COMPOST A Guide to Managing Organic Yard Wastes. Sam Angima Extension Agent OSU Extension

Transcription

1 COMPOST A Guide to Managing Organic Yard Wastes Sam Angima Extension Agent OSU Extension

2 Using the natural process of decay to change organic wastes into a valuable humus-like material called compost Grass clippings Food scraps Compost Leaves

3 Its Recycling Naturally

4 But Why Compost?? Promotes soil health Supplies organic matter to soil Attracts earthworms Stimulates beneficial soil microorganisms Increases soil water holding capacity Increases soil nutrient retention

5 Composting - Speeding up the natural decay process A compost pile or bin allows you to control Air (oxygen) Water Food, and Temperature By managing these factors you can speed up the otherwise slow natural decay process

6 Why compost yard and kitchen wastes? Average U.S. household generates over 650 lb of compostables every year Burning prohibited in some cities Detrimental to add fresh organic materials to soil (N issues)

7 Limited landfill space should be reserved for materials that cannot be recycled or composted Garbage handling is the 4 th largest expense for many cities. Composting can reduce those costs

8 1998 U.S. Municipal Solid Waste Municipal Solid Waste Paper products 35.2% (48) Generation Production in the U.S. Total = 236 million tons/yr Food 11.7% (2.7) Yard 12.1% (56) (4.5 lb/person/day) or 3.7 lb/person/day in OR } 24% (30% in Lincoln County) Metals 8% Glass 5.2% Plastic 11.2% Other 16.6% Backyard composting can increase recycling of yard and food wastes.

9 Materials Recovered in Oregon Wood waste 20% Yard debris 19% Metals 14% Papers 35% Plastic 1% Other 7% Glass 4%

10 What do You Need to Make Compost? Decomposers Your composting work crew. These are the microbes (mainly bacteria and fungi) that do all the work for you (Bugs) Food for the decomposers The organic materials to be composted The right amount of air, water, and warmth to keep the work crew happy

11 Where do the Decomposers If you build it, they will come Soil Leaves Food scraps Manure, and Finished compost Each of these will add microorganisms to the compost pile Come From?

12 One teaspoon of good garden soil to which compost has been added contains 100 million bacteria 800 feet of fungal threads

13 Do we all need Composting Containers? No, use slow (cold) composting It just takes a longer time Dig a trench in your garden and bury veg and fruit wastes No heat, so weed seeds are not killed

14 Numerous additives and starters are available but are not needed for good or rapid composting Finished compost best source of microorganisms

15 What is the Best Food for your Decomposers? All organic materials will compost, but not all should be added to a backyard compost pile Organic wastes that should be composted include: Garden trimmings Kitchen scraps Grass clippings Leaves Also Used potting soil Manure Sawdust Hair

16 Materials to Avoid Avoid organic materials that could cause problems during or after composting Oil, fat, grease, meat, fish or dairy products, unwashed egg shells (tend to attract pests, vermin) Hard to kill weeds (bindweed, quackgrass) and weeds that have gone to seed (could infest garden area when compost is used).

17 Materials to Avoid Manure: Pig manure, and Cat or dog waste (parasites survive a long time) (attracts pests, could spread disease) Diseased or insect ridden plants (could infect or attack garden plants when compost is used)

18 Materials to Avoid Lime (increases compost ph and promotes ammonia odor problems = loosing N If large quantities of acid materials such as pine needles, spruce needles, or fruit wastes are composted, additional lime may be necessary. Wood ash - add sparingly to the pile - add no more than 1/2 cup per five gallon bucket

19 Can I Use Fresh Manure? Not recommended May contain bacteria e.g. E. coli or salmonella sp. Pathogens not taken up by plants but may adhere to root crops or low growing leaves

20 Is Shredding Necessary? Smaller particles decompose faster Greater surface area per unit volume Allows microbes to get at more of the food (particle size = 1/8 to ½ inches diameter) Chipping or shredding coarse materials (twigs, stems) will speed up the rate at which they decompose

21 Layering Composters? Layering is not recommended as it reduces mixing of browns and greens

22 More about Food for your Decomposers Your compost workers will thrive if you give them a balanced diet. Composting will be most rapid if the decomposers are fed a mix of carbon rich and nitrogen rich materials. Carbon rich organic wastes are known as BROWNS (>30:1)= bulking agents Nitrogen rich organic wastes are known as GREENS (<25:1)=energy materials Balanced Materials: Have right C:N ratio for direct composting

23 High carbon materials such as Leaves (30-80:1) Straw (40-100:1) Paper ( :1) Sawdust ( :1) Animal bedding mixed with manure (30-80:1)

24 High nitrogen materials such as Vegetable scraps (12-20:1) Coffee grounds (20:1) Grass clippings (12-25:1)

25 Balanced Materials Low to medium moisture Medium porosity Medium nitrogen Ground up tree and shrub trimmings Legume hay Deciduous leaves Animal bedding mixed with manure (30-80:1)

26 Approximate ratio: 2/3 browns to 1/3 greens

27 Oxygen Requirement Aeration: microbes need oxygen Less oxygen leads to odors unless using plastic bag method (fully closed) Adequate O 2 you need free air space of 55-65% by volume.

