BIO TEAS
THE BASICS OF MAKING COMPOST TEAS
Compost teas are a wonderful means of allowing your soil and plants to reach their full potential by bolstering resistance to pest and disease and increasing humus in the soil. Note that in my last article I spoke about the mould named Phytophora (root rot disease). Compost teas can be used to combat this disease through encouraging fungi and bacteria that protect roots against attack but must be applied regularly to be effective (at least once every season, remember the original inhabitants of this country identified 6 seasons).
30 litres of concentrated compost tea can be diluted to inoculate a hectare of land depending on the quality (more about quality later).
What is a compost tea? It is a liquid brew containing microbes beneficial to soil and plants. Compost teas in general will only contain beneficial microbes if the brew is aerobic and providing the source of ingredients is not contaminated with pathogens.
A small library has been written on microbes in soils but much still remains unlearnt. About 2000 species of soil occupants have been scientifically classified yet it is estimated at around 1,000,000 species exist. Knowledge in microbiology, soil chemistry, physics and plant physiology is required to fully understand the more technical requirements of making quality compost teas but for the purpose of this article we will keep it simple.
In general, producing a quality compost tea (a quality tea is required for effective outcome), means a tea as free of active pathogens as possible and containing sufficient numbers of beneficial microbes to effectively improve a plants vigour /production/protect, and not be harmful to humans. You will also need to understand the requirements of broadcasting the tea/microbes without killing them (i.e. nozzle size and PSI specifications).
Much of what I have learnt about compost teas comes from my own research and Elaine Ingham’s series of lectures on the Soil Food Web (highly recommended). The following is a crash course with some general do and don’ts regarding creating successful compost teas.
How to Create a Tea
First you need a source of healthy microbes to ‘seed’ your brew.
Sources of Microbes:
A quality compost with diverse and safe composition in the correct proportions is required e.g. dry organic material (carbon), legumous plants (nitrogen), rock minerals, seaweed, water grown plants (containing cyno bacteria), composted cow manure (note that some manures contain harmful pathogens and cannot be used e.g. dog manure). Alternatively you may like to borrow a few handfuls of quality mature compost from an experienced compost maker.
A mature compost should exhibit fungal mycelium (white threads the width of cotton seen throughout the compost). See Dave Wilson’s advice in previous editions of Just Organics re making compost. The quality of the compost is paramount for determining the effectiveness of your tea.
Although there are more advanced means of inoculating teas with specific microbial species, it is beyond the boundaries of this article.
Animal manures can be used as a source for microbes to inoculate teas but health issues abound if the brew is not kept aerobic and pathogens emerge as dominant. My advice is to steer clear of manures as a microbial source, unless you are prepared to naturally brew for months and wait until the natural processes of microbiology ‘successioning’ has stabilised (the process where by the conditions gravitate between aerobic and anaerobic states until an aerobic state becomes constant).
Remember if manure based fertilisers have come into contact with the above ground parts of a cropping plant you will need a 90 day withholding period before picking fruit/leaf to avoid contracting disease.
Equipment Required to Brew your Tea;
A 60 litre bin with lid (1/2 filled with rainwater)
An Aeratind Device (details below)
You need a device to create fine bubbles in your bin to ensure a high rate of dissolved oxygen available to the microbes, but the action of the aerator should be gentle enough to avoid harming the microbes. For practical purposes I will recommend the use of an aquarium pump capable of powering two air stones.
Some conjecture exists over the use of aquarium air stones for aeration in compost teas due to the rate of blockage that occurs potentially reducing the effectiveness of aeration and being a source of contamination when the stones are used in subsequent brews. However, since we are trying to create a Tea brewer on a limited budget, I suggest using two aquarium air stones of 4cm in length placed vertically arranged on either side of the 1/2 filled bin. The stones should be run on half power and air stones placed inside two suitable sized PVC pipes in an upright position to manage the ‘bubble tower’ .
Either discard the air stones after each brew or try disinfecting in a bleach solution overnight (or disinfect by some other organic means as you prefer) and keep dry until further use.
Aquarium Heater (optional but recommended)
Your microbial population will multiply faster at optimum temperatures (25C) is a good yardstick (most aquarium heaters have an adjustable range). The summer months can provide sufficient and consistent temperature to negate the need for a heater; however extreme hot weather will kill the microbes and produces unpredictable outcomes. Brewing in spring and autumn or in a controlled environment is best to avoid the pitfalls of fluctuating conditions.
Remember, the more consistent your temperature the more consistent the growth and outcome.
Your microbes will require adequate food (discussed later) and sufficient dissolved oxygen as explained above (extremely important to prevent a population collapse).
