Transcript الشريحة 1

1
2
*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.
3
Composting is a
process.
4
5
6
7
Grass clippings
Food scraps
Compost
Leaves
8
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.
9
10
*Obtain energy to carry on life processes.
*Acquire nutrients (N, P, K) to sustain population.
11
oxygen
Anaerobic
composting
Aerobic
composting
absent or in
limited supply
presence
toxicity
odor
12
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.
13
14
1. Oxygen and
Aeration
Hot air
low
O2
O2
O2
rich
cool
air
15
16
Turning the pile mixes
fresh air into the pile
Turning tools can make the
job easier
17
2. Moisture level
*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.
18
19
3. Temperature
20
4. Particle size
*Particle size regulate microbial access to food.
*Small particles have more surface area than large
particles ; easy access.
21
shredding
22
5. Types of organic matter
23
6. Carbon/nitrogen ratio
*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.
24
*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).
25
Rules of thumb
*Green materials have lower C:N ratios than woody
materials or dead leaves.
26
Browns
High carbon materials
such as
Leaves (30-80:1)
Straw (40-100:1)
Paper (150-200:1)
Sawdust (100-500:1)
Animal bedding mixed
with manure (30-80:1)
27
Greens
High nitrogen materials such
as
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 (1318:1)
– Hog (5-7:1)
28
Feedstock C:N Ratios
Materials High in
C:N Ratio
Carbon
Fall leaves
30-80
Straw
40-100
Wood chips or sawdust
100-500
Bark
100-130
Mixed paper
150-200
Newspaper or cardboard
560
29
Materials High in
Nitrogen
C:N Ratio
Vegetable wastes
15-20
Grass clippings
15-25
Manure
5-25
30
*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.
31
Improvement of soil by
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
32
33
34
2. Physical Contributions
*Increased water absorption
*Increased water retention
*Improved drought tolerance
*Reduced soil erosion
35
3. Chemical Contributions
*Increase cation exchange (more negative charges)
to hold which increases soil ability capacity
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.
36
Garden
trimmings
Grass
clippings
Kitchen scraps
Also
• Used potting soil
• Manure
• Sawdust
• Hair
Leaves
37
Cat or dog waste
(attracts pests, could spread disease)
Diseased or insect ridden plants
(could infect or attack garden plants
when compost is used)
38
*Lime (increases compost pH and promotes
ammonia odor problems.
39
40
*Simplest technologies are composting bins or
backyard piles.
41
Bin/pile construction
42
43
Manufactured bins
44
The Earth Machine Bin
45
46