Li Kangmin
Chinese Academy of Fishery Sciences, Freshwater Fisheries Research Center
Asian Pacific Regional Research & Training Center for Integrated Fish Farming
No. 9 Shanshui West Road Wuxi 214081 China
Abstract This
paper reviews the history of vermiculture, indicating it is an
important component of macro-agriculture. Earthworms seem to be the
missing link of ecological agriculture in China. Earthworms can treat
large amounts of organic garbage, livestock manure and poultry
droppings and turn them into premium organic fertilizers, and thus
could greatly improve the ecological environment in rural areas to
restore the fertility of the soil because humus only exists in
earthworm feces and castings compared with other fertilizers.
Earthworms can supply quality animal protein for feed and even for
human consumption, and offer the best raw materials for biochemical and
pharmaceutical industries. As industries and agriculture develop and
urban construction is booming, the discharge of wastewater and sewage
soars and wastewater treatment plants are set up everywhere around
cities; stabilizing the sludge presents a big challenge and earthworms
could play an important role in facing this challenge. Vermiculture
should be oriented to stabilize sludge and organic wastes in
circulation economy, for it is an approach to sustainable agriculture
and a measure in promoting organic farming so as to break technical
barriers of production in international trade. It should be supported
by policies under the guidance of scientific development viewpoint and
be put into whole circulation economy as a means of protecting the
environment, maintaining ecological balance, and fully utilizing
resources. However, it should be combined with other technologies such
as EC
(electro-coagulation), EH (energized hydrolyser), and especially EM (effective microorganisms). We should promote
courtyard earthworm composting as well as large-scale vermiculture, which should be mechanized and automated.
Keywords:
Vermiculture, macro-agriculture, sludge stabilization, circular economy, earthworm composting
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3000
years ago written record on earthworms appeared in The Book of Songs.
Up to Warring Period (475-221 BC) Xunzi described earthworms, “with
neither sharp teeth and claw nor strong bone and muscle,” could however
“feed on dust at the upper layer and drink from netherworld at the
lower” in his “Article to encourage learning”. Earthworms have been
introduced into medicines in China for more than a thousand years. In
the West, the Greek philosopher Aristotle (384-322 BC) called
earthworms the intestines of the earth. He believed that soil was an
organic entity and he understood that earthworms played an important
role in maintaining the life of soil. But even at the end of 19th
Century, some Westerners still thought that earthworms would eat the
roots of plants and so hinder the growth of plants and destroy crops,
and thus they suggested earthworms be killed. The reputation of
earthworms was not rehabilitated until Darwin published his works on “The Formation of Vegetable Mould
Through the Action of Worms with Observations on their Habits” in 1881. It
indicated that the understanding of earthworms in ancient China was earlier than in the West, whereas vermiculture (the
scientific name for worm farming) in China now lags behind the
West.
Since
adopting economic reform and open policies China has started to throw
away narrow-minded agricultural concepts with grains as its core
sector, while promoting the development of macro-agriculture and
diversification to develop crop planting, forestry, animal husbandry,
side occupation and fisheries simultaneously. The well-known scientist
Qian Xuesen says that five sectors are not enough for
macro-agriculture, and in addition we should have apiculture,
vermiculture, snail culture, edible fungi, fodder grass, etc. He has
put forward his concept: “the 6th
Industrial Revolution---Macro Agriculture Revolution would be launched
in China not later than the 2030s”. He thinks that “once the concept of
macro-agriculture is put into practice, it is the beginning of the 6th
Industrial Revolution in the world.” Earthworms are an important part of macro-agriculture.
Necessity to develop vermiculture
industry |
As
agriculture modernization speeds up, the livestock, poultry and fishery
sectors are marching on the road of intensive management development.