If the environment is too warm microbial growth may outstrip oxygen and food supply and the beneficial microbes will die. While insufficient food will slow microbial growth, too much food can kill the brew by creating anaerobic conditions which will occur due to excessive food decaying and the subsequent rise of anaerobic organisms. Hence less rather than excessive food is best.
Brewing Method (your brew will take around 24-36 hrs to be ready for broadcasting, depending on whether the temperature is sufficient and constant, and whether adequate dissolved oxygen is available etc)
Once you have your microbial source (i.e. compost) it’s time to suspend two handfuls of your compost in a webbed bag in your bin, ½ filled with rainwater (Bags used to contain socks and undies in a washing machine are excellent or find an organic vessel of sorts if you prefer).
You can add hydroyslated fish (eco fish etc) to enrich the brew and feed the microbes but I generally believe if your compost is balanced this will not be required and the addition of molasses will be sufficient as a microbial food source. The addition of seaweed solutions is sometimes suggested but I believe this can muck with the balance and so I leave it out at this stage. I prefer to add seaweed to the compost and allow it too breakdown before brewing.
IMPORTANT! Your brew must remain aerobic throughout the brewing and delivery process, otherwise undesirable microbes will flourish in your system and the good anaerobic guys will die or become dormant. Bad compost tea brews are not beneficial to plants and potentially harmful to humans.
.
Activating the Aeration and Feeding the Microbes
Activate your aeration device one hour after you submerge your compost in the bin (the hour allows time for microbes to adjust to the new environment). Keep the aerators running until you’re ready to broadcast.
The type and volume of food given to your microbes can be a tricky area to discuss so I am using a general formula;
1) Add a teasponn of molasses two days before you add the compost
2) Wait one hour after the compost has been added to your bin before activating your aeration device (as already explained). Start with a single air stone on low setting and bring the second air stone online in a few minutes to effectively circulate the water and produce an even saturation of oxygen.
3) Wait two hours before adding a further two teaspoons of molasses to the brew (allows time for the microbes to multiply.
4) Repeat the addition of two tablespoons of molasses three more times during the next 24 hours as microbe populations increase (this method expects a constant temperature range of between 21-25).
This is very general advice and technically should be varied greatly depending on factors like temperature, type of microbe under cultivation, stage of brewing and rate of intended broadcasting etc etc. However we are trying to produce a safe, simple brew for domestic purposes and it is recommended you research further if you wish to learn more.
Your Brew is Ready!
In about 2 days your brew will be ready to broadcast (if conditions have been favourable). A microscope is about the only means of technically checking your brew is ready by identifying the type and volume of microbe present. Assuming most people do not have a suitable microscope we will guest out process has been successful.
Time to consider the rate of dilution and distribution method. The rate of dilution will vary according to the density of population you have cultivated hence we will assume a rate of 30/1 is sufficient i.e. 30 additional parts rain or distilled water to one part of your completed brew.
Distribution of the Tea
A couple things to keep in mind.
Important: to avoid killing the microbes in the process of broadcasting use a bucket with holes or a spray device with appropriate nozzle holes (bigger than your average aquarium net webbing). Avoid using highly pressurised devices; a pump action back pack would be acceptable on lower compression.
The tea can be used as a foliant spray because raw animal manures were not used in our tea brewing. We can also spray the soil with tea to inoculate with beneficial microbes. I recommend spraying 5 to 10 full pumps of tea from a spray unit, per fruit tree (on top and under leaves) or similar pumps on each square metre ofsoil.
Note you may not see instant results and you may need to play with the concentrations etc. For best results deliver the spray in the early morning. Broadcast quickly and do not leave the brew standing in a bucket too long before use.
Preparation of Soil Structures Before Spraying to maximise the effect of tea
Soil micro pore ranges (how big or small the gaps are between soil particles) is important in getting the best response from your tea i.e. the right mix soil micro pores improves the habitat for microbes to survive and propagate within. To reap maximum benefits, apply the brew before or after a full moon when soil moisture levels rise upwards.
If you have clay like soils, ‘rip’ the soil in preparation (use a tool like a pick to drag 20 cm deep trenches at 20 cm apart) or add organic matter to sandy soils before you spray your tea.
Ongoing Feeding of the Microbes in the Soil
Avoid using tap water in the areas where you applied the ‘tea’ as this contains undesirable contents such as chlorine. Apply ‘fish’ and ‘seaweed’ based fertilisers at recommended rates to feed to microbes in the soil, along with molasses at the rate of two teaspoons per litre each fortnight.
