1,721,545 research outputs found
Improving Semi-Arid Agroecosystem Services with Cover Crop Mixes
No full textWinter wheat (Triticum aestivum, L.) production in the semi-arid US Northern High Plains (NHP) is challenged by frequent droughts and water-limited, low fertility soils. Composted cattle manure (compost) and cover crops (CC) are known to provide agroecosystem services such as improved soil health, and in the CC case, increased plant diversity, and competition with weedy species. The main concern of planting CC in winter wheat fallow rotation in regions that are more productive than the NHP, however, is the soil moisture depletion. It is unknown however, whether addition of CC to compost-amended soils in the NHP will improve soil properties and agroecosystem health without compromising already low soil water content. The main objective of this study was to assess the effects of four CC treatments amended with compost (45 Mg ha-1) or inorganic fertilizer (IF) (.09 Mg ha-1 mono-ammonium phosphate, 11-52-0 and 1.2 Mg ha-1ammonium sulfate, 21-0-0) on the presence of weeds, soil and plant total carbon (C), nitrogen (N), and biological dinitrogen (N2) fixation (BNF). Mycorrhizal Mix (MM), Nitrogen Fixer Mix (NF), Soil Building Mix (SB), a monoculture of phacelia (Phacelia tanacetifolia Benth L.) (PH), and a no CC control (no CC) were grown in native soil kept at 7% soil moisture in a greenhouse for a period of nine weeks. When amended with compost, MM was the most beneficial (48 g m-2 BNF and 1.7% soil C increase). SB had the highest germination, aboveground biomass, and decreased weed biomass by 60% . It also demonstrated the second highest amount of BNF (40 g m-2) and soil C increase by 1.5%. On contrary, IF hindered BNF by almost 70% in all legume-containing CC treatments and reduced soil C by 15%
Phyllodesmium Ehrenberg 1831
No full textGenus Phyllodesmium Ehrenberg, 1831 Type species: Phyllodesmium hyalinum Ehrenberg, 1831, by monotypyPublished as part of Moore, Elizabeth & Gosliner, Terrence, 2009, Three new species of Phyllodesmium Ehrenberg (Gastropoda: Nudibranchia: Aeolidoidea), and a revised phylogenetic analysis, pp. 30-48 in Zootaxa 2201 on page 32, DOI: 10.5281/zenodo.18962
The Inclusion of Cover Crop Mixes During Dryland Winter Wheat (Triticum aestivum, L.) - Fallow Rotation Under Semi-Arid Conditions Short Communications Paper Data Set
No full textAbstract:
Winter wheat (Triticum aestivum, L.) (WW) is the primary dryland crop in the semi-arid US Great Plains. Local producers in extremely low precipitation areas are interested in incorporating cover crops (CC) into a WW-fallow rotation. Information on suitable CC mixes and their impact on soil and competition with weeds is limited. A producer designed and planted two CC mixes: (1) legume dominated three species mix (69-17-14) (3 species legume-dominated): forage pea (Pisum sativum, L.), red clover (Trifolium pratense, L.), and daikon radish (Raphanus sativus, L.) and (2) grass dominated four species mix (55-35-7-3) (4 species grass-dominated): oat (Avena sativa, L.), forage pea, daikon radish, and purple top turnip (Brassica rapa, L.). The CC performance was compared to a weedy fallow (WF) (tilled once and allowed to fallow without weed control) and a cultivated fallow (CF) (tilled five times for weed control). Soil and vegetation sampling took place at 11 weeks and 26 weeks after CC planting. Soil was analyzed for water content and inorganic nitrogen (IN) concentrations and CC and weedy species vegetation biomass was analyzed. Results suggest that soil moisture at the time of WW planting was not negatively affected by CC. The 4 species grass-dominated mix resulted in 97% higher soil IN than weedy fallow and outperformed the 3 species legume-dominated mix in competing with weedy species (73% reduction in weedy biomass). In conclusion, for areas of extremely low precipitation, fallow could be replaced by planting the 4 species grass-dominated CC mix tested in this experiment. </p
Transitions, vol. 4, no. 3, March 1991; Controlling Corporate Cutting, 70 years of warnings from conservationists go unheeded. Battles over spotted owls and wilderness just symptoms, National policy on sustaining forests long overdue
No full textOsborn, John--Controlling Corporate Cutting; Timber lobby cuts down proposed regulations--The Spokesman Review, 1991-3-6(Spokane, WA); Future of forests--The Spokesman Review, 1989-9-28(Spokane, WA); Advice for securing state's forest future--The Seattle Times, 1990-8-16(Seattle, WA); Pinchot, In His Fighting Mood, Defies Corporate Interests And Delegates Cheer, Chief forester declares paid lawyers are at every convention. Says great water power trust is being formed to embrace nation--Spokane Daily Chronicle, 1909-8-10(Spokane, WA); Pinchot, Gifford--1919: Gifford Pinchot, Society of American Foresters, The lines are drawn--Journal of American Forestry, 1919-12; Wallace, H. A. and Tugwell, R. G.-- A national plan for American forestry, Letter from the Secretary of Agriculture--The Copeland Report, U.S. Senate, 1933-3-27; Wallace, K. A.--Order For 500 Big Bombers Planned, Wallace analyzes forest problems, urges Northwest to lock barn door 'before timber horse is stolen'-- Seattle Post-Intelligencer, 1940-8-25(Seattle, WA); Severson, Kim and Moore, Elizabeth--The Rush To Cut, Private forests losing ground to timber company saws--The Morning News Tribune, (Tacoma, WA); Gillie, John--Tax Breaks add to timber profits--The Morning News Tribune, 1990-3-27(Tacoma, WA); Moore, Elizabeth--Logging's environmental damage more serious than previously thought--The Morning News Tribune, 1990-5-28(Tacoma, WA); Deer Creek went from fisherman's dream to nightmare--The Morning News Tribune, 1990-5-28(Tacoma, WA); Excessive logging destroys more than views--The Morning News Tribune, 1990-5-28(Tacoma, WA
FIGURE 9 in Three new species of Phyllodesmium Ehrenberg (Gastropoda: Nudibranchia: Aeolidoidea), and a revised phylogenetic analysis
No full textFIGURE 9. Strict consensus of 7 most parsimonious trees. L = 116, CI = 0.302, RI = 0.597. Numbers above branches are decay analysis values, key character synapomorphies are indicated in italics. Key synapomorphies include: 6―ceratal shape flattened, 7―ceratal apex curved, 22―radular denticles congested, 31―prostate short, 32―prey soft corals only, 11―post cardiac cerata not arch-shaped, 5―ceratal texture nodulose, 12―second group of cerata not archshaped, 13―third group of cerata not arch-shaped.Published as part of Moore, Elizabeth & Gosliner, Terrence, 2009, Three new species of Phyllodesmium Ehrenberg (Gastropoda: Nudibranchia: Aeolidoidea), and a revised phylogenetic analysis, pp. 30-48 in Zootaxa 2201 on page 46, DOI: 10.5281/zenodo.18962
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Review of Secret Language, by Portland author Monica Wood.
No full textReview of Secret Language, by Portland author Monica Wood
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