Water Quality

Rapporteur: Laura L. Jackson, Ph.D., University of Northern Iowa

Participants: George Hallberg, Ph.D., The University of Iowa

Rodney L. Huffman, Ph.D., North Carolina State University

Dennis Keeney, Ph.D., Iowa State University

Les E. Lanyon, Ph.D., University of Pennsylvania

Nancy Lynch, Ph.D., The University of Iowa

Dennis D. Schulte, Ph.D., University of Nebraska

Distinctions between surface water, groundwater, and precipitation are artificial. Customary approaches to livestock have concentrated on only one aspect of the food chain – from animals to manure. These types of issues result in a disregard for larger system issues that include the way animal feed is produced. Little attention has been given to actual performance of swine operations relative to water quality, in contrast to the abundant availability of engineering specification data detailing how operations ought to perform.

1. There is a surprising lack of population/field survey data on actual performance, e.g., water use, lagoon performance, pit performance, field application of waste, stream and groundwater quality, of swine facilities in contrast to the large amount of information about how they are designed. Anecdotal information about individual farmers, corporations, or facilities is the rule rather than the exception.

2. Where facilities have become larger, livestock have become more concentrated, and management of nutrients from livestock waste has become more complex. At some undefined scale, the local ecosystem can handle leakage, accidents, etc., but as the scale increases, the ecosystem's capacity to absorb pollution without serious damage is surpassed. This scale has not been determined in any systematic way for any region.

3. There are several unknown but potentially devastating risks associated with human pathogens and antibiotic-resistant organisms in swine waste that we currently lack the techniques to assess.

4. Several known, foreseeable problems associated with long-term, high density livestock systems, such as atmospheric deposition of nitrogen and accumulation of heavy metals and phosphorus in soils, have received little attention in this country even though their causes and consequences are well understood.

5. The ratio of animals to land on which their manure can be applied is the ecological bottom line. If the ratio in a region is too high for any given nutrient (N, P, K), then there will be no way of preventing waste management problems, only methods of coping with them. This problem cannot be addressed only at the level of the individual operation, but rather must be addressed regionally. Regulations and standards that have traditionally focused on the individual producer will increasingly need to be rewritten to keep in mind region-wide patterns and the burdens they place on the regional ecosystem.

6. A common assertion is that industrialization in the hog industry is economically "inevitable." The implication is that research should focus on solving the problems of large-scale operations. This widely accepted point of view encourages an unhealthy uniform research agenda. Specifically, it leads to accommodation and management of the intrinsic problems of industrial livestock production, while several legitimate research areas remain unexplored. As the above conclusions demonstrate, many problems with large-scale and/or concentrated livestock production are intrinsic and therefore cannot be "solved" in any normal sense; only partially mitigated at some cost. Meanwhile, other important and relevant avenues of research – including the development of alternative methods of livestock and feed production – do not receive adequate funding or sufficient attention from a diverse array of talented scientists.

A major risk of restricting research and research dollars in this way is that the full consequences of land use choices, including the opportunity costs of going one direction and abandoning another, are not made explicit. Researching only industrial livestock production is like offering society the choice of apples or nothing, instead of offering apples, oranges, and bananas, or some combination of the three. Experience with concentrated livestock production has shown that associated environmental degradation can have extremely long-term effects on the resilience and productivity of agricultural ecosystems and the health of human populations. Therefore, we need to adopt a conservative approach and fully explore all options.

• The most pressing need is for local and regional surveys of actual confinement facilities, the performance of their pits and lagoons, their land use practices, waste disposal methods, ammonia emissions and atmospheric deposition, and the chemical, physical, and biological integrity of surface and ground waters that they can potentially impact. It is not sufficient to base answers to citizens’ questions on theoretical ranges found in state regulations, engineering specifications and waste management plans, because as the saying goes, "the road to hell is paved with good intentions." Studies should focus on the performance of hog confinements, using stratified random sampling of facilities over a comprehensive range of operation types and sizes.
• Our knowledge of the performance of conventional livestock production methods is also lacking. Non-point and point source pollution from agriculture is widespread and most of this is from small-scale operations. Attention to large-scale operations, while easier because the production facilities are more obvious and controversial, should be accompanied by a renewed look at conventional or medium- to small-sized operations, which still account for the majority of production systems in Iowa.
• Direct measure should be made of phosphorus, potassium, copper, zinc and other feed additives in lagoon waste, sludge, and soils where waste is routinely spread. Methods of predicting and assessing long-term accumulation of these elements should be developed, and such estimates should be included in waste management planning.
• The amount of atmospheric dry and wet deposition of nitrogen compounds should be measured around sources of ammonia release, such as lagoons and fields spread with animal waste. Natural areas close to and far from sources of ammonia release should be monitored over the long term for changes in their nitrogen budgets and species composition.
• It would be useful to develop regional, spatially explicit models of nutrient imports and exports, including fertilizer, crop, soil, livestock, and manure pools, imports from fertilizer, feed, animals etc., and losses to ground and surface water, the atmosphere, and other regions (via export of feed or animals). Such models could be used to simulate proposed or predicted changes in the density and distribution of livestock production on a scale relevant to the functioning of regional ecosystems. Alternative trends could also be modeled: dispersal of livestock onto more farms, diversification of crops and livestock, spatially closer links between nutrients, feed, and livestock; and increased reliance on endogenous (on-farm, as opposed to purchased off farm) sources of nutrients (biological nitrogen fixation, more efficient nutrient cycling, mycorrhizal enhancement of phosphorus uptake) for crop production. These models could also be tied to information on surface waters, geology, groundwater systems, and drinking water supplies to assist in predicting impacts of accidents on particular human populations. An overall ecosystem management approach to agricultural landscapes will require these models.
• The burden of excess animal waste in a region could be relieved by developing alternative methods to handle and process the animal wastes to create economically transportable forms. The regional/transregional nutrient imbalance could be lessened if wastes could be transported back to feed production areas, or at least used to replace purchased fertilizer in the region. The nutrient imbalance created by the extreme concentration of animals, with current, local disposal of wastes, cannot be sustained without serious environmental damage.
• Continued research is needed on human pathogen transmission from field application of animal wastes and transfer of antibiotic resistance. The spread of strains of common bacteria, whether or not they are pathogenic, which posses broad-spectrum resistance to antibiotics, is a potentially serious effect of swine confinement proliferation that deserves close monitoring and intensive study.
• If market mechanisms could reward farmers who practiced more environmentally responsible forms of crop and livestock production, much environmental damage and expensive government regulation could be avoided. Economic research should focus on ways that this could be accomplished.

Currently, ecosystems are being "managed" by default, by a social, political, and economic system that is largely unaware of ecosystem constraints or consequences. Increasingly, other sectors of the economy, e.g., timber and fisheries, are beginning to realize the value of ecosystem services and the prudence of managing whole ecosystems, rather than individual resources. Social and economic research in agriculture could benefit from the "ecosystem management" philosophy now embraced by the U.S. Forest Service and other federal agencies.

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