Category Archives: Permaculture Composting Techniques

How to make a worm farm with an old fridge

A fridge provides with heat, rain and predators protection, has a very convenient size and allows an easy way to monitor worm bedding and worm monitoring.

Finding an old fridge

old fridge used to make the worm farm

remove all equipment and keep only the fridge body, laying down on its back.

liquid casting evacuation on the fridge

Identifying the hole at the back of the fridge. This will be used as the out flow for worm tea. The fridge should be leveled in a way that the outflow is the lowest part of the body with maybe a slight inclination of the fridge, to ease the liquid evacuation.

connection of the tap for worm casting liquid evacuation

The photo shows the tube of evacuation

tap for monitoring the worm casting liquid evacuation

The body and the tap must be high enough to allow enough space for a bucket underneath. The liquid waste (worm tea) forms the leachate. This organic manure is a liquid fertilizer rich in nutrients. Dilute with water to 1/10 before giving plants. To prevent the worm tea becoming anaerobic in the drainage layer verse pure water from time to time on the drainage layer through the air filter (see photos below to identify this filter). Then harvest the blend in a bucket. This will dilute the tea and clean the drainage layer.

positioning the filter

The outflow is filtered by a recycled shower head.

layer for drainage of worm casting

A layer of gravels is used for drainage (about 3/4 cm or 1  inch thick) and reduce contact between the organic layer (worm bed) and the water.
This layer will reduce anaerobic decomposition on the bottom of the farm.

making the separation filter between the drainage and the worm bed 2

Structure of aluminum for supporting the filter of separation between the drainage and worm bed layers. Wood would decompose and iron would degrade rapidly in this humid environment. The structure is not mandatory and the filter can be laid down directly on the drainage layer. In this case the filter should enroll entirely the gravel layer in order to ensure that the filter will stick to the walls of the fridge. Here the structure has internal reinforcement to avoid its sides to bend and let open the filter for worms to end up in the drainage layer. The alternative solutions found on internet use staples to fix the filter to the fridge body. This solution is not Cradle to Cradle (irreversible) preventing a proper maintenance of the drainage layer.

making the separation filter between the drainage and the worm bed 3

The sheet is doubled or tripled to prevent baby worms to go through.

positionning the filter of separation with the drainage layer

and installed on top of the drainage layer.

removing the fridge rubber to allow worm farm ventilation

The door insulation rubber is remove to allow ventilation (worms need to breath oxygen)

cutting the fridge rubber

The rubber is cut in pieces

removing the

And the inside magnet (used to ensure magnetic closure of the fridge door) removed.

filling the holes between the filter and the fridge body

The rubber pieces are then used to fill the holes in between the filter structure and the fridge body.


A ventilation funnel is made of various tubes.


and positioned on the top of the drainage layer.


Coconut fibers are used as a guaranty for humidity conservation. Furthermore the fiber allows oxygenation, habitat for the worms and the numerous microorganisms which will develop in the worm bed.


If you use cardboard (preferred to white paper chemically treated) make sure they have been soaking into water for  day.

Colocar_separacao_en_cima_do papelao

Since it is always a matter of risk management and experimentation separate the farm body in 3 compartments which will receive different type of worm bed, giving the possibility to the worms to find their best environment. Later these 3 compartments can have different functions like one for food , another one for collecting the casting, another one for testing different nutrients, e.g. possible toxic leaves from the garden where tropical organic matter is sometime aggressive.


This compartment receives chicken manure.


This one semi composted leaves.


All 3 compartments are generously watered. The watering depend mainly on your climate (ambient humidity). Over time you’ll know how to manage the worm farm humidity depending on where are migrating the worms. If the go on the bottom it means they are looking for humidity then add water. If they go on the top it means they look for aerobic conditions, meaning that you have to remove humidity either by removing soaking material of by adding dry organic matter.


You are ready to start , letting the worms acclimatized in the middle compartment with neutral context. Over time add green stuff, not aggressive. Avoid acidity, onions, animal proteins, fat. Make sure that hot composting does not start inside the farm by not creating too dense pile of very humid organic / green material. Time to time you can add some egg shells to compensate acidity. Purist will clean then before, to avoid attracting pest.

