Source of Material

Material is screened on entry to site so the removal of all containments and non-biodegradable materials. This is the first and most important process to ensure that the quality of the end product will meet our standards and the beneficiary’s of our products, the plants and soil.

Shredding

The main purpose of shredding is to reduce the volume and increase the surface area of the green material. All material is shredded on our facility. This decreases the volume and makes handling the material through to finished product far easier. The Shredding mechanical action tears apart the material. This provides an exposed area for the micro-organisms to breakdown the structure of the green plant cell structure.

Composting Process

Enrich have adopted the open windrow process to increase aerobic composting.
Aerobic composting is the controlled biological decomposition of organic material under optimum conditions. In this process of composting, micro organisms breakdown organic matter, and produce carbon dioxide, water, heat and humus. The heat is produced by the metabolism of the micro organisms as they decompose the organic matter.

Composting is largely about maintaining a suitable environment in which the naturally occurring micro-organisms can multiply and decompose the organic matter. Ensuring optimum contains requires controlling a number of parameters, specifically Porosity, Nutrients, Moisture Content and Oxygen level and temperature.

i) Porosity – The composting material must be such that air can diffuse throughout the pile. The most critical influence on porosity is particle size distribution. Excessively large particles will reduce the quantity of surface area available for microbial decomposition and slow down the process. A very small particle size will result in the material compacting down on top of itself due to poor pile structure. In such instances air cannot pass through the material and conditions quickly become anaerobic.

ii) Nutrients – Carbon (C), nitrogen (N), phosphorus (P) and potassium (K) are the primary nutrients required by the micro-organisms involved in composting. Nitrogen, phosphorus and potassium are also the primary nutrients for plants, so nutrient concentrations also influence the value of the compost. Many organic materials contain enough quantities of nutrients for composting. Excessive or insufficient carbon or nitrogen will affect the process. Carbon provides micro-organisms with both energy and growth; nitrogen is essential for protein and reproduction. Biological organisms need about 25 times more carbon than nitrogen. Therefore it’s important to provide carbon and nitrogen in appropriate proportions.

iii) Moisture – Content-Moisture is the lifeblood of the metabolic processes of the microbes. Water provides the medium for chemical reactions, transport nutrients and allows the microorganisms to move from place to place. Activity ceases entirely below a 15% moisture content. Efficient activity is achieved when the moisture is maintained between 40% and 60%. At moisture levels above 60%, water displaces much of the air in the pore spaces of the composting materials. This limits air movement and leads to anaerobic conditions.

iv) Oxygen Level – The composting process consumes large amounts of oxygen. During the first days of composting, easily degradable components of the organic materials are rapidly metabolized. The need for oxygen and the production of heat are greatest during the early stages and then decrease as the process continues. If the supply of oxygen is limited, the composting process slows and the process becomes anaerobic (without oxygen). A minimum oxygen concentration of 5% within the pore spaces is required.

v) Temperature occurs in three distinct phases:
The mesophillic , within each phase of the composting there are different communities of micro organisms. They quickly breakdown soluble elements found in soil residue and plants. The initial decomposition is carried out and heat is produced rapidly. Once the heat rises above 40°C, the mesophillic micro organisms become less competitive and the next phase begins.
The thermophillic. At temperatures of 55°C and above, many microorganisms that are human or plant pathogens are destroyed, including harmful bacteria and weed seeds. It is very important to aerate the windrows, by turning on a regular basis. During the thermophilic phase, high temperatures accelerate the breakdown of proteins, fats, and complex carboydrates like cellulose and hemicellulose, these are major structural molecules in plants. This phase takes between 8-10 weeks. Once the food for the micro organisms has decreased, they become less active in the windrow and produce less heat. The final phase begins.

The maturation phase, or “curing”, the micro organisms are exhausted and are less active.This phase can last for at least 2-4 weeks before finished product can be extracted from the windrow. Allowing the compost to mature and stabilise is critical in the development of our various products.

Did you know that compost can benefit the soil through:

• Supply of slow and stable nutrients for plants when needed
• Improved Cation Exchange Capacity(CEC), resulting in greater uptake of nutrients
• Energises tired and poor performing soil
• Increased Water Holding Capacity, leading to increased water uptake during dry periods
• Increasing the biological activity in soils
• Provides food for soil microbes which cycle nutrients and fight plant diseases
• Greater workability than regular soils
• Elevates compaction and improves drainage
• Better root development in plants
• Reduce or eliminate the need for chemical fertilisers
• Promote higher yields of agricultural crops
• Facilitate reforestation, wetlands restoration and habitat revitalization efforts by amending contaminated, compacted and marginal soils