USDAAgricultural Research Service

Lincoln, NE, United States

USDAAgricultural Research Service

Lincoln, NE, United States
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Wallace C.W.,Purdue University | Flanagan D.C.,Purdue University | Flanagan D.C.,USDAAgricultural Research Service | Engel B.A.,Purdue University
Agricultural Water Management | Year: 2017

The Soil and Water Assessment Tool with downscaled weather data generated using the MarkSim weather file generator was used to evaluate the impact of long-term conservation practice implementation on runoff, sediment, atrazine, nitrogen (N) and phosphorus (P) losses in an agricultural watershed located in northeastern Indiana. As part of the Conservation Effects Assessment Project, evaluation of these conservation practices is required to provide insight on how their implementation is benefiting the environment. The results indicate that individual conservation practices were effective in reducing a particular pollutant load, but combined practices were more effective in reducing multiple pollutant loads simultaneously. Of the individual best management practices (BMPs) assessed, no-till was the most effective in reducing multiple pollutant loads (reduced surface runoff by an average of 25%, sediment by 46%, atrazine by 46%, total N by 9%, soluble P by 16%, and total P by 29%). When BMPs were combined, pollutant load reductions were increased significantly (at α = 0.05) for all pollutants, both under baseline and future climate scenarios. The reductions in runoff and pollutant loads for each decade of future climate ranged from 15 to 25% for surface runoff, 32–68% for sediment loss, 37–60% for atrazine loss, 5–13% for soluble N loss, 12–35% for total N loss, 9–41% for soluble P loss, and 33–60% for total P loss. © 2017

Crous P.W.,Fungal Biodiversity Center | Wingfield M.J.,University of Pretoria | Guarro J.,Rovira i Virgili University | Cheewangkoon R.,Chiang Mai University | And 57 more authors.
Persoonia: Molecular Phylogeny and Evolution of Fungi | Year: 2013

Novel species of microfungi described in the present study include the following from South Africa: Camarosporium aloes, Phaeococcomyces aloes and Phoma aloes from Aloe, C. psoraleae, Diaporthe psoraleae and D. psoraleae-pinnatae from Psoralea, Colletotrichum euphorbiae from Euphorbia, Coniothyrium prosopidis and Peyronellaea prosopidis from Prosopis, Diaporthe cassines from Cassine, D. diospyricola from Diospyros, Diaporthe maytenicola from Maytenus, Harknessia proteae from Protea, Neofusicoccum ursorum and N. cryptoaustrale from Eucalyptus, Ochrocladosporium adansoniae from Adansonia, Pilidium pseudoconcavum from Greyia radlkoferi, Stagonospora pseudopaludosa from Phragmites and Toxicocladosporium ficiniae from Ficinia. Several species were also described from Thailand, namely: Chaetopsina pini and C. pinicola from Pinus spp., Myrmecridium thailandicum from reed litter, Passalora pseudotithoniae from Tithonia, Pallidocercospora ventilago from Ventilago, Pyricularia bothriochloae from Bothriochloa and Sphaerulina rhododendricola from Rhododendron. Novelties from Spain include Cladophialophora multiseptata, Knufia tsunedae and Pleuroascus rectipilus from soil and Cyphellophora catalaunica from river sediments. Species from the USA include Bipolaris drechsleri from Microstegium, Calonectria blephiliae from Blephilia, Kellermania macrospora (epitype) and K. pseudoyuccigena from Yucca. Three new species are described from Mexico, namely Neophaeosphaeria agaves and K. agaves from Agave and Phytophthora ipomoeae from Ipomoea. Other African species include Calonectria mossambicensis from Eucalyptus (Mozambique), Harzia cameroonensis from an unknown creeper (Cameroon), Mastigosporella anisophylleae from Anisophyllea (Zambia) and Teratosphaeria terminaliae from Terminalia (Zimbabwe). Species from Europe include Auxarthron longi-sporum from forest soil (Portugal), Discosia pseudoartocreas from Tilia (Austria), Paraconiothyrium polonense and P. lycopodinum from Lycopodium (Poland) and Stachybotrys oleronensis from Iris (France). Two species of Chryso-sporium are described from Antarctica, namely C. magnasporum and C. oceanitesii. Finally, Licea xanthospora is described from Australia, Hypochnicium huinayensis from Chile and Custingophora blanchettei from Uruguay. Novel genera of Ascomycetes include Neomycosphaerella from Pseudopentameris macrantha (South Africa), and Paramycosphaerella from Brachystegia sp. (Zimbabwe). Novel hyphomycete genera include Pseudocatenomycopsis from Rothmannia (Zambia), Neopseudocercospora from Terminalia (Zambia) and Neodeightoniella from Phragmites (South Africa), while Dimorphiopsis from Brachystegia (Zambia) represents a novel coelomycetous genus. Furthermore, Alanphillipsia is introduced as a new genus in the Botryosphaeriaceae with four species, A. aloes, A. aloeigena and A. aloetica from Aloe spp. and A. euphorbiae from Euphorbia sp. (South Africa). A new combination is also proposed for Brachysporium torulosum (Deightoniella black tip of banana) as Corynespora torulosa. Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa. © 2013 Naturalis Biodiversity Center & Centraalbureau voor Schimmelcultures.

