Turning the dirt on carbon farming


Could it be the piece of the climate change puzzle agriculture is looking for?

With growing knowledge and new tools, carbon farming is emerging as a major consideration for agriculture in its effort to combat climate change.

The USA lead the world in exploring the sequestering of carbon in soil. Californian Jeff Creque, who has a PhD in rangeland ecology, has been to the fore since the early 2000s, co-founding the Marin Carbon Project (MCP), a consortium of university researchers, county and federal agencies, non-profits and a science advisory task force.

“Most folks don't understand soil and its potential as a carbon sink,” Creque told Fonterra. “And most (of) agriculture does not understand or engage with that process either. Carbon has been missing from our agricultural curricula for a very long time and we see it finally coming back into the conversation today.”

The premise of carbon farming is to slow down the release of carbon back into the atmosphere after it has been absorbed into the soil via plants and grass during the photosynthesis process. Practices that build soil carbon, such as good manure management, composting and minimising tillage need to be promoted, whereas cultivation, over-drainage and over-irrigation need to be discouraged.

Carbon's journey through the soil

Interest in carbon farming has risen as it has become clear that reducing emissions will not sufficiently halt or limit global warming. A risk assessment by the International Panel on Climate Change (IPCC), that operates under the auspices of the United Nations, puts the world’s current situation like this “emission reductions will no longer stop this runaway destabilization of the climate we must develop an ongoing strategy of removing carbon from the atmosphere that is sustainable.”

Creque says it is ignorance, more than irony, that leaves agriculture out of the solution side of the climate equation.

To help farmers with that change of thinking the MCP developed a carbon plan for different types of land use – orchards, vineyards, dairy, beef, sheep – that provides a step-by-step guide on the best and most feasible ways to absorb CO2 long term. Other tools are also available to farmers. Collaboration among USDA’s Natural Resources Conservation Service, Colorado State University and USDA’s Climate Change Program Office, developed COMET-FARM™ that, once loaded with information such as soil characteristics, land uses, tillage practices and nutrient use, will allow farmers to estimate carbon sequestration and greenhouse gas emission reductions associated with conservation practices for cropland, pasture, rangeland, livestock operations and energy. 

New Zealand is not as advanced as the USA yet but research is happening. Whether it can be as promising as it looks now in California is unclear because our soils tend to be higher in carbon than the degraded Californian soils the MCP are working with. Also, some practises and processes see a lot of carbon released from the soil already. In New Zealand, we need to assess the potential gains from carbon farming against any possible downsides, but it’s clear we need to invest far more time and research resource into our soils. Figuring out if carbon farming might work and how are our stepping stones.

Fonterra and other leading international dairy companies Danone, Arla Foods and Friesland Campina, are part of a group looking at how to develop an internationally recognised and globally adopted carbon sequestration calculation method that can be used at farm level. The objective is to have a method that will support and encourage farmers to adopt and implement activities and practices that promote carbon sequestration and mitigate climate change. It’s hoped to have draft proposals by mid-2019 ahead of seeking approval from the International Dairy Federation.

For Creque, it’s a case of pushing on, continuing to educate farmers and working with regional and federal agencies to spread the word.

“Fundamentally, all we are talking about is managing our ecosystems to optimize photosynthetic gain, and carbon conservation, using a circular model of resource conservation and re-utilisation to build an upward spiral of increasing soil organic matter/fertility/water holding capacity and productivity.”

As with many farming challenges, good soil and land management is fundamental, and protecting and building the soil base of farming is in all our interests.