Biodigestor with Evapo-Transpiration

This technique uses 4 sustainable practices;

– Brown water recycling
– Low environmental foot print for tank construction with ferro-cement technique
– Old tires recycling
– Building material recycling

The cost of such a biodigestor is very low (less than 3 bags of cement, less than 1m3 of sand, 24 meters of chicken wire by 1 m high, transportation of 8 m3 of concrete building material waste) for a tank of 10 m3.

The goal is to create a close chamber to gather brown water as a nutrient for Banana trees and other tropical edible plants liking humidity and fertility. The bacteria decompose the brown water to produce edible nutrients for the plants. The tank is hermetic so the system is closed and all polluted water is recycled. The different variations of construction found on the net show either a chamber made with bricks and cement (this one is made with recycled tires) or a tank made in a classical way with cement blocks. The construction process described here is the best of breed (lower environmental impact) of these different techniques.

Here is the construction process of a Biodigestor – evapo-transpiration with pictures;


Making a hole 1 m deep, 2 m large. The length depends on the capacity you wish to setup.
The ratio is 1 m length for 1 inhabitants using the WC (e.g 10 people = 10 m long).


Positioning the chicken wire which will be use as the armature of cement (ferro-cement technique).
This technique reduce the need for cement (only 3 bags of cement will be used here and no block of concrete).


the wire is elevated from the floor and pushed away from the wall (1 cm)
in order to be entirely embedded in the cement.
The first step is cementing the floor.


Once the tank is done the recycled tires are positioned
in order to form a large tube corresponding to the main chamber of bio-digestion of brown water.
The pipe from the WC is connected to one extremity of the large tube made of tires.


The next phase consist in filling the tank with stones or blocks of concrete (recycling building materials)
with the biggest on the bottom and the smallest on upper layers.


Pipes are settled for further maintenance (inspection of the water levels and composition)


A layer of rock dust recover the small blocks or gravels.
You may observe the state of the banana trees planted here
to compare them with their evolution on the next photos.


Dirt is added as the last layer where will be planted the banana trees, papayas
and other plants liking humidity.


After only 3 months the banana trees thrive.


After 6 month they reach a respectable size, continue to grow and propagate.
Only 33% of the surface is filled in waiting to gather silt and sand from a swale for the top layer.
We may expect here 40 thriving banana trees in fine with a fair production of bananas !!!

After 10 to 11 months the banana trees reach an adult size with 3 banana bunches.
Ozgur, in the photo is 6 feet high


Bunch of bananas getting more gorgeous day after day.


Papaya and chuchu (Chayote) do not really work here with the test being done.

The design (schema at the top of the page) was found from Rede Permear, a brazilian ONG.

A critical point is to make sure that the tank is protected from water overflow from the land. This can be done by elevating the tank border or by creating a mount around the tank with vegetation (e.g. Citronela in our example) to prevent erosion (lower foot print solution).

The main labor was to dig the hole manually and to sort the building waste by size for the different layers. The top layer (dirt) was a mix of small concrete gravels, concrete dust and dirt. We may assume the composition of this dirt to play an important role in plant growth having a lot of minerals made certainly quickly edible for plants take thanks to the high level of bacterial activity.

A source of carbohydrate

The biodigestor is to be considered as part of a large biological cycle and the banana trunks when removed after banana harvesting do not need to be recycled inside the biodigestor but used in other parts of the farm, assuming that the incoming flow of brown water is continuous. The biodigestor is both a food producer (banana) and organic matter transformer and cleaner (brown water transformed into banana trunk and leaves). Banana trunks can be chopped as mulch material or used to plant cassava or yam in dry parts of the farm. Then a hole is made in the soil, the size of the trunk log, the log is put in the hole and the cassava cutting directly planted in it. The trunk will be a reserve of nutrient and hold humidity for a long time.

Dry Toilets

The main benefit of a dry toilets is the economy of water. Water conservation and recycling is becoming the next challenge of the 21st century. If you live in a humid area you can afford recycling brown water using a bio-digestor with evapo-transpiration, if not, the dry toilets is the best practice you may settle to reduce water usage.

