Composting is an essential part of organic waste management, converting organic materials into nutrient-rich soil amendments. There are several methods of composting, each with their own advantages and disadvantages. Here we highlight the advantages of windrow composting with turning.
1. Enhanced Oxygen Supply
Windrow turning composting involves stacking organic material in long windrows and turning them periodically to introduce oxygen and mix the composting materials.
This turning increases the oxygen supply and maintains a homogeneous mixture with the C/N (carbon/nitrogen) ratio distributed throughout the material being processed. Optimal aerobic conditions allow organic matter to decompose more efficiently and shorten the composting process.
2. Improved Temperature Control
Windrow turning exchanges surface and edge material with that from the higher temperature zones within the compost pile. This allows for temperature control and ensures that all organic material is exposed to the optimum temperature range for microbial activity at all stages of the process. The rotation of materials through the high temperature zones eliminates pathogens, seeds and insect larvae for the most part.
3. Increased Nutrient Retention
Studies have shown that windrow composting produces compost with higher nutrient retention than other types of composting processes. Turning adapted to the process conditions helps prevent nutrient loss through leaching and volatilisation.
The result is a nutrient-rich compost for soil fertility.
4. Reduction of impacts due to odours and leachate.
The addition and mixing of structural material (dry plant and woody shredded material) increases the porosity of the compost windrow and retains oxygen in the windrow. Turning helps to maintain these conditions and eliminates points of compaction and anaerobic decomposition that produce unpleasant odours and leachate. The temperatures of the aerobic process at its various stages cause evaporation of moisture. Leachate produced at any stage of the process can be returned to the process for evaporation.
5. Accelerated decomposition
Mechanised turning ensures oxygen supply, temperature control, carbon/nitrogen homogenisation and moisture distribution. If necessary, liquids can be applied to increase moisture to levels required for the process. These controlled conditions promote microbial activity and accelerate the decomposition of organic matter and reduce process time.
6. Flexibility of scale
Infrastructure and space for windrow composting is an important economic factor when considering this process. Considerations on windrow dimensions, such as row spacing and operational and logistical space, are factors determined by the machinery available.
The current technology and design of compost turners allows for adaptation to different needs and economics.
7. Cost-Effectiveness
The investment in and operation of windrow composting technology is generally cheaper than other composting systems. The machinery required for composting is relatively simple and affordable for a wide range of users. The faster decomposition process reduces the overall composting time and associated costs such as space, infrastructure and operation. The machinery is mobile and usually diesel powered, reducing the need for electrical infrastructure.