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Food Waste and Composting Frequently Asked Questions
Below are some of our most frequently asked questions, if you cannot find an answer to your question, please click here to email us your enquiry.
Why compost anyway?
| Composting reduces the demand for landfill sites. | Apart from being offensive and unsightly, especially for people living nearby, landfill sites are expensive and have to be paid for either by industry or local council taxpayers. They produce unpleasant odours despite the greatest efforts of the managers to avoid them and can release greenhouse gases like methane. | |
| Compost improves soil structure. | Both water holding capacity and fertility are improved by adding humus to sandy soil whilst heavy clay soils gain improved structure and porosity. | |
| Compost improves soil structure. | Both water holding capacity and fertility are improved by adding humus to sandy soil whilst heavy clay soils gain improved structure and porosity. | |
| Compost Helps Suppress Disease. | Various scientific studies show that the addition of helpful micro organisms present in the compost help plants to fight disease and some of the effects are quite dramatic. Work done at the University of California (1994-2000) highlighted the suppression of Brown Rot in Peaches, End Rot in Onions and Avocado Root Rot. | |
| Compost reduces the need for pesticides. | Tests have shown up to 90% reduction in whitefly and complete elimination of aphids and red spider mite and they believe it is because the compost activates natural plant repellents. | |
| Compost reduces the need for artificial fertilisers. | By providing natural growth promotion, NPK fertilisers are less necessary and in agriculture, the run off of fertilisers into water courses are also reduced and nutrients from compost are less likely to leach out. | |
| Compost reduces costs. | The need to purchase soil improvers, composts and artificial fertilisers is reduced. | |
| Compost suppresses weeds. | When used as a mulch, a layer of compost will help suppress weeds by reducing the amount of available light. Properly made compost will not contain weed seeds, but will also provide soil nutrients. Un-composted mulches e.g. woodchip or bark can reduce nitrogen levels in the soil and cause damage to plants, however compost used slightly before it is mature is extremely valuable for Vermiculture. | |
| Compost helps to preserve Peat stocks. | It is regularly reported that peat stocks are approaching extinction with current levels being down to 4%. Whatever the figure is, it is undoubtedly a finite resource and replacement products have been found wanting. In this regard, a ‘Gardening Which’ report (Jan/Feb 2001) shows germination of Impatiens (Busy Lizzies) seeds in peat free or reduced peat compost is down to a minimum of 30% compared to minimum 54% in peat based material. Correctly made naturally made compost does not suffer this deficiency. | |
| Compost enables organic horticulture. | Although there is a need to take care that no substances banned by the Soil Association are included in waste to be composted, properly made compost is the very basis of organic horti/agriculture. | |
| Compost can eliminate digging. | Compost used as mulch will be dragged into the soil by earthworms and this helps with soil aeration as well as providing the required nutrients and in shrubby borders it can remove the need to dig. | |
What is the process of composting?
Composting is a biological process which, in the absence of anything, else will happen on its own. Visit a wood or forest where an investigation with a fork or trowel will reveal various levels – un-composted leaves, semi-rotted material down to dark crumbly damp soil that would be a delight in any garden.
In fact composting is as scientific as bread or wine making. Leave flour, milk, water, salt, sugar, fat and yeast in unmeasured proportions in a bowl in the kitchen at any old temperature and although a bio-reaction will no doubt proceed, the result will hardly be a gastronomic delight!
The same applies to composting and there are laws to follow if a successful product is the aim.
There are 7 rules of composting. Expressed simply they are as follows: -
- Take ‘Green’ waste. (A simple word for high nitrogen waste - grass, weeds, animal manure etc.)
- Take ‘Brown’ waste (high carbon) - usually dry in nature, e.g. tree and shrub prunings, waste paper, woodchip, straw etc.
- Shred and mix them in the proportion 3:1. (approx.)
- Add micro-organisms for speedy action.).
- Preserve and control the heat produced by the composting process.
- Provide the correct water content (preferably 60% of the dry mass) and control it in its need to change.
- Control aeration.
To explain the rules further –
Green waste. waste containing high nitrogen is often green. Grass, vegetable waste, green Leaves, weeds and some of their products of decomposition like manures of herbivorous animals like horses, cows, sheep etc.. Although hardly green they contain, not only high nitrogen but also many micro-organisms responsible for decomposition of organic matter. This waste provides the heat necessary to raise temperatures to levels where the process is rapid and where pathogens like e-coli 157, weed seeds, slug eggs etc are destroyed. (Above 500c for 3 days)
Brown Waste. The addition of ‘high carbon’ both adds structure to the compost and reduces nitrogen depletion in the finished product. These materials – like prunings, paper, (use non glossy) wood chip, sawdust, straw, etc.
