Composting. Turning waste into a resource!

Transcription

1 Composting Turning waste into a resource!

2 Benefits of Composting Environmental Benefits: Waste reduction Keep soil fertile! Air Quality Resource conservation (water!) Gardening Benefits: Saves money Enriches soil Contributes to healthy lifestyle

3 Compost Processes & Critters in the Compost Pile

4 A Compost Pile is an Ecosystem Function = decomposition of organic matter into stable humus

5 The Compost Process depends on: Organic Matter Composition Carbon (Browns) Nitrogen (Greens) Microorganisms Macroorganisms Water Oxygen Temperature

6 Organic Matter: Carbon or Browns Carbon rich sources are called browns Usually dry, low moisture content, lightweight Examples: dry leaves, straw, sawdust, wood chips, corn stalks

7 Organic Matter: Nitrogen or Greens N is needed to get the decomposition process started and keep pile cookin Examples: vegetable and fruit scraps, grass clippings, coffee grounds, manures, and alfalfa hay

8 Carbon:Nitrogen Ratio Optimal C:N ratio is 30:1 at an elemental level Carbon supplies energy for bacteria and Nitrogen supplies nutrients (proteins). Balance material ratios to get 30:1 ratio: e.g. 1/5 oak leaves 26:1 1/5 poultry manure 10:1 1/5 pine needles 85:1 1/5 grass clippings 20:1 1/5 food scraps 15:1 C:N ratio = ~31:1 Approximately equal volumes of greens and browns provides a good C:N ratio

9 The Decomposers: Microorganisms Bacteria begin breakdown process aerobic bacteria feed on plant sugars and respire to heat up pile In the right conditions, population growth is amazing bacteria can double every hour!

10 If you build it, they will Four Types of Bacteria come Psychrophilic: work at lower temperatures Mesophilic: thrive between F Thermophilic: work from F short work week 3-5 days, turn pile to reactivate Anaerobic Closed air bins, wet piles or too dense - not aerated Fermentation & odors from anaerobic decomposition Pile does not heat up, so doesn t kill pathogens/weeds

11 More Microorganisms Fungi: active in end stages of composting - live on dead or dying material Actinomycetes: halfway between bacteria & fungi gray-white cobweb type material in compost pile, also active in later stages of composting actinomycetes

12 Microorganisms As temperatures decline, population diversity increases: Nematodes: sightless, brainless roundworms, <1 mm long. prey on bacteria, protozoa, fungal spores Fermentation or mold mites Springtails, tiny white insects

13 Macroorganisms Wolf spiders: build no webs, run free hunting their prey Centipedes: flattened body, long legs, fast moving Millipedes: worm-like body with hard plates, up to 6 long. Slow moving vegetarians that help in breaking down OM. Sowbugs & pillbugs (Isopods) small, fatbodied decomposers with gills. Pillbugs roll into a ball, sow bugs don t. Feed on rotting woody materials Pillbug Sowbug

14 Macroorganisms Beetles: rove beetle, ground beetle, and feather winged beetle Earthworms: native redworms Enchytraeids, (Ehn kee tray' id) white or pot worms, ¼ - 1 long, white & segmented Whiteworms Flies: feed on any organic matter. Bury kitchen scraps well, keep fatty foods out of the pile to control.

15 Macroorganisms Snails and Slugs: Feed on living plant material, garbage and plant debris. Fruit beetle larvae: large grubs, 2 long & C- shaped; translucent white, head is dark brown. Ants: feed on aphid honeydew, fungi, seed, sweets, scraps, other insects, and other ants. Compost provides food and shelter. Ants usually mean pile is too dry. Earwigs: predators of all stages of insects, mites & nematodes, also algae, fungi & plants.

16 Water & Oxygen Balance oxygen and water in the compost pile: 50% moisture + 50% O 2 Consider moisture content of added materials (food scraps!) Compost should be about as moist as a well wrung-out sponge. It should be moist to touch but yield no liquid when squeezed.

17 Water in the Pile Wet pile: pull it apart, loosen it, incorporate dry materials and remake it. Dry pile: turn & rewet material as it is being turned (some browns are hard to moisten) Seasonal considerations!!!