They are other benefits (or specificity which can be considered as benefits depending on the objective) such as;

– creation of compost in a aerobic way (no methane production)
– compacting of residues (a dry compost chamber of 1m3 can handle few thousands of utilization before to be emptied)
– urine and feces separation for direct urine usage as organic fertilizer

Here is a step by step construction of a dry toilets with urine and feces separation (urine diversion).


A wooden structure is prepared using mortises.


and ankles.


Positioned on the ground,


leveled and cemented on the floor to increase stability and protect the wood from decomposition.


2 chambers for the feces are built with boards, made of recycled packaging, on the ground. 1 chamber will be used and when full will be closed for letting the compost to mature. The other chamber will be then used, and so on with regular rotation.


The roofs are made in order to protect the edifice and work as well when raining. The cabin is located on the first floor. The dry toilets is located in an area with sea view and sea breeze. Later on trees will surround the construction to add cool down and better integrate the dry toilets in the landscape. The transparent roof plays a role in letting the sun come through and keep the place dry, reducing moisture for hygienic reason.


The urine gutter diverts the flow to a banana circle beside the dry toilets.


Here is a view of the banana circle at start.


The bench is simply made and both the cabin and the feces chamber are very well ventilated. This ventilation provide with comfort and speed up the process of feces drying.


The gutter is better made of zinc (vs plastic) to handle energetic maintenance. The zinc allows as well to be slightly reshaped in order to ease the positioning of the gutter with regard to urine feces separation accordingly to human morphology. Here an old gutter has been reused. The feedback I have from female users is positive when it comes to pee in the gutter.


After every usage a large handful of leaves is thrown of the feces to complement the compost (with carbohydrates) and speed the drying process. In case of smell, meaning anaerobic decomposition due to humidity excess, more leaves need to be added.


A sink is added for hygiene.


After 6 month of use the small banana trees have benefited from the urine recycling and reach now the top of the roof.


An explanation board is there to optionally learn Portuguese from brazil.

Some tips about dry toilets;

– mixing urine and feces may increase bacteriologic activity (quicker composting) but will produce more smell

– when you build your dry toilets think “big” enough. People who have made very small compartment end up carrying the humanure to the compost pile every day or half-week, including the production from visitors. Usually they do not see this as a nice experience. In the example shown here there is no handling of feces. Only handling of earthy compost done after 6 or 9 months of maturation.

– The compost chambers should be located at ground level for easy access. The bottom of the chambers may be insulated so that no feces parasites/worms can infiltrate the ground before the composting phase start. This is mandatory in a place where people walk barefoot.

– If you integrate the compost chamber into your house study first the ventilation process and the prevailing wind direction mainly during the humid season.

Composting with limited resources in land rehabilitation

It may be frustrating sometime to read articles describing the different methods of composting. The gathering of such materials as cow manure, horse manure, chicken manure, duck manure, lawn cuttings, kitchen scraps, seaweed, fine straw, etc… may be difficult to perform at affordable price or to transport when it comes to make 1 m3 of compost, the minimum size for successful hot composting.

When doing land rehabilitation with financial constraints each of the materials indicated as being part of composting may represents a scarce resource.

For example;

Manure may exist only if animals exist which themselves are introduced taking into account the capability to be fed with adequate and local food. Humanure is a solution but requires time to be produced.

Brown matter is maybe the easiest material to find. However it is often a hard to break material having been able to resist harsh conditions (drought and poor soil imposing slow growing).

Green material is usually rough and does not easily degrade to provide with nitrogen, sugar and carbohydrates.

Here are some tips and strategies to obtain these composting materials in a difficult context.

Obtaining animal manure

Animals digestive system participate in an up-cycling process of food production. Animals can eat and process certain food not edible by human then produce manure that can be used to create compost to help grow human edible and more delicate plants.

Animal introduction requires to identify the plants or other edible organisms, assess the capacity of production of such food and determine the number of animals the farm can afford to host. Usually the first phases of implementation use small animals easy to shelter and to monitor in term of quantity.

Chicken for example eat a lot of insects which are themselves able to process even harder basic material in this up-cycling process. They can go errand and feed on plants and seeds including weeds.

Another animal of choice is the guinea pig. They are happy eating forage easy to grow in poor soil, for example elephant grass. Their diet can be balanced by kitchen scraps. Their size and their reproduction speed ease their monitoring.

