The Solvita soil test method has been published in more than 90 peer-reviewed journal articles, a recent tally shows. A nearly equal amount of published papers report the Solvita compost test, a widely-popular procedure that combines CO2 and NH3 emissions to obtain a useful index for practical compost maturity. The worldwide presence of Solvita includes many countries where access to laboratories is limited with interest in soil health and amendment quality growing.
Examples include a paper just accepted for Communications in Soil Science and Plant Analysis in which UME and UNH researchers report soil health of recently converted no-till cornfields in Maine using multiple test indicators. Farmers’ own ordering of their best to worst soils showed a majority selected similar ranking as attained from Woods End’s comprehensive Soil Health Score, a lab test which includes SOM, Solvita CO2, SLAN and VAST aggregate stability. The paper shows the utility of various tests and raises an important question about farmers-own soil rankings versus lab test results.
In another recent paper, Virginia Tech researchers compared Solvita CO2 rates after applying biosolids to damaged soils. While they report that Solvita correlated well with soil organic-N and 7-day N-min, the paper may raise some valuable questions about the usefulness of very low CO2 rates to adjust N rates for crops. CO2 rates < 30 ppm are extremely low and so it becomes a question of relevancy when chemical fertilizer rates are likely to be as much as 150 kg N ha. Under such circumstances, perhaps the best use of Solvita (and similar tests) are to gauge improvements over time and forego N-min estimations when their magnitude is very small.
Finally, we highlight a valuable thesis published in South America about concerning, degraded pastures on Brazilian oxisols. Two agronomy majors showed that Solvita combined with SOM and biomass can form an index with highly significant differentiation of soil improvement attributable to varying cover crops over time, using virgin forest soil as a benchmark.
Overall it appears that Solvita is being used constructively to frame questions and discover answers to a great variety of soil quality issues. Solvita was first introduced by Will Brinton at the World Symposium on Organic and Sustainable Farming in Oxford England, in 1996. The listing of research and applications is found at solvita.com/papers.