Evaluating the impact agricultural practices have on agroecosystem functions is essential to determine the sustainability of management systems. This paper presents an approach to determine the relative sustainability of agricultural practices. A simple ranking procedure using a relative scoring method is proposed to discriminate among treatments based on the status of crop and soil parameters within different agroecosystem functions. Summing scores across agroecosystem functions allows for the identification of agricultural practices that are performing optimally based on functions included in the procedure. An example, using data from a long-term cropping systems experiment in the western Corn Belt, found the indexing procedure to successfully discern differences in overall performance across four agroecosystem functions between conventional [continuous corn (Zea mays L.) cropping sequence at a fertilization rate of 180 kg N ha-1] and alternative (corn-oat (Avena sativa L.) + clover (Trifolium pratense L.)-grain sorghum [Sorghum bicolor (L.) Moench]-soybean [Glycine max (L.) Merr.] cropping sequence at a fertilization rate of 90 kg N ha-1) management systems. The simplicity, inclusiveness, and inherent flexibility of the indexing procedure can be considered benefits and drawbacks, depending on the point of view taken. Data requirements of the approach, however, are stringent. Consequently, its most appropriate use may be with data from long-term agroecosystem experiments.
