AGRICHAR: SINKS CARBON, GROWS PLANTS

Good for farmers, good for breathers. Anybody left?

Soils Offer New Hope As Carbon Sink
June 1, 2007 (New South Wales Department of Primary Industries via Science Daily)

WHO
senior research scientist Dr Lukas Van Zwieten, agrichar advocate Tim Flannery, NSW DPI environmental scientist Steve Kimber
Pyrolysis (click to enlarge)
WHAT
Pyrolysis, or the heating of biowaste in the absence of oxygen, produces a fuel and Agrichar, a carbon waste product that is more inert than common waste carbon. It can be mixed into soil and, like fertilizer, enriches the soil. But, unlike fertilizer, it prevents the release of greenhouse gases (GHGs) from the soil to the atmosphere.

WHEN
Experiments and trial projects are widely under way. BEST Energies Australia, involved in the trials, has a pilot plant producing minimal amounts for research purposes. It is otherwise currently scarce.

WHERE
University of New South Wales Department of Primary Industries’ (DPI) Wollongbar Agricultural Institute in Sydney, Australia

WHY
- Australia’s carbon-depleted soils have doubled and tripled crop productivity when agrichar is mixed into them.
- Pyrolysis advocate Tim Flannery ranked it as one of 5 steps to save the planet because crop waste becomes fuel and agrichar to restore soil fertility and hold down GHGs.
- Normally, soil turns over 10 times the GHGs as burning fossil fuels. The trials found significantly lower carbon dioxide and nitrous oxide emissions. The carbon in agrichar stays locked in the soil for many years longer than compost, mulch or crop residue. Agrichar also raised soil pH, increased calcium and lowered aluminum toxicity
Farming with char (click to enlarge)
QUOTES
- Van Zwieten: “So it is not surprising there is so much interest in a technology to create clean energy that also locks up carbon in the soil for the long term and lifts agricultural production…When applied at 10 [tonnes/hectare], the biomass of wheat was tripled and of soybeans was more than doubled…Soil biology improved, the need for added fertiliser reduced and water holding capacity was raised…”
- Kimber: “We broadly categorise carbon in the soil as being labile (liable to change quickly) or stable – depending on how quickly they break down and convert into carbon dioxide…Labile carbon like crop residue, mulch and compost is likely to last two or three years, while stable carbon like agrichar will last up to hundreds of years. This is significant for farmer costs because one application of agrichar may be the equivalent of compost applications of the same weight every year for decades. For the environment, it means soil carbon emissions can be reduced because rapidly decomposing carbon forms are being replaced by stable ones in the form of agrichar.”