Composting and Vermiculture for the Backyard Gardener North Peace Applied Research Association Lance Ouellette, M.Sc., CCA-ON, Assistant Manager November 18 th , 2019
The Idea of Composting We want to turn this Into this
Yet why do we often get this?
What is compost? • Composting is the biological decomposition of organic waste such as food or plant material by bacteria, fungi, worms and other organisms under controlled aerobic (occurring in the presence of oxygen) conditions. • The end-result of composting is an accumulation of partially decayed organic matter called humus.
Aerobic Composting Stages Mesophilic: organism that grows best in moderate temperature, typically between 14 and 21 ° C. Thermophilic: organism that thrives at relatively high temperatures, between 41 and 122 ° C
Guidelines for Composting Parameters Conditions Reasonable Range Preferred Range C:N ratio 20:1 – 40:1 25:1 – 30:1 Moisture Content 40-65% 50-60% Oxygen concentrations Greater than 5% Much greater than 5% Particle Size 1/8 – 1/2 Varies pH 5.5 – 9.0 6.5 – 8.0 Temperature (⁰F) 110 – 150 130 – 140
Carbon to Nitrogen Ratios • Microorganisms use carbon for both energy and growth , while nitrogen is essential for protein production and reproduction . Feedstocks C:N Wood 700:1 < 20:1 > 40:1 Sawdust 500:1 N becomes Excess N leads to limiting. Process Straw 80:1 the production of slows Leaves 60:1 ammonia and dramatically. unpleasant odors . Cornstocks 60:1 Fruit waste 35:1 Solution : Add Solution : Can be Rotted manure 20:1 browns. Turn over countered by Grass clippings 19:1 compost heap reducing particle more often. size. Add greens. Food waste 15:1 Alfalfa hay 12:1
How do I achieve the right C:N Ratio? General rule of thumb • You want to have 4 times as many browns as greens • If in doubt, put more browns. • Excel Spreadsheet – C:N ratio calculator available
Preferred feedstocks
Tips for Filling up your Composter • Layering allows for: • Efficient distribution of browns to greens (maintaining adequate C:N ratio). • Improves aeration, thus may not have to mix as often. • If layering is done correctly, it should allow you to identify problems more easily (too moist, too much greens, etc).
Moisture • The composting process requires water! • Rule of thumb, it should be the consistency of the wrung-out sponge . • Too moist Backyard watering • The pile will subside and eventually become anaerobic. • Too dry • The microorganisms won’t be able to thrive. • The composting process will halt completely. Commercial watering
Aeration • Backyard compost piles should be mixed and turnover once every 2 weeks. • If you turn over the pile too often (i.e once a day) • You may disturb the thermophilic process by cooling it. Tumbler Composter • More of an issue when outside temperature are low. • If you don’t turn over the pile often enough • It may lead to anaerobic conditions • Also makes it difficult to assess the overall conditions of the pile. Mixing with a pitchfork
Particle size • The rate of aerobic decomposition increases with smaller particle size • May also reduce the effectiveness of oxygen movement within the pile. • Review pile often to make sure no matting occurs, particularly at the bottom of the pile. • Optimum composting conditions Finished compost covers a wide range of particle sizes. • Ranging from 1/8 to 2 inches average diameter. Best to cover the range, if possible.
Temperature • Maintaining the temperatures between 43 and 66 ⁰C is ideal. • Necessary to destroy pathogens, weed seeds and fly larvae. • Should feel warm to the touch. • If you are unable to increase the compost’s temperature, you may have completed the active stage of composting.
Time • The length of the active composting stage will depend on: • The moisture added to the pile. • Frequency of turning. • Feedstocks used (C:N ratios) • Length of the thermophilic stage. • The amount of time required varies significantly with the previously mentioned factors. • 3-4 weeks under ideal conditions. • 10-14 weeks for dairy cattle waste.
Curing • Curing is a very important stage, and often neglected part of the composting process. • Occurs at mesophilic conditions • Immature compost can contain high levels of organic acids (high C:N ratio) • The curing stage begins once the compost pile no longer reheats after turning. • Usually last 3-4 weeks.