Since 1988 when China put “Vegetable Basket Engineering” into effect,
million-broiler farms, thousand-pig farms, hundred-cow farms and
large-sized aquaculture farms have been founded everywhere. Intensive
managed sectors are approaching the suburbs of cities and densely
populated areas. On the one hand it greatly improves the living
standards of the inhabitants of cities and towns; on the other hand
there is neither sufficient land to utilize the livestock manure and
poultry droppings produced from animal husbandry, nor abundant water
resources to self-purify the effluent from aquaculture ponds, resulting
in two problems: scarcity of quality feeds, and serious pollution of
soil, air and water. Traditional organic manure looks dirty, smells,
and is full of pathogenic bacteria. In vast countryside it was labor
saving and easy to use that this has promoted the application of large
amount of chemical fertilizers for years as a result the fertility
degraded, the soil hardened and impervious. This is what would come
from fossil fuel agriculture in developed country. Now the UN has
proposed the concept of sustainable development and China also proposed
the developmental concept of ecological agriculture. No matter what we
call it, “zero emissions research initiative” in recent decades or
“circular economy” at the beginning of this century, vermiculture
should be an important part of macro agriculture, an important link in
the agricultural circular economy which is internationally called
Integrated Biomass Systems (IBS). But in a book which comprehensively
described “Waste treatment and reuse of wastes in ecological
agriculture” there is not a single line mentioning earthworms [1]. We
have to say that earthworms seem to be a missing link in ecological
agriculture in China. Earthworms can treat organic wastes, livestock
manure, and poultry droppings, and turn them into quality organic
manure and greatly improve the ecological environment in rural areas.
Earthworms are also a very good food source, with crude protein in dry
weight reaching about 70%, and an excellent industrial raw material as
well. Many enzymes and active matter can be extracted from earthworms
for pharmaceutical, food, cosmetics and environment protection. Owing
to the development of industry and agriculture and the boom in
urbanization, the discharge of industrial and agricultural wastewater
and sewage effluents has rapidly increased. Thus there are many
wastewater treatment plants established around cities. How to stabilize
the sludge from those plants is an urgent challenge, and earthworms can
play a unique role to stabilize sludge in the circular economy as a
whole.
Status of the vermiculture industry |
In the late 1970s, thousands of Americans were victimized by hucksters claiming that backyard worm breeders could easily gross over $14,000 a year
by tapping the wrigglers' potential as bait, soil enrichers, and even food. Vermiculture collapsed at the end of 1970s. Up to the environment-friendly
90s, the feeding habits of earthworms which consume large amount of rotten food made them a viable waste-disposal alternative. The
tiny creatures' ability to devour virtually any organic
waste--livestock manure, rotten food, even ratty T-shirts--and excrete
it as premium organic fertilizer (dubbed "black gold" by organic
farmers for its nitrogen richness) is proving profitable for a host of
non-squeamish entrepreneurs. Earthworms are
the missing link that makes sustainable agriculture a reality.
Vermiculture is booming thanks to environmentalism and the demand for
organic foods. Vermiculture ventures in America, the biggest of which
involve 50 million worms chewing down on almost 90 tons of waste per
week, have boomed over the past few years. Nearly 300 large-scale
vermi-culturalists formed the International Worm Growers Association in
1997 to help promote the trade. Many outfits are prospering thanks in
part to the growing popularity of organic foods, which became a $6.5
billion-a-year business by 2000. With the U.S. Department of
Agriculture estimating that 25 percent of Americans purchase
organically grown foods at least once a week, organic farmers' demand
for worm feces far outstrips supply.
Vermicycle
Organics, which harvests worm droppings in high-tech greenhouses,
produces 7.5 million pounds of a natural fertilizer a year. The company
expects sales of the fertilizer to grow by 500 percent this year.
Vermi-technology Unlimited has doubled its business every year since
1991, despite prices that can run twice as high as those of synthetic
fertilizers. Vermi-technology founder Larry Martin predicts that "In 5
to 10 years, every commercial fertilizer company will be selling worm
castings." With many local and state governments trying to divert waste
from clogged landfills, forward-thinking cities are promoting "backyard
vermin-composting." Traditional compost piles can take weeks to produce
low-quality humus; a pound of worms, on the other hand, needs only 48
hours to convert a pound of waste into nutrient-rich castings. In San
Jose, California, where state law has mandated that the amount of
garbage going to landfills be cut in half by the year 2000, about 1,200
residents used city-distributed discount vouchers to purchase
garbage-eating worms from Chambers's Worm Farms. This small operation
sells 4,000 pounds of worms a year--about 4 million of the critters--at
around $20 per pound [2].