The issue having small manure production capacity is that manure needs to be used fresh when doing composting. Therefore by stocking the weekly increments of animal production a large part of nitrogen will transform to gas and reduce the nitrogen proportion of your manure. The outcome is a higher C/N ratio with the necessity to add more manure than described in documentation.

A quick solution is to get manure from a farm. Making a pile of 1 m3 of compost, assuming that you already have your local production will require only few buckets more. If no farms can be found on the surrounding then you may look for places where horse are used to go and gather dung, the fresher the better.

Once you get the quantity you need then the compost should be done as soon as possible.

Since this source of nitrogen may be difficult to obtain it is important to get a larger quantity of fresh green manure to compensate the low nitrogen ratio.

Certainly the most convenient way to gather nitrogen is to store human urine in closed container. Urine contains more nitrogen than solid excreta and is usually sterile unless the person has some specific disease (e.g. urinary tract infections or fecal contamination). By storing urine (not diluted) in a close recipient the pathogens are killed (1 to 2 months in the tropics, 4 to 6 months in cooler climates).

Using urine as a direct fertilizer (diluted 5 times) is feeding the plant more than feeding the soil ecosystem although experience show that long term effects are positive on soil fertility. Urine lacks carbon to sustain plant growth on the long term. Urine may be high in salts depending on human diet and it requires an active microbiological substrate to recycle these salt, usually associated with dense vegetation and good humidity and drainage. Studies show that human urine performs better when used in combination with compost which help among other things to reduce salts accumulation.

When applied on carbon based material (to make compost) then urine plays the role of humidification and nitrogen addition (+ phosphorus + potassium). Human urine as all excreta from omnivores is very high in nitrogen and easy to gather for example in dry toilets with urine diversion or in urinal. Urine usage as nitrogen source (or as main nitrogen material) resolves the issue of compost planning constrained by fresh manure availability. Storing this liquid resource in closed containers is easy and prevent nitrogen evaporation.

Urine, which contains urea has better fertilizing capabilities than urea alone. Two of urine properties (there are others) when used in compost are nitrogen loss reduction and increased availability of organic carbon in the soil.

Obtaining green manure

Improving the availability of green material requires spending time to observe the ecosystem of the farm and identify adequate plants. They should have fine texture and have a high ratio of soft leaves. They should be propagated in locations which suit them and be harvested when their leaves are the most tender and green. You may plan the compost making when the rain season has produced enough of soft and green manure.

The oasis of humidity or fertility can be used as well to be stretched in order to propagate plants having a high productivity of green and soft biomass.

A third solution for obtaining green manure is to plant pioneer perennials leguminous like leucaena which have fine leaves rich in nitrogen which can be chopped, or leguminous cover crops resistant to drought like arachis pintoi. This latter plant does not impact perennials and grows high when competing for light against weeds. The combination of high grass and arachis is easily harvested providing with a fine green material.

If you have a pond or open tanks you may use aquatic plants which usually propagate very fast. Growing azola (leguminous aquatic plant generating a high ratio of nitrogen) is a perfect solution to get a material rich in nitrogen.

You may as well use Moringa (perennial) leaves high in many different minerals. Moringa is a tree well adapted to the tropics.

Obtaining brown material

This can be obtained fairly easily as long as you have trees in or beside your garden. Leaves can be used and should have a fine texture to be able to degrade easily. Planting giant bamboo is a good solution since it produce a lot of biomass and provide with fine leaves with plenty of silicate.

Another source of brown material is the bedding of animals which is partly mixed with animal manure. Leaves are used as well in compost toilets mixed with humanure. Using this material will influence the nitrogen ration by being mixed with manure.

Fungus are an important part of your compost and gathering small degraded branches in the surrounding forests will provide with beneficial diversity. Compost is a soil inoculum which requires soil ecosystem biodiversity.

Spreading compost

Compost is an inoculum meaning that it should not be used as a substratum to grow plant but as a material added on the soil or injected in the soil to increase its fertility. Injection can be done by first making compost tea which gives a soluble material. Many recipes can be found on Internet on the way to make compost tea.


About bacteria

Understanding the composting process requires some overview on the different microorganisms responsible for the degradation of organic material.

