| Aerated compost tea (ACT) is applied to either the root zone or leaf surface of plants to support or improve the biological diversity, the host resistance to pathogens, and or the nutrient status. Compost, water, and amendment(s) are maintained under conditions conducive for biological process for 24 to 72 hr before course filtering and application. Rather than increase bacteria, fungi and other organisms in a liquid phase, the compost was amended and cultured to increase microorganisms in the solid phase prior to a 20 minutes water extraction. A 0.5 L bioreactor was developed to provide reliable control of temperature, gas flow, oxygen levels, and moisture content of the media amended with an alfalfa based substrate (alfalfa meal, poultry protein, potassium sulfate, molasses) as an available energy source for the resident micro flora. The biomass of fungi and bacteria, enumeration of bacteria and nematodes, genetic signature of the bacteria, pH and electrical conductivity, moisture content, of carbon dioxide and oxygen, gas concentration (%), gradient (%), and respiration (g), of carbon dioxide the hour of half maximum and the total potential maximum respired, and volatile compounds released over the incubation period were quantified. Results from MSU and independent labs provided consistent data between replicates within a study and as well between studies with the same parameters. Manipulation of oxygen (3% vs. 20%) and temperature (25 °C vs. 40 °C) influenced the rate of substrate decomposition and the characteristics of the final water extract. |
