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Introduction
Soil erosion robs the landscape of more than three billion tons of topsoil each year. A large amount of this erosion takes place on lands that are highly erodible. Runoff from depleted soils can increase siltation and contribute to agricultural non-point source of pollution. While pesticides, fertilizers, and field residues are carried into our local water supply due to water erosion.
Another problem that is affecting urban and rural citizens is inadequate space for landfills. Therefore, it is imperative that we recycle and extend the useful life of our landfills. The following proposal and information demonstrates a win – win situation for the urban, rural, and agricultural communities.
A properly formed, maintained and monitored windrow will produce quality compost.
Composting can be defined as a managed biological oxidation process that converts heterogeneous organic matter into a more homogenous, fine particle, humus like material. Throughout the composting process, organic matter is decomposed (first rapidly, then at a slower rate) until a stable organic mass is formed. In nature, decomposing organic materials are being stabilized or matured on a more or less continual basis. Compost maturity is important because it determines the usefulness of the compost as a soil amendment.
Recycle and Composting Equipment’s aim is to help farmers and companies to start composting using the correct implements or machinery which will give a clean, safe and healthy compost in a time frame that makes it commercially and financially viable.
Best management practices identified during a recent study (Natural Resource, Agriculture and Engineering Service USA) showed beef cattle (average 450kg per beast) produces 0.03m³of compostable material per day / beast.
Farmers benefit from using compost on broad acre farming by obtaining of higher yields and production, less chemical use, erosion control and increased organic matter.
Drying Manure or Composting Manure ?
A feedlot can choose whether to just dry their manure or go the next step and compost the manure to Australian Standards AS4454.Composting of manure may offer better control of odour and flies than other handling methods. Also, field application of composted manure is greater per acre and more beneficial than application of dried manure.
Due to water concerns and time available some large cattle feedlots choose the quicker method of drying the manure, which is providing adequate results at the present moment for re-dispersion to land.
Some advantages of drying manure instead composting are that it reduces weight and volume, and with the exception of some airborne loss of ammonia, conserves manure nutrients in a stable organic form.
On the other hand, composted manure can be marketed at a much higher cubic metre value. An incentive for marketing manure compost off-farm is that composted material can be used in a variety of residential and horticultural applications where raw manure simply would not work. A well-made farmyard manure compost is about the most ideal garden fertilizer. When mixed with other composts, soil, or peat, manure compost is highly recommended for starting seedlings. Compost containing manure has shown significant antifungal potentials.
What Happens during Composting?
Cow manure is unique and composting begins as soon as the moisture level drops below 60% by volume. Initial mixing of raw materials introduces enough air to start the process. Almost immediately, microorganisms consume oxygen, and settling materials expel air from pore spaces. Aeration is provided using a specialized windrow turner either by aeration and fluffing.
Temperature increase caused by microbial activity is noticeable within a few hours of windrow formation. The temperature of composting materials usually increases rapidly to a temp around 49°C – 60°C and must remain in this range for several weeks. As active composting slows, temperatures gradually drop to 40°C and then to ambient air temperature.
A curing period usually follows the active composting stage. While curing, the materials continue to compost but at a much slower rate. The rate of oxygen consumption decreases to a point where the compost can be stockpiled without the need for turning and aerating.
The composting process does not stop at any particular point. Material continues to break down until the last remaining organisms consume the last remaining nutrients and until nearly all carbon is converted to carbon dioxide. However, the compost becomes relatively stable and useful long before this point. Compost is judged to be “done” by characteristics related to its use and handling, such as carbon-to-nitrogen ( C:N ) ratio, oxygen demand, temperature, and odour.
