Soil scientists commenting on the potential of Australian soils cannot be believed because the science has not been done, according to a farmers’ lobby group.
“Two senior CSIRO soil scientists set limits on the amount of carbon we farmers can capture and hold in soils, but their science is out of date,” says Michael Kiely, convenor of the Carbon Coalition.
No attempt has been made to test the 'potential' sequestration capability of Australian soils. And there is no work underway that will reveal it. There is no attempt to study the impact of biological farming on its own and, more to the point, there is no plan to study 'portfolio planning' or combinations of land management practices that complement and reinforce each other to maximise soil C sequestration.
“This is the reality on the farm. This is what Carbon Farmers do. (Eg. At "Uamby' we use grazing management, pasture cropping and probiotic innoculants, on the same piece of ground.) We have developed the Soil Carbon Optimising Tool to help farmers build a carbon farm plan to 'mix and match' their sequestration techniques. So while Science is measuring the potential of the past, we are seeking to live the potential of the present while helping to create the future.”
The facts are as follows:
Australia’s soils have not been studied comprehensively for their potential as a carbon sink.
Australian soils have only been fully studied for their capacity as a source of emissions.
There has been no major investment in research in this field until the Commonwealth Government arranged for a total of $26.5m to be allocated to studies overseen by the CSIRO. This research is yet to be completed. It is not designed to reveal the upside potential of different soils to sequester total carbon.
The data relied upon by CSIRO scientists to make statements about soil carbon potential must always be at least 5 years out of date due to the requirements of the scientific ‘peer review’ system. The actual research takes at least 3 years. Then it must be reviewed by a panel of scientists who can recommend changes to the report or even that work be redone. After clearance, the paper must appear in a scholarly journal of note before it is widely accepted.
Most of the research relied upon to ‘prove’ that Australian soils can sequester little or no carbon do not meet the basic Kyoto requirement that there be a change in land management beyond ‘business as usual’ Without a change in land management there can be no sequestration.
No research conducted or being conducted in this field is focusing on land management practices which have demonstrated in on-farm trials the greatest impact on sequestration rates. They are: 1. Biological Farming and 2. Carbon Farming (or portfolio planning), the latest innovations in this field.
Dr Jeff Baldock is wrong when he says “if you really want to capture enough carbon to start affecting our total emissions, a big chunk of land is going to have to be converted from the agricultural use it has seen into something else.” Practical experience reveals that actively grazed pastures and rangelands sequester more carbon than other land uses. There are more than 400m hectares of these lands in Australia. Even in croplands, changes to land management do not mean land must go out of production. It is the active life of the roots of plants that produces soil carbon.
Corn crops can sequester 5tonnes of carbon per hectare per year, according to NSW Industry & Investment researchers. (See below) That is the equivalent of more than 15 tonnes of CO2.
Dr Mike Gundy is wrong when he says that the Opposition could not reach its target when sequestering only half a tonne of carbon per hectare. 0.5 tonnes of carbon is equivalent to 2 tonnes of CO2. Australia has more than 400m hectares of agricultural lands. At 2tonnes CO2-e, the potential annual sequestration is 800m tonnes.
WHITE PAPER: A comprehensive analysis of why formal science suppresses soil carbon sequestration rates can be found in a white paper titled “Good Science & Snake Oil” posted at http://goodscienceandsnakeoil.blogspot.com
Michael Kiely
Convenor
Carbon Coalition
(02) 6374 0329
Corn crop can sequester 34 tonnes CO2-e per hectare per year (DI&I)
Corn can be used to build soil carbon levels. Total carbon added from corn roots averaged five tonnes per hectare per year with cotton-corn and 9.3t/ha/year with back-to-back corn, says Industry & Investment NSW senior research scientist, Nilantha Hulugalle. THIS IS THE EQUIVALENT OF BETWEEN 18 TONNES OF CO2-E AND 34 TONNES OF CO2-E PER HECTARE PER YEAR. Soil organic carbon dynamics in these farming systems have focussed on inputs of above-ground material.
“Addition of root material to soil carbon stocks either in the form of roots dying and decaying during and after the crop’s growing season are, however, significant," she said in a Land Newspaper report.
A project examining grey clay cotton soils near Narrabri found root death and decay contributed more than half of corn’s carbon to soil. Corn is a summer crop often grown under irrigation after cotton.
“We measured corn root growth in back-to-back corn and a cotton-corn rotation sown on one metre beds during the summers of 2007-08 and 2008-09, Dr Hulugalle said. Root measurements were made at intervals of two to four weeks during the growing season by using a combination of soil cores, a minirhizotron and an image capture system, using a video camera inserted into the soil through a clear plastic root observation tube. “The video camera was connected to a field computer with software which is able to take root images at specified depths. Carbon was analysed in roots sampled by coring.
The amount of carbon held in the crop roots at the end of the season and the amount of carbon added to the soil by roots dying during the growing season, were measured. Corn root densities, particularly towards the latter part of the growing season, were higher with back-to-back corn than with cotton-corn rotation.
“The amount contributed by root death during the growing season averaged 11% of the total amount.
“Relative to carbon contributed by the whole corn crop, above and below the ground, the amount of carbon contributed by roots can range from 50% to 65%.”
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