Sunday, April 22, 2007

Review: Soil Health Assessment Training Manual

Cornell’s Soil Health team has completed a final version (”1st edition”) of a comprehensive “Soil Health Assessment Training Manual” (PDF).

At 59 pages, it touches on many areas of interest.

This well organized, and informative, manual has helped warm my still tepid enthusiasm for the soil health assessment movement as well as the closely related soil quality assessment movement.

The soil health assessment movement is a good hearted effort to better understand soil biology and soil function, but it is sabotaged by a dependence on simplistic numeric indexes. Since this could describe the history of the whole of soil science, it seems I have been unfair, condemning the soil health assessment movement in isolation and simply because it is new.

The Manual provides some qualifying documentation that I truly appreciate. The larger list of indices considered and the test locations used for developing the approach are described. This is important information which adds considerably to the value of the Manual. The discussion sections in support of the indicators and in support of the management options are well informed. I am gratified to see that the indices in this manual are much better suited to the challenge of assessing soil health than I have seen in past efforts. Beyond that, I was impressed with how the language used reflects an unfolding understanding of the complex interaction of soil biology, physical characteristics and chemical regimes, especially the forms of carbon involved. I get the distinctive impression that the wording is different than would have been used a year ago, and different than will be used even a year from now. For instance soil fungi is described in terms of thriving in slightly more acidic soil regimes than bacteria. In the past, that distinction would have been left out as inconsequential. In a future soil health assessment, discussion on how to manage soils to enhance beneficial fungi and, later, assessing soils for the presence of beneficial fungi would be natural advancements.

This Manual is a regional and cropping-system specific in nature. It describes "soil constraints and soil quality issues common to soils in New York and the Northeast region, especially in vegetable and field crop production systems." The defined focus frees it from the generalizations that limit broader assessment approaches. At the same time it provides a provides a structure for those interested in applying a soil health assessment approach in other areas.

Users of the Manual send soil samples and data sheets to Cornell's laboratory for analysis and interpretation. The training provided through the Manual is in support of gathering field data and in understanding the resulting report from Cornell.

It will be difficult for self-directed individuals to use the Manual as a resource to delve deeper into some of the assessment techniques. Take for instance, the root health rating. This involves germinating bean seeds in the sampled soil and observing the developed roots for indications of damage by pathogens. No specific references are provided in support of readers seeking to better inform themselves on this approach.

My criticisms of the manual are minor. I highly recommend anybody interested in soil quality, soil health, soil assessment, and soil function download the Manual as a PDF and treat yourselves to at least a quick thumb through.

Blog sources that announced the Manual: Lori Bushway, Molly Day