NOVELTY - The system for generating compost, comprises a positively aerated floor (50) having a gas flow channel (40) connected to a gas supply, a semi-permeable cover (10) for a compost biomass (30) pile placed on the positively aerated floor, and a suction system positioned generally near an upper surface of the compost biomass pile. Withdrawal of gas by the suction system generates suction between the cover and an outer surface of the compost biomass pile, and inhibits the release of gas from the biomass pile into the atmosphere. The cover is impermeable to gases and liquids.    USE - The system is useful for generating compost (claimed).    ADVANTAGE - The system ensures effective generation of compost with reduced odor emission and dried evaporation, and improves the disposal and the beneficial re-use of organic wastes such as garden waste, bio-solids, agricultural waste and municipal solid waste.    DETAILED DESCRIPTION - The system for generating compost, comprises a positively aerated floor (50) having a gas flow channel (40) connected to a gas supply, a semi-permeable cover (10) for a compost biomass (30) pile placed on the positively aerated floor, and a suction system positioned generally near an upper surface of the compost biomass pile. Withdrawal of gas by the suction system generates suction between the cover and an outer surface of the compost biomass pile, and inhibits the release of gas from the biomass pile into the atmosphere. The cover is impermeable to gases and liquids, and allows an airflow rate equal to or less than 0.2 cfm/ft2. Edges of the cover are weighted. A strapping unit is connected to fastening points in the positively aerated floor. The suction system is present in the form of a longitudinal tube having apertures, integral to the compost cover, and connected to a port provided in the compost cover. A forced air system is connected to the gas flow channel. Atmospheric air is drawn into the gas flow channel by the suction system. INDEPENDENT CLAIMS are included for:    (1) an another type of system for generating compost; and    (2) a gas permeable cover.    DESCRIPTION OF DRAWING(S) - The figure shows a perspective view of a first negative aeration compost generating system.    Aerated composting zone (5)    Compost cover (10)    Biomass (30)    Gas flow channel (40)    Aeration floor. (50)