James, how can you compare the benefits of compost tea to miracle grow?
While miracle grow will provide nutrients to the plant, it does absolutely squat for the soil, compost tea introduces beneficial fungi and bacteria to the soil, the more beneficial microbes in the soil, the fewer bad guys will be there.
The biggest issues is that most folks think that making a batch of compost tea is making a vat of fertilizers, that is as far from the truth as you can get.
What we are doing when making compost tea, is breeding beneficial bacteria and fungi to introduce into the soil, and yes, we have sprayed our plants with compost tea.
The following is part of a presentation that I gave in front of a couple hundred competitive growers, commercial growers and AG business related folks:
To brew a good tea, you really have to think about what we are trying to accomplish.
We are trying to breed microorganisms, make them multiply.
Compost Tea is a water-based environment wherein beneficial microorganisms are extracted from compost or vermicompost (worm compost) and multiplied by the millions and billions.
Some form of agitation breaks the microbes free from the compost and they multiply because food, like black strap molasses, has been added to the water, which at least one type of microbe digests. Oxygen is a must, without it, the microorganisms will die off.
When one or more type of microbe begins to multiply in response to the food, other microbes respond to this growth and begin to consume these initial microbes and multiply in turn and so on and so on. For example the initial microbes are usually bacteria which are food for protozoa so the protozoa multiply in response to the bacteria. The end result is a functional feeding cycle or microbial nutrient cycle. This develops over a period of 12 to 72 hours or more and is then applied to the soil and plants.
Aerated Compost Tea helps to ensure the multiplication of mostly aerobic microbes which are more desirable. Plus the aeration provides the agitation necessary to dislodge the microbes from the compost. Therefore most Compost Tea machines or brewers, as they are commonly known, involve the introduction of air into the water and compost.
Now that we have that all out of the way, the more the microbes multiply, the more food they need, the more they grow the more oxygen you need, the dissolved oxygen should not fall below 6.0 mg/L. The only real way to be certain of that is to test with a D.O. meter, since these are expensive, the best bet is get the strongest pump that you can, making sure that the water is agitated and enough oxygen is being introduced into the brew.
Aerobically brewed organic liquid compost is alive, filled with millions of healthy soil biota (living creatures). Because it is oxygen brewed, Compost tea contains high levels of beneficial bacteria.
The best way we know to reinvigorate artificial or exhausted soils is to inoculate them with an aerobically brewed compost tea.
These teas are concentrates that can contain billions of beneficial soil biota in a single teaspoon
Essentially, compost tea production is a brewing process that extracts microorganisms from compost followed by microbial growth and multiplication. This includes beneficial bacteria, fungi, protozoa, and nematodes. When compost teas are sprayed onto the leaf surface, these beneficial organisms occupy spatial niches on the leaf surface and gobble up leaf exudates that pathogenic organisms would otherwise feed on to prosper; other microbes directly interfere with pathogenic organisms through antagonism.
Ideally, compost teas contain both Abundance (immense total number) and a Diversity (vast mixture) of beneficial microorganisms which perform different functions.
Pathogenic organisms that land on the leaf surface simply cannot compete with the beneficial organisms and therefore have a greatly reduced chance to initiate disease in the first place.
Compost teas are applied either to the soil or to the plant foliage. Those applied to the soil will move into the root zone and affect the rhizosphere of the plant. Nutrients carried in the tea will be used by the plant as well as the microorganisms in the soil.
The microbes in the compost tea may have a lot of competition with other soil microorganisms, but have the opportunity to become a part of the soil and rhizosphere microbial ecology.
Alternatively, compost teas applied to the plant foliage will immediately impact the plant and there is very little room for forgiveness from the plant if a tea with toxic qualities is used.
A good quality compost will provide beneficial microorganisms and nutrients to the surface of the plant to assist the plant in disease suppression and nutrient availability. A poor quality compost tea may be supplying the plant surface with unwanted components such as salts and problem microorganisms.
Compost tea destined for foliar applications in particular should only be made with the highest quality of compost to avoid problems such as salt burn and the distribution of pathogens in critical areas of the plant.
What are the potential benefits of Compost Tea?
Compost Tea provides:
Direct nutrition - A source of foliar and soil organic nutrients. - Chelated micronutrients for easy plant absorption - Nutrients in a biologically available form for both plant and microbial uptake
Microbial Functions
Compete with disease causing microbes -Degrade toxic pesticides and other chemicals -Produce plant growth hormones - Mineralize plant available nutrients - Fix nitrogen - Plant surfaces are occupied by beneficial microbes leaving no room for pathogens to infect the plant (squatters rights)
Compost Tea will help to create a balanced soil foodweb.
A balanced Soil Foodweb will:
1. Suppress disease-causing and pest organisms
2. Improve the nutritional quality of the plant.
3. Produce good soil structure, improving water infiltration, oxygen diffusion, and water-holding capacity.
4. Retain nitrogen and other nutrients such as calcium, iron, potassium, phosphorus, etc.
5. Make nutrients available for plant growth at the times plants require at the rates plants require.
6. Decompose plant residues rapidly
7. Reduce worker exposure to potentially harmful chemicals
8. Produce hormones that help plants grow.
If we want to feed bacteria we emphasize sugars, a protein source, and provide extra minerals.
If we want to create an environment suitable for fungi we add more complex foods including fish hydrolosate, soluble kelp, and protein meals such as feather meal or whey.
How does compost tea help nutrient cycling and why is that good?
Plant nutrition is mediated by the microbes and higher organisms in the soil. Through their digestion of organic matter, they pass a steady stream of mineral nutrients to the plant roots. Healthy soils, containing high numbers of diverse microbes have the capability of passing a full spectrum of mineral nutrients, hormones, amino acids and vitamins to plants. By enhancing soil biology, compost tea builds the capacity of the soil to pass nutrients to the plants.