Advantages of Composting
Specific advantages of composting include:
• An efficient recycling method for green waste and animal waste from landfill
• A more stable form of nitrogen that is less likely to leach into water supplies
• A slower release of plant-available nutrients in the final product
• Reduced moisture, weight and volume of stored green waste
The most important effect of turning a windrow is rebuilding porosity to improve air exchange. Turning also exchanges material at the windrow surface with material from the interior. In this way, materials are composted evenly and weed seeds, pathogens and fly larvae may be destroyed by the high interior temperatures. Turning further blends and reduces particle size of the composting materials thus, increases their biologically active surface area.
The equipment Recycle and Composting Equipment can provide for turning windrows will determine the size and shape of individual windrows. Depending on the size of each operation a windrow turner can be matched to individual requirements. Products, production needs and end product use will all influence which model best suits a project needs.
Composting Feedlot Manure with Green Waste
This practice is not new to anybody but must now be considered as part of moving to a Zero Waste Policy – a policy that is becoming more the norm than not.
Receiving an income for accepting a certain amount of green waste alone, can justify this method of composting rather than disposing of the green waste through current methods. At the end, a feedlot can either contract out the whole practice or value add the compost to increase their revenue.
Feedlot manure is a significant source of organic matter, which is an important supplier of carbon. Organic matter improves soil and plant efficiency by improving soil physical properties, providing a source of energy to beneficial organisms, and enhancing the reservoir of soil nutrients. The organic content of a soil can be built up slowly through repeated applications of compost or other organic materials.
Through education consumers of compost are successfully learning the advantages of applying compost and utilizing a bulking agent of green waste such as lawn clipping sourced from the local landfill with prolong landfill life.
Just to step back for a minute, once a grinder has processed the green waste, the waste is far more compact and easily managed for the purpose of either reducing landfill or utilizing the ground product for a bulking agent in compost.
Pictured below is
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The product typically produced by a horizontal or
tub grinder that is contracted to various landfills throughout Australia.
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Window temperature and pH should be monitored every day and windrow’s must remain active and within the correct temperature and pH range for a minimum of 15 days. Comprehensively turning of the windrow is vital for compost to reach maturity whilst complying to minimum standards (per EPA regulations). A windrow must be turned at least 4 times within a 15-day period.
Proper mixing and aeration by the use of a properly designed and purposely built windrow turner, will give better fluff and oxygen supply to the compost as well as giving better temperature control of the mix.
In the background of the photo below, you can see stockpiles of compost already completed and awaiting sale or distribution by landscape gardeners and/or members of the public.
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Bulking material of ground green waste
and lawn clipping from landfill
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O.H & S.
A compost site must be operated in a responsible manner to safeguard public health, safety, and the environment. Studies from (Natural Resource, Agriculture and Engineering Service USA) have shown that the common tractor with front-end bucket does not produce compost that is safe to the surrounding environment nor give adequate temperature control consistently through the entire mix.
Minimizing or eliminating nuisances: -
– such as odours,
– run off,
– vectors,
– dust,
– traffic and noise
Public health as well as environmental and aesthetic benefits can only successfully be managed though a properly constructed windrow, utilizing purposely built windrow turners.
Most safety problems at composting sites are related using equipment not designed for the task of windrow turning.
Workers need to be informed about appropriate practices and health issues related to composting.
For example: -
• Particulate respirators should be provided for all workers in areas of excessive dust.
• Sealed, ventilated cabs on equipment should have washable or disposable filters.
• Workers should be given the responsibility and time to clean or change these filters regularly.
• Drainage facilities should be provided in work areas to remove ponded water and leachate that may contain pathogens or vectors or cause workers to slip and fall. Workers need to follow sensible precautions regarding protective clothing and equipment and treating and disinfecting cuts. Normal sanitary measures such as washing hands before touching food or eyes are important for workers.
Using Brown Bear Equipment
Brown Bear Corporation over the last 25 years have been designing and developing a superior type of windrow turner that gets the correct amount of “fluff” and oxygen into a windrow to ensure that temperatures rise to an acceptable level to commence the process of turning green waste and manure into safe and manageable compost for the end user to handle with confidence. Brown Bear specialized equipment assists in producing compost in the minimum timeframe.
