Cover crops offer many benefits for farmers seeking to reduce their reliance on external inputs. These include maintaining and improving soil quality, preventing erosion and, in some cases, allelopathic weed control. Allelopathic potential has been well documented for cover crops such as cereal rye (Secale cereale L.), hairy vetch (Vicia villosa Roth) and red clover (Trifolium pratense L.). Much less is known about other potentially allelopathic cover crops, including certain brassicaceous species that are normally grown for their oilseeds, including canola and rapeseed (both Brassica napus L.) and mustards (e.g., Sinapis alba L., white and yellow mustard). Because of their potential contribution to pest management, there is increased interest in growing brassicas, both as cover crops and as seed crops harvested for oil production. In this review, we first discuss unique attributes of brassicas that make them promising options for pest management, as well as generally beneficial cover crops. Next, we review the literature from controlled settings on the effects of brassicas, brassica extracts and isolated compounds contained therein on seed germination, seedling emergence and establishment, and seedling growth—effects that, combined or taken alone, could contribute to reducing the density and vigor of weed communities in the field. Field studies examining the detrimental effects of brassicas in rotation with other crops, as well as examining the effects of brassica cover crops on weed dynamics in subsequent crops, also are reviewed. Finally, we review some important agronomic considerations about the use of brassica cover crops.

A survey was conducted in 2002 to measure the success of technology transfered to growers (i.e., changes in attitudes and behaviors) from a long-term, large-scale, integrated cropping systems experiment called the Ralston Project, near Ralston, Washington, USA. Non-irrigated, cereal and oilseed growers who participated in biennial field tours (1996–2000) were mailed a self-administered questionnaire, which asked about: (1) their interest, use and adoption of technology developed or demonstrated in the project; (2) their opinions about the project's collaborators, planning and design; and (3) their overall impressions of the project. One hundred and one eligible growers responded to the questionnaire, for a 55% overall response rate and a 62% completion rate. Survey results confirmed that the Ralston Project field tours were a successful means of technology transfer among participants. Seventy-seven percent of growers found one or more project technologies particularly useful to their own production operation(s). More than 60% conducted independent trials with one or more technologies, with 50% of these trials resulting in permanent adoptions. The project's planning and design had a more positive effect on growers' opinion of the project than the type of collaborations and sources of funding. Specific strategies that had a substantially positive effect on growers' opinions included: (1) the project's ‘whole system’ treatment design; (2) use of large plots to accommodate field-sized equipment; and (3) collaboration among scientific disciplines and with local growers. Seven variables known to influence the adoption of innovation were also tested against growers' decisions to try any of the project's technology in their own farm operations. Personal character variables influenced individuals' decisions to try project technology more so than environmental conditions. Level of education, previous adoption behavior and average annual rainfall significantly influenced growers' behavior (P<0.05). Our survey population consisted of early users of conservation-based farming technology, primarily innovators and early adopters. The Ralston Project made the greatest impact on current adopters and users of conservation-based farming technology. Interest among non-users was also high enough to suggest that the Ralston Project contributed positively to the diffusion of conservation cropping systems and associated technology into the greater grower community. We discovered from this survey that the planning and execution of field research plays a significant and influential role in transferring more complex, and perhaps high-risk, conservation-based farm technology. By understanding how research and field design affect different user groups within the grower community, professionals can identify appropriate strategies to expand interest beyond their primary target audience and influence attitudes and behaviors that facilitate widespread adoption.

One increasingly successful approach to enhancing small farm viability is for farmers to market their products directly to consumers and food-oriented businesses and institutions within their local area. This localized approach to food production and distribution is based on theoretical concepts often articulated as community, local or regional food systems. But is there sufficient consumer support to make local food systems viable? Do communities differ in their potential for developing a local food system based on their dominant socio-economic and/or political characteristics? This study reports on the results of a random mail survey of households in two Oregon communities. Although the two communities contrast socio-economically and politically, they show common but somewhat different support for local agriculture. The results demonstrate the potential for the development of more localized food systems in both communities. However, the type of products, their method of delivery and pricing will likely need to be tailored to fit each community.

In a series of focus groups during 2001 and 2002, organic farmers from different regions of the United States identified a wide range of risks to their operations. The focus groups were facilitated by the University of Maryland in cooperation with a research team from USDA's Economic Research Service, to explore the risks faced by organic farmers, how they are managed, and needs for risk management assistance. Contamination of organic production from genetically modified organisms was seen as a major risk, particularly by grain, soybean and cotton farmers. Focus-group participants producing grains and cotton—many of whom knew about and had obtained crop insurance—raised concerns about coverage offered, including the need for insurance to reflect the higher prices received for organic crops. Most fruit and vegetable producers participating in the focus groups had little knowledge of crop insurance. When provided with basic information about crop insurance, operators of small fruit and vegetable farms were skeptical about its usefulness for their type of operation.

Agricultural industrialization, Green Revolution technologies, environmental change and civil conflicts have all been cited as contributing to the erosion of crop biodiversity. An additional factor is change in the characteristics of markets, including distance to market. Proponents of sustainable agriculture claim that one benefit of local food systems is the preservation of crop biodiversity. This paper explores that claim, examining Ohio orchardists' understanding and valuation of apple varieties and relating these to the preservation of biodiversity. Growers provided lists of apple varieties and then performed pilesorts on them. Analysis using multidimensional scaling reveals the underlying dimensions growers use to distinguish those cultivars. Salient characteristics are taste, use and market focus. Demands of the conventional commercial market with regards to transportation, appearance and storage exclude the old varieties. On the other hand, there is a strong congruence between sales in local markets and production of old varieties. Local markets, such as roadside stands and ‘pick-your-own’ operations, play an important role in the preservation of heirloom varieties of apples.

We consider the adoption of biologically integrated agricultural practices from the perspective of farm management style. Adoption decisions for farming practices must fit into a broader farm decision-making context that incorporates economic, environmental, social, family and personal considerations, as well as use of agricultural information sources. Drawing from a study of California almond and winegrape growers, we demonstrate that management styles differ substantially among farmers, these differences affect use of information sources and adoption of biologically based practices on the farm, and such adoption does not negatively affect crop performance. We used Q-methodology, a method for eliciting qualitative data using a variant of factor analysis, to identify three distinct management styles among a purposive sample of 40 growers. The Environmental Stewards' management style places higher priority on conservation of natural resources than on getting the highest possible yields or profits. Production Maximizers, with a different style, prioritize more traditional goals of producing the highest possible yields and quality and focusing resources on the farm rather than on outside concerns. Networking Entrepreneurs, on the other hand, value learning about innovative techniques in social contexts such as informational field days, evaluate new information with a business-like attitude and enjoy off-farm interests. A two-season mail survey of farming practices and information sources demonstrated that differences in management styles affect the adoption of practices. Environmental Stewards were more likely to practice biological pest control and encourage wildlife and less likely to use the most toxic chemicals. Production Maximizers had a greater tendency to use prophylactic and broad-spectrum chemicals, while Networking Entrepreneurs preferred more innovative biological pest controls but tended to avoid time-consuming cultural practices. Production Maximizers were distinguished by less use of more social forms of communication, such as attending field days and talking with other growers. Crop health and quality indicators showed that almost all growers were managing their crops very successfully, regardless of management style or choice of practices. These results hold important implications for efforts to increase the adoption of sustainable agriculture, especially by showing that contents and methods of outreach efforts must vary to accommodate diverse farm management styles.