Peng X.,Northeast Agricultural University | Maharjan B.,University of Nebraska - Lincoln | Yu C.,Harbin University of Science and Technology | Su A.,Northeast Agricultural University | And 2 more authors.
Agronomy Journal | Year: 2015

In a series of field studies, differing rainfall patterns within the first month after N fertilizer application to a coarse-textured soil significantly affected yields and N-use effciency of irrigated corn (Zea mays L.), and responses varied with N source. A laboratory study was conducted to evaluate effects of N source with precipitation following N application to a coarse-textured soil. Nitrogen sources included urea-ammonium nitrate solution (UAN), UAN with additives of either nitrapyrin (2-chloro-6- [trichloromethyl] pyridine) as a nitrification inhibitor or maleic-itaconic acid copolymer as a urease and nitrification inhibitor, or polymer-coated dry urea (PCU).fiese products were applied to soil in chambers from which ammonia (NH3) volatilization and nitrate (NO3-) leaching were measured over 31 d following fertilization. Precipitation events simulated rainfall frequencies and amounts that occurred in field studies in dry and wet conditions. Ammonia volatilization was lower in wet than dry conditions. Total NH3 loss for the dry precipitation regime ranged from 11 to 18% of applied N fertilizer for all treatments except PCU (<1%). In contrast, all treatments in wet conditions had low NH3 loss (<1% of applied N). However, substantial NO3- leaching occurred with wet conditions, comprising 48 to 66% of applied N for most treatments. Leaching loss was the greatest for UAN, followed by UAN with additives. For either dry or wet environments, losses of N from PCU to either NH3 volatilization or NO3- leaching were negligible. © 2015 by the American Society of Agronomy, 5585 Guilford Road, Madison, WI 53711. All rights reserved.

Sheley R.L.,USDAAgricultural Research Service | James J.J.,USDAAgricultural Research Service | Vasquez E.A.,USDAAgricultural Research Service | Svejcar T.J.,USDAAgricultural Research Service
Invasive Plant Science and Management | Year: 2011

Rangeland health assessment provides qualitative information on ecosystem attributes. Successional management is a conceptual framework that allows managers to link information gathered in rangeland health assessment to ecological processes that need to be repaired to allow vegetation to change in a favorable direction. The objective of this paper is to detail how these two endeavors can be integrated to form a holistic vegetation management framework. The Rangeland Health Assessment procedures described by Pyke et al. (2002) and Pellant et al. (2005) currently are being adopted by land managers across the western United States. Seventeen standard indicators were selected to represent various ecological aspects of ecosystem health. Each of the indicators is rated from extreme to no (slight) departure from the Ecological Site Description and/or the Reference Area(s). Successional management identifies three general drivers of plant community change: site availability, species availability, and species performance, as well as specific ecological processes influencing these drivers. In this paper, we propose and provide examples of a method to link the information collected in rangeland health assessment to the successional management framework. Thus, this method not only allows managers to quantify a point-in-time indication of rangeland health but also allows managers to use this information to decide how various management options might influence vegetation trajectories. We argue that integrating the Rangeland Health Assessment with Successional Management enhances the usefulness of both systems and provides synergistic value to the decision-making process. © 2011 Weed Science Society of America.

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