Control of agricultural policymaking by the “agricultural establishment” has been challenged by a wide range of interests concerned with the externalities of modern industrialized agriculture. An “externalities/alternatives” or “ex/al” coalition appears to be an emerging force in agricultural policy debates. We surveyed three alternative agriculture groups, three conventional agriculture groups, and a statewide sample of farmers to learn whether each category forms a distinct, unified interest group whose perspectives on agricultural policy diverge substantially from the others'. There is considerable similarity among the alternative agriculture groups and among the conventional agriculture groups, the differences between them being much greater than the differences within each category. The statewide farmer sample is generally intermediate between the two sets of interest groups, but is closer to the conventional perspective on most issues.

On-farm and farmer-directed research is claimed to lack validity when produced by methods that limit the generalizability of its results. However, farmers may consider such findings sufficiently valid for use in agricultural production even though agricultural scientists may not consider them scientifically valid. A general social-psychological theory of knowledge and information processing called lay epistemology suggests that farmers may assess the validity of any research report by its plausibility in relation to their knowledge and experience. Other communication research suggests that readers will look for cues to help them decide whether the research and findings are valid and useful.

To identify validity cues used by farmers in evaluating production research reports, we asked 56 Illinois cash-grain farmers to mark phrases and other items that influenced their confidence in a popularized research report and to explain the reasons for each mark. The kinds of validity cues that farmers used or sought had little relationship to their personal or enterprise characteristics. The researcher's name, location and affiliation were critical cues, but information on the methods and results were no more important than data about costs, risks, growing conditions, and longer term outcomes. Plausibility plays a key role when farmers decide whether production research is valid. It would be useful to farmers if research reports included more information about the system being studied, such as its costs and risks, along with data on the research methods used.

We coupled a nonlinear mathematical programming model with sensitivity analysis and evaluated some economic barriers to adoption of low-input agriculture by farmers in Richmond County, Virginia. Collection of primary data made the model more realistic. We analyzed potential barriers to adoption, including poultry litter price, yields, labor requirements, and variable input costs. We found the adoption of low-input practices to be sensitive to the price of poultry litter and relatively insensitive to yields, labor requirements, and variable costs. However, when several of these barriers are combined, the model predicts that farmers would use conventional practices. Therefore analysis of the farm as a system rather than practice by practice is important when identifying the effects of economic barriers.

The nutrient composition of swine excreta can be altered by manipulating the composition of the pig's diet Several approaches are reviewed: feeding according to the pig's growth phase, formulation according to the feed's digestible amino acids, use of crystalline amino acids, the ideal protein approach, formulation according to available phosphorus, and the addition ofphytase enzymes. Each has the potential to lower nitrogen or phosphorus excretion levels. Together they can dramatically reduce the nitrogen and phosphorus concentration of swine manure, which could be a major advantage in regions with a high density of swine or for swine operations with limited access to arable land. However, the value of the swine manure would be much less as a fertilizer because these two elements are important plant nutrients.

The transformation of agriculture according to an industrial model has had clear benefits in improving efficiency and lowering production costs, but also has had adverse consequences on rural culture and the environment. Sustainable agriculture offers alternative practices and values intended to promote environmental stewardship, conserve resources, preserve farm traditions, and support rural communities. Strong arguments can be made that it will have these consequences, based on the interactions among agricultural structure, rural community viability, and environmental quality. However, counterarguments can also be made, and the claimed benefits of sustainable agriculture for rural communities must be regarded as not yet demonstrated.