Managing a Compost Heap Over Winter • More challenging to do, but still possible! https://www.youtube.com/watch?v=X y417xt-bco • The idea is to maintain your pile in the thermophilic stage between 41 and 122 ° C (106 and 252 ° F). • Requires careful monitoring.
Managing a Compost Heap Over Winter 1) Do not turn the pile as much (i.e once a month) • Frequent turning may result in heat escape. 2) Reduce the size of your compost pieces (i.e. particle size). 3) Keep the pile covered over the winter. 4) When adding water, it should be warm. 5) To avoid trips to the compost, keep a compost bucket in the house with a tight-fitting lid • Proper layering should reduce odors. • Scraps will be partly decomposed by the time they make it to the compost heap.
Aerobic Composting Methods Advantages Disadvantages • Convenient to set up. • Cost-efficient. 1) Static pile • Easy to monitor. • Exposed to the elements. • Can process high volumes. • Backyard gardeners may not have 2) Turned windrow enough volume. • Convenient to set up. • Beware of the compost condition 3) Aerated • Improved aeration when static pile at the bottom of the pile. compare to the static pile concept • Convenient way to aerate • May be costly. 4) Tumbler • Volume may be a limiting factor your compost pile. for backyard gardeners.
Anaerobic Composting Method - Bokashi • Bokashi composting process relies on inoculated bran to ferment kitchen waste, including meat and dairy, into a safe soil builder and nutrient-rich tea for your plants. • End product is partially decayed organic matter that will decompose rapidly in your garden soils. • https://youtu.be/EzpovMjq434
Anaerobic Composting Method - Bokashi • Advantage versus standard composting process • Ideal C:N of 10:1 compared to 30:1 in a normal composting bin. • Decreased reliance on carbon inputs, which are often limiting. • Able to host a wider variety of feedstocks including meat, dairy, oily products. • Timeline • 2 weeks in the bucket, and 2-4 weeks in the soil.
Anaerobic Composting Method - Bokashi • Compost tea must be emptied regularly (every 2 days), and can be used as: 1) Nutrient-rich fertilizer • Dilute 100x for plant use. 2) Compost enhancer • Millions of microbes can serve as inoculum in compost pile. 3) Drain unblocker • The bokashi bacteria can help to unblock clogged drains and are beneficial to the water treatment works as well.
Black soldier fly composting • Are normal inhabitants of compost piles during the summer. Larvae are voracious eaters and help speed up the composting process.
Ver ermicultur miculture e or or Ver ermi mi-composting composting • Vermicomposting in an aerobic process. • There are two processes happening concurrently a worm bin: 1. Normal compositing process 2. Addition of litter (non-burrowing) worms to turnover the organic material in nutrient dense material, otherwise known as worm castings. • Biggest advantage compared to the standard composting process is that it is approximately 3x faster.
Time-lapse Vermiculture https://www.youtube.com/watch?v=n9Mnf9ysNSs https://www.youtube.com/watch?v=0Z6FdcIuEfg
Worm Anatomy
Worm Species Suitable • There are several worm species in the epigeic family that are suitable for the composting process, including: • Red wigglers • European nightcrawlers • African nightcrawlers • Malaysian Blue Worm
Red Wigglers ( Eisenia foetida ) A runaway favorite of all composting worms with gardeners. They are one of the most adaptable of the non-burrowing types. 1. They eat a lot : as much as half their weight each day. 2. They reproduce a lot : double their population in 90 days. 3. They are not picky eaters : consume a variety of organic materials. 4. They adapt to any environment : too moist, too dry, low to high pH.
Normal inhabitants of a worm bin Springtails Pill bugs Red mites Pot worms Fruit Flies Millipedes Centipedes Microbes
Types of Vermi-Composters • Stackable Unit • Efficient in separating feeding tray from casting tray. • Worms will migrate to feeding tray. • Spout at the bottom for collecting compost tea. • Can be costly 150-300$ CAD. Things to consider : will have to re-moisten often.
Types of Vermi-Composters • Home-built unit • Only has one chamber for the worms. • Can become too moist if not well drained. • Cost-effective 15-40$ CAD. Things to consider : compost is usually too wet. Add shredded paper to decrease excess moisture.
Commercial Worm Farms https://www.youtube.com/watch?v=OgWY_AWrcK8
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