Why co-utilization?

The land application of by-products from agricultural, industrial or municipal sources is certainly not a new phenomena. Wood ashes, manures, crop residues and even some of the first food processing wastes, such as oyster shells, were applied to the land and, dependant upon site specifics, probably showed a beneficial response by the next crop. These positive responses led to agricultural practices which were continued over time. Today, with renewed interest in concepts such as sustainability, biodynamic farming, and natural resource conservation, the practice of applying by-products to land continues. However, a problem exists. This problem is concentration. Society, has developed technologies for the production of food, fiber, energy and the whole gamut of consumer goods with little regard for the by-products that these technologies produce, or the effects that the processes themselves may have upon the environment. The concentration per se of resources such as manures, coal ashes, waste mineral fines from crushing rock, paper mill sludges, sewage sludges, etc. is further complicated by economics. Even if an individual by-product has some intrinsic value, like the fertilizer value of manure or as source of trace minerals like waste mineral fines, there is a finite, albeit small, radial area within which these materials can be transported and utilized economically. Thus, the stockpiles continue to get larger and research dollars are spent on better liners for landfilling materials. The concept of co-utilization is simply the blending, mixing, and/or co-composting of two or more by-products in order to produce a value-added "designer" material which can be beneficially utilized to solve an agricultural problem, remediate soils, and/or fulfill a market niche. There are numerous examples, many of which will be noted in the presentations throughout the Symposium, where materials that were once called wastes are being co-utilized as value-added products. The goal of this Symposium is then two-fold: first, to identify areas where co-utilization is being practiced and to foster this utilization to better use our natural resource base; and second, to highlight where good science can be practiced in developing co-utilization products that will have a significant impact on our society at large.