The main category of organisms at work is bacteria with 3 classes playing different roles in this process, differentiated depending on the temperature ranges where they survive and grow;

– Psychrophiles; grow at low temperatures, down to 20C (59F)
– Mesophiles; grow at medium temperatures, from 20C (68F) to 45C (113 F)
– Thermophiles; grow over 45C (113F), and some can survive to the boiling point of water 100C (212F).

Mesophiles include human pathogens like E.Coli, found in human intestine.

Thermophiles are in high proportion and may represent one of the most ancient form of life. They stay dormant at ambient temperature and will thrive under extreme heat.

Chemical resources

bacterial-degradationBacteria use carbon and oxygen as a source of energy (sugar, carbohydrates) and nitrogen to build protein they need for their bodies. You may see it the following way; Carbon Oxygen and Hydrogen are the chemical fuel, nitrogen is the biological fuel. This is the reason why nitrogen is an important part of a compost pile. A Carbon/Nitrogen ratio ranging between 25:1 and 30:1 is the optimum combination (these ratio will fit with different categories of plants). When adding material high in Nitrogen in the compost pile (e.g. manure) you need to take into account the fact that carbon is present as well, therefore to adjust the ratio to 1/4 or 1/2 to obtain a 1/25 of nitrogen/carbon ratio.

Aerobic degradation is the most rapid, effective and healthy composting process. To perform this the oxygen level should be over five percent. This is the reason why compost piles need to be ventilated. This kind of composting requires some labor or specific techniques for ventilation. Aerobic degradation is as well necessary to kill pathogens.

Decomposer organisms need water to grow and reproduce. Too little moisture will cause bacteria to go dormant. Too much moisture will reduce aerobic decomposition and increase anaerobic one. To identify the right level of moisture few drops of liquid should be expelled when squeezing compost material in your hand.

4-phases-of-compostingComposting phases

There are 2 different types of composting. The cold composting and the one inducing high temperatures (called hot composting, including the famous Berkeley composting method).

The latter happens in compost piles having enough volume to substantiate a critical mass of thermophile bacteria. Usually a compost pile newly formed of 1m3 will have this critical mass. Smaller piles or piles made by small and regular addition of organic matter over time will not generate high temperature reactions.

If we consider a complete process including the high temperature phase we identify 4 different phases;

– mesophilic phase (conducted by related bacteria which proliferate at this stage);
– thermophilic phase (thermophiles bacteria take over while temperature is raising above 45/50c);
– cooling phase;
– curing phase.

During the thermophilic phase an important proportion of mesophile bacteria is destroyed by high temperatures. It is often considered as the way to kill pathogen for a safe compost (and destroy seed weeds for later use of compost in the garden) .

The pile needs to get to 55 C within 3 to 7 days from starting day and stay at this temperature for 10 to 15 days

The Berkeley method (the most famous method of hot composting) proposes following timing;

1) Create the pile

2) Keep the pile untouched for 4 days in a row to start the thermophilic phase in a stable environment

3) Turn the pile every 2 days for a duration of 14 days in order to provide oxygen to the bio-combustion

The pile is then ready to use. The curing phase in this case is quasi nonexistent.


Although the thermophilic phase has a pathogen curing effect the final curing is performed through microbiological competition in aerobic conditions during the last phase (curing phase). Two effects combine; pathogens end up dying over time (limited life span in aerobic conditions) and biological competition happens within the pile (e.g. competition for food, inhibition and antagonism, predation, antibiotics production). This maturing phase is essential and remove not only human pathogens but as well phytotoxins that are toxic to plants. The maturation phase may take 6 to 12 months. An immature compost may as well jeopardize oxygen and nitrogen availability from the soil (due to bacteria competition for food) and highly increase the levels of organic acids, impacting the plant growth. A mature or finished compost is a material where nutrients and chemical energy have been embedded into a stable organic mass. Humus is an example of such a stable material and is usually the result of cold composting.

Some plants have better capabilities to deal with raw compost (if you are in a hurry to grow vegetables). It is the case for Cucurbitaceae (squash, watermelon, cucumbers…).

