Carbon & Topsoil - The Happy Coincidence

This article explores two emerging and fortunately convergent concepts – Carbon Sequestration and Soil Health.

Most of the carbon dioxide and global warming debate to date has focused on the science of measuring and monitoring emissions, the levels of CO2 in the atmosphere and the potential effect it will have. Another field of analysis has been the political reality of whether we can make the necessary changes to reduce emissions to some theoretical, potentially sustainable level.

In this blog I want to step outside that debate and focus on some practical issues from the emerging field of soil health that uses carbon sequestration to enhance soil properties.

Fascinatingly, healthy topsoil has a higher percentage of carbon than wood. It also makes up a greater total in the environment than previously realized. A typical open woodland or forest will have more carbon stored in the undisturbed topsoil than in the timber. And critically there is really no limit to how much topsoil can be created. Healthy topsoil is much more stable/long lived than a forest and is full of carbon based life; from microbes to nematodes to earthworms, fungus, bacteria, molds etc. In future blogs I will elaborate on these concepts.

There is a growing wave of environmentalists, practitioners and scientists going back to the drawing board to work out where we went wrong with our farming and land management over the last 70 years or so and to start exploring options to move forward. Happily, my research to date leads me to estimate carbon sequestration is probably the single biggest element of topsoil creation strategies and so we are (optimistically speaking) on the verge of an amazingly sublime renaissance. We can pull Carbon from the atmosphere and store it in a stable, healthy form – topsoil which creates a positively reinforcing feedback. The more we learn about creating topsoil the more carbon we will draw from the atmosphere which will also result in stronger more robust plants and crop yields. Topsoil has the scale and manageability to act as a genuine carbon sink to impact CO2 based climate change. Very exciting times!

I will explore this theme in coming weeks examining the chemistry, the history and trends, the players and forces promoting or resisting this potentially very positive change.

The first topic I would like to examine is a brief history of soil health in agriculture and of the science that emerged in the 1950’s.

The original ‘Green Revolution’ was the explosion in productivity and yields that accompanied the application of artificial fertilizers, especially NPK – Nitrogen, Phosphate and Phosphorous and the pesticides and herbicides that emerged from the new chemistry after the Second World War. This was a phenomenally successful transition – at least in the short term – from Farmers in the field for 10,000years using largely intuitive knowledge of biology to produce food and fiber to a world where scientists and engineers in laboratories and factories used chemistry to improve yields. That’s a terrible oversimplification but I’m trying to convey the enormity of the transition that occurred in agriculture after WW2. There was nothing like it since the very beginning of agriculture – domesticated plants and animals.

Productivity really did soar and literally billions of people are alive today because of the food security the new farming techniques generated.

Curiously, within a few years of the original ‘Green Revolution’ farmers noticed a reduction in basic soil health and vitality. By the early 1960’s, the organic movement had already been born. Literally an absolute handful of years and farmers were seeing the detrimental effects on soil health and plant robustness after thousands of years of sustainable agriculture.

The emerging soil science paradigm is based on amazingly perceptive and insightful research. One classic story comes out of Africa, researchers realized the soils trampled by migrating herbivores (Wildebeests, Zebras) recovered and produced more total feed than adjacent areas not trampled. This concept was initially described as Carnivore created landscapes. The lions kept the Wildebeest in a tight group so their hooves churned nutrients into the sod. Wolves did the same thing with the buffalo on the great western plains of the USA. Counter intuitively this improved the soil and productivity, sparking a raft of new grazing and land management practices, Cell Grazing, Break Cropping, Precision agriculture etc.

Measuring and monitoring the role of carbon in that soil health evolution has proved very difficult. Uniform measurement and analysis techniques are gradually emerging. Again this is a topic for a future blog as the science evolves and standardization emerges.

I look forward to engaging in discussions and ongoing research of these issues.