Composting & Humus Management Workshop
Monday 4th - Saturday 9th September 2017 (6 days)
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Controlled Microbial Composting and Humus Management

The CMC method was developed through on-farm and laboratory research by Siegfried and Uta Luebke of Austria. CMC (Controlled Microbial Compost) is a premium grade well humified compost that has been inoculated, aerated and monitored to ensure high standards of quality. “Humus management” is a soil management system the Luebkes use in conjunction with CMC Compost.

Humus Management

The humus management system relies on forage and cover crop based rotations, green manures, proper tillage operations, rock dusts, microbial inoculants and CMC compost to build soil humus and meet fertility and pest control needs. Indicators of success with humus management as reported by the Luebkes include the following:

  • In a ten year period, the organic matter content of a clay loam soil on their farm was changed from 2% to 15%.
  • Following downwind fallout from the Chernobyl nuclear reactor accident, root vegetables raised on their farm were uniquely free of radioactive contamination in comparison to other farms in the region.
  • The nitrate content of vegetables raised on their farm was significantly lower than conventionally grown produce in Austria.
  • Soil and compost samples on their farm have well developed humus crumb and high numbers and diversity of microbes.

One outcome of Siegfried Luebkes research is a database of 3600 microbe-driven enzyme reactions in soils and composts.

The CMC Process

CMC Stands for Controlled Microbial Composting. Meaning the composting process is controlled and guided.

When building compost windrows attention must be given to material combination, making sure that the material ingredients have a Carbon to Nitrogen Ratio of 25:1 to 30:1. Consideration must also be given to materials that give the windrow porosity to allow proper aeration. When laying materials out in the windrow lighter materials are placed on the bottom with the heavier materials on top. A clay soil is added at 5%-10%to the recipe as it provides the microbes a base upon which to build the “clay-humus complex”. 10% finished compost is also added to a new windrow in order to inoculate the windrow, improve moisture conditions and aid in moisture handling during the starting phase. A windrow size of 3m wide by 1.5m high is preferred; the windrow turner is then able to mix the ingredients to start the composting process.

After the materials have been blended, the compost is inoculated usually on the second day. The inoculant consists of aerobic microorganisms that should be in every soil. Their task is to break down, build up and stabilize the compost within 6 to 8 weeks. The compost turner is equipped with an inoculation system that mists the inoculants into the moving material as it is being blended. The fine mist spreads the inoculant evenly through the windrow and covers every particle.

Daily monitoring of temperature, C02 and moisture take place to control the composting process. When temperature reaches a certain level (65 degrees c in the break down phase), or the percentage C02 in the pile is to high (over 10%) the compost turner is used to turn the compost which reduces temperature and releases C02. By releasing the C02 and replacing it with air you are able to keep the process aerobic. Moisture can also be added through the irrigation bar on the compost turner, water is sprayed on each particle of material as it passes over the rotor of the compost turner giving even incorporation and treating every particle. This is to keep the compost pile at a moisture level of 50%-55%. Generally the compost gets turned once a day during the first week, every second day during the second week, every three days in the third week and once a week for the next three weeks. Well composed and managed CMC compost is finished within 6 weeks.

What will compost do?

Compost provides both macro and micro nutrients. Compost contains organic sources of NPK (nitrogen, phosphorus and potassium) and supplies trace minerals such as boron, cobalt, copper, iodine, manganese, molybdenum and zinc.

Good compost will contain aerobic bacteria and fungi that will service the nutritional needs of the plant at the proper rate and time as they are required.

Quality compost acts as a carrier for hundreds of millions of aerobic bacteria and fungi per gram of finished material. They stimulate soil digestion and therefore help complete the carbon, nitrogen and other nutrient cycles.

Research is proving that quality compost, with its related micro flora, has a healing effect on plants and the soil. Microorganisms provide natural soil antibiotics, enzymes and vitamins as a byproduct of their metabolism. The microorganisms in compost are natural enemies of fungi or bacteria that cause plant diseases and an effective tool in battling nematodes and other persistent problems.

References:
S. Diver, Fayetteville, Arkansas. Controlled Microbial Composting and Humus Management: Luebke Compost
S & U Luebke, Peuerbach, Austria. Pioneers of Controlled Microbial Composting
B. Pike, Pike Agri-Lab Supplies Inc. Using Quality Compost to Build Humus in Soil