To summarize; high temperature accelerate the pathogen destruction but aerobic conditions provide with the environment adequate for biodiversity to overwhelm pathogens through different mechanisms based on competition. External resource : Read more about pathogens destruction

In some cases the thermophilic phase by removing most of beneficial mesophile bacteria may prevent as well later microbiological competition and if a pile is re-infected by pathogens those may thrive (not having competitors) and produce a compost with a high concentration of pathogens. This is why, once the cooling period has started, the contamination by pathogen should be avoided. The maturation phase will see the aerobic colonization of the compost pile by beneficial bacteria and macro-organisms increasing biodiversity therefore the diversity of nutrients.

The thermophilic phase is useful as well to detoxify the de-worming substance that may exist in the manure from treated animals. In this situation no more than 5% of this type of manure should be used. Antibiotic does not represent a problem in the compost and is degraded under aerobic conditions.

Once again biodiversity is key in creating a balance and make the system resilient. It is important to note that bacterial infection is not due to the presence of one isolated bacteria but by a certain concentration level. In biological mechanisms bacteria may even communicate to share this information (concentration) and decide or not to deploy an attack against a plant based on a certain density of presence.

Other actors in composting

micro-and-macro-organisms-on-compostingAt the end of the thermophilic phase remains still non degraded material like lignin, too resistant for bacteria, which will be digested by actinomycetes and then fungus during subsequent phases. Avoid branches larger than 1 cm of diameter or hardy vegetation. In tropical climate many tree species have leaves with strong structure which will resist to bacteria alone.

When gathering the material for your pile you may harvest various types of fungus (in the litter) found in the forests around and add them in a humid place of your compost pile during the cooling phase.

Microorganisms (bacteria, fungi, and actinomycetes) are chemical decomposers and the most active in the composting process. However macro-organisms (mites, centipedes, sow bugs, snails, millipedes, spring-tails, spiders, slugs, beetles, ants, flies, nematodes, flatworms, rotifers, and earthworms) which are physical decomposers play as well an important role by reducing materials into smaller pieces, by ventilating the compost pile for aerobic bacterial digestion and by triggering all sort of bacterial transformations.

Worms play particularly an important role in increasing the quality of the nutrients through the mechanisms at work in their digestive system.

Another very important role played by macro-organism is bacteria control through predation. If your compost lacks these organisms not only bacteria will compete with plants for nitrogen but the food web will as well lack the transformation of bacteria in minerals available for plant. Bacteria are the organisms with the most concentrated amount of minerals on earth (NPK; etc..). The Macro-organisms which feed on bacteria need less nitrogen than bacteria and release nitrogen and other minerals when they eat them, which will be used by plants. This mechanism is key in plant feeding.

Compost piles management

The best way to handle the different phases of composting is to have 3 different piles;

– The one you are building
– The one which is maturing
– The mature compost pile you use for your garden or orchard

Dry material can be soaked up into water the day before the pile creation.

In places with heavy rain the pile should be covered to avoid nutrients wash out and anaerobic degradation due to humidity excess. Covering them reduce as well evaporation.

You may use a wire as shown on the photo, covered with the lead of a water tank, a very common equipment;


This solution has many advantages;

– not expensive and very easy and quick to make. The lead can be made using wooden board and plastic sheet. A diameter of 110cm by 100cm high gives roughly 1m3 which is the minimum volume for efficient thermal composting phase.
– portable, meaning that you can make compost in different locations of your garden. You can for example make a pile in a location where once removed you wish to plant vegetables. The compost pile will have then improved the soil where it was settled. It is convenient if you have a source of mulch in a specific location and don’t want to carry the mulch to zone 1.
– good ventilation on the side of the pile for aerobic reaction
– vertical wall of the pile improving the shape of the combustion chamber (pyramidal shape of a pile require more compost for the same result)
– ease the visualization of the pile evolution; material evolution and pile level
– easy removal of the wire when turning the compost or starting the cold composting phase
– you can make slightly different diameters so to embed them one into another like Russian puppets.

In places very dry the pile should be kept humid with regular control of the humidity.

In order to ensure ventilation you may turn 1 to 5 times the pile entirely with at least 3 days of interval between each operation or build a pile having larger branches at the base and in some layers of the pile in order to easy bottom up air passage through the pile. The intervention of macro-organisms will help in creating air pathway through the pile.

