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3 *Compost is a mixture of decayed organic materials decomposed by microorganisms in a warm, moist, and aerobic environment, releasing nutrients into readily available forms for plant use.

4 Composting is a process.

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8 Leaves Food scraps Grass clippings Compost

9 Decomposers These are the microbes (mainly bacteria and fungi) that do all the work for you. Food for the decomposers The organic materials to be composted.

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11 *Obtain energy to carry on life processes. *Acquire nutrients (N, P, K) to sustain population.

12 Aerobic composting Anaerobic composting presenceabsent or in limited supply oxygen toxicity odor

13 1. Chemical makeup of raw ingredients or feedstocks. 2. Physical size and shape of feedstocks and porosity of the pile. 3. Population of organisms involved in composting process.

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15 Hot air low O 2 rich cool air O2O2 O2O2 1. Oxygen and Aeration

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17 Turning the pile mixes fresh air into the pile Turning tools can make the job easier

18 *Optimal range 45-60% by weight. *Low moisture impededs composting process because 1. microbes need water 2. dry pile will become cool, slow down composting. 2. Moisture level

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20 3. Temperature

21 *Particle size regulate microbial access to food. *Small particles have more surface area than large particles ; easy access. 4. Particle size

22 shredding

23 5. Types of organic matter

24 *Carbon (C) and nitrogen (N) are the primary nutrients required by the microorganisms involved in composting. *Microorganisms use carbon for both energy and growth, while nitrogen is essential for protein production and reproduction. 6. Carbon/nitrogen ratio

25 *If amount of C relative to N is too high, slows composting process. *If C:N ratio is too low, more likely to lose N as ammonia gas (bad odor).

26 *Green materials have lower C:N ratios than woody materials or dead leaves. Rules of thumb

27 Browns High carbon materials such as Leaves (30-80:1) Straw (40-100:1) Paper ( :1) Sawdust ( :1) Animal bedding mixed with manure (30-80:1)

28 High nitrogen materials such as Greens Vegetable scraps (12-20:1) Coffee grounds (20:1) Grass clippings (12-25:1) Manure –Cow (20:1) –Horse (25:1) –Poultry (10:1), with litter (13- 18:1) –Hog (5-7:1)

29 Feedstock C:N Ratios C:N RatioMaterials High in Carbon 30-80Fall leaves Straw Wood chips or sawdust Bark Mixed paper 560Newspaper or cardboard

30 C:N RatioMaterials High in Nitrogen 15-20Vegetable wastes 15-25Grass clippings 5-25Manure

31 *Provides humus or organic matter, vitamins, hormones, and plant enzymes which are not supplied by chemical fertilizers. *Kills pathogenic organisms, weeds and other unwanted seeds when temperatures of over 60oC is reached. *Acts as buffer to changes in soil pH. * Improves soil.

32 1. Biological Contributions: *Inoculation or increased microbial diversity. *Increases microbial activity in soil, primarily by providing carbon as a food source for the microorganisms *Can reduce soil borne plant diseases Improvement of soil by

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35 2. Physical Contributions *Increased water absorption *Increased water retention *Improved drought tolerance *Reduced soil erosion

36 3. Chemical Contributions *Increase cation exchange (more negative charges) which increases soil ability capacity to hold nutrients. *Good source of micro nutrients. *May buffer pH ( greater stability or resistance to change pH). Have many nutrients that not exist in chemical fertilizer.

37 Garden trimmings Kitchen scraps Grass clippings Leaves Also Used potting soil Manure Sawdust Hair

38 Cat or dog waste (attracts pests, could spread disease) Diseased or insect ridden plants (could infect or attack garden plants when compost is used)

39 *Lime (increases compost pH and promotes ammonia odor problems.

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41 *Simplest technologies are composting bins or backyard piles.

42 Bin/pile construction

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44 Manufactured bins

45 The Earth Machine Bin

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