In
the 1970s several species of earthworms were cultured in simulated
natural ecological conditions in China, the same as in
North America. On the one hand it met the market’s demand for
aquaculture, livestock and animal husbandry as quality protein feeds
with high performance-to-price ratio, and also the pharmaceutical
industry’s demand for raw materials; on the other hand it was somewhat
a profiteering activity as well. Especially after the Japanese premier
presented the hybrid of red wiggler and local earthworm as a gift to
China, it aroused a small boom in vermiculture in many places, but in a
small and scattered scale with low technology, low unit yield (about 3
tons/mu/year), and competitive for land with crop planting. The
direction of rearing earthworms fell wrongly on selling earthworm
breeding stock to farmers for profit only, not for waste disposal on a
large scale and selling earthworm feces and castings to improve the
soil. In recent decades vermiculture has experienced ups and downs
owing to the fluctuation of market requirements, narrow developmental
concepts, and a lack of science and technology support or integrated
development capability. In some places there is almost no vermiculture
industry except scattered and sporadic farms.
Where is the orientation of
vermiculture ? |
l
Organic waste disposal
In
other countries vermiculture has been promoted to stabilize sludge and
other organic wastes for 50 years, while vermiculture in China is still
a side occupation of households. There is no large earthworm farming
facility to treat large amounts of organic wastes. This is due mainly
to a lack of scientific guidance and of awareness that earthworms can
play an important role in a circular economy. Certainly the constraints
of commercial application come from many factors such as engineering,
investment, risks in the process of production, high cost, and lack of
policy support.
Many
cities in the world are surrounded by garbage; for example, the world
garbage capital New York City produces 11,000 tons of garbage each
day[3]. The cost of landfill is higher and the land is less available
for garbage. Thus many countries seek to avoid sending organic waste to
landfills through legislative measures. In order to control water
pollution and to use wastewater as resources China brings forward its
clear requirements of wastewater treatment for cities: by 2005 the
wastewater disposal rate from cities with a population of 500,000
should reach 60%; by 2010 the wastewater disposal rate from all cities
should not be less than 60%; for cities under direct jurisdiction,
provincial capitals, independent cities out of planning, and tourist
cities the wastewater disposal rate should not be less than 70%. How to
deal with huge amounts of sludge is a challenge faced by many big
cities.
In
general we call the stabilization and dehydration (reduced to the
moisture 70-80%) of sludge the treatment of sludge; we call compost,
landfill, drying and heating and final treatment the disposal of
sludge. There are two methods to stabilize sludge, one aerobic and the
other anaerobic. Aerobic treatment has many advantages but consumes a
great deal of energy. Anaerobic treatment adopts anaerobic digest
methods at medium temperatures (35℃).
After the sludge has been digested, organic matter will be reduced and
performance stabilized, and total volume reduced. During the digestion
the large amount of biogas which are produced (1kg COD can produce 350L
biogas) can be recovered for use [4]. Stabilizing sludge by earthworms
is considered the most attractive option [5] [6] [7]. The method is to
mix sludge with solid garbage from cities, bark, and sawdust, and to
feed this mixture to earthworms [8]. The development and application of
earthworm technologies are most often performed in temperate climates,
but Vermibloc in Russia developed year-around vermiculture methods in
the northern harsh and temperate climatic conditions.
Tests
predict that building an earthworm culture farm which can treat 55,000
tons of garbage a year can produce 2,500 tons earthworms and 18,000
tons of earthworm feces a year. It can reimburse the investment in
construction of the farm in about one year, saving the energy otherwise
consumed to burn garbage in incinerators and avoiding secondary
pollution to air and water. Every wastewater treatment plant should
have its own earthworm culture farm. An earthworm culture farm in Los
Angeles in America rears 1,000,000 earthworms and can treat 7.5 tons of
garbage each month. Each earthworm can usually treat 0.3 g of garbage a
day. If one wants to treat 1 ton of sludge from a paper mill per day he
needs to culture more than 3,000,000 earthworms. Some countries use
earthworms to collect heavy metals because their capability to collect
heavy metals such as cadmium, lead, and mercury is 2.5-7.2 times
greater than that of soil alone [9].