Apart from this average indication turning the pile is done;
– When temperature exceed 60C which means that the reaction is going to quick and all oxygen is used in the chemical reaction
– When white ashy actinobacteria appears. It means that the combustion becomes anaerobic with the creation of antibiotics arming fungus and bacteria.
– When bad smells appear, meaning as well that the combustion becomes anaerobic with Nitrogen, Phosphorus, and Sulfur being lost as gases and pathogen thriving.
– When temperature or humidity is not homogeneous in the same layer of the pile

When added to the fields compost should not be mixed with dirt in a ratio of more than 30 percent (compost is an inoculum and does not replace soil).

manureTypes of manure and nitrogen resource

We may identify various types of available animal excretion

– Animals dejection mixing urine and feces (e.g. birds). This type of manure is high in nitrogen since it incorporates the urine component high in nitrogen. As for human and pigs birds eat as well high nitrogen content food compared to pure herbivores.
– Ruminant (e.g. cows). The digestive system of ruminants produce a manure exempt of weed seeds and a high concentration of beneficial bacteria.
– Others, including herbivore and carnivore may have various behavior in relation with the way they are managed in a farm. Sometime only feces are available, other time animal bedding will help gather both urine and feces. This should be taken into account when reading documents which provide with C/N ratios.

Different recipes can apply based on required end result. This mixture is an average;

– 45% material high in carbon; Woody material in the form of cellulose and lignin. Wood chips (better than sawdust since saw dust prevent air to pass through), small stalks, brown paper, cardboard. The C:N ration is 60
– 35% green material. Contain still nitrogen when green but the important part is sugars, proteins, and carbohydrates, an important part of the food for bacteria to thrive. If you store green material it needs to be dried and the C:N ration will go up to 60. If fresh and green the C:N ratio will go down to 30.
– 20% material high in nitrogen. The manure needs to be fresh to keep a high ratio of Nitrogen. C:N Ratio is 10

The compost should be planned depending on fresh manure availability.

In absence of manure the nitrogen can be obtained by using fresh green vegetation and kitchen scraps (grass cuttings, small and soft pruning, remains of annual plant and weed before they have set seed, tea bags and coffee grounds). Special strategies can be developed in places lacking adequate resources (e.g. lack of fresh manure, soft green material) – Read more about making compost with limited supplies.

A mature compost may contain 25% more nitrogen than put initially thanks to nitrogen fixing bacteria.

Usually brown organic matter (e.g. mulch) has lost its nitrogen content. Natural compost found on the forest soil is a combination of carbohydrates coming from the fallen leaves and the nitrogen coming either from the dripping line of the trees during rain or from the activity of the forest soil ecosystem where leguminous are present (mineral exchanges conveyed by soil micro and macro organisms).

Covering an open air garden bed with brown mulch only may create some nitrogen deficiency in the soil not having nitrogen resources available, especially on poor soils.

balanceTypes of compost

Composts vary in their respective quantities of bacteria and fungus. Compost high in fungus are more suitable for trees planting and orchard maintenance (perennials in general). Compost high in bacteria are more suitable for annuals (vegetable garden).

The type of compost will depends;

– on the material used during the composting process. A higher quantity of lignin (branches, fibers) will favor fungus presence.
– and the type of composting; hot composting favors bacterial development and is low in fungus therefore mostly adapted to annuals.

These are some variations on the materials you may use depending on your compost usage;

– Compost high in fungus for orchard or plants needing lignin structure; 10% High Nitrogen, 30% Green Plant Materials, 60% Woody Materials.
– Compost with average fungus and bacteria quantities; 10% High Nitrogen, 40% Green Plant Materials, 50% Woody Materials.
– Compost for vegetable garden; 25% High Nitrogen, 30% Green Plant Materials, 45% Woody Materials. (this type of compost is quicker to make)

When doing kitchen scraps compost, assuming you will get humid incremental material a strategy is to prepare a strata of 30cm high of green and woody material where you will deposit the scraps and recover them to prevent them to dry. over time you cover the surface and start another layer. When you want to start the composting process, at least 2 weeks after the end of the last layer add 10% of manure (high in Nitrogen) and turn the pile.