Apply a 1-2 cm layer of ‘fluffy’ well aged compost on a fortnightly basis to increase aerobic microbial habitat. Create a minimum disturbance in the treated areas unless reapplying teas.
Hopefully this brief overview should give you enough information to understand how to produce a quality compost tea!
30 litres of concentrated compost tea can be diluted to inoculate a hectare of land depending on the quality (more about quality later).
What is a compost tea? It is a liquid brew containing microbes beneficial to soil and plants. Compost teas in general will only contain beneficial microbes if the brew is aerobic and providing the source of ingredients is not contaminated with pathogens.
A small library has been written on microbes in soils but much still remains unlearnt. About 2000 species of soil occupants have been scientifically classified yet it is estimated at around 1,000,000 species exist. Knowledge in microbiology, soil chemistry, physics and plant physiology is required to fully understand the more technical requirements of making quality compost teas but for the purpose of this article we will keep it simple.
In general, producing a quality compost tea (a quality tea is required for effective outcome), means a tea as free of active pathogens as possible and containing sufficient numbers of beneficial microbes to effectively improve a plants vigour /production/protect, and not be harmful to humans. You will also need to understand the requirements of broadcasting the tea/microbes without killing them (i.e. nozzle size and PSI specifications).
Much of what I have learnt about compost teas comes from my own research and Elaine Ingham’s series of lectures on the Soil Food Web (highly recommended). The following is a crash course with some general do and don’ts regarding creating successful compost teas.
How to Create a Tea
First you need a source of healthy microbes to ‘seed’ your brew.
Sources of Microbes:
A quality compost with diverse and safe composition in the correct proportions is required e.g. dry organic material (carbon), legumous plants (nitrogen), rock minerals, seaweed, water grown plants (containing cyno bacteria), composted cow manure (note that some manures contain harmful pathogens and cannot be used e.g. dog manure). Alternatively you may like to borrow a few handfuls of quality mature compost from an experienced compost maker.
A mature compost should exhibit fungal mycelium (white threads the width of cotton seen throughout the compost). See Dave Wilson’s advice in previous editions of Just Organics re making compost. The quality of the compost is paramount for determining the effectiveness of your tea.
Although there are more advanced means of inoculating teas with specific microbial species, it is beyond the boundaries of this article.
Animal manures can be used as a source for microbes to inoculate teas but health issues abound if the brew is not kept aerobic and pathogens emerge as dominant. My advice is to steer clear of manures as a microbial source, unless you are prepared to naturally brew for months and wait until the natural processes of microbiology ‘successioning’ has stabilised (the process where by the conditions gravitate between aerobic and anaerobic states until an aerobic state becomes constant).
Remember if manure based fertilisers have come into contact with the above ground parts of a cropping plant you will need a 90 day withholding period before picking fruit/leaf to avoid contracting disease.
Equipment Required to Brew your Tea;
A 60 litre bin with lid (1/2 filled with rainwater)
An Aeratind Device (details below)
You need a device to create fine bubbles in your bin to ensure a high rate of dissolved oxygen available to the microbes, but the action of the aerator should be gentle enough to avoid harming the microbes. For practical purposes I will recommend the use of an aquarium pump capable of powering two air stones.
Some conjecture exists over the use of aquarium air stones for aeration in compost teas due to the rate of blockage that occurs potentially reducing the effectiveness of aeration and being a source of contamination when the stones are used in subsequent brews. However, since we are trying to create a Tea brewer on a limited budget, I suggest using two aquarium air stones of 4cm in length placed vertically arranged on either side of the 1/2 filled bin. The stones should be run on half power and air stones placed inside two suitable sized PVC pipes in an upright position to manage the ‘bubble tower’ .
Either discard the air stones after each brew or try disinfecting in a bleach solution overnight (or disinfect by some other organic means as you prefer) and keep dry until further use.
Aquarium Heater (optional but recommended)
Your microbial population will multiply faster at optimum temperatures (25C) is a good yardstick (most aquarium heaters have an adjustable range). The summer months can provide sufficient and consistent temperature to negate the need for a heater; however extreme hot weather will kill the microbes and produces unpredictable outcomes. Brewing in spring and autumn or in a controlled environment is best to avoid the pitfalls of fluctuating conditions.
Remember, the more consistent your temperature the more consistent the growth and outcome.
Your microbes will require adequate food (discussed later) and sufficient dissolved oxygen as explained above (extremely important to prevent a population collapse).
If the environment is too warm microbial growth may outstrip oxygen and food supply and the beneficial microbes will die. While insufficient food will slow microbial growth, too much food can kill the brew by creating anaerobic conditions which will occur due to excessive food decaying and the subsequent rise of anaerobic organisms. Hence less rather than excessive food is best.
