Vermiculture key to reducing greenhouse emissions

Researcher Dr Rajiv Sinha said vermiculture had potential to combat climate change by reducing emissions of greenhouse gases that plague current landfill waste management programs.

"Methane and nitrous oxides from landfills are several times worse than CO₂ as greenhouse gases," said Dr Sinha.

Dr Sinha has spent the past 25 years in India and now in Australia studying vermiculture practices worldwide.

He is now working to encourage governments, policy makers and landowners in Australia to adopt vermiculture on a commercial scale following the success of his trials in India where it has also enhanced the life of farmers.

Two studies in vermiculture published this year in the UK in the journal The Environmentalist found worms were also useful in sewage treatment, or 'vermifiltration'. Worms reduced the biological oxygen demand loads by over 90% and total solids by 90–95%.

"There is no ‘sludge formation’ which is a biohazard, unlike conventional sewage treatment plants which need landfill disposal at high cost. This was an innovative study made at Griffith University."

A second study supported the efficiency of worms at removing heavy metals, pesticides and organic micropollutants from soil, a technique know as vermiremediation.

"This has significance in Australia as large tracts of arable land are being chemically contaminated due to mining activities, heavy use of agro-chemicals and landfill disposal of toxic substances," Dr Sinha said.

He is currently studying the potential of greenhouse gas emissions from various composting systems with Dr Andrew Chan in a project done by Honours student Richard Middleditch.

He is also studying the growth promoting values of earthworms and their vermicompost over conventional compost and chemical fertilisers.

"Our glasshouse studies showed vermicompost is three to four times more nutritious than conventional compost and takes nearly half the time to produce, while a field study by farmers in Argentina found it 5–7 times more nutritious.
It can promote growth from 50 to 100% as compared to conventional compost and over 30 to 40% as compared to chemical fertilisers."

Dr Sinha has completed trials on wheat and vegetable crops such as okra and eggplants in India and on corn crops in Australia alongside chemical fertilisers and conventional compost, and is now testing on tomatoes.

"Wheat crops grown on vermicompost @ 2500 kg/ha gave yield over 4000 kg/ha whereas those on full doses of chemical fertilisers was about 3400 kg/ha. On cattle dung compost @ 10,000 kg/ha – four times that of vermicompost – the yield was just over 3300 kg/ ha.

"In Australia we send thousands of tonnes of organic waste to landfills, which is an economic and environmental burden for society.

"Political will is required to integrate waste management with organic farming programs promoted by vermiculture. We have known the benefits of vermiculture for centuries. We now have the scientific data to prove it."