Evaluating Healthy Soil Functioning
INTEGRATION: Technically, “soil health” is a misnomer since soil alone cannot be healthy. Rather, healthy functioning of soil arises to the extent that plants, microbes and soil-inhabiting animals actively participate in building and sustaining their whole environment. The phenomena of organisms acting to modify and improve their habitat is recognized in modern biology as niche construction.
THE CHALLENGE: Farmers are often characterized as needing to shift management practices favoring healthier soil. But agricultural scientists should be equally implicated. Scientific practices of soil analysis have traditionally not recognized biological factors as playing an important role in productivity. Both modern farming practices and the conduct of the agricultural sciences bear some responsibility for the deepening dilemma of soil degradation and carbon loss.
Cornerstone soil tests that integrate biological traits include Solvita®-CO2 for microbial activities and Solvita®-SLAN for humus quality.
Woods End’s brand Solvita® has advanced across several markets and is inspiring soil conservationists, farmers, grain processors and composters in new ways to gauge the quality of their environment.
DYNAMIC SOIL AGGREGATES: A key innovation at Woods End is “VAST”, a test which helps establish the prerequisite that for soil health, testing must be more comprehensive. While VAST was originally developed early in the 1980’s within Woods End, it has been made available recently to soil labs under the Solvita brand. The test provides a powerful visual and quantitative means to assess the stability of soil micro-structures, the intersection of degradative and soil-building biological forces.
CORNERSTONES OF SOIL HEALTH TESTING – Solvita Soil Health Suite: Putting all the new tests together – active respiration, aggregate stability, organic nitrogen pools – results in a comprehensive soil bio-chemistry test, the Solvita Soil Health Suite, that may serve as an indicator of healthy functioning. Combining this test with rainfall, soil-temperature and physiographic models helps tailor it to the local environment, the only way that soil health tests can ultimately be usefully interpreted. Woods End labs is one of the few labs presently working on this integration – and if history is any guide, it is a work in progress.
Aggregates – the foundation of “erosion resistance” and basis of a new test offered to soil labs by Wood End Labs
MOVING FORWARD With new excitement for soil quality evident across wide sectors of farming, a caution is needed. Historically soil test methods have evolved slowly. Soil improvement and soil decline themselves are very slow over decades or centuries, and are not readily noticed. There are new concerns about sensitivity of soil tests to adequately show relevant gains. For example, it has been determined statistically that it is not possible to measure soil carbon changes in less than 2 years without a sample size of hundreds probes per individual field. For routine sampling, a resolution more precise that 5 tons/carbon/acre is barely possible. By drawing on some of the best long-term soil management studies conducted around the world over the past 5 decades, it may be possible to adjust to the required “imprecision” in short-time of soil quality measurements.
As a summary, the Solvita Soil Health Suite:
- Accounts for soil microbial activity, with a view that this is very nutrient-relevant;
- Evaluates N + P mineralization potential, the core of the nutrient supply mechanism for plants
- Represents nutrients such as organic-amino-N likely to be “plant relevant”