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<!-- NEEDS REFERENCES AND A REVIEW OF TYPES OF COMPOSTERS WITH THEIR PROS AND CONS RELATED TO YOUR CRITERIA -->
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==Description of Opportunity==


===Who===
Robert Duncan, a junior at Humboldt State University, is building a comprehensive Composting system for CCAT-  The Campus Center for Appropriate Technology.
===What===
I will be designing a compost system that includes kitchen and yard wastes. The compost system will allow for multiple phases of compost to be “curing” simultaneously. Finished compost material will be used to amend CCAT’s present and future garden soils.
===When===
Ideally, the system will be maintained year round. Compost can work year round especially in milder climates such as Coastal California. Freezing temperatures may not damage a compost pile too much, but you will see slowed microbial action.
===Where===
On CCAT grounds somewhere. Ideally out of direct sunlight, in an easily accessible area (both for input user such as kitchen and output user such as garden).
=== Why===
*Eliminates yard and food scraps from the waste stream. According to the EPA, 23% of our current waste stream is yard/food material.
*Breaks down large materials in a shorter period of time than natural decomposition, ie branches
*Compost can be used to amend CCAT soils to increase agricultural yields, improve the physical and chemical properties, increase soil stability (prevents erosion), and increasing topsoil quantity and health.
*Breaks down weed seeds and certain pathogens with high temperatures. “cleans the soil”
*Promotes microbial growth, the main factor in breaking down rock materials in to a size usable as plant nutrients. Encourages earthworm production  important ecosystem engineers.
*Soil loss, decreased nutrient availability and lower microbial populations are all very important environmental issues that should be of major concern. If every person were to take their organic materials from the waste stream and return it to the soil through composting, all three of these issues could be significantly reduced in severity.


==Criteria==
==Criteria==

Revision as of 17:25, 7 May 2008

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What is compost?

Compost is a mixture of decaying organic materials (plants) that is used for to fertilize and condition land . Compost can be anything from a pile of sticks and brush to food scrap bins using worms to digest organic materials (vermiculture). The main purpose of compost is to recycle food and garden wastes in to fertile soil.

Nature recycles the Essentials of life

As plants grow, huge amounts of organic materials are strewed across landscapes in the form of leaves, needles, branches, and other leafy matter. These “dead” materials are broken down by an armada of bacteria, fungi, insects, birds and animals to produce topsoil. Mostly by consuming plant material and excreting a more broken down form, all of these “composters” recycle important plant nutrients like nitrogen and carbon back in to the soil profile to be absorbed by the next season’s growth. This process is very slow adding just inches of soil every thousand years.

How Does this do anything for me?

The very same bacteria and fungi from nature can break down your kitchen scraps and grass clippings and create nutrient rich soil. As these micorbes break down your wastes they generate huge amounts of heat that speed up the breakdown process. In most of nature, soil development is a multi-year process, but warm compost piles can break down huge amounts of material in just a few months!

Description of Opportunity

This comprehensive composting system will be a system that decomposes kitchen and yard wastes. A three-tiered system will allow for multiple phases of compost to be “curing” simultaneously. Finished compost material will be used to amend CCAT’s present and future garden soils. Ideally, the system will be maintained year round. Compost can work year round especially in milder climates such as Coastal California.


Why does CCAT want a Composting system?

CCAT has had several composting bins throughout the years. All of the other systems have either broken down due to age, were taken apart during the mutli-year moving process, are not efficient, or are too accessible to rodents. I attempted to fix all of these problems by designing a more permanent system out of non-biodegradable materials. More on the design later...
Furthermore there are many benefits that come from Composting:

  • Eliminates yard and food scraps from the waste stream. According to the EPA, 23% of our current waste stream is yard/food material.
  • Breaks down large materials in a shorter period of time than natural decomposition, ie branches
  • Compost can be used to amend CCAT soils to increase agricultural yields, improve the physical and chemical properties, increase soil stability (prevents erosion), and increasing topsoil quantity and health.
  • Breaks down weed seeds and certain pathogens with high temperatures. “cleans the soil”
  • Promotes microbial growth, the main factor in breaking down rock materials in to a size usable as plant nutrients. Encourages earthworm production important ecosystem engineers.
  • Soil loss, decreased nutrient availability and lower microbial populations are all very important environmental issues that are of major concern. If every person were to take their organic materials from the waste stream and return it to the soil through composting, all three of these issues could be significantly reduced in severity.

