Alternative Biomass Production Study for Resilient Economic Agricultural Practices in Morris, Minnesota The Tillage Study was established in 1997 to assess the effect of a variety of tillage intensities on soil C. The initial eight treatments included no-tillage, moldboard + disk tillage, chisel tillage, and fall and spring residue management, with or without strip-tillage and strip-tillage + subsoiling (Archer and Reicosky, 2009). In 2004, treatments were reduced to no-tillage, moldboard tillage, and fall and spring residue management without strip-tillage, but all had an early or late planting date. The last comprehensive set of soil samples were collected in 2006. In 2008, the strip-tilled subset of the Tillage Study plots were repurposed for the Alternative Biomass Production Systems study, which was designed to explore alternative strategies to support bioenergy including planting of cellulosic feedstock. The Alternative Biomass Production plots included perennials in an extended 6-year rotation, winter cereal rye cover crops in a corn-soybean rotation, and an alternative Sorghum-Sudan grass hybrid forage system, all of which have and will continue to be monitored for agronomic and soil properties.

This study assessed the acute and chronic risk of pesticides, singly and as mixtures, for fish using comprehensive chemical data of four monitoring studies conducted in small- and medium-sized streams of Switzerland between 2012 and 2018. Pesticides were ranked based on single substance risk quotients and relative contribution to mixture risk. Concentrations of the pyrethroid insecti-cides, λ-cyhalothrin, cypermethrin and deltamethrin, and the fungicides, carbendazim and fenpropimorph, posed acute or chronic single substance risks. Risk quotients of eighteen addi-tional pesticides were equal or greater than 0.1, and thirteen of those contributed ≥30% to mixture risk. Relatively few substances dominated the mixture risk in most water samples, with chronic and acute maximum cumulative ratios never exceeding 5 and 7, respectively. A literature review of toxicity data showed that concentrations of several pesticides detected in Swiss streams were sufficient to cause direct sublethal effects on fish in laboratory studies. Based on the results of our study, we conclude that pesticides detected in Swiss streams, especially pyrethroid insecticides, fungicides and pesticide mixtures, pose a risk to fish health and can cause direct sublethal effects at environmental concentrations. Sensitive life stages of species with highly specialized life histo-ry traits may be particularly vulnerable; however, the lack of toxicity data for non-model species currently prevents a conclusive assessment across species.

Data from five laboratory bioassays and three field mesocosm studies performed by Dr. Patrick Moran of the USDA-ARS Invasive Species and Pollinator Health Research Unit, to examine the toxicity of five herbicides (2,4-D, glyphosate, imazamox, penoxsulam and diquat) and two surfactants that are often applied with herbicides (a paraffinic-oil based one and a vegetable oil-based one) to the planthopper Megamelus scutellaris (Hemiptera: Delphacidae) released in the US for biological control of waterhyacinth (Eichhornia crassipes or Pontederia crassipes) an invasive floating aquatic weed. The studies were performed between 2016 and 2021 to support integrated management of waterhyacinth in the Sacramento-San Joaquin Delta of northern California. The planthopper has also been released in Florida and Mississippi, and in South Africa. Herbicide applications are often still necessary where this planthopper and other biocontrol agents have been released. The research question was 'can the planthopper survive exposure to the herbicides and surfactants?'. In lab bioassays, planthoppers from greenhouse colonies were exposed to herbicide-dipped leaves for 24 hours and then allowed to feed for six days on untreated plants. Planthoppers were then collected, frozen and counted. Exposure to diquat or the paraffinic oil-based surfactant caused 40% to 69% greater mortality than did exposure to water-dipped leaves in more than one trial, while the other four herbicides and the vegetable oil-based surfactant were not toxic. In field mesocosm tests, mesocosms were established in 21L tanks caged with mesh tents, and plants allowed to grow for 4 weeks. Between 150 and 240 adult planthoppers were then released into each mesocosm. The following day, mesocosms were sprayed with herbicide, surfactant or insecticide solutions or an insecticide positive control. Three days later, planthoppers were collected with vacuums, frozen and counted. Only treatment with the paraffinic oil-based surfactant reduced final counts (by 36% to 49%) in a manner that was statistically significant compared to water-sprayed mesocosms in more than one mesocosm field trial, along with the insecticide positive control (by up to 98%). Diquat reduced final counts by 64% in one trial. The results indicate that, with the possible exception of diquat, exposing planthoppers to herbicides does not cause significant mortality, consistent with prior regulatory evaluations of these herbicides as being safe for insects. A surfactant that is often applied with the herbicides is toxic to the planthopper, consistent with expectations that this surfactant, designed to break down plant waxes on leaf surfaces, is likely also harmful to insect cuticular waxes, which insects rely on to contain body fluids. Leaving unsprayed refuges for the planthopper may be a useful component of integrated waterhyacinth control programs. Resources in this dataset: Resource Title: Data dictionary for dataset on toxicity of five herbicides and two surfactants towards the planthopper Megamelus scutellaris File Name: Data dictionary for AgPub archive plain text.txt Resource Description: Plain text file providing definition of each column in the data file and further information. Resource Title: Toxicity of herbicides and surfactants to the waterhyacinth planthopper Megamelus scutellaris File Name: Waterhyacinth planthopper herbicide toxicity data PMoran.csv Resource Description: Five herbicides, two surfactants tested, along with a negative control (water exposure) and, in some tests, a positive control (insecticide)

