Chapter 10

Compost Management on Organic Farms

(book excerpts)

Composting is the decomposition of organic matter through a controlled microbiological process. Composting transforms raw organic materials (e.g., plant or animal materials) into a biologically stable, humic substance that makes excellent soil amendments. The use of compost has long been considered a defining feature of organic farming systems in building long-term soil fertility, soil structure, and soil biology by feeding the soil with a variety of natural amendments. While fewer nutrients are immediately available for crop growth, compost’s real agronomic value lies in the gradual release of nutrients that are slowly, converted from stable organic compounds into available nutrients. In addition to adding nutrients to the soil, compost can improve long-term soil health. Organic farmers are strongly encouraged to use compost because it reduces human, plant, and animal pathogens; destroys weed seeds; decomposes organic matter; and makes nutrients more available to plants.

Click on the following topics for more information on compost management.

Topics Within This Chapter:

  • Introduction to Compost Management on Organic Farms
  • National Organic Program Standards for Compost
  • NOP Standards for Composts Used for Crop Production
  • Vermicompost
  • Benefits and Limitations of Compost
  • Benefits in Using Compost
  • Improved Manure Handling
  • Reduced Odor Nuisance
  • Improved Soil Structure
  • Improved Soil Moisture Management
  • Modifies and Stabilizes Soil pH
  • Increases Soil Cation Exchange Capacity
  • Provides Plant Nutrients
  • Disease Suppression
  • Limitations in Using Compost
  • Cost, Management, and Time
  • Odor
  • Site Requirements
  • Government Regulation
  • Slow Release of Nutrients
  • Composting Process
  • Initial Mesophilic Phase
  • Second Thermophilic Phase
  • The Curing Stage
  • Time for Curing
  • Compost Pile Management
  • Carbon-to-nitrogen (C:N) Ratio
  • Material Characteristics
  • Pile Porosity
  • Moisture Content
  • Temperature
  • Aeration
  • pH
  • Substrate Physical Properties Influence on Composting
  • Composting Methods
  • Passive Windrow Composting Method
  • Passively Aerated Windrow Composting Method
  • Aerated Static Windrow Composting Method
  • Turned Windrow Composting Method
  • In-vessel Composting Method
  • Vermicomposting
  • Properties of Compost
  • Nutrient Concentration of Compost
  • Nitrogen
  • Phosphorus
  • Potassium
  • pH
  • Electrical Conductivity
  • Carbon-to-nitrogen (C:N) Ratio
  • Moisture Content
  • Organic Matter Content
  • Bulk Density
  • Heavy Metals
  • Compost Stability and Maturity
  • Compost Stability
  • Compost Maturity
  • Other Undesirable Substances in Compost
  • Compost Application Rates
  • Compost Teas
  • Application of Compost Tea
  • National Organic Program Standards for Compost Tea
  • References