glucosidase activity are developed using the described protocol. This protocol will assist users of the SMAF in understanding how the existing scoring curves were developed, as well as aid users interested in developing scoring curves for indicators that are not in the current version.