NVND Study for Greenhouse gas Reduction through Agricultural Carbon Enhancement network in Sidney, Montana Management practices, such as irrigation, tillage, cropping system, and N fertilization, may influence soil greenhouse gas (GHG) emissions. We quantified the effects of irrigation, tillage, crop rotation, and N fertilization on soil CO2, N2O, and CH4 emissions from March to November, 2008 to 2011 in a Lihen sandy loam in western North Dakota. Treatments were two irrigation practices (irrigated and non-irrigated) and five cropping systems (conventional-tilled malt barley [Hordeum vulgaris L.] with N fertilizer [CTBFN], conventional-tilled malt barley with no N fertilizer [CTBON], no-tilled malt barley-pea [Pisum sativum L.] with N fertilizer [NTB-PN], no-tilled malt barley with N fertilizer [NTBFN], and no-tilled malt barley with no N fertilizer [NTBON]). The GHG fluxes varied with date of sampling while peaking immediately after precipitation, irrigation, and/or N fertilization events during increased soil temperature. Both CO2 and N2O fluxes were greater in CTBFN under the irrigated condition but CH4 uptake was greater in NTB-PN under the non-irrigated condition than in other treatments. While tillage and N fertilization increased CO2 and N2O fluxes by 8 to 30%, N fertilization and monocropping reduced CH4 uptake by 39 to 40%. The NTB-PN, regardless of irrigation, might mitigate GHG emissions by reducing CO2 and N2O emissions and increasing CH4 uptake relative to other treatments. To account for global warming potential for such a practice, information on productions associated with CO2 emissions along with N2O and CH4 fluxes are needed.

Nitrogen Rate Study for Greenhouse gas Reduction through Agricultural Carbon Enhancement network in Fort Collins, Colorado Nitrogen fertilization is essential for optimizing crop yields; however, it increases N2O emissions. These emissions were monitored from several irrigated cropping systems receiving N fertilizer rates ranging from 0-246 kg/ha from years 2002-2006. Cropping systems included conventional-till continuous corn and no-till continuous corn at varying N rates. Nitrous oxide fluxes were measured during four growing seasons using static, vented chambers and a gas chromatograph analyzer. This work shows that the use of no-till can potentially reduce N2O emissions from irrigated systems and increase soil carbon storage.

Nitrogen Source Study for Greenhouse gas Reduction through Agricultural Carbon Enhancement network in Fort Collins, Colorado Nitrogen fertilization is essential for optimizing crop yields; however, it increases N2O emissions. The study objective was to compare N2O emissions resulting from application of commercially available enhanced-effi ciency N fertilizers with emissions from conventional dry granular urea in irrigated cropping systems. These emissions were monitored from several irrigated cropping systems receiving N fertilizer rates ranging from 0-246 kg/ha from years 2007-2008 with intermediate rates of 157 kg/ha applied to the barley crop in corn-barley rotation and 56 kg/ha applied to the dry bens in the corn-dry bean rotation. Cropping systems included conventional-till continuous corn (CT-CC), no-till continuous corn (NT-CC), no-till corn–dry bean (NT-CDb), and no-till corn–barley (NT-CB). Nitrous oxide fluxes were measured during ten growing seasons using static, vented chambers and a gas chromatograph analyzer. This work shows that the use of no-till and enhanced-effi ciency N fertilizers can potentially reduce N2O emissions from irrigated systems.