Soil Test Calibration Research and Recommendations: Framing the Issues and Funding for the Future.

Soil testing connects a half-century of science to the on-farm decision making process. It has traditionally served as the foundation of nutrient management in North America. But, is it yesterday’s technology that served a purpose during its time and is no longer relevant, or is it a time-tested and proven set of practices that is in need of recapitalization to serve the decision support needs of crop producers during a time when many are asking much of the producer’s decision making ability? Since the time today’s dominant soil testing procedures for analysis and interpretation were developed, amazing changes have occurred. At the rhizosphere scale, roots are often healthier but two to three times more nutrients must move into the plant per unit time, the soil matrix is more diverse due to tillage reduction, and from a root’s perspective, the community you live is likely a lot more crowded. At the whole farm scale, the stakeholder pool interested in the impacts of nutrient management decisions has changed at least as much as the rhizosphere world below ground, and now in addition to the crop producer, includes neighbors, other countries needing our agricultural exports, the local biofuel refinery and feedlots, downstream residents, government agencies, environmental groups, and numerous organizations concerned about climate change, food safety, biodiversity, air quality, water quality and quantity, natural resource depletion, etc. Considering these changes, a recapitalization of the supporting science in both the laboratory and the field and a thorough reevaluation of the soil test interpretation process would seem in order. Both will require an investment, not a disinvestment as is the current trend, in research and education directed at these needs. Securing funding will require greater creativity in hypothesis definition and methods than in the past, much greater partnering among states, and looking beyond government institutions for support.