From: Perry Clutts (addy@dragonbbs.com)
Date: Mon Dec 30 2002 - 12:58:46 EST
http://www.chicagotribune.com/features/home/chi-0212280312dec29,1,4685004.s=
tory
Tea and fertility
Some gardeners swear by a potion brewed to boost soil and banish bad bugs -=
- harmlessly
By Adrian Higgins
The Washington Post
December 29, 2002
In a Virginia field, 50 organic gardeners gather around Elaine Ingham for w=
hat is likely to be the weirdest cooking demonstration they have ever seen.
Ingham's dark, bubbling brew is not from the garden but rather for the gard=
en. Into a 35-gallon kettle of water she has thrown measured amounts of dri=
ed seaweed and an inky liquid called humic acid.
"We have got loads of good stuff going into the mix," she says, filling a n=
ylon sock with screened compost and earthworm castings. Soon, this "tea bag=
" is submerged in the water and bombarded by bubbles produced by an air pum=
p.
This is neither high cuisine nor dark sorcery, but the latest innovation in=
the world of organic gardening and farming.
Liquid fertilizers made from manure and compost, simply soaked in a bucket =
of water for a few days, have been around for centuries. What's new are the=
bubbling technique and specific ingredients, which cause the growth of ben=
eficial microbes that displace and even go after all the bad spores and ger=
ms that prey on and kill plants.
Spray the tonic on the leaves and the bad bugs have nowhere to land, say ad=
vocates. Pour it on the soil, and you form a protective barrier for the roo=
t zones.
Enthusiasts say that when used repeatedly, the tonic revitalizes soil and a=
llows the cultivation of plants without the need for chemical fertilizers a=
nd pesticides.
Among the testimonials: roses that never get black spot; thick, green turf =
grass; ornamentals of amazing vigor and health--all without the use of envi=
ronmentally harmful chemical fertilizers and pesticides.
Organic farmers are using the tea to repair strawberry fields rendered life=
less by toxic fumigants. Growers of crops such as potatoes have seen greate=
r yields using no chemicals. Some are even spraying it from crop dusters, s=
aid Ingham, a soil scientist and consultant to organic farmers. She heads a=
laboratory named Soil Foodweb Inc., based in Corvallis, Ore. (www.soilfood=
web.com).
An early pioneer of the technology, she is regarded as a leading light in o=
rganic gardening and farming circles.
Scientists skeptical
Not everybody is convinced.
"I have a lot of colleagues rather concerned about the hype," said Linda Ch=
alker-Scott, an associate professor at the Center for Urban Horticulture at=
the University of Washington. "We are all waiting for the science behind t=
he claims."
Ingham and other scientists who advocate the product say lab tests reveal t=
hree basic beneficial aspects of compost tea: plant nutrients; biostimulant=
s such as enzymes and amino acids; and beneficial bacteria, fungi and nemat=
odes (wormlike animals) that suppress disease and also may fight plant pest=
s.
Chalker-Scott said Ingham is "an extremely good soil scientist," but her da=
ta have not yet been subjected to sufficient review by other scientists. On=
e of the problems, said Chalker-Scott, is that every batch of compost tea s=
eems to produce different results, making it difficult to conduct more defi=
nitive studies that might isolate the merits of one microbe over another.
Another concern is that the brewer might inadvertently create a brew contai=
ning E. coli bacteria. Ingham says this is a valid concern but only if corr=
ect steps are not observed. Any compost containing animal manures should be=
thoroughly composted at 130 degrees for 10 days. A soil thermometer can te=
ll you if your pile gets hot enough.
Alternatively, use compost not made with animal manures or use earthworm ca=
stings, she said. They are sold in bags at garden centers.
Spreading the word
If the scientists are squabbling, gardeners, farmers and manufacturers of e=
quipment and supplies are forging ahead.
