Wetland buffers are no substitute for landscape-scale conservation

Wetlands in farmland are at risk of contamination by fertilizers and pesticides. One recommendation for reducing wetland contamination is to maintain a buffer of contiguous uncropped land around the wetland (a wetland buffer). Many agricultural water protection policies around the world recommend 5 to 50-m wide uncropped buffers around water bodies, but it is unclear how large wetland buffers must be to effectively protect against these chemicals. In addition, it is unclear whether wetland buffers have similar—or stronger—effects on fertilizer and pesticide contamination than reducing the amount of cropped land within the larger landscape context around wetlands. Our study, conducted across 37 wetlands in eastern Ontario, Canada, addressed the following questions: (1) Does increasing buffer width, or increasing the amount of contiguous uncropped land within recommended buffer width guidelines, reduce nutrient and pesticide levels in agricultural wetlands? (2) Does increasing uncropped land cover in the broader landscape reduce nutrient and pesticide levels in agricultural wetlands? and (3) What is the relative importance of buffer size and landscape-scale uncropped cover for reducing nutrient and pesticide levels in agricultural wetlands? A rigorous site selection process was employed to minimize the correlation between buffer size and landscape-scale uncropped cover, minimize spatial gradients in these predictor variables, and minimize variation in potentially confounding variables. We obtained nutrient and pesticide data by collecting water samples from each wetland under similar weather conditions in June–July 2015. Nitrate concentrations were measured using ion chromatography, and atrazine and neonicotinoid (pesticide) concentrations using a combination of high-performance liquid chromatography and mass spectrometry. We found that nitrate, atrazine, and neonicotinoid concentrations in study wetlands were unaffected by wetland buffer size. However, concentrations of each chemical decreased with uncropped land cover in the surrounding 150 to 300-m radius landscapes. To effectively protect w

Cross-Sectional Staining and Surface Properties of DDGS Particles and Their Influence on Flowability

With the U.S. fuel ethanol industry projected to grow during the next several years, supplies of distillers dried grains with solubles (DDGS) are anticipated to continue to grow as well. DDGS is used primarily as livestock feed. Much of the DDGS must be shipped, often over large distances, outside the Corn Belt (which is where most of the corn-based ethanol plants are currently located). Stickiness and caking among particles is a common issue for DDGS, and it often leads to flowability problems. To address this, the objective of this study was to understand the cross-sectional and surface natures of DDGS particles from five ethanol plants, and how they interact with DDGS properties. This study examined the distribution patterns of chemical components within cross-sections, within section edges (i.e., surface layers), and on surfaces using standard staining techniques; chemical composition was determined using standard protocols; and physical and flowability properties were also determined. Crude protein in the samples was 28.33–30.65% db, crude fat was 9.40–10.98% db, and neutral detergent fiber (NDF) was 31.84–39.90% db. Moisture contents were 4.61–8.08% db, and geometric mean diameters were 0.37–0.52 mm. Cross-sectional staining showed protein levels of 19.57–40.39%, and carbohydrate levels of 22.17–43.06%, depending on the particle size examined and the production plant from which the DDGS was sampled. Staining of DDGS particles indicated a higher amount of surface layer protein compared with carbohydrate thickness in DDGS particles that had a lower flow function index (which indicated potential flow issues). Additionally, surface fat staining suggested that higher surface fat also occurred in samples with worse flow problems. This study represents another step toward understanding why DDGS particles stick together during storage and transport, and will hopefully help to improve DDGS material handling strategies

Tri6 is a global transcription regulator in the phytopathogen Fusarium graminearum

In F. graminearum, the transcriptional regulator TRI6 is encoded within the trichothecene gene cluster and regulates genes involved in the biosynthesis of the secondary metabolite deoxynivalenol (DON). Targeted disruption of TRI6 confirmed its role as a positive regulator of trichothecene genes and previous studies designated Tri6 as a pathway-specific transcriptional regulator. The Tri6 protein with its Cys2His2 zinc-finger may also conform to the class of broad-domain transcription regulators. This class of global transcriptional regulators mediate various environmental cues and generally responds to the demands of cellular metabolism. Expression profiling of F. graminearum grown under nitrogen-limiting conditions revealed that 49 out of 198 target genes are differentially regulated by TRI6. The identification of potential new targets together with deciphering novel binding site for Tri6, casts new light into the role of this transcriptional regulator in the overall growth and development of F. graminearum. Overall design: Three biological replicates of Fusarium graminearum wildtype strain GZ3639 (NRRL 38155) (reference) and a tri6∆ mutant derived from GZ3639 were grown under nitrogen-limiting conditions in liquid culture for 5 hrs at 28o