Global Warming/Climate Change, Rehabilitation, Soil Biology, Soil Composition, Soil Conservation, Soil Erosion & Contamination, Water Contaminaton & Loss — by Craig Mackintosh PRI Editor October 30, 2010
Carbon deficient soil at left, carbon rich soil at right.
It’s not difficult, but it could make all the difference.
If I were to compare industrial, monocrop agriculture with permaculture or organic biological agricultural methodologies, and then boil my observations down to their base differences, I would describe them thus:
- Industrial agriculture focusses on feeding the plant
- Permaculture and organic biological agriculture focus on feeding the soil
For the industrialists, if they have a big green flush of foliage, in their mind they’ve succeeded. Whether the plant is healthy, or tasty, or whether the soil is being depleted, eroded, polluted and salinated in the process of growing it, is of secondary importance. The industrial system is about standardisation, transportability, externalised costs and instant gratification — or instant profits. Such plants normally have nutrient imbalances, and trace mineral deficiencies, that make them prone to pest and disease attack and make them less healthy for animals and humans. In addition, industrial agriculture turns our vast agricultural lands into carbon sources. Nitrogen fertiliser inputs systematically ‘burn up’ carbon rich humus, sending it into the atmosphere to act as a greenhouse gas rather than the foundation of soil fertility it was meant to be. Indeed, this form of farming should not be called agriculture at all, as ‘culture’ means to refine or foster, to bring about an improved state. Industrial agriculture does quite the opposite.
But, for the land steward who wishes to farm not just for today, but dependably for many generations to come, and who wants to bestow land fertility and physical health upon his/her children, farming becomes less about extraction than it is about wise management. The focus of the conscientious land steward must necessarily become the soil, from which the plant is just the fruit. Healthy soils with a diversity of organic matter and soil life produce plants with more dry matter (or "more strawberry in the strawberry") instead of water — giving them a longer shelf life and providing us with higher quality nutrition.
But, as I’ve shared before (here and here for example), the benefits of sustainable agricultural practices go well beyond our plates and our farms. Soil-focussed agricultural systems employ, instead of destroy, the vast armies of microorganisms that work unseen and underappreciated beneath our feet. Fungi and bacteria are far better at feeding our plants than any agribusiness factory (and they do it for free) but what they do is also a critical factor in maintaining balance within the entire biosphere. These are Gaia’s helpers. Their work benefits not just cabbages and cauliflowers — but also the climate. Microorganisms break down organic matter until it becomes humus — the final stage of decomposition and an extremely carbon rich material. Humus is highly stable, being able to retain its carbon content for centuries.
Next to the oceans, our soils are the largest potential carbon sink on the planet, and yet, due to mismanagement of our land, our oceans are now reaching CO2 saturation point as atmospheric CO2 levels are extreme and still rising.
These facts are almost wholly overlooked by the mainstream media, politicians and industry in climate discussions. The latter (industry) of course have a vested interest in not discussing the topic, and they have major influence, or control over, the former (media and politics). What needs to be trumpeted far and wide is that climate change is as much, or even more, about deforestation and soil mismanagement than it is about smoke stacks and tailpipes.
On this topic, I’d like to share an excellent website that has brought together a huge amount of excellent evidence, gathered from research made over several decades, on the ability of our soils, if we were to transition them to sustainable farming methods, to ameliorate our situation, and to actually reverse climate change. This occurs simply by letting nature work — in rapidly pulling CO2 out of our atmosphere and storing it back where it belongs.
In more than 30 long range farm trials held in Australia, the US and Europe, carbon sequestration rates varied between 0.2 tonnes – 3.0 tonnes carbon per hectare/ year which equals 0.7 tonnes – 11.0 tonnes CO2 equivalent per hectare/year (CO2-e). The amount of carbon sequestered depends on farming methods, soil type, climate and crop varieties. In comparative tests, organic systems accumulated a 12% increase in soil carbon and biodynamic systems accumulated a 16% increase. Increasing carbon sequestration is dependent on continuous bio-agricultural processes. if after sequestering carbon into the soil, we were to return to current conventional farming methods the carbon would gradually be released back into the atmosphere.
Over the long term conventional chemical based farming has been shown to decrease soil carbon. In research by the Rodale Institute it was found that “the application of soluble nitrogen fertilizers stimulates more rapid and complete decay of organic matter, sending carbon into the atmosphere instead of retaining it in the soil as the organic systems do.”
Analysis of the US’s oldest continuous cropping test plots in Illinois showed that, contrary to long-held beliefs, nitrogen fertilization does not build up soil organic matter. Some Midwestern soils that in the 1950s were composed of up to 20 percent carbon are now between 1- and 2-percent carbon. – bio-agriculture.org
The site also has an excellent carbon calculator that allows you to gauge the climate impact, or value, of various speeds of transition to soil-focussed agricultural methods.
Check out the site, familiarise yourself with the concept and the facts, and be sure to let others know. There’s a lot more to sustainable agriculture than just what immediately meets the palate. We need to farm like our lives depend on it — because, actually, they do.
Soil carbon sequestration is a win-win strategy. It mitigates climate change by offsetting anthropogenic emissions; improves the environment, especially the quality of natural waters; enhances soil quality; improves agronomic productivity; and advances food security. It is the low-hanging fruit and a bridge to the future, until carbon-neutral fuel sources and low-carbon economy take effect. – bio-agriculture.org