Australia
uses dehydrated sludge direct from a water plant without compost to
feed earthworms. Earthworm treatment systems are installed in many
sites. Redland in Brisbane, Queensland, is the largest installation in
Australia, which has a capacity of 400 m3 per week. They first analyze the input contaminants of sludge, mix it with clean organic material so as
to reduce the ultimate level, and then
to feed earthworms, thus making earthworm castings to meet the
stabilization standards Grade A or B for permission to be sold.
Vermiculture in large scale provides an ecological, commercial and
sustainable stabilization method to replace compost and limestone
stabilization. This has several advantages: no pollution, no odor, and
no leaching; low cost; installation set up near the wastewater
treatment plant; transportation of sludge is avoided; it is possible to
treat organic wastes from other regions; and the production of quality
products to supply new markets.
l
Call for castings to improve soil
Macro agriculture must have earthworms. It is imperative
that all of us reach a unanimous conclusion: society must return to
nature and human beings and nature should develop in harmony in
co-evolution, and we should return badly needed
organic matter back to the soil. Farmers have now realized they should
change their production practices and reverse the degradation of soil,
and they must use earthworm castings to replace chemical fertilizers or
crop yields and quality will both fall further, with fruits and melons
no sweet.
Darwin
wrote in “Earthworms and plant loam” in 1837 that “earthworms as a
plough is one of the most ancient valuable inventions of human being.
Long before human society emerged soil had been ploughed, have been now
ploughed and will be continuously ploughed by earthworms afterwards”.
Earthworms are called ‘living ploughs’ by virtue of their excellent
ability to loosen soil, gather nutrients and increase fertility. In
general the land ploughed by earthworms for 3 years will become high
yielding land. Healthy soil is rich in minerals, soil microorganisms,
earthworms and humus. Earthworms loosen the soil as they move through
it. Air and water can penetrate soil through earthworm tunnels.
Earthworms climb up to the surface of soil to grab remnants of plants
and feed in tunnels and thus fertilize all strata of soil. One square
meter of healthy soil contains 1,000 earthworms. According to the
estimate of an American researcher, 1,000,000 earthworms in a garden
plot provide the same benefit as three gardeners working 8 hours in
shifts all year round, and moreover having 10 tons of manure applied in
the plot [8].
But
what soil needs is not only manure, but more importantly humates, the
salts of humic acids. Compared with other manures, only earthworm feces
contain humic acid [Table 1]. Without humus and humic acids plants
cannot grow and survive. Humic acids are found in humus, and humus is
formed by the decomposition of vegetable and animal matter. The humic
acids (humic, ulmic and fulvic) are essential to plants in three basic
ways: humic acid enables plants to extract nutrients from the soil;
ulmic acid stimulates and increases root growth: and fulvic acid helps
plants overcome stress and helps dissolve unsolved minerals to make
organic matter ready for plants to use. Humates help aerate the soil
and increase moisture retention. As any vegetable and animal matter
decomposes it produces humus. Often people confuse organic fertilizers
such as manure or sludge with humates. Manure, sludge and other waste
products require a period of time to further decompose so as to become
active and available to benefit the soil and plants. Time makes humus.
The Romans were aware of humus, but it was not until the 18th
century that scientists discovered the humic acids, and not until the
early 1960’s was science able to find a way to analyze humus and
humates to determine their humic acid content. For mankind and the
environment, unfortunately, research grants to agricultural
universities abroad have come primarily form the commercial fertilizer
companies, many of who considered humates a competitor. Therefore, the
effectiveness of humic acids has not been widely published. Humates’
time has now arrived. More and more people are aware of the earth’s
environment. More and more people are aware of the effects of chemicals
and fertilizers on the soil and the fact that our soil has become
depleted and worn out. Research has shown that humates can restore the
vitality of the soil and increase the soil’s capacity to retain
moisture, and even help chemical fertilizers become more effective.
