As farmers and gardeners grow their crops, nutrients are removed from the soil as the plants grow and produce fruit. To keep the soil in condition for future crops, nutrients must be reintroduced to the soil. Natural and man-made fertilizer s are the most common source of introduced nutrients. Field composting is a major supplement to fertilizing. Farmers achieve composting by simply "plowing under" the crop's remains, or trash, allowing it to decompose in the field during the fallow months. Compost heaps are especially beneficial to dedicated gardeners, greenhouse farmers, and nursery operators. For the gardener who must continually reuse the same plot of ground, the compost heap can be a major source of soil nutrients. For the greenhouse grower, introduction of soils from outside sources every year is comparable to moving to a different farm annually. Since gardeners cannot develop their soil the way that a farmer...