18 Oxygen Aerobic composting is preferable Anaerobic decomposition or fermentation may produce compounds toxic to plants produces ammonia & methane gas smelly! Passive aeration: air is warmed by the compost process, rises through the pile, pulls in fresh air from the sides. Active aeration: turn and mix the compost, or build the pile effectively so surface air diffuses in

19 Temperature! Temperature is a function of: pile size, oxygen & moisture content Temperature affects biological activity: Most microorganisms active between ºF Best decomposer bacteria thrive at ºF. Above 140ºF kills pathogens & weed seeds, but slows decomposition.

20 Temperature Optimum is 2 weeks of temperatures around 135º Turning the compost whenever temperatures get above or below the optimum range produces high quality compost in the shortest possible time. If compost is properly moist and turning does not cause temperatures to rise, the compost is finished or needs more nitrogen.

21 How long does it take? It depends on: Density of material Particle size (amount of exposed surface area) C & N content Moisture content Aeration Volume Insulating materials around the pile

22 Making the Pile

23 What kind of bin should I use?

24 Making the Pile: Important Considerations Size of pile should be 3 x3 x3 to 5 x5 x5 Do you have all the organic material (batch) or will you add continuously (continuous)? Have you chopped up your materials? Moisture and aeration: what s the rule? Compost tools: hay fork, aerator

25 Composting Methods Standard Method: Need a variety of materials Turn it each week 4-6 weeks for finished compost (summer)

26 Rapid Composting Method Need large supply of organic materials Requires substantial chopping and shredding and more turning of the pile Can take less than one month in ideal conditions.

27 Slow, Continuous or Static Method If a steady supply of organic materials is not available Takes very little time or labor Requires 6 months to 2 years to produce compost Smaller compost area needed, because pile is built as materials are available Little if any heat is produced, so weeds & pathogens are not killed

28 What goes in the Pile? Grass clippings Yard waste Leaves, pine needles Vegetable trimmings Food scraps Wood chips (shredded to size) Newsprint Sawdust

29 What does NOT go in the Pile? Disease infected plants Plants with severe insect attack Ivy, morning glory and succulents Pernicious weeds, e.g. Bermuda grass, oxalis, cheeseweed Cat and dog manures Meat and fish scraps Wood ash (add after composting is finished)

30 Compost Happens! BUT What are some issues that complicate composting???

31 Trouble shooting 1. The pile smells: Too much water - Turn the pile. Don t water as often. Too much nitrogen- Add leaves or other carbon-rich material to the pile.

32 Trouble shooting 2. The pile will not get hot. Not enough water Add water. Pile too small Gather more material & make the pile larger. Not enough nitrogen Mix in fresh nitrogen-rich materials grass, fruit, coffee trimmings. grounds, vegetable Particle size too large Chop or grind material to reduce size.

33 Trouble shooting 3. The pile is attracting flies, rodents: Avoid meat, bones, oily foods, protein- rich, fatty or sugary foods and dairy products. Food is exposed. Bury the fruit and vegetables trimmings at least 6 12 inches deep.

34 When is it ready to use? Pile should be cool and full of life. Material should have an earthy smell. Material should be mostly amorphous. Large uncomposted materials like twigs, woody pieces, can be screened out and added to the next compost pile.

35 Course compost can be screened.

36 Compost uses Mulch Seed Starting Potting Soil Soil Amendment

37 Grass Cycling 1. Leave grass on the lawn as a mulch. Use a mulching blade. 2. Will not create thatch conditions. 3. Less green waste. 4. Feeds the lawn. 5. Less work, fertilizer, time and $.

38 Reducing Green Waste A 40 x 100 lawn annually produces about 1,200 pounds - nearly 50 bags of green waste.

39 Vermiculture: Composting with Worms

40 What is Vermiculture? Red worms transform decaying organic matter into worm castings Also known as Vermicomposting or Worm Composting Castings contain available plant nutrients Not hot composting But Univ. Wisconsin research has shown that pathogens and weed seeds can be killed by worms Usually done in containers, indoors or out

41 Why compost with worms? Ideal for small spaces Good for small amounts of green waste (food scraps) Requires less physical activity - little effort Produces excellent soil amendment!

42 Why compost with worms? It contains beneficial microbes. It has a high concentration of plant nutrients. Worm castings contain five to 11 times more plant-available nitrogen, phosphorus, and potassium than the soil the worms ingest. It is made up of organic matter, which helps soil hold more water and nutrients.