Forward mounted PTO windrow turner
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Rear PTO windrow turner mounted
on a standard 3 -point linkage |
Sittler 509 working
through a windrow turner |
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Sittler 512 showing a windrow being turned.
In-built and purposely designed water delivery systems, provides excellent
moisture control for the windrow
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This machine below is the actual unit being used at the landfill in Nebraska USA.
Turning with proper equipment allows good temperature control and quicker composting
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A properly maintained windrow should have
minimal odour problems
Brown Bear GM400 |
Pictured is a
Brown Bear PTO 10.5
This turner is a popular model
in Australian Feedlots |
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Composting Mortalities and dealing with BSE
After the “mad cow” (BSE) scare in Canada and the UK a policy of not returning mortalities within the diary, poultry and piggery directly back into the food chain has now been adopted.
Traditional mortality handling methods include burial at the farm or at landfills, incineration, and renderer pick up. Composting mortality is gaining popularity because it is cost effective, environmentally sound, biosecure, and easy. Composting decomposes mortalities to a useful farm product (soil amendment) without the production of objectionable odours or the attraction of flies or scavenging birds and animals. Composting avoids putting mortalities in the soil, where groundwater contamination is a risk.
A correctly constructed windrow can breakdown a beast (diary cow) within 12 days, smaller animals are composted quicker. The photo below is a windrow from a diary farm in Missouri USA taken May 2004.
Mortality windrow on Dairy Farm
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Sittler Manufacturing
PTO driven Windrow Turner |
Although farmers in Australia do not have this problem to contend with currently, it is always good business practice to be able to have a plan if confronted with an issue such as BSE or infection control.
Screening to produce a quality product
Screening separates materials of different sizes, shapes, and weights and can improve compost quality by removing
• oversized materials,
• clumps of compost,
• small inerts such as rocks, sand and other annoyances.
• unwanted material that is not fully composted.
Larger organic particles that are screened out after curing can be recycled back to the feedstock preparation step to next windrow. If screening is delayed until after curing, larger particles will continue to maintain pile porosity in the curing piles. Also, screened compost that is stored too long may develop clumps that can reduce its usefulness. If necessary, refining operations to remove small inert pieces such as glass can follow screening, metal fragments, plastic bits, and film plastics. Most on-farm composters do not perform refining operations, since farm-generated feedstocks are relatively free of small inerts.
Screening plants not only produce quality compost that will be usable of international grade golf courses for top dressing, but also a domestic product that the local nursery would sell to the “Average-Joe” gardener.
A screening plant will produce up to two to four products at the same time. Quality and final product size can be varied to suit individual applications. A typical screening plant can produce; Fines, Secondary and Over’s.
Pictured below is a screening plant that has been designed to be portable and easily set-up for on farm use. The unit can be driven by the tractor PTO or using an auxiliary engine.
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Screening plants can be either
Auxiliary or PTO driven |
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Sittler Trommel Screen |
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Driven by tractor PTO mobile and portable unit
Sittler Trommel |
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Grinding Green Waste
To grind green waste similar to the product in the photo below, you can use either a horizontal grinder or a more traditional tub grinder.
Type of product obtained from a
horizontal or tub-grinder |
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Conclusion
This information package was complied to demonstrate that feedlot manure and yard trimmings such as grass, leaves and tree trimmings from our landfills can be combined and composted to provide income source to a farm. Many Councils contractors and general public are willing to pay a small fee (usually lower rate than landfill) to dispose of their green waste. Agricultural land provides a large-scale market for this material.
It must be remembered that an investment into the correct equipment in the beginning can save time, give better quality to the product and increase the bottom line of a farms balance sheet.
Recycle and Composting Equipment has aligned itself with the latest technology in waste grinding, composting equipment and screening plants. Our portfolio of products and range variety is extensive and our sales team will be only too happy to discuss your option or options for your contractors and quote competitively on what machinery best suits the application.
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