Today is Thursday, 11 July 2024.
“Carbon has gone from being a benevolent force, a protector of the Earth system in a stable state, but now she’s being released and increasing in the atmosphere. She is becoming a destroyer” said climate scientist, Will Steffen in the instigating film “Carbon: The Unauthorised Biography”.
Agriculture seems also to play a key role, in spite of the fact that much of the increase in the atmospheric concentration of CO₂ comes from the combustion of fossil fuels.
Recent article from Nature makes reference to studies basically indicating that. And in also adds that soil organic carbon has been drastically depleted by intensive farming practices around the World towards feeding its growing population.
Indeed if at the start of the industrial age the global population was around 800 million, there exist nowadays 10 times more people to feed.
Besides this growth, it is also interesting to see how the daily supply of calories per person evolved overtime. See for example this graph from Our World in Data, where you can select your country or region and see for yourself. The Global average, for example, increased from 2.181 kcal to 2.940 kcal just in the last 60 years.
In other words, these are also times to pay full attention to soil organic carbon and expand the potential of agriculture as a carbon sink
Coming from ancient times, the practice of tilling the soil by revolving organic matter and nutrients, leading to bountiful crops might be also leading to its exhaustion overtime. Regardless of the use of fertilizers. That process breaks up the soil, including the root systems of the crops and grasses, causing the release of CO2 into the atmosphere. Not to mention other risks such as erosion.
One way to potentially keep that carbon in the soil is to revise tilling, depending on climate and soil types. “Instead of turning over large amounts of soil to plant seeds or seedlings, farmers use equipment that creates either a narrow channel or a hole into which the seed or seedling can be planted. The residue of the previous season’s crop — stubble, stalks and stems, for example — is left in the soil and on the surface. The idea is that this reduces the disturbance of the soil structure and leaves more of the soil organic carbon in place.”
Another interesting process quoted is called enhanced weathering. “A four-year study, which was published in February, of the United States corn-belt region found that applying crushed basalt to maize (corn) and soya bean fields was associated with sequestration of an extra 10 tonnes of CO2 per hectare per year, while also increasing crop yields by 12–16%”.
Coming to a close, the article also discusses how much carbon an area of land can sequester.
“By 2100, the [carbon] sink capacity of the land is about 150 to 160 gigatonnes of carbon, and another of the same amount for trees,” says a soil scientist from the Lal Carbon Center at Ohio State University.
“Agriculture could be a part of the solution”, he adds.
Click at the image below for this full Nature article “How farming could become the ultimate climate-change tool”. It includes 13 references with links to great scientific studies related to all these topics and several others.
And here for Carbon Credit Markets “fertile” list of articles related to agriculture.