43 Composting Worms Two main species: Most common: Eisenia fetida Next: Lumbricus rubellus aka Red Wigglers & Red Worms

44 Composting Worms Redworms are not soil-dwelling worms, require large amounts of organic material Natives of litter layers of forests, manure piles, and backyard compost heaps Nightcrawlers are not suitable for worm composting - dig burrows & require lots of soil

45 Worm species: Red Wigglers Eisenia fetida most common composting worm processes large amounts of organic matter in ideal conditions, eats its body weight daily reproduces rapidly tolerant of variations in growing conditions

46 Worm Reproduction- quick Very prolific, but they understand population control fact If worms are removed, e.g. for starting another worm bin, population quickly returns to its former level

47 Tolerate a wide temperature range Prefer temperatures 55-77ºF Need good air circulation Like moist, but not wet, environment Worm Ecology

48 Worm Ecology Eat between ½ and their full weight in organic material per day so On average, 1 lb. of redworms will process about ½ lb. of food scraps per day

49 What do worms eat? Vegetable & fruit scraps Pasta, bread, leftover cereal Egg shells crushed up Food scraps Coffee grounds and filters Tea leaves, tea bags, paper towels, and napkins Shredded paper & newsprint Manure if you have horses put worms in manure piles

50 What does NOT go in the Bin? Seeds, e.g. tomatoes and melons - not broken down Woody yard waste Leaves, pine needles Citrus peels - small quantities, cut up Animal products, e.g. cheese, oils, bones, or meat Herbicide treated plants

51 Worm castings: Nature s Fertilizer Contain plant-available, but stable nutrients intestinal secretions make nutrients available to plants release many micronutrients Biologically active 5 to 11 times richer in N-P-K than the material the worms consumed and ph neutral Contain plant hormones

52 The Worm Bin Must be dark inside, as light can harm worms Lids -keep out flies and rodents Drainage holes in the bottom (¼" or smaller) for ventilation and drainage Many types of bins

53 The Worm Bin Shallow (8-12" deep) Redworms are surface feeders, need air Too deep, moist materials pack down & reduce air space => anaerobic conditions shallow bins - bury food on a rotating basis

54 PROs Plastic Worm Bins Shallow plastic storage boxes, 8-12 deep Easy to construct Last for many years CONs Need good drainage & aeration Plastic doesn't breathe contents may get soggy need to check moisture do not overfeed

55 Wooden Worm Bins Can be built to size Use exterior grade plywood since the box will be damp most of the time Don t use aromatic woods, e.g. redwood or cedar Don t use chemically treated woods Place on blocks or a platform to avoid contact with the ground & rapid rotting Latches & weather stripping on the lids reduce warping and keep out flies.

56 Worm Bedding needed to hold moisture protect from light place to bury materials USE: Shredded newspaper - not glossy sections Shredded office paper Cardboard, shredded corrugated boxes Leaf Mold

57 Setting Up A Worm Bin 1. Drill holes in bottom, around sides. 2. Fill bin with 4-6 of well-moistened bedding 3. Add redworms 4. Purchased worms: separate & spread worms over surface of the bedding 5. Expose the worms to the light for awhile so they migrate down into the bedding.

58 Setting Up A Worm Bin 6. Once worms are inside the bedding, add food 7. Push aside some bedding, add ½ - 1 of food, cover food with 1-2 of bedding 8. Rotate the placement of food in the box each time materials are added 9. Worms need to adjust to their new environment, so add only small amounts of food at first

59 Setting Up A Worm Bin Don t overload your bin Anaerobic conditions can develop Correct problem by not adding materials for awhile With a supply of food, worms can go for weeks without being fed How often to feed depends on temperature rate of food generated in household how finely food is chopped

60 Critters in the bin Centipede Millipede Springtails Spiders Centipedes Millipedes Sowbugs & pillbugs Echytraeids Mites Fruit flies Ants Slugs, snails Beetles Whiteworms Sowbug Pillbug

61 Harvesting Castings As worm castings increase, worms environmental quality declines When much of the bedding in the box becomes casting, worm population will suffer. Castings should be harvested before the bedding is completely converted to castings

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63 Using Castings Castings are too fine grained & dense to use as a growing medium by itself Make planting mix with 1/5-1/3 worm castings e.g. equal parts of worm compost, peat moss and coarse sand Use castings as soil conditioner for container plants Sift onto lawns Spread around the base of vegetable plants Work into the soil around shrubs & trees

64 Troubleshooting

65 Where to find red wiggler worms: P. J. Dunn Working Red Worms N. Kennefick Rd. Galt CA Google Buying Red Worms for many sites that sell worms

66 Questions