1 03/09/2012 1Composting Bill DeKramer

2 03/09/ What is Compost? Nature recycles organic matter (OM) in place Composting is a man-made system to recycle OM more quickly and efficiently

3 03/09/ Topics for tonight Compost and soil structure / value Elements of a compost pile What makes compost work - the bugs involved Types of composting Building some models

4 03/09/ A Compost pile is not a garbage pile

5 03/09/ Compost and soil structure Structural components of soil –Sand –Silt –Clay

6 03/09/ What ratios would you like in your garden? Medium Loam: –20% clay –40% sand –40% silt

7 03/09/ Benefits of compost to the soil Organic Matter (OM) Microbes

8 03/09/ What is Organic Matter?

9 03/09/ Organic Matter Food for soil food web microbes Humus (not hummus) –OM that has reached a point of stability, i.e. won’t break down any more –Humus is a colloidal substance, and increases the soil's cation exchange capacity, hence its ability to store nutrients by chelation.

10 03/09/ What Microbes are in Compost?

11 03/09/ Microbes Bacteria Fungi Amoebas, slime molds, multi-celled algae Nematodes Bugs

12 03/09/ Essential Elements for Compost Carbon Nitrogen Oxygen Water

13 03/09/ Elements to Control in Compost Food stock: Carbon and Nitrogen Moisture Air Temperature Particle Size pH

14 03/09/ Food stock Carbon sources: –Hay and Straw –Leaves –Black and white newspaper –Sawdust and Wood chips Nitrogen sources –Kitchen scraps –Weeds (without seed heads) –Animal manure (except dog, cat, pig or human)

15 03/09/ What not to add Kitchen scraps like meats, oils, fish, dairy products, and bones Weeds that have gone to seed or spread by their roots (quack grass, etc.) Herbicide treated grass clippings or weeds Dog, cat, pig or human faeces

16 03/09/ Carbon / Nitrogen ratio Having the right carbon / nitrogen ration makes a difference in how quickly the food stock breaks down. Ideal is 25 : 1 carbon to nitrogen

17 03/09/ Common Compost Materials Kitchen / Table scraps 15:1 Grass clippings 12:1 Old manure 20:1 Fruit waste 25:1 Corn stalks 60:1 Old leaves and straw 80:1 Paper 170:1 Sawdust and wood chips 500:1

18 03/09/ Prohibited for Organic Production Prohibited –Sewage sludge –Glossy paper and coloured ink –Paraffin from waxed cardboard (not to exceed.75%) Regulated –Slaughterhouse, hatchery, fish-farm waste –Yeast fermentation waste –Whey –Mushroom compost

19 03/09/ Moisture Ideal is about 50% Rule of thumb: like a wrung out sponge The amount of moisture determines if the pile is aerobic or anaerobic

20 03/09/ Air There are 2 types of compost piles –Aerobic –Anaerobic (Bokashi) If an aerobic bin gets too wet, it can become anaerobic and create toxins

21 03/09/ Temperature Hot Compost Cool Compost

22 03/09/ Hot Compost (50º-75º C) Relies more on aerobic bacteria Makes compost quickly Can kills pathogens and weeds Requires frequent turning Requires attention to brown/green ratio Very fertile, but not as fertile as cool compost

23 03/09/ Cool Compost (25º-50º C) Low maintenance Can be built (layered) over time Takes longer to finish than hot compost Doesn’t kill pathogens or weeds

24 03/09/ Particle Size The smaller the particle, the quicker it decomposes For example, grated apples break down faster than whole apples

25 03/09/ pH Ideal pH is around 7 (neutral) Usually don’t need to worry about pH if including a wide variety of food stocks, but some things like an excess of coffee grounds can make the pile acidic.

26 03/09/ Types of Composting Layered Worm (vermiculture) Bokashi Sheet composting

27 03/09/ Building a layer When starting a new pile, lay some twigs in the bottom to help keep air in Alternate layers of brown and green Sprinkle a handful or shovel full of soil or compost in with the layers as inoculate Finish with a layer of brown material that acts like a “scab” –Up to half the carbon and nitrogen can be lost to the atmosphere if exposed to the sun and air. When starting a future set of layers, pull the scab back to allow the materials to be in contact

28 03/09/ Layered Compost This is the most common form of composting Layered composting is an evolution of the Indore method that focused on the carbon/nitrogen ratios and moisture. Layers of brown and green material are alternated Batch method is when the layers of the whole pile are built in one go. This is usually for the hot method Continuous method is when layers of the pile are built periodically as the materials come available. This is usually for the cool method.

29 03/09/ Demonstration pile

30 03/09/ Composting in Winter

31 03/09/

32 03/09/ Screens for Finished Compost

33 03/09/ Worm Composting (vermiculture) Composts food waste rapidly Bin needs to stay between 12º - 25º C Needs a moist environment (worms breathe through their skin) Worms need oxygen and produce CO 2 pH around 7 but can tolerate Bedding can be cardboard, shredded paper, decaying leaves or peat moss

34 03/09/ Worm Castings Worm castings are very rich –Produce plant-available nutrients –Wide variety of microbes inoculating the rest of the compost pile Worms can produce their weight in castings every 24 hours

35 03/09/ Storing the Worm Bin

36 03/09/ The Worms

37 03/09/ Feeding the Worms

38 03/09/ Demonstration Building a Worm Bin

39 03/09/ Bokashi Bokashi is a Japanese term meaning 'fermented organic matter' Bokashi is anaerobic composting utilizing a starter to inoculate the pile with specific organisms (facultative anaerobes) Quick way to compost food scraps Carbon / Nitrogen ratio is much less important Microbes that grow in bokashi are very different from aerobic compost so it adds diversity to the soil food web

40 03/09/ Facultative Anaerobes Facultative anaerobes are organisms that can be simultaneously aerobic and anaerobic They adapt to the oxygen level of their environment When low oxygen they switch to their fermenting metabolism, which utilizes enzymes to break down food. Fermentation only partially breaks down the food so it needs to be finished by other microbes

41 03/09/ Sheet Composting Sheet composting is a method of building a garden bed by creating a compost “pile” as the bed itself Sheet composting is designed to mimic the natural processes that occur in forests. You build it right on top of grass or weeds so all the natural organic matter that's already there and the microbial populations don't get hauled away with stripping off the sod or weeds.

42 03/09/ Layers in a Sheet Compost Cover the area with cardboard or newspaper and water it in well To accelerate the decomposition of the grass and cardboard, put a thin layer of manure down under the cardboard Cover the cardboard or newspaper with organic matter like compost, peat moss, straw, or leaves and water this well so it's like a damp sponge. Plant it. Wherever you want to put a plant, push the straw and leaves away a bit, add a little soil and compost and put the plant in it. This is covered more in Building a Garden Bed

43 03/09/ Quiz

44 03/09/ Summary What are the most important points about composting? Why would you want to compost? How will you apply this information?

45 03/09/ nd Summary Composting is one of the most effective ways to improve your soil and the soil food web There are many ways to create compost. The most important way is your way, the way that fits your time and lifestyle “Just do it!”

46 03/09/ Evaluation Please fill out the evaluation form