Translating Soil Physical Measures to Estimate on-Farm and Off-Farm Benefits: Linking Indicators.

Soil science, and especially soil physics, has a long history of measuring soil properties. Soil properties of interest include inherent properties, like texture, and dynamic properties. Dynamic properties are particularly important to assessing soil health or condition because these are the properties that respond to changes in management. Soil physical properties, such as plant available water, soil structure, and infiltration, can serve as some of the best tools to evaluate soil function. Translating these properties into useful indicators of soil function can be problematic, but is necessary to communicate benefits to on-farm and off-farm stakeholders for understanding on-farm benefits as well as off-farm social and economic benefits. Stakeholders, both on- and off-farm, can be better motivated to change behaviors when they have a clear understanding of the benefits that soil functions provide to them. These factors will be used to develop a set of linking indicators, i.e., those physical measurements that convey value to the audience they were intended for with minimal need for interpretation. A suite of indicators that complement biological and chemical measures and can be easily interpreted by non-soil scientists is needed to encourage the adoption of soil health promoting practices by demonstrating measurable, valuable change in field soils. Indicators of soil physical properties that provide the most decision-making information to land managers and stakeholders must be selected and tested in the field for reliability, accuracy, and ease of collection. Strategies for translating these indicators to usable decision-making information are presented. As well, we provide an example of the value and complexity of measuring soil hydraulic conductivity and translation into a linking indicator. Preliminary values for changes resulting in improved physical soil condition are presented.