Shredding and mixing. Reduction of particle size by any means possible brings the waste particles into close proximity and enables the micro-organisms to move from one particle to the next in search of food. The exposure of the internal parts of wood and other vegetable matter is extremely helpful.
Add micro-organisms. The composting process is dependant on these in the form of fungi, protozoa, bacteria etc. to work and many are present in the atmosphere and are really the ‘yeast of the process’ as in bread or wine making. However, for rapid results it would not be prudent to await the arrival of the correct ones. Certain accelerators can be purchased to contain specific micro-organisms to deal with the various organic materials which predominate in the waste to be composted. These kick-start the process and facilitate rapid composting.
Maintain and control heat. Decomposing organic matter will provide heat up to 900c given certain conditions, but this would be too high for most purposes. Normally, in domestic compost heaps under 8 cubic metres, the heat produced will escape and the mass will not reach the required 500c. Pathogens, weed seeds, slug eggs etc. will not be destroyed and the process of composting will take a long time.
Provide the correct moisture content. Micro-organisms live and have their being in the film of liquid that surrounds the particles of solid waste that is their food. Too little and they starve and too much excludes the very necessary oxygen for aerobic fermentation and which would prevent the production of methane, a major greenhouse gas and which has a rank, very unpleasant odour.
Provide aeration. Oxygen is essential in correct composting for the promulgation of the correct bacteria and allows the mass to reach the required temperature. It can be achieved by turning the heap or by air injection, but it must be carried out on a regular basis.
What should and should not be composted?
A study of horticultural and composting books and other publications shows that they give conflicting advice on this subject. Not much of it is backed by scientific study. What is certain is that any organic matter will eventually decompose and therefore must be a candidate for composting.
Using the Rocket anything that has ever lived can be safely composted with very few exceptions.
Meat or fish scraps which normally encourage rodents and flies can be included as it is a closed system which denies access to these pests.
Avoid plants with serious diseases like honey fungus or sweet pea root rot, potato blight for etc. as small amounts may linger and affect future crops. Also omit grass and other plants that have been treated with hormonal weed killers etc. as residuals even in small concentrations can cause damage.
How does composting work?
The Microbiology of Composting.
The biological degradation process of composting
can be broadly described in terms of four stages
of micro-organism activity, characterised by different
temperature ranges.
At the beginning (Mesophilic stage) bugs operating
at ambient temperature are required. These include
fungi, bacteria and actinomycetes. At the same
time acarines, millipedes and isopods will ingest
the organic wastes. The soft tissue of the decaying
plants supports growth of nematodes and enchytraieds.
-These consumers then attract and become food
for the next level of consumers – collembolans
eat fungi, ptiliids feed on fungal spores. Nematodes
ingest bacteria and protozoa and rotifers feed
on bacteria.
The energy liberated during this conversion causes
a rise in temperature to between 45 and 70°c.
At these higher temperatures (Thermophilic stage)
a specialised flora of bacteria, fungi and actinomycetes
take over.
It is then that organic degradation is rapid and
pathogens, fly larvae and weed seeds are destroyed.
As thermophilic activity declines and temperature
falls to 30-40° (Cooling stage) there is another
series of organisms capable of growth at normal
temperature.
Finally, as the compost is left in a heap, preferably
protected from too much rain (Maturation Stage)
the nitrification stage proceeds and ammonia turns
into nitrites and the nitrates. It is this final
material that aids plant growth
Unfortunately, in any batch process all the micro
organisms – spores and all - are largely
discarded and have to build up again in the next
batch.
It was with all these considerations in mind and to find a way to overcome the various shortcomings of the present systems that the ’Rocket’ was devised.
Why does The Rocket work so quickly?
Largely because it meets the 7 requirements of successful composting and importantly the other main reason is because normally in all batch processes the micro-organisms are all ejected as the compost container is emptied. However because the ‘Rocket is a truly continuous process and the waste mass passes gently through the reactor it leaves the organisms behind to continue their work.
What are the advantages of using The Rocket?
- Speed of decomposition
- Quality of finished compost
- Freedom from weed seeds, slug eggs and pathogens
- Cost effective
- Little manual effort required
- Conforms with current DEFRA rules for food processing
- Virtually odour free
- Access to rodents and flies is denied.
How do we work with The Rocket?
Once
the waste material has been selected and if necessary,
reduced in size, it is fed into the hopper of
the equipment. Water, containing an accelerator
is added in proportion to the mixed waste –
usually about 25% by volume.