Earthworm feces are also better than other organic fertilizers in other
ways: they generate no mold or odor, they conform with hygiene
requirements, and can be preserved for a long time. The value of
earthworm castings is much better. The result recently achieved by Lunt
and Jacobson of the experimental station in
Connecticut indicates that compound nitrogen, available phosphorus and
potash in earthworm castings are 5 times, 7 times and 11 times upper
soil respectively. China Agriculture University further hydrolyzed
earthworm protein to extract compound amino acids and has developed a
new generation of amino acid fertilizers and amino acid
insecticides.
Table 1 Comparison between nutrient contents of earthworms and manure (%)
|
TN |
TP |
TK |
C |
Humus |
Organic matter |
Moisture |
Worm feces |
0.82 |
0.80 |
0.44 |
16.51 |
7.34 |
29.93 |
37.06 |
Cow dung |
0.32 |
0.25 |
0.16 |
- |
- |
14.50 |
83.03 |
Pig manure |
0.60 |
0.40 |
0.44 |
- |
- |
15.00 |
81.50 |
Horse manure |
0.58 |
0.30 |
0.24 |
- |
- |
21.00 |
75.80 |
Sheep drops |
0.65 |
0.47 |
0.23 |
- |
- |
31.40 |
65.50 |
l
Source of animal protein feed
It
is an ancient practice in China to feed earthworms to livestock and
poultry, i.e. to dig earthworms from fields to feed chickens and ducks
or to graze chicken and ducks to feed on earthworms at ease. Earthworms
are rich in nutrients with high protein. According to measurements, the
crude protein in dry earthworms reaches about 70%, while in wet
earthworms about 10-20%. The amino acids of earthworm protein are
complete, especially the contents of Glutamic acid, Leucine and Lysine, among which Arginine is higher than fish meal, and Tryptophan is 4 times higher than in
blood powder, and 7 times higher than in cow liver. Earthworms are rich in Vitamin A and Vitamin B. There is 0.25 mg of Vitamin B1 and 2.3 mg
of Vitamin B2
in each 100 g of earthworms. Vitamin D accounts for 0.04%-0.073% of
earthworms’ wet weight. In view of the great effects of El Niño, fish
meal from
Peru
can not meet the market demand in the world. Thus earthworms are the
best substitute with the functions of supplements, anti-diseases and
allurement. Earthworms are used as additive to produce pellet feeds in
the USA, Canada and Japan, which account for 50% of the pellet feed
market [9]. However, when earthworms are used as feeds one must note
that earthworms degrade quickly and should be processed within several
hours by hot wind or freeze drying. In general earthworms contain more
pollutants than fish meal because it is hard to clean residues from the
epidermis and seta of earthworms. Some people realize that it is better
to feed earthworms in wet. For fowls the earthworm amount could reach
50% and for swamp eel 100%.
Earthworms are the best bait for anglers. Pay attention to the palatability of various species of
earthworms. It is said that Eisenia foetida can produce a substance fish do not like. In
Australia they culture 3-4 species of earthworms: red wiggler Lumbricus rubellus, Indian blue Perionyx excavatus, African earthworm Eudrilus eugeniae,
and Eisenia foetida. Different fish prefer different species
of earthworms as bait, but according to Rodriquez et al. from Colombia,
the palatability of earthworms is out of question [10].
The
protein content of earthworms is complete, containing 8-9 essential
amino acids for human beings, including 9%-10% tasty glutamic acid.
