Total carbon sequestration potential

We can now revisit the potential sequestration issue. We had already recognized that global arid lands had the potential to hold 500 billion tons of carbon. Now that we recognize that ordinary crop land can eventually hold fifty tons of carbon per acre, it becomes very clear that agriculture alone can eventually absorb over a trillion tons of carbon while supporting a human population of fifty billion. This is likely all the geological carbon that we will ever burn so the ecological equation becomes nicely balanced.

Our only problem is to simply use what we already know to make sure it happens.

One other thing that I have alluded to needs to be addressed. That is the charcoaling or simpler charing of crop waste.

The indications are that this will become a major mechanism for the maintenance of crop land fertility, while also suppling an outlet for disposing of wood waste from adjacent woodlots. The principal tool will be a burn chamber that is setup for the handling of crop waste which is easily and normally collected at harvest time.

Current protocols use straight burning or mulching into the soil. Each is clearly flawed. Burning simply releases all the carbon back into the atmosphere for no soil benefit and the nutrients are released as highly mobile solubles that are swiftly leached away. Mulching, while clearly superior has two drawbacks. The most serious is that the breakdown process often merely releases the bulk of the carbon into the atmosphere because of a lack of sufficient nutrients. Again it is also fairly fast with the same problems of leach loss. More critically, much of the stubble is difficult to work into the soils in the first place. In other words a better way would be very welcome.

Sequestering the nutrients annually in carbon char prevents leaching and the carbon itself will actually take years to break down. On top of that, it should be possible to mix the char with crop fertilization for better management.

The one glaring crop that just screams for this type of farm practice is corn. A field produces between 10 and 20 tons of stubble per acre, which is huge. Reducing that to a ton or two of Biochar would be the best thing that happened to the corn business. Corn borers would be eliminated and the only nutrients lost would be in the corn itself. Since corn growing has always been recognized as very hard of the soils and in need of heavy fertilization, this could be a major turn around.

The real power of this protocol is that both carbon and nutrients are delivered into the working crop bed and held there until used. That means that nutrients lifted up by deep rooted plants are been placed on the surface and kept there. This virtuous cycle will create rich fertile soils everywhere and will eventually hugely reduce if not eliminate the need for any chemical fertilization.

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