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Best of the Humusphere


Lawrence F. London, Jr.
Title: Best of the Humusphere

Best of the Humusphere

"Best of the Humusphere" are hand-picked essays of interest, announcements, releases, etc. that the managers of the Humusphere believe represent the core of the issues and discussions surrounding composting and sustainability. Read on to get a taste. If you like it, try other topics.


Larry J. Forney and James M. Tiedje
NSF Center for Microbial Ecology, Michigan State University
East Lansing, Michigan


There is considerable interest and debate about the efficacy of using "specialized" microorganisms to enhance biological remediation processes -- so called bioaugmentation. In the typical scenario, pure cultures or mixtures of microorganisms that are especially adept in degrading specific classes of contaminants in the laboratory are selected. These specialized cultures are then used to amend soils or injected into the subsurface with the intent of increasing the rate of specific metabolic processes. To perform their intended function, the introduced organisms must survive, grow and function. However, ecological theory states that only species can occupy any given niche. So each species introduced into the environment must compete with the high numbers of different indigenous species present and must displace one or more of the species present. This is a formidable task given that each species, by definition, is well-suited and effectively competes for the niche that it occupies. In many cases, the introduced species will not be more fit. This is probably true because the indigenous species for the introduced organisms would have been selected under conditions that did not mimic the natural environment closely enough. Given the heterogeneity of soils and the subsurface, and the obvious difficulty of mimicking natural systems in the laboratory, the "specialized" microorganisms selected might be used effectively in some but certainly not all environments (sites). Thus, conclusions as to whether particular "specialized" microorganisms would be effective in a given environment can only be made based on empirical, site-specific data. Exceptions to this general principle would be instances in which none of the indigenous species are able to efficiently metabolize a contaminant. Under these circumstances, the introduced species would occupy a 'unfilled' niche. Alternatively, other perturbations (changes) in the environment might create ecological niches that could be occupied by introduced species. In sum, it should be recognized that it is very difficult to predict the efficacy of "specialized" microorganisms because factors that determine the competitive ability of microorganisms in the environment are not well understood.

Why Organic Matter?

Organic Matter influences the moisture-holding capacity of the soil, serves as a supply of nutrients, feeds microorganisms, insects, earthworms, etc., and improves soil tilth and structure. The amount of organic matter depends on temperature, rainfall, aeration and other factors. It tends to be a characteristic of soil type in a given environment and is not easily changed. Excessive tillage results in a loss of organic matter. Large additions of crop residue, compost, mulch, manure, etc. cause only small changes in soil organic matter. Ideal soils have about 5% organic matter. Excessive applications of organic matter may tie up available nitrogen. More organic matter found in mulches would not hurt the garden soil. Compost from the compost piles is an excellent addition to the gardens, either worked into the soil or placed on top as a superb organic weed control.


ZeroWaste is a planning principle for business and citizens in the 21st Century. Waste is inefficiency and businesses must be encouraged to strive towards environmental efficiency. Just as businesses don't want to waste time or money, they should be discouraged from wasting natural resources. Nor should they be allowed to pass their waste on to consumers, in the form of "disposable" products and packaging. In a ZeroWaste marketplace, businesses will create reverse distribution systems to take products and packaging back into production, rather than dumping the problem on community incinerators and landfills. Nature is a ZeroWaste system. Business must learn to be more like Nature.

Is ZeroWaste necessary?

If all businesses operated as wastefully as do businesses in the "developed world", we would need THREE PLANET EARTHS to support them. In our daily lives, we use much more than our fair share of the earth's resources. As more and more people join the human family, and all aspire to live the way we live in the "developed world", the inefficiency we now take for granted will not be tolerable. ZeroWaste is a discipline we must begin to practice now. We must learn to eliminate unnecessary waste, in order to preserve the true quality of life that we aspire to as human beings -- the quality of life defined by having just enough of what you want, rather than an abundance of waste -- which no- one wants.

The North American economic system stands for...

