16.4 RESEARCH

16.4 RESEARCH

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RESEARCH


Applications for brown coal in
Australian agriculture

By David McManus, Research Investment Manager, BCIA

The BCIA workshop ‘Agricultural applications for brown coal’, held in December 2015, identified a range of prospective new opportunities for Victorian brown coal. Detailed discussion of these options was hampered however, by a lack of information on the work that was done in the past.

To fill this information gap, BCIA has prepared a report for BCIA members, titled ‘Applications for Brown Coal in Australian Agriculture’. The report summarises the publicly available literature and illustrates the broad range of potential agricultural products that can be derived from brown coal.

One surprising result of the analysis undertaken in the report is the quantity of off-farm carbon inputs required to improve the carbon content of Australia’s agricultural soils. If this demand were met solely by products derived from Victorian brown coal, it would require 170 million tonnes per annum of run-of-mine coal – far in excess of current Victorian production rates!

As recommended by workshop delegates, a central theme of the report is the potential of brown coal products to increase the concentration of organic carbon in Australian soils. Since European settlement, the concentration of soil organic carbon (SOC) in Australia has fallen, by as much as 60% in some areas, adversely affecting plant productivity and soil health. Similar declines in SOC stocks have occurred worldwide and it is vital that this trend be reversed.

In recognition of this problem, Australia was the first of 25 nations to endorse the “4/1000 Initiative: Soils for Food Security and Climate” during COP21 in Paris in December 2015. The ‘4/1000 Initiative’ represents a shared commitment to increasing the global SOC reserve by 0.4% annually. It aims to improve agricultural productivity and help feed a growing world population, and to assist in slowing the rate of global warming by ‘locking up’ carbon from atmospheric CO₂ in the soil.

While Australian soils are generally poor in organic carbon, Victoria is blessed with abundant deposits of ancient decomposed plant matter, in the form of its massive brown coal reserve. In principle, Victorian brown coal is ideal for boosting the carbon content of soils.

When used as a soil amendment, brown coal can help to build soil carbon, improve productivity and increase profitability. As was discussed in the workshop, industry-led research will be needed to transform raw brown coal into commercial products that can cost-effectively be transported and utilised on farming land across Australia.

One of the main challenges identified in the report is that there is currently no well-defined way to quantify the financial benefits of increased SOC in agricultural soils. This makes it difficult to define the value proposition for products intended to boost SOC levels. Large-scale field trials are needed to properly quantify the costs and benefits of using brown coal to build soil carbon levels, and to understand the longevity of coal-derived organic carbon in the soil.

At the present time, humic substances represent the main agricultural market for coal-derived products, both in Australia and elsewhere. Humic substances represent the ‘active ingredient’ in brown coal and, in dry form, are much cheaper to transport but more expensive to produce. The report suggests that humic substances will continue to be regarded as premium, high-performance ingredients in specific applications, e.g. foliar sprays and fertigation.

Humic substances appear to have potential for use in animal feed supplements, where they are reported to improve stock health, growth rates and feed conversion efficiency. This is a premium application with great potential significance for Australian agriculture.




The report identified organo-mineral fertiliser products as another attractive market opportunity. Organo-mineral fertilisers are based on blends of brown coal and/or humic substances with proven fertiliser ingredients (either chemical or biological). There is good scientific support for the use of such products to increase the efficiency of N and P fertilisers, which makes for a simple value proposition. The report suggests that there is potential for a number of new manufacturing businesses in this area.

Surface application of brown coal is an inexpensive way to reduce ammonia emissions from intensive animal rearing operations, such as beef cattle feedlots. Most Australian beef cattle feedlots are in NSW and Queensland, so transportation cost is an issue to be addressed. The report recommended that opportunities be investigated in similar intensive industries (e.g. poultry, pork) in Victoria.

The report also considers potential agricultural uses for Latrobe Valley fly ash, a by-product of electricity production from brown coal. Applications for the fly ash are generally limited because of its strong alkalinity and high concentration of boron. The report suggested that there may be potential agricultural applications in areas of high rainfall and/or acidic soils, where boron deficiency is a problem. In these areas, the high boron content of fly ash would be an advantage.

Production of agricultural inputs from brown coal is an attractive way to create a new manufacturing industry in Victoria. The capital and processing costs are relatively low, and there is a large potential market. There is definitely a role for the use of brown coal in boosting the organic carbon content (hence productivity and profitability) of Australian agricultural soils. Innovative, cost-effective new products are needed to achieve this, along with performance data that establishes a clear value proposition for the farmer. Industry needs to take the lead in developing these opportunities, supported by the academic expertise that is already in place.

BCIA intends to facilitate further industry-academic collaboration in this area, to support the creation of new industries and employment in Victoria.




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