A recent research project conducted at Woods End shows that the simple-to-perform Solvita test for compost gives essentially identical information about compost aging as does more expensive IR (infrared) analysis. The funded research project compares two types of compost (manure vs yard-waste) over a 180-day period, subjecting the piles to quadruplicate tests to see how various indexes change with time.
Like many biological data, CO2 rate versus time fit a power-curve closely. A noteworthy feature about decomposition is that it drops rapidly in the first month, then very slowly over the next several months. The lab ran infrared CO2-rate on the same samples alongside Solvita volumetric tests, and the curves were nearly identical (see image). Woods End offers a lab-based version of Solvita so that test labs can offer it to their customers.
What all this means is that expensive lab protocols like IR may not offer any distinct advantages over simple and much less expensive tests like Solvita for routine testing. There is very little credible published information on how to interpret IR or Base-Trap CO2-rate tests for compost maturity. In contrast – there is a growing wealth of published data and user-experience with Solvita. “We think labs would prefer a cost-effective method that is also meaningful to their customers, and Solvita fills that gap.” says Brinton, inventor.
Woods End plans to publish the data on indexes of composting later in the year.