Measuring Soil Carbon Change
As we all (should) know well, land use changes over the last several centuries have significantly increased atmospheric CO2 levels. Soil mismanagement, which has increased in tandem with our burgeoning human population, has released mammoth amounts of carbon from the soil, where it is a positive, into the atmosphere, where it becomes, in its present excessive levels, a negative instead. Correct soil management, in contrast, can play a significant role in reversing that trend by pulling excess atmospheric CO2 out of the sky, through photosynthesis, and returning it to the soil in humus, the stable, final state of decomposition of organic matter – thus transforming excess CO2 from being a pollutant into a rich habitat for the micro- and macro-organisms that are the foundation of all life on this planet. Permaculture, through its favouring small scale, low-to-no till polycultures, and where the soil is always protected by a ‘skin’ of plant or mulch cover, and maintained by appropriate naturally harvested moisture levels, is a powerful system for restoring the Gaia state of carbon balance.
If you’re building humus/carbon levels in your soil, you’re building fertility and health. More, you’re a hero – setting an example that if all were to follow, would rapidly put this planet back onto a sustainable path.
For those interested to more accurately gauge the effectiveness of their soil management, the document linked to here may prove entirely useful.
It is intended as a guide for do-it-yourselfers as well as part of the operating method for the Soil Carbon Challenge. It is also the first guide that attempts to understand and accommodate the variety of purposes or objectives people have in measuring soil carbon. Up to now, soil carbon measurement has been treated almost exclusively as a technical issue. But the main sources of risk and uncertainty in achieving the objectives are social, having to do with beliefs and attitudes.
Based on published literature and experience, this method outlines how to establish fixed plots, take samples, get them analyzed with the dry combustion method, and make calculations from the results.
Though targeted primarily at those who want to show possibility, and get feedback for their management, the guide should be helpful for those who wish to quantify carbon tonnage for "offsets" or research projects as well. How and what you measure, as well as the sources of uncertainty, depend on your purpose.
Measuring carbon change means establishing and measuring baseline plots, and then remeasuring them after 3 years or so. – Soil Carbon Coalition