of the cover is synchronized with movement of the turning machine the motor when driven in one direction rotates a chain drive 52 to which one end of the panel is secured this acts to pull the insulating panel up track 50 when driven in the opposite direction of rotation the insulating panel is repositioned over the channel positive aeration of compost within the channels is achieved through use of blowers as seen in fig2 as the cover 40 advances along the channel 30 it is stored in the overhead track much like that used in housing an overhead garage door this storage arrangement is best seen in fig2 and 5 alternative arrangements for storage of the cover are to roll it up in a tight overhead coil or to provide for the cover to be stacked in an accordion like fashion the former of these two arrangements would require the articulated segments comprising the cover to be of shorter length to accommodate the sharper turning radius required for coiling the cover it would of course be possible particularly when using channels of short length to simply extend the cover directly off the end of the channel on suitable flat supports this latter arrangement would allow for use of a flat unhinged slab of insulating material in summary the use of a heat insulating cover overlying the curing channels allows for greater control of the thermal gradients within the stored compost thereby materially improving pathogen destruction from both a qualitative standpoint and from the standpoint of the efficiency of operation this procedure is additionally enhanced by the recirculating air system shown in fig6 which both improves temperature and odor control having described.