Methods
What is a Method?
A Method refers to a specific approach or technique used to create compost, which is a nutrient-rich soil amendment produced by the decomposition of organic materials. There are various composting methods, and the choice of method depends on factors such as available space, the types of organic materials to be composted, and the desired speed of decomposition.
Which Methods are assessed?
Aerated Static Pile (ASP)
An Aerated Static Pile (ASP) is a composting method that involves the use of aeration systems to facilitate the decomposition of organic materials in a controlled and efficient manner. In an ASP system, organic waste materials are piled or stacked in a way that allows for the circulation of air throughout the pile. This continuous aeration promotes the growth of beneficial aerobic microorganisms, which break down the organic matter into compost while minimizing odors and preventing the accumulation of harmful anaerobic bacteria.
Metrics for ASP
Temperature
PFRP
Temperature must be maintained at or above 131ºF (55ºC) for 3 days
Moisture
Target: 40-60%
Oxygen
Reasonable Range: 5-10%
Preferred Range: 10-25%
Turns
Not Applicable
In-Vessel
In-vessel composting is a controlled composting method that takes place within an enclosed container or vessel. This approach is used to efficiently decompose organic materials, typically on a larger scale, while providing a controlled environment that allows for precise management of factors like temperature, aeration, moisture, and odor. In-vessel composting systems come in various designs, including rotating drums, agitated bays, and enclosed tanks, among others.
Metrics for In-Vessel Method
Temperature
PFRP
Temperature must be maintained at or above 131ºF (55ºC) for 3 days.
Moisture
Target: 40-60%
Oxygen
Reasonable Range: 5-10%
Preferred Range: 10-25%
Turns
Not Applicable
Turned Windrow
The Turned Windrow composting method is a popular and widely used approach for large-scale composting operations, particularly for municipalities, agricultural facilities, and commercial composting facilities. It involves creating long, narrow piles or rows of organic materials, which are periodically turned or agitated to provide aeration and promote efficient decomposition. The resulting windrow piles resemble long, raised rows of composting materials.
Windrow heights typically range from one to two meters (3-6 feet) but may be as high as 3-4 meters (8-12 feet). Widths vary greatly from as low as 3 meters for short windrows to 8 meters or 25 feet. In principal, a windrow should be sized such that between turnings it establishes a gradient of oxygen concentration from the surface to the center that starts at ambient concentration (20.9%) and reaches 1%-2% at the core.
Metrics for Turned Windrow Method
Temperature
PFRP
Temperature must be maintained at 131ºF (55ºC) or higher for 15 days or longer.
Moisture
Target: 40-60%
Oxygen
Reasonable Range: 5-10%
Preferred Range: 10-25%
Turns
The windrow must be turned a minimum of five times times during the period that the temperature remains at 131ºF (55ºC) of higher.
Vermicompost
Vermicomposting is the process of using worms to decompose organic waste, turning it into nutrient-rich compost.
Metrics for Vermicompost Method
Temperature
Temperature must be maintained at 60-80ºF (15.5-26.6ºC)
Temperature must not exceed 95ºF (35ºC)
Moisture
Target: 70-80%
Oxygen
Reasonable Range: 5-10%
Preferred Range: 10-25%
Other
Other composting methods including:
Open-Air or Static Pile Composting: This is a basic composting method where organic materials are piled outdoors without the use of specialized containers or turning equipment. The pile is periodically turned manually to provide aeration. It's a simple and cost-effective method commonly used in small-scale operations.
Continuous Flow or Flow-Through Systems: These systems involve a continuous input of organic materials at one end of a container or system while finished compost is harvested from the other end. This method allows for a consistent supply of compost over time.
These composting methods offer various options for managing organic materials and producing nutrient-rich compost, each with its own advantages and considerations. The choice of method often depends on the scale of operation, available space, desired speed of decomposition, and specific goals.
Metrics for Other methods
Temperature
PFRP
Temperature must be maintained at 131ºF (55ºC) or higher for 15 days or longer.
Turns
Turn is an option
What's next?
Now that you understand how Measurement Positions, Metrics and Methods inform analysis, let's get started!
Last updated