Compared with other meat, the protein of earthworms is higher than meat
and the lipid, 2% lower than meat. From the view point of health,
earthworms might be one of ideal food with high protein and low lipid
for human beings. In southern
China and Taiwan people used to eat earthworms. There are many dishes
of earthworms: mince meat of earthworm as stuffing for dumplings to
increase delicacy and prevent it from going bad. It is said that spiced
sauce from ROK has a big market in SEA. For human consumption a worm
farm should use beer spent grains or mushroom spent substrate to feed
earthworms. The Edible Fungi Scientific Center in Qingyuan Zhejiang as
well as Shanghai Academy of Agriculture has developed artificial logs
which do not require pure hardwood chips. Each year Qingyuan produces
some 50,000 tons of used logs. This substrate of shiitake Lentinus edodes
could also generate
as much as 5,000 tons of earthworms and in turn can be processed to
quality human food. It is said that there are 200 kinds of food from
earthworms in the U.S.A.
l
Raw materials for pharmaceutical biological medicines fracture healing
The earthworms
called “earth dragon” in China have been used as an important
ingredient in traditional Chinese medicine recipes. “Compendium of
Materia Medica” by Li Shizhen (1518-1593) listed 40 usages, such as
allaying a fever, alleviating pain, smoothing asthma, lowering
hypertension, anti-bacteria, anti-convulsions, dilating blood vessels,
expediting child delivery, relieving impotence, promoting lactation,
tonic, and protecting the skin. As biochemical technology develops some
effective medicinal compounds can be extracted from earthworms such as
Lumbritin, Lumbrofebrin, and Terrestrolumbrolysin and several enzymes
such as Lumbrokinase (Milhara et al. 1983).
CAS
Biophysics Research Institute developed Lumbrokinase in 1984; it was
appraised by specialists in 1987 and also gained a medicine license in
1992 from the Health Department. This technology was transferred to
Jiangzhong Pharmaceutical Co. and Double Dragon Pharmaceutical Corp.
Ltd. in 1992 and 1995, respectively. Slovak and Holland scientists
adopted Contifocuser, a novel continuous flow iso-electric focusing
apparatus to extract five enzymes on a medium-sized industrial scale:
eisenase, fellulase, fetilase, fetipase and wormase [11]. Fibrinolysin
is an enzyme extracted from
earthworms which has high cellulolytic activity as well as proteolytic
activity. It can reduce the viscosity of blood and apparently has
beneficial effects on paralysis of limbs or aphasia caused by
cerebro-vascular disease. The main function index of this type of
fibrinolysin is better than urikase, streptokinase and other types of
fibrinolysin. It has been predicted in medical circles that the man who
found collagenase would succeed in curing thrombus-type diseases. The
researchers of Zhongyuanwei Pharmaceutical Company have found highly
active collagenase in earthworms, which cleaves peptide bonds in
timeworn, triple-helical collagen. Because of its unique ability to
hydrolyze timeworn collagen, it can be used to cut the strong outer
cover of an old thrombus. It enables the other two enzymes—fibrinolysin
and fibrinokinase—to enter into the thrombus, and dissolve the
thrombus. Then, the plugged blood vessel is once again opened up and
the oxygen supply restored. Qinghua University has recently obtained a
patent for the extraction of four medicinal compounds from earthworms
using modern biotechnology methods: a large molecular compound, which
has some anti carcinogen functions; a medium molecular compound, which
has some active efficacy in anti-thrombosis & thrombus dissolution;
a small molecular compound, which contains 17 kinds of amino acids,
polymers, trace elements and vitamins; and a 4th
product which can cure burns and scalds [12]. According to the
statistics of the World Health Organization (WHO), about 12 million
people die of cardiopathy and cerebro-vascular diseases each year. As
reported, 2 million people die of cardio-vascular disease each year,
and 900,000 people die of cerebro-vascular disease. In large cities,
the incidence of these diseases reached more than 20% of the
population. The forecast indicates demand for 199.8 million capsules.
Medicines and health products extracted from earthworms include
anti-carcinogen “funaikang”, “xuezhikang” (Beijing University),
thrombus dissolving capsule (Shanxi), “longjing capsule” (Nanjing),
Qinghua No. 2 (Qinghua University), “longmaikang” (Wuxi Jinchang), etc.
Moreover there are earth dragon syrup, wine, and bone connecting
powder, etc.
