790 likes | 939 Views
Composting. Bill DeKramer. 1. 03/09/2012. Sustainability. What makes something sustainable?. 2. 03/09/2012. Sustainability. What makes something sustainable? How then do we define unsustainable?. 3. 03/09/2012. Sustainability. What makes something sustainable?
E N D
Composting • Bill DeKramer 1 03/09/2012
Sustainability • What makes something sustainable? 2 03/09/2012
Sustainability • What makes something sustainable? • How then do we define unsustainable? 3 03/09/2012
Sustainability • What makes something sustainable? • How then do we define unsustainable? • What is the importance of sustainability? 4 03/09/2012
Sustainability Life on this planet is the flow of nutrients through different life forms Nutrients In Nutrients Out 5 03/09/2012
Sustainability Life on this planet is the flow of nutrients through different life forms Nutrients In Nutrients Out And, for life to thrive, the nutrients need to come in and go out in the proper the proportions. 6 03/09/2012
Sustainability • What does this have to do with Organic Gardening? 7 03/09/2012
Sustainability • What does this have to do with Organic Gardening? • How do we manage nutrients in the food we grow? 8 03/09/2012
Sustainability • What does this have to do with Organic Gardening? • How do we manage nutrients in the food we grow? “There’s a universe beneath our feet” - The Soil Solution (movie) 9 03/09/2012
Topics for tonight • Compost and soil structure / value • Elements of a compost pile • What makes compost work • Types of composting • Building some models 10 03/09/2012
What is Compost? 11 03/09/2012
What is Compost? • Nature recycles nutrients as organic matter (OM) in place • Composting is a man-made system to recycle these nutrients as OM more quickly and efficiently • Composting in one form or another has been used in agriculture since ancient times 12 03/09/2012
Compost and soil structure • What are the structural components of soil? 13 03/09/2012
Compost and soil structure • Structural components of soil • Sand • Silt • Clay • OM 14 03/09/2012
What ratios would you like in your garden? 15 03/09/2012
What ratios would you like in your garden? • Medium Loam: • 20% clay • 40% sand • 40% silt 16 03/09/2012
What benefits does Compost bring to the soil? 17 03/09/2012
What benefits does Compost bring to the soil? • Organic Matter (OM) • Microbes 18 03/09/2012
What is Organic Matter? 19 03/09/2012
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, i.e. its ability to store nutrients in the soil that won’t leach out in a rain. 20 03/09/2012
Organic Matter Herbicides and pesticides from conventional farming kill not only weeds and pests, but also Organic Matter. As soil organisms die off in their natural, sustainable cycle of life, their structures become the Organic Matter that stabilizes the soil and feeds other organisms. By killing the soil organisms, this cycle ends and the OM build up ends as well. 21 03/09/2012
What Makes Compost Work? • Microbes
What Makes Compost Work? • Microbes One system’s waste is another system’s food (This is a key principle of sustainability) Me: Food (O2) Waste (CO2) Plants: Waste (O2) Food (CO2) In nature there is no such thing as waste.
What Microbes are in Compost? 25 03/09/2012
What Microbes are in Compost? • Bacteria • Fungi • Amoebas, slime molds, multi-celled algae • Nematodes • Bugs 26 03/09/2012
Controlling Nutrients for Compost • Carbon • Nitrogen • Oxygen • Water 27 03/09/2012
Elements to Control in Compost • Food stock (Carbon and Nitrogen) • Moisture (Water) • Air(Oxygen) • Temperature • Particle Size • pH 28 03/09/2012
Food stock • Carbon sources: • Hay and Straw • Leaves • Black and white newspaper • Sawdust and Wood chips • Old Natural Fibre clothing • Nitrogen sources • Kitchen scraps • Weeds (without seed heads) • Animal manure (except dog, cat, pig or human) 29 03/09/2012
What not to add • Kitchen scraps like meats, oils, fish, bones and dairy products • 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 30 03/09/2012
Diseased Plants in Compost There are different opinions about whether to add diseased plants to compost or not. • In favor of: • By adding diseased plants, the microbes in the compost that feed on the disease multiply and in this way strengthen the soil food web • Against: • The disease may not be controlled by the composting process and spread into the soil
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 • Current discussion at NOSB is that a range of 15 : 1 to 60 : 1 produces good quality compost 32 03/09/2012
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 33 03/09/2012
C / N - Rule of Thumb When adding the materials you’ve collected for your compost, the rule of thumb to achieve the 25:1 C / N ratio is 70% brown and 30% green. Roughly 3 parts brown to 1 part green
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 35 03/09/2012
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 36 03/09/2012
Air • There are 2 types of compost piles • Aerobic • Anaerobic (Bokashi is fermentation) • If an aerobic bin gets too wet, it can become anaerobic and toxic to the other microbes, slowing the decomposition and quality of the compost produced. 37 03/09/2012
Temperature • Hot Compost • Cool Compost 39 03/09/2012
Hot Compost (50º-75º C) • Relies more on aerobic bacteria • Makes compost quickly • Can kill pathogens and weed seeds • Requires frequent turning • Requires attention to brown/green ratio • Very fertile, but not as fertile as cool compost • To certify as Organic, NOP requires that all feedstock reach 55º C for 3 days 40 03/09/2012
Hot Compost - Sweden 41 03/09/2012
Hot Compost - Sweden 42 03/09/2012
Hot Compost - Sweden 43 03/09/2012
Cool Compost (25º-50º C) • Low maintenance • Can be built (layered) over time • Takes longer to finish than hot compost • Doesn’t kill all pathogens or weed seeds 44 03/09/2012
Particle Size • The smaller the particle, the quicker it decomposes • For example, grated apples break down faster than whole apples 45 03/09/2012
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. 46 03/09/2012
Types of Composting • Layered • Worm (vermiculture) • Bokashi • Sheet composting (permaculture technique) 47 03/09/2012
A Compost pile is not a garbage pile 48 03/09/2012
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. 49 03/09/2012
Building a layer • When starting a new pile, lay some coarser material 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 each layer as an inoculant • 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 the next layer, pull the scab back to allow the materials to be in contact 50 03/09/2012