Brewing Method (your brew will take around 24-36 hrs to be ready for broadcasting, depending on whether the temperature is sufficient and constant, and whether adequate dissolved oxygen is available etc)
Once you have your microbial source (i.e. compost) it’s time to suspend two handfuls of your compost in a webbed bag in your bin, ½ filled with rainwater (Bags used to contain socks and undies in a washing machine are excellent or find an organic vessel of sorts if you prefer).
You can add hydroyslated fish (eco fish etc) to enrich the brew and feed the microbes but I generally believe if your compost is balanced this will not be required and the addition of molasses will be sufficient as a microbial food source. The addition of seaweed solutions is sometimes suggested but I believe this can muck with the balance and so I leave it out at this stage. I prefer to add seaweed to the compost and allow it too breakdown before brewing.
IMPORTANT! Your brew must remain aerobic throughout the brewing and delivery process, otherwise undesirable microbes will flourish in your system and the good anaerobic guys will die or become dormant. Bad compost tea brews are not beneficial to plants and potentially harmful to humans.
.
Activating the Aeration and Feeding the Microbes
Activate your aeration device one hour after you submerge your compost in the bin (the hour allows time for microbes to adjust to the new environment). Keep the aerators running until you’re ready to broadcast.
The type and volume of food given to your microbes can be a tricky area to discuss so I am using a general formula;
1) Add a teasponn of molasses two days before you add the compost
2) Wait one hour after the compost has been added to your bin before activating your aeration device (as already explained). Start with a single air stone on low setting and bring the second air stone online in a few minutes to effectively circulate the water and produce an even saturation of oxygen.
3) Wait two hours before adding a further two teaspoons of molasses to the brew (allows time for the microbes to multiply.
4) Repeat the addition of two tablespoons of molasses three more times during the next 24 hours as microbe populations increase (this method expects a constant temperature range of between 21-25).
This is very general advice and technically should be varied greatly depending on factors like temperature, type of microbe under cultivation, stage of brewing and rate of intended broadcasting etc etc. However we are trying to produce a safe, simple brew for domestic purposes and it is recommended you research further if you wish to learn more.
Your Brew is Ready!
In about 2 days your brew will be ready to broadcast (if conditions have been favourable). A microscope is about the only means of technically checking your brew is ready by identifying the type and volume of microbe present. Assuming most people do not have a suitable microscope we will guest out process has been successful.
Time to consider the rate of dilution and distribution method. The rate of dilution will vary according to the density of population you have cultivated hence we will assume a rate of 30/1 is sufficient i.e. 30 additional parts rain or distilled water to one part of your completed brew.
Distribution of the Tea
A couple things to keep in mind.
Important: to avoid killing the microbes in the process of broadcasting use a bucket with holes or a spray device with appropriate nozzle holes (bigger than your average aquarium net webbing). Avoid using highly pressurised devices; a pump action back pack would be acceptable on lower compression.
The tea can be used as a foliant spray because raw animal manures were not used in our tea brewing. We can also spray the soil with tea to inoculate with beneficial microbes. I recommend spraying 5 to 10 full pumps of tea from a spray unit, per fruit tree (on top and under leaves) or similar pumps on each square metre ofsoil.
Note you may not see instant results and you may need to play with the concentrations etc. For best results deliver the spray in the early morning. Broadcast quickly and do not leave the brew standing in a bucket too long before use.
Preparation of Soil Structures Before Spraying to maximise the effect of tea
Soil micro pore ranges (how big or small the gaps are between soil particles) is important in getting the best response from your tea i.e. the right mix soil micro pores improves the habitat for microbes to survive and propagate within. To reap maximum benefits, apply the brew before or after a full moon when soil moisture levels rise upwards.
If you have clay like soils, ‘rip’ the soil in preparation (use a tool like a pick to drag 20 cm deep trenches at 20 cm apart) or add organic matter to sandy soils before you spray your tea.
Ongoing Feeding of the Microbes in the Soil
Avoid using tap water in the areas where you applied the ‘tea’ as this contains undesirable contents such as chlorine. Apply ‘fish’ and ‘seaweed’ based fertilisers at recommended rates to feed to microbes in the soil, along with molasses at the rate of two teaspoons per litre each fortnight.
Apply a 1-2 cm layer of ‘fluffy’ well aged compost on a fortnightly basis to increase aerobic microbial habitat. Create a minimum disturbance in the treated areas unless reapplying teas.
Hopefully this brief overview should give you enough information to understand how to produce a quality compost tea!