"When it comes to things in organic farming, in general, the farmers tend t=
o be quite a few years ahead of the scientists," said Steve Diver, an agric=
ultural specialist with Appropriate Technology Transfer for Rural Areas, a =
non-profit funded by the U.S. Department of Agriculture that provides techn=
ical advice to small farmers.
He said compost tea has yielded remarkable results. When it was used on a f=
ield of bell peppers succumbing to viral disease--usually a death knell in =
the vegetable garden--it not only stopped the virus in its tracks but also =
allowed infected plants to recover.
"This is absolutely mind-boggling that an organic approach was able to arre=
st a virus and get the crop to grow out," he said.
Diver said, if you were to look at a leaf through a microscopic hand lens, =
you would see hairs so thick that they resemble a jungle. By coating all th=
ose surfaces with compost tea, the good microbes provide a barrier to any b=
ad ones that want to feed on the plant. "There's no room for them, there's =
no food for them, and they are knocked out of the loop," he said.
Preparing the brew
Gardeners prepared to make a trip to the pet store can make their own brewi=
ng kit using aquarium equipment.
Ready-made versions, some costing in excess of $1,000 and geared to commerc=
ial customers, are also available. Some manufacturers are getting into the =
homeowner market.
SoilSoup (www.soilsoup.com) makes a 6.5-gallon brewing kit priced at $329, =
plus shipping and handling, and has started selling commercial dispensers t=
o garden centers, where customers can arrive with their own containers and =
fill up for a fee.
Another company, Keep It Simple Inc. (www.simplici-tea.com), makes a 5-gall=
on kit for the home gardener for $99.50, plus shipping and handling.
Mary Robson, an extension agent in Renton, Wash., said gardeners have made =
non-bubbly compost teas for thousands of years for their nutrient values al=
one.
In the Pacific Northwest, where the brewed article has taken off among gard=
eners, "we all want it to work," said Robson. "We don't know exactly whethe=
r, or if, it does. At least, I don't."
How to make your own
Commercial brewing kits for compost tea can cost $99.50 to $8,000, dependin=
g on size and equipment. But soil scientist and compost tea guru Elaine Ing=
ham says you can assemble your own kit.
If you do not have a hot compost pile, you can use earthworm castings. Thes=
e, along with powdered kelp and humic acid, are available from many garden =
centers.
Equipment
5-gallon plastic bucket
aeration pump for 70-gallon aquarium
tubing, connectors and two or three air stone bubblers (these supplies are =
available at pet or aquarium stores)
nylon knee sock
Ingredients
water
1/2 pound earthworm castings or screened compost from a hot pile
1 to 2 fluid ounces each: liquid molasses, dried kelp and liquid humic acid
Directions
1. Place air stones in the bucket, but keep the air pump outside and dry. F=
ill the bucket with water. Run the pump for an hour to allow the chlorine i=
n the water to bubble out.
2. Add the molasses, kelp and humic acid. Fill the sock with castings or co=
mpost, leaving enough space for the material to move around. Knot the sock.=
Either place the sock loose in the water or brace it with wire so that it =
hangs submersed and directly beneath the air stones.
3. Run the pump for 24 hours to allow the liquid to brew fully.
Using the brew
Pour the mixture into a garden sprayer and use as a spray on leaves.
For the growing season, Ingham says, spray two weeks before plants start gr=
owing, at a rate of 10 gallons to the acre. Then spray at 5 gallons to the =
acre every 10 to 14 days for three months "or until you see no more disease=
."
Then spray monthly. In the third year of doing this, she says, you need onl=
y spray three times annually.
Or, apply the compost tea directly to the soil around plants.
Safety considerations
The equipment must be cleaned and disinfected between brewings to prevent t=
he subsequent brewing of bad bacteria, which can damage plants and even cre=
ate a health hazard. Foul odors from the finished mix signify a batch that =
contains unwanted bacteria.
-- Adrian Higgins
Copyright © 2002, Chicago Tribune
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