AN opportunity to learn more about using alternative biological management techniques to maximise pasture production efficiency was a drawcard to last week's Healthy Soils: Healthy Future workshop at Biloela.
Queensland Primary Industries and Fisheries extension officer Valeria Berry, leader of the Healthy Soils: Healthy Future project, organised the workshop attended by 80 predominantly Central Queensland cattle producers – many of whom are keen advocates for cell grazing management practices.
Ms Berry said the three-year ground-breaking farm trial project launched in the 2008-09 summer season aimed to assess the impact of new and alternative management practices on soil health.
Participants were keen to hear from keynote speaker Dr Elaine Ingham who provided her recommendations about the project’s interim biological management trial results from the on-farm demonstration sites.
Dr Ingham is an internationally recognised United States soil microbiologist whose research has targeted the microorganisms contributing to the health of the soil food web.
Dr Ingham is currently the director of research and president of Soil Foodweb Inc, a company which operates 12 laboratories world-wide including the Soil Foodweb Institute Laboratory at Lismore, NSW.
Ms Berry said the farm trials and demonstration sites involving 12 producers from Baralaba, Biloela, Calliope and Kingaroy districts and two at Mareeba had been kick-started with a $507,000 National Landcare Program (NLP) funding grant.
This project – “Healthy Soils, Healthy Future: Bridging the gaps for sustainable agriculture” – is funded through “Caring for Our Country: Landcare Sustainable Practices Program”.
It represents a collaborative approach between QPIF, Fitzroy Basin Association, Northern Gulf Resource Management Group and Landcare Groups.
To service the on-farm project sites, Soil Foodweb has been contracted to test the biological products being applied while also identifying the diversity and quality of existing biological soil activity.
Additional soil nutritional testing is being done through Southern Cross University (Lismore) and soil carbon testing is going through the Department of Environment and Resource Management’s Indooroopilly laboratory.
Ms Berry said that to address productivity issues linked to soil fertility decline, soil organic carbon loss, nutrient availability for plant growth, soil compaction and erosion, there was a need for a practical understanding of the management of soil biology combined with a reduction of fertiliser and chemical inputs.
While it is too early to draw any conclusions from the trials now underway, the workshop provided delegates with a practical overview of what had been undertaken to date.
“We now have 10 demonstration sites each averaging 25 hectares where we are trialling the use of biological soil treatments such as compost teas, biodynamics (which are composts) as well as food sources such as humic acid, hydrolysed fish and others to promote the activity of existing soil microorganisms,” Ms Berry said.
“The trial work aims to prove that issues such as soil compaction, plant available nutrients, water holding capacity and pasture rundown can be dealt with in the long term by improving the soil biological activity which contributes to a build-up of organic matter.
“Our demonstration trials also involve the application of a range of tested biological products to enhance the regenerative process of the soil.
“As an example, we have sprayed 100 litres/ha of compost tea combined with 2 L/ha of hydrolysed fish (fish by-product) and 0.4 kg/ha of humic acid in a total volume of 150-200 L/ha onto pasture country following a decent rainfall event to promote spoil microbial activity.
“Our objective is to apply these sprays three or four times a year provided there is enough moisture in the system.”
Ms Berry said many landholders were preparing their own compost tea formulations based on commercial compost inoculums mixed with water, aerated and brewed to reproduce the desired concentrate of microorganisms.
Dr Ingham recommends that before applying compost tea preparations, it was important to have a sample tested qualitatively by a qualified laboratory.
“Testing ensures there is a good variety of desired microorganisms and it is just not brown water being applied to the paddock.
“It is also essential to have soil samples analysed to benchmark what is present and then simply adjust biological management practices to support the role of specific soil organisms to enhance plant nutrient availability,” Dr Ingham said.
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