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Erin M. Silva and Geraldine Muller

In 2008, a collaborative project was initiated between the La Farge School District (La Farge, WI), University of Wisconsin–Madison College of Agriculture and Life Sciences, Organic Valley Cooperative Regions Organic Producers Pools (La Farge, WI), and Kickapoo Valley Reserve (La Farge, WI). The overarching mission of the program is to build a sustainable, hands-on educational farm and corresponding curriculum to teach organic agriculture principles to high school students and increase the number of students entering agriculture-related professional fields. Secondary goals of the project include delivering locally grown organic produce and related organic agriculture educational opportunities to the broader community. To achieve these goals, a multifaceted student internship program was created that includes a range of experiential learning opportunities for students. With the participation of each of the project partners, about ten students per year engage in the field production of certified organic vegetables, participate in field trips to sites related to organic agriculture, and distribute the produce to the school and the broader community. Through the integration of these activities, students are taught key principles of successful organic management, including ecologically based disease, weed, and insect management, development of a soil fertility plan, market analysis and its implications of crop selection, and determination of costs of production. In the face of both successes and challenges, through informal evaluation of students and the project team, the program continues to develop each year.

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Erin M. Silva, Bill B. Dean and Larry Hiller

Successful pollination of onion (Allium cepa L.) flowers greatly depends on adequate nectar production. In order to understand the nectar production dynamics of onion flowers, nectar was collected at regular intervals during a 24-hour period. Hourly nectar volumes were compared to a variety of environmental conditions, including amount of solar radiation, relative humidity, temperature, wind speed, and evapotranspiration. Production patterns showed mid- to late-morning peaks and late evening peaks in nectar volume. Nectar appeared to be reabsorbed by the flowers during the afternoon and overnight hours. Individual flowers produced the highest amount of nectar several days after initially opening. Nectar production was significantly and inversely related to relative humidity while the effects of temperature, evapotranspiration, wind speed and solar radiation on nectar production were not significant in this study.

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Kate A. Ivancic, Matthew D. Ruark, Francisco J. Arriaga and Erin M. Silva

Spring-planted green manure cover crops may provide a nitrogen (N) benefit to a subsequent sweet corn (Zea mays L.) crop, but spring growth and lack of consistent benefits documented in previous studies provide limitations to adoption. Berseem clover (BC; Trifolium alexandrinum) and chickling vetch (CV; Lathyrus sativus L.) are two legumes that could be beneficial when spring-seeded, but they have not been well studied in this context. The objectives of this study were to measure spring-seeded cover crop biomass and N yield, and the subsequent effects on sweet corn yield and response to N fertilizer. The study was conducted in 2014 and 2015, and the experimental design was a randomized complete block split-plot design with cover crop as whole-plot treatments [CV, BC, berseem clover and oat (Avena sativa) mixture (BC + O), oats, and no cover crop] and N rate as split-plot treatments. Cover crop growth and effects on sweet corn production varied greatly between years, with both cover crop and sweet corn biomass greater in 2015, although BC produced very little biomass (<0.7 Mg·ha–1) and thus is not recommended for spring seeding. In 2014, CV resulted in the lowest agronomically optimum N rates (AONRs) compared with no cover crop, suggesting a potential N credit when only having an N yield of 11.6 kg·ha–1, but this effect was not seen in 2015. There was also no evidence that oat would supply N to the subsequent crop. Overall, evidence is lacking that any spring-seeded cover crop will provide a consistent N benefit on sandy soil, and limitations to spring growth may preclude widespread adoption.

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Erin M. Silva, Rebecca Claypool, Jim Munsch, John Hendrickson, Paul Mitchell and Jean Mills

Organic sales continue to increase in the United States, particularly in the category of fruits and vegetables. Many organic vegetable producers are highly diversified in both crop production and marketing strategies, selling many different crops through several different market channels. With this level of operational complexity, determination of cost of production and calculation of breakeven prices for each crop in each market channels is extremely challenging. A spreadsheet-based tool called Veggie Compass was created to assist growers in tracking their operational costs and determining crop-specific and market-specific costs of production, breakeven prices, and gross profits. The spreadsheet uses farm-specific data regarding expenses, sales, and labor inputs in its calculations. A farmer can define the crops grown and markets sold to tailor the information specifically for their operations. Continued development in collaboration with farmers will improve the program and allow growers to perform analyses that enable them to set prices that more accurately reflect their respective operational costs.