12 pages, via Online journal, Corn (Zea mays) grown in the southern Piedmont requires 200 to 280 kg nitrogen (N) ha−1 annually and requires up to 0.87 cm of water per day, making groundwater systems susceptible to nitrate (NO3−) leaching. A perennial white clover (Trifolium repens L.) living mulch (LM) system may reduce NO3-N leaching by using legume N to replace mineral N, though little information is available on such a system in the southern Piedmont. Therefore, a HYDRUS-1D model was used to simulate water and NO3-N flux in three cover crop systems. Cereal rye (Secale cereal L.) (CR), crimson clover (Trifolium incarnatum L.) (CC), and a white clover LM were fertilized with 280, 168, and 56 kg N ha−1. The HYDRUS-1D model was calibrated and validated with observed water contents and NO3-N data that were collected over two years. Water and NO3-N flux models were created for each treatment and evaluated using coefficient of determination, percentage bias, and index of agreement, and showed good agreement to observed data. Nitrate leaching below 1 m in 2015/2016 was 23.5, 12.7, and 21.4 kg ha−1 for the CC, LM, and CR treatments, respectively, but was less than 1 kg ha−1 for all treatments in 2016/2017 due to prolonged drought. Differences in leached NO3-N among treatments were attributed to variation in mineral N application rate and NO3-N uptake by cover crops. Overall, results suggest that the use of a perennial LM system may reduce NO3-N leaching when compared to annual CC and CR cover crop systems.
20 pages., Via online journal., Agricultural technology continues to evolve to meet the demands of a growing world, but previous advancements in agricultural technology have been met with resistance. Improved science communication efforts can assist in bridging the gap between expert and lay opinion to improve reception of scientific information. Using the framework of the heuristic model of persuasion, the purpose of this study was to examine the impact of emphasizing elements of source credibility – trustworthiness and expertise – and the gender of the source on perceptions of source credibility. A sample of 122 undergraduate students were exposed to one of the four possible developed message treatments. Data collection took place in a laboratory setting using an online instrument that had a randomly-assigned stimulus research design. The results indicated the treatment conditions had higher mean scores for source credibility than the control. Further inferential analysis, however, showed the differences to be non-significant. One significant finding showed the gender of the source can influence perceptions of credibility. This suggests merit in using female sources when presenting scientific information to the Millennial population. While choosing credible sources to present information is important, more research is needed regarding the effect of emphasizing various credibility components and the role of source gender on perceptions of source credibility.