Literature Review

Types of Composting Systems

There are many ways to build a compost pile. As long as each design fits the needs of the users, almost any design can be an efficient composting system. Below are a few of the shapes and sizes and purposes of different composting bins

  • Single Bin- A stationary bin where new material is applied to the top of the bin and processed compost is removed from the bottom or left to further decompose.
    Singlebin.JPG
  • Compost Tumbler- Many systems are available that use a round cylinder to house the compost. Rotating the barrel is effectively turning the compost. These bins are very efficient for small amounts of material and for the user who wants a minimal amount of work to manage their compost.
    Tumbler.jpg
  • Block Bin- Concrete blocks or bricks can be used to build a makeshift container. Not suitable for kitchen wastes as not secure from rodent access- would need additional barriers
    Blockbin.jpg
  • Vermiculture - Using worms to process organic material is a very exciting sector of composting. Red wrigglers are a very fast way of processing huge amounts of material. Worms are sensitive to high acidity and waterlogged compost- citrus is a not able to be processed in this system. Worm castings, a by-product of the worms consuming food, can be used as a great soil amendment rich in nitrogen and other nutrients. To see an example of worm bins, check out CCAT's Vermicomposting Bin
  • Multi-stage bins- Several cells contain compost in different stages of decomposition. This system is the most forgiving (almost any material can go in the bins) and of conventional systems-meaning not vermiculture- is able to process the most compost in the shortest time.
    Multi-stage.jpg

Advantages of Compost Farming

  • General fertility of the soil is increased
  • Mechanical structure is improved- clay soils looser, sandy soils more cohesive
  • Ease of cultivation-reduces effort in farming due to improved soil quality
  • Increases water holding capacity
  • Prevents hardening of soil- a major cause of soil erosion
  • Earthworms multiply- artificial fertilizers kill worms, provide pores/increased breakdown
  • Increases Microbial populations- Fungi and bacteria extend plant root matrices, increased nutrient uptake
  • Increases topsoil layer- builds rich medium for roots
  • Darkens color of soil- absorbs heat more readily, increases plant/microbe growth
  • Compost kills weed seeds- nutrient robbing weeds are kept to a minimum
  • Pest/Disease prevention- Healthy plants don’t attract as many bugs
  • Humus counteracts toxicity- Salt and Aluminum is decreased in potency

Factors in Composting

The key elements to building nutrient rich compost are organic materials, proper moisture and aeration. Other factors such as particle size, climate, and time also affect compost.

Organic Materials

Creating healthy compost requires that you feed the organisms good food. The little beasties that do our dirty work of chewing up the material like almost anything that is made of plant matter. Kitchen rinds, veggie leftovers, husks, even rotten plants are all delicacies. Avoid substances such as dairy products and meats. These wastes create odor problems and can attract flies and other rodents . Maintaining the proper nutrient balance is also important for creating balanced compost. Adding grass clippings, kitchen wastes or manure supplies nitrogen and little carbon while sticks, hay, and leaves provide almost exclusively carbon.

Moisture Content

Composting microorganisms need a decent amount of water to survive. Desiccation (drying out) damages the microbial populations and the overall effectiveness of your compost pile. Saturating the pile decreases the amount of oxygen available to microbes causing the material to sit and rot as opposed to breaking down. Many materials that can be added to a compost pile contain moisture but often times it’s not enough. Rainfall will affect this factor so monitor the soil around your pile for excessive moisture. Cover the pile with a tarp, lid etc. to prevent too much water from entering the compost pile. A good moisture content will not drip any water from a handful of compost just resting but will if you squeeze the material; like a sponge.



Criteria

  • Easy Upkeep- Composting requires preiodic turning and maintenance. The design and location should make it easy to use the compost system
  • Aesthically pleasing- Composting is an important Appropriate Technology and should be presented in a manner that will appeal to everyone
  • Durable Design- Compost incorporates moisture, heat, and microbial action. These factors combine to break down materials, including you compost bins, in a short time. The bins must be made of materials that will endure the composting process as well as external environment conditions.
  • Security- Compost piles can be potential food sources for rodents. The design of the bins must prevent rodent access while maximizing airflow
  • Flux Capacity (hehe)- CCAT experiences huge variation in the amount of material produced by the grounds depending on whether school is in session or not. The bins must be designed to accommodate a large variation in amounts of matter.


Cost Table

Material Cost/unit Total cost
Trex 2.09 /ft None-recycled from CCAT stores, around $300 new
Concrete blocks ~ $1/ea none-recycled
Corrugated Tin .50c/lb $40

References

The Complete Book of Composting, J.I. Rodale Editor-in-Chief, Rodale Books Inc. Emmaus, Pennsylvania. 1971. Complete Book Of Composting
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