It is preferable in the ‘Rocket’ to
commence composting with a high water content,
which produces almost anaerobic conditions and
gets the process off to a quick start.
The moisture level is controlled throughout the
process so that the compost develops rapidly and
then gradually dries out to emerge some 10-14
days later in a dry and friable condition –
ready for use.
Composting generates heat rapidly and the equipment
has a heating element surrounding the first part
of the reactor to kick-start the process and to
ensure it can meet the required temperature for
the needs of the particular process. The equipment
is insulated to prevent heat loss.
The waste material is then turned to aerate it
by a shaft which is fitted with angled blades
that lift to aerate it and at the same time move
it forwards towards the exit.
The heating has been designed to be variable to meet the different types of waste. High temperatures are achieved in the composting process by the normal reaction of decomposition during the thermophilic stage and are maintained for several days. During this stage, weed seeds, fly larva, slug and snail eggs are destroyed as well as most intestinal worms and pathogens that may be present, especially if animal manures are incorporated into the waste.
What are the running costs?
These are minimal – normally only a few pence per day!
When is the composting process finished?
It depends on the use to which it is going to be put e.g. is it required as a soil conditioner, as a mulch, or as a seed or potting compost? The equipment can be programmed so the compost emerges in about 9 days when it will be slightly under composted where it is ideal for vermiculture as it has a residual food value for the worms.
Leave it in for 14 days to spread it in the ground as a mulch where, because of the lack of oxygen in this slightly under composted material it helps to suppress weeds better. For seed and potting purposes it is preferable to leave it in a covered heap for at least 2 weeks to allow it to mature. For the very enthusiastic it can be tested for maturity by placing it in a vacuum flask, taking the temperature and if tested again in a week’s time the temperature should not have risen.
The ‘Rocket’ continues to use the generated heat to dry the compost to make it easy to handle and it can also be shredded further, or riddled at this stage if required.
The type of waste, ambient conditions and the required end product can all have an effect on time of completion.
ACL can be contacted on 01260 222942 for a free demonstration and further details
Quick contact details
Please contact Huw Crampton on 01260 222942 or email huw@quickcompost.co.uk for enquiries within:
England - Bath, Bedfordshire, Berkshire, Bristol, Buckinghamshire, Cambridgeshire, Cheshire, Cleveland/Teesside, Cornwall, County Durham, Cumbria, Derbyshire, Devon, Dorset, Essex, Gloucestershire, Greater Manchester, Hampshire, Herefordshire, Hertfordshire, Kent, Lancashire, Leicestershire, Lincolnshire, London, Merseyside, Middlesex, Norfolk, Northamptonshire, Northumberland, Nottinghamshire, Oxfordshire, Rutland, Shropshire, Somerset, Staffordshire, Suffolk, Surrey, Sussex, Tyne & Wear, Warwickshire, West Midlands, Wiltshire, Worcestershire, East Yorkshire, North Yorkshire, South Yorkshire and West Yorkshire.
Wales - Mid Wales, North Wales, South Wales and West Wales.
Northern Ireland - Belfast, County Antrim, County Armagh, County Down, County Fermanagh, County Londonderry and County Tyrone.
Offshore counties - Guernsey, Jersey, Isle of Man, Isle of Wight, Isles of Scilly, Orkneys and Shetland Isles.
Europe & The Rest of the World
Please contact Doug Boyle on 07780 610873 or email douglasboyle@hotmail.com for enquiries within:
Scotland - Angus & Dundee, Argyll, Ayrshire & Arran, Borders, Dumfries & Galloway, Edinburgh & the Lothians, Fife, Glasgow, Grampian, Highlands, Isle of Islay, Isle of Mull, Isle of Skye, Lanarkshire, Perthshire, Stirlingshire and Western Isles
Please contact Sam Wareing on 01260 222942 or email sam@quickcompost.co.uk for enquiries within:
Southern Ireland / Eire - Carlow, Cavan, Clare, Cork, Donegal, Dublin, Galway, Kerry, Kildare, Laois, Leitrim, Limerick, Longford, Louth, Mayo, Meath, Monaghan, Offaly, Roscommon, Sligo, Tipperary, Waterford, Westmeath, Wexford and Wicklow.
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Due to our policy of continuous development we reserve the right to change design and specifications without prior notice. Accelerated Compost Limited does not accept responsibility for any loss as a result of any company or person relying on material in this website, or for any mistakes or misprints. Although every care is taken to ensure accuracy, this site is a general guide only and specific technical advice is recommended before proceeding with any transaction. Specific fact sheets, or, technical information is available from Accelerated Compost Limited technical department on 01260 222942.
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