28 Aerobic Composting and Temperature Active composting occurs in the temperature range of 55 o F to 155 o F Pile temperature may increase above 140 o F but this is too hot for most bacteria and decomposition will slow until temperature decreases again A thermometer is a nice tool but is not essential for good composting You need degrees F for 15 days or longer 155

29 Heat & Bacteria Psychrophilic work between 0-50 o F Mesophilic bacteria work btw o F Thermophilic bacteria o F Work fast Live only 3-5 days unless pile is turned When done, they feed on each other

30 Pile Aeration Mix Your Pile Every 5-7 Days Turning the pile mixes fresh air into the pile Turning tools can make the job easier

31 Water Rapid decomposition requires optimum water content If too dry, bacterial activity will slow or cease If too wet, loss of air in the pile will lead to anaerobic conditions Approximately 50% to 55% moisture is best As wet as a squeezed out sponge If too dry, add water as you turn the pile If too wet, add browns and/or turn the pile

32 Taking Care of your Compost Pile The most rapid composting is achieved by Adding mixed browns + greens Regularly turning (mixing) the compost pile once per week Controlling water content (50 % moisture content) When pile no longer heats after mixing, allow it to cure (stand without mixing) for at least 8 weeks before using the compost (4 weeks in warmer climates)

33 Notes If paper is composted, it should not be more than 10% of the total weight of the material in the compost pile.. Fertilizer can be added to increase nitrogen content Avoid composting plants that have been treated with herbicides or pesticides.

34 When is Compost Finished? Compost is mature when The color is dark brown It is crumbly, loose, and humus-like It has an earthy smell It contains no readily recognizable feedstock Curing takes at least 8 weeks The pile has shrunk to about 1/3 of its original volume

35 100% 30-35%

36 Uncured Compost Uncured compost mixed directly into gardens or planter mixes can "burn" plants through a stress condition called "phytotoxicity". Fresh compost can damage young seedlings by fostering the fungus diseases known as damping off and root rot. Fresh compost, like fresh manure, can also rob the soil of nitrogen temporarily while it finishes its curing process.

37 Simple Tests for Finished Compost Bag test: sealing compost in a plastic bag for several days should produce no foul odor Germination test: will seeds germinate in the compost? (good test to use if compost will be part of a potting mix)

38 Compost Troubleshooting Odors Odors are one of the most frequent but easily avoidable composting problems. Rotten odor Putrid smell or rotten egg smell Usually results from anaerobic conditions Excess moisture, compaction Turn pile, add dry porous material (browns), cover kitchen scraps Ammonia odor Too much nitrogen (greens) or ph too high Add high carbon material (browns), turn pile

39 Using Finished Compost Lawn topdressing Be sure compost is very mature to avoid harming the lawn Use fine (screened) compost, ¼ depth raked over lawn Best if lawn is cored before applying compost Retains moisture, supplies slow release nutrients, prevents soil compaction Potting mix Compost must be very mature to avoid injury to plants Use fine textured compost Mix no more than 1/3 compost by volume

40 Manufactured Bins

41 The Earth Machine Bin

42 Bin Type Structures A circular bin can be made by using a length of small spaced woven wire fencing and holding it together with chain snaps The bin should be about 4-5 ft in diameter and at least 4 ft high With this design, it is easiest to turn the composting material by simply unsnapping the wire, moving the wire cylinder a few feet, and turning the compost back into it.

43 Three-Chambered Bin The three-chambered bin works on an assembly line idea, having three batches of compost in varying stages of decomposition. The compost material is started in the first bin 3-6 wks (min: 1 cubic yard) Then turned to the next for 4-8 wks and finally to last bin 4-8 wks Meanwhile 1 st & 2 nd bin have fresh materials Use removable slats in the front for complete access to the contents for turning.

44 Notes Use rot-resistant wood e.g. redwood or cedar or wood and metal Each bin should be about 5 ft by 3 ft & about 4-5 ft high for heat and ease of turning compost No one structure is best Invent your own, or for a more thorough description of different structures, refer to Rodale's Complete Guide to Composting

45 Plastic Bag Method (Fully Closed) gallon plastic bags filled with plant wastes, fertilizer, and lime About 1-3 tablespoons of a garden fertilizer with a high N content should be used per bag. Lime (one cup per bag) helps counteract the extra acidity caused by anaerobic digestion. Add about 1-2 qts of water. Close tightly. Double-bag to keep air tight Set the bag in secure site for 6-12 months Requires no turning or watering Slow due to low oxygen Materials should have 30:1, & 50% by volume water

46 Vermicomposting ~Rich in plant nutrients Castings ( worm poop) ~Contain a high percentage of humus ~Biologically active containing thousands of bacteria, and enzymes ~ 5 times the available nitrogen, 7 times the available potash, and 1 ½ times more calcium than found in good top soil Good stuff!!

47 Vermicomposting Facts Two species of red worms, Eisenia foetida and Lumbriscus rubellus, work best for vermicomposting They're also called bandling, red wigglers, or manure worms You can feed worms any non-meat organic waste such as vegetables, fruits, eggshells, coffee grounds and paper coffee filters, and shredded garden waste. Worms especially like melons and pumpkin You have to maintain temp o F and newspapers for grit A box 1x2x3 feet can handle 6 lb of kitchen waste/week

48 Green Cone Composting Some materials, such as meat, fish and dairy products may cause problems if composted in a standard compost unit. A Green Cone should be used for these (do not add cheese) The Green Cone is a digestion unit that converts the waste into a liquid form that seeps into the soil surrounding the unit. The unit is designed to require little maintenance - all you need to do is add food to it, a little at a time.

49 Compliments