Our economic system is built on the trust we have in the free market to regulate the production and consumption of goods. Consumers have the freedom to choose, and their choices guide the producers in the production of goods. But a free market only works if the prices of products tells the truth about the costs of production. For many years, product prices have misled consumers. Cheap, mass-produced convenience products bear hidden costs that the consumer never thinks about. Landfills, incinerators, litter clean-up -- these are all costs that are passed on to local communities, not paid for by the producers of the products that become waste. Taxpayer subsidies and tax breaks that support the squandering of natural resources. Welfare checks paid to the unemployed -- productive workers who lost their jobs to automation and mass-production. These environmental and social costs are hidden subsidies, ways in which the taxpayer inadvertently encourages businesses to be wasteful and inefficient.

The Solution

A ZeroWaste economy will shift these environmental and social costs back into the prices of the disposable products and packaging where they belong, signalling to the consumer that these are not such bargains after all. In a ZeroWaste economy, the competitive producer is the one who learns to avoid waste and invest in jobs that produce high-quality products and services.

The Grassroots Environmental Network is calling for a shift to a ZeroWaste economy. We want to create jobs, not waste. We want to end subsidies for waste.

From: Tim Myles t.myles@utoronto.ca

Re: Possible use of termites on spent mushroom substrate or other agricultural byproducts.

Spent mushroom substrate is likely to be an excellent physical and nutritional medium for termites. Termites are the main group of invertebrate animals that digest low-nutrient, lignocellulosic, "brown" matter. We northern hemisphere biologists have a profound blind spot when in comes to appreciating the stupendous importance of termites in the carbon cycle. Termites are the major animal bioconverters of plant cell wall matter into animal biomass on this planet. I'll just repeat that: Termites are the major animal bioconverters of plant cell wall matter into animal biomass on this planet. In performing this they support a huge percentage of small vertebrate insectivore biodiversity.

One popular misconception about termites is that they eat only wood. This is true of only the most notorious pests. It is estimated that over 50% of all termite species are humivorous. Entire subfamilies of the higher termite family Termitidae, such as the Apicotermitinae and Termitinae are humivourous. Many other termites feed on surface litter, dry leaves, grass, and even lichens. In arid areas, where animal dung rapidly becomes too dry for dung flies and dung beetles, termites are the major decomposers of herbivore dung. In fact, many of the most abundant termites in arid and semi-arid regions of the world are dung feeders. This is true in the American Southwest, where several species of Amitermes, Gnathamitermes, and even Reticulitermes are commonly found in dung. In fact, I am in the process of describing a new dung-specialist genus which is found in the American southwest and Northern Mexico.

Decompiculture, or the culturing of decomposer organisms, is the inevitable next step in mankind's utilization of natural resources and ecological integration in the biosphere. Large scale composting is the first evidence that we are waking up to this ecological imperative.

The most important candidate decomposer organisms are bacteria, actinomycetes, fungi, earthworms, termites, beetles and flies. Up until now, these organisms (decomposers) have not been seen as sources of production. Those of us who study these organisms tend to study the relatively few that are pests. The majority however are beneficial and essential cogs in the cycling of nutrients. Now that humankind has progressed to the point of having numerous large organic waste streams we must now develop intensive decomposition systems to match our intensive production systems.

"Termite ranching" or termiticulture inevitably will be much more important than vermiculture because termites are able to utilize lower nutrient substrates, wood and humus. Termiticulture could probably be easily integrated with mushroom production. However termites do not develop quite as quickly as many other insects thus the start up time might be several years before the population could consume at the rate of spent compost delivery. Containment and rearing facilities would have to take into account their social habits.

Termiticulture may not be feasible out of doors in the temperate part of the northern hemisphere. The southern tier state of the US would be adequate for a few genera such as Reticulitermes and Amitermes, but large scale termiticulture would work best in conjunction with tropical agriculture, especially wherever there is a large cellulosic waste component in the food processing. Termite production could also be integrated with dairy and livestock production as a manure management system. Matching species to wastes and to stage of waste would be necessary.

If anyone knows of an innovative tropical agribusiness that would be interested in putting up the capital for a pilot study, I'd like to hear from them.


Tim Myles
Dr. Timothy G. Myles, Faculty of Forestry, University of Toronto, 33 Willcocks Street, Toronto, Ontario M5S 3B3, CANADA. t.myles@utoronto.ca phone: (416) 978-5755
fax: (416) 978-2403
home phone (905) 877-9351