Small Scale Composting Sejal Lanterman Cooperative Extension Educator
TOPICS WE WILL EXPLORE Compost defined Importance of Composting Compost Rate Feedstocks Undesirable Feedstocks Manure & Food Safety Application Holding Units
COMPOST DEFINED Composting is the managed practice of the biological breakdown of organic matter, such as leaves and food scrapes, into a rich soil amendment called humus.
Humus creates a loose structure that simultaneously holds moisture & improves drainage. HUMUS IN DETAIL Humus creates an environment that supports living organisms that convert soil nutrients into a form plant roots can use, building soil fertility.
IMPORTANCE OF COMPOSTING from the gardeners perspective Adding compost to garden/landscape: Reduces the need for commercial soil conditioners & fertilizers Improves moisture retention and soil structure Adds nutrients and beneficial microbes Helps reduce plant diseases & pests Improves plant growth Increases organic matter Encourages healthy root structure Lightens clay soils and helps sandy soils hold water Helps balance ph Helps protect plants from drought and freezes Moderates soil temperature and reduces weeds when used as a mulch
Importance of Composting from an environmental perspective Adding compost to garden/landscape: Conserves water by helping the soil hold moisture and reduce water runoff Benefits the environment by recycling organic resources while conserving landfill space Reduces the amount of hauling to landfills therefore reducing emissions Reduces the need for fertilizers, therefore reducing potential for storm water pollutants Creates healthy soil
Don t organic waste breakdown in landfills? NO!
www.epa.gov
The Science of Composting Yard and Food Wastes + Oxygen and Water Microbial Decomposition Compost + Water + Heat + Carbon Dioxide
Decomposers Microorganisms Bacteria fungi (molds) Actinomycetes Protozoa Macrooranisms worms mites insects CARBON: digested for an energy source Nitrogen: ingested for protein synthesis Oxygen: needed to attract the right (aerobic) decomposers
Fast & Slow Composting Fast (hot) composting Favors the growth of thermophilic microorganisms Piles heat rapidly (120 o F 150 o F) Kills most weed seeds and pathogens (disease organisms) Slow composting If ideal conditions for fast composting are not met, microorganism will still break down the wastes. Decay will be slower, cooler and less effective at killing weed seeds and pathogens
FACTORS AFFECTING THE COMPOST PROCESS Particle size Mixing Pile size Moisture Aeration Feedstocks
PARTICLE SIZE Grinding, cutting, smashing or chopping raw materials reduces particle size. Small particles have more surface area for microbial activity & makes it easier to mix. *Hot composting requires a relatively uniform particle size of 1/8-1 inch in diameter.
MIXING Layering is not the best way to build a pile If all materials are on hand mix them thoroughly If materials accumulate over time, add new materials to the center of the pile
PILE SIZE The pile must be big enough to hold heat. At least 3 x3 x3 A pile of one cubic yard is big enough for yearround composting, even in cold-winter areas. The maximum dimension of the pile is 5 x 5 x any length
MOISTURE All materials should be moist, but not soaking wet. At dry times of the year, water may need to be added. In rainy winter locations, a pile may not heat up unless you cover it to keep out rainwater. Check moisture when you turn the pile.
AERATION The microorganisms responsible for fast decomposition need oxygen Turning the pile, using an aerating tool, or adding bulking agents (wood chips, straw, corn stalks etc.) improves aeration. Heat is generated in the core of the pile. Be sure that all of the materials on the outside of your pile get a cycle near the core.
FEEDSTOCKS 3 parts carbon (brown) TO 1 parts nitrogen (green)
CARBON SOURCES Straw Tomato Stalks Newspaper Cardboard Woody prunings Leaves Egg Carton Dryer Lint Wood shavings & chips Sawdust Pine needles
NITROGEN SOURCES Fruit and Veggie Scraps Egg Shells Manure Grass Clippings Non-Diseased Expired Plants Tea bags Lobster shells Coffee Grounds Hair
ONE METHOD OF SLOW COMPOSTING 1. Mix nonwoody yard wastes into a pile and let them sit for a year or so. 2. Add fresh wastes to the pile by opening the pile, placing fresh wastes in the center, and covering them. 3. Decomposition can take from 6 months to 2 years. 4. Turning is not necessary, but will speed up the process. *finished compost using the slow method should only be added to edible gardens in the fall after harvest period.
ONE METHOD OF FAST COMPOSTING 1. Collect enough material to make a pile at least 1 cubic yard in volume. Chop, shred, mow or smash coarse materials. 2. Add correct ratio of Carbon:Nitrogen and mix with a pitchfork. 3. Add water if pile is dry. If too wet, mix in drier material i.e. shredded leaves. 4. Continue adding carbon & nitrogen, mixing & checking moisture until the pile is built. 5. Turn the pile weekly, and add water when needed.
CURING PHASE (HOT COMPOSTING CONTINUED) 1. After initial mixing, a pile usually stays hot (120 o F- 150 o F for several weeks 2. The pile then needs to sit another 4-8 weeks to cure. Temperatures during curing are 80 o F 110 o F 3. Compost is ready to use when at least 8 weeks have passed since initial mixing, the pile no longer heats when turned, and the material looks dark and crumbly
COMPOST & FOOD SAFETY Using compost in the edible garden Pathogens can be found in decaying matter, especially manure. If adding compost to an edible garden it is recommended that temperatures reach at least 131 o F for 15 days, during which time materials need to be turned a minimum of 5 times.* This is recommended whether you are using manure in your pile or not. *If time/temperature has not been met or are unsure, the recommendation is to apply compost in the late fall after harvest period.
COMPOST & FOOD SAFETY Using compost in the edible garden Herbaceous Manure: manure that comes from animals that have a plantbased diet Goats, chickens, cows etc Compost with Caution Contains pathogens Can be removed with thermophilic composting i.e. a pile that heats up to 131 o F for at least 5 days, during which time materials are turned a minimum of 5 times. Recommended only for experienced composters! If unsure of temperature/time, the recommendation is to apply compost in the fall after harvest period.
NOT RECOMMENDED FOR COMPOSTING 1. Diseased plants 2. Wood Ash 3. Invasive Plant Species 4. Chemically treated plants or grass clippings 5. Poisonous plants i.e. Poison Ivy 6. Meat, bones, fat, grease, oil 7. Dairy products 8. Cooked foods in sauces, butter, oil etc. 9. Carnivorous manure (dog, cat, etc) 10. Cat liter
HOLDING UNITS
URI COMPOST EDUCATION PROGRAMS URI Master Composter Training The next two-day training will be offered on May 31 & June 14, 2014. Practical Composting a hands-on workshop being offered twice on April 26 & May 3. Registration is not open, but give us your email at the Master Composter table if you would like more information!