December 16, 2004 | General

Can Hormones Increase Earthworm Biomass Production?

BioCycle December 2004, Vol. 45, No. 12, p. 49
When treatments were applied at right levels, impact of waste conversion by worms was increased more than 50 percent.
Shova Patrabansh

VERMICOMPOST biotechnology can contribute to efficient conversion of organic solid wastes into easily handled and readily available products for plant growth. Research is being done to devise new ways to utilize worms in waste management as well as to enhance the production of compost and animal proteins for aquaculture. In one research project, we investigated the possibility of increasing earthworm biomass production through hormone treatment. Our results were reported at the 13th National Conference of the Composting Council of Canada held last year in London, Ontario.
Three different growth hormones – Naphthalene acetic acid (NAA), Indole-3-acetic acid (IAA) and Giberellic acid (GA) – were used at different concentrations. Feedstocks given the Eisenia foetida worms were poplar leaves and sericulture (silk production) residuals treated with these hormones. Based on our results, when certain hormones were applied at the right levels, efficiency of waste conversion by worms was increased more than 50 percent as compared to untreated worms.
Vermicompost offers promising value|to increase agricultural productivity. Unlike other animal manures, vermicompost contains readily available plant nutrients. The silk industry generates huge amounts of waste litter in the form of unused leaves, twigs and shoots; during the autumn season, poplar trees generate large quantities of biomass.
Eleven different concentrations of all three hormones were used – from 50 to 4,000 ppm in the experiment. The feedstock was treated with different concentrations of hormones before giving it to the worms. Water was sprinkled over the mass to maintain substrate moisture content around 65 percent. Earthworms were acclimatized to the container environment before feeding with treated feedstock. Treatments were given once during a three-week period.
Earthworm biomass weight increased up to the certain limits of hormone concentration. With excessive concentration, there was a gradual decrease in weight. Figure 1 illustrates the effect of hormone NAA at various amounts. A similar trend was observed with GA treatment where the highest percentage of increase was noted at 2000 ppm concentration. Response to hormone IAA was not very encouraging as compared to responses to NAA and GA. Based on the results of our preliminary studies, we believe that the use of hormones in vermiculture is a simple and ecofriendly way towards organic waste reduction. Upgrading the role of earthworms in management of municipal waste can mean more efficient utilization.
This report was excerpted from a presentation by Shova Patrabansh, Ph.D., entitled “Production of More Efficient Earthworms for Speeding Up the Waste Treatment Process,” at the Composting Council of Canada National Conference in London, Ontario. The author can be contacted via e-mail at

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