Measures taken in
vermiculture industry
l
First
of all we must deepen our understanding that vermiculture industry is
an important part of developing macro-agriculture, an approach to
sustainable agriculture getting away from the side effects of fossil
fuel agriculture, and a measure to cope with the technical barriers
from other countries in developing organic farming.
l
We must work out correct policies to help develop the earthworm industry under the guidance of
scientific development concepts. Vermiculture
industry must be put into the whole circular economy so as to make it
an important means to protect the environment, maintain ecological
balance, utilize resources, and stabilize sewage sludge. Worm farms
should be an indispensable part of every wastewater treatment plant and
urban garbage treatment facility.
Vermiculture
must combine with EC (electro-coagulation), EH (energized hydrolyser),
and EM (effective micro-organisms) [13]. The installation of the former
two technologies is readily supplied at home and abroad. EC technology
is used to absorb heavy metals to decompose the residues of
agricultural chemicals. EH technology is used to sterilize bacteria, to
eliminate toxins, to deodorize, and to turn large molecules into small
molecules which can be easily absorbed by plants. EM contains more than
80 probiotics including photosynthetic bacteria, lactic acid bacteria,
yeast, actinomycetes, fermenting fungi such as Aspergillus and
Penicillium,
nitrogen fixing, phosphorus dissolving, and potassium dissolving micro-organisms, sillico bacteria,
mainly aerobic bacteria as well as anaerobic bacteria and facultative
bacteria. EM developed by Professor Teruo Higa at the University of the
Ryukyus in Okinawa, Japan was introduced into China at the end of
1980’s, and was tested in the 1990s. The result proved that it could
increase yields and could be widely used in various aspects. After
application of EM in animal husbandry it can raise the feed conversion
rate, eliminate odor in livestock barns and poultry houses, improve the
environments of animals, strengthen the health of animals; promote
their growth, raise their propagation and survival rates; improve the
quality of products; manure and excreta could be used as quality
fertilizers; and reduce or even eliminate the need for antibiotics so
as to produce green food. Applied in environment protection it can
promote dissolution of organic pollutants, reduce BOD and COD so as to
purify water; raise the purifying capacity of wastewater treatment
systems so as to reduce the amount of sludge and cost; eliminate odors
in the environment, restrain the growth of pathogenic bacteria; and
dehydrate sewage sludge with no breeding of flies and mosquitoes. The
degradation of EM strains in many places is serious after its
introduction into China. In recent years only Fengben Brand is the most
effective. If earthworms are used to treat manure it is better to use
EM technology during animal raising and it will greatly increase the
efficiency of vermiculture and improve its quality.
l
Vermiculture
industry should be done on a large scale so as to permit mechanization
and automation. Simultaneously we should promote courtyard earthworm
compost if the conditions permit. There are many earthworm bins on sale
and the local government should give some subsidy for household to buy
them, among which multi-tray worm bins are better (see Fig. 2).
l
For
different earthworm products we could use different wastes, e.g. for
earthworm products such as animal feeds or for human consumption, the
wastes fed to the earthworms might include used mushroom substrate,
residues from citric acid plant, sawdust, crude bran, fruit peel and
vegetable peel, etc. For earthworm products such as medicines and
health foods, clean feed is used, such as wastes from potato processing
and food factories. For sludge stabilization the known methods suggest
mixing sludge with bulking materials such as solid urban wastes, peat,
straw, bark and sawdust to feed to earthworms.
Acknowledgement
I’d like to
express my sincere gratitude to Chet Van Duzer, Wang Tingzhang of the
Worm farm in Wuxi, Ji Enguang of Jinchang Bio Engineering, and Xie Jun
of FFRC for their information.
References
[1] Bian Yousheng et al., 2000. Treatment and Reuse of Wastes in Ecological Agriculture (in Chinese), Chemical Industry
Publisher. [2] U.S. News & World Report, Sept 22, 1997, v. 123 n. 11 p 53(1)
[3] Lester Brown, 2002. The Earth Policy Reader, pp. 236
[4] 城市污水处理厂的污泥处理和处置 (http://www.chinaep.net/feiwu/wuni/wuni-02.htm)
(in Chinese)
[5] M.J. Mitchell, R. M. Mulligan, R. Hartenstein, E.F. Neuhauser, Compost Science, 18, 4 (1977).
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