1. windrow porosity, height and width.

2. aeration of the windrow (e.g. via the windrow turning frequency, O2 and/or CO2 concentration in the windrow, temperature of air streams in the case of forced aeration);

3. The invention pertains to a process and device for biological treatment, especially composting of biogenous or abiogenous substances and/or substance mixtures in a windrow (10) in the presence of biologically active components, particularly microorganisms, in a closed reactor (RX1 to RXN) with more than one reactor zone, namely the windrow (10) itself and at least one reactor gas space bordering the windrow, wherein regulating means are used to set, maintain, control or adjust, in short to regulate, milieu conditions, changes in milieu conditions and/or process parameters in the windrow (10) through a steady state, quasi-steady state and/or unsteady operation of the reactor (RX1 to RXN).

4. Progress 01/01/02 to 12/31/02 Outputs A rainfall-runoff model for windrow composting yards was constructed at the UGA Bioconversion demonstration and research center using runoff data for the past two years