Some municipal waste consists of moist kitchen garbage and grass clippings.  Most of the rest is dry paper.  If this mixture results in a moisture content that is too high the pile gets soggy, sags promptly, and easily goes anaerobic.  Turning not only restores aerobic conditions, but also tends to drop the moisture content.  If the initial moisture content is between 60 and 70 percent, the windrow is turned every two days.  Five such turns, starting two days after the windrow is first formed, finishes the processing.  If the moisture content is between 10 and 60 percent, the windrow is first turned after three days and thence at three day intervals, taking about four turns to finish the process.  If the moisture content is below 40 percent or drops below 40 percent during processing, moisture is added.

No nuisances can develop if turning is done correctly.  Simply flipping the heap over or adding new material on top will not do it.  The material must be blended so that the outsides are shifted to the core and the core becomes the skin.  This way, any fly larvae, pathogens, or insect eggs that might not be killed by the cooler temperatures on the outside are rotated into the lethal high heat of the core every few days.

The speed of the U.C. method also appeals to the backyard gardener.  At home, frequent turning can be accomplished either in naked heaps, or by switching from one bin to the next and back, or with a compost tumbler.  But a chipper/shredder is also essential.  Grinding everything that goes into the heap has other advantages than higher heat and accelerated processing.  Materials may be initially mixed as they are ground and small particles are much easier to turn over than long twigs, tough straw, and other fibrous materials that tie the heap together and make it difficult to separate and handle with hand tools.

Backyard shredders have other uses, especially for gardeners with no land to waste.  Composting tough materials like grape prunings, berry canes, and hedge trimmings can take a long time.  Slow heaps containing resistant materials occupy precious space.  With a shredder you can fast-compost small limbs, tree prunings, and other woody materials like corn and sunflower stalks.  Whole autumn leaves tend to compact into airless layers and decompose slowly, but dry leaves are among the easiest of all materials to grind.  Once smashed into flakes, leaves become a fluffy material that resists compaction.

Electric driven garden chipper/shredders are easier on the neighbors’ ears than more powerful gasoline-powered machines, although not so quiet that I’d run one without ear protection.  Electrics are light enough for a strong person to pick up and carry out to the composting area and keep secured in a storeroom.  One more plus, there never is any problem starting an electric motor.  But no way to conveniently repair one either.