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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Determining optimum plant population densities for three annual green manure crops under weedy and weed-free conditions

Lawley, Yvonne 22 December 2004
Green manure crops are critical to maintaining soil fertility in organic cropping systems. However, little research has been conducted to address their contribution to weed control. Indianhead black lentil (Lens culinaris Medikus), AC Green Fix chickling vetch (Lathyrus sativus L.), and Trapper field pea (Pisum sativum L.) are legumes developed for use as annual green manure crops in the Northern Great Plains. Currently, no plant population density recommendations exist for these three species when grown as green manure crops under weedy conditions. The objective of this research was to determine the yield-density response of these three species under weedy and weedy-free conditions and to develop plant population density recommendations for use as annual green manure crops. Each species was grown at five plant population densities (10, 24, 64, 160, and 400 plants m-2) with weedy and weed-free treatments. Wild oat (Avena fatua L.) and wild mustard (Brassica kaber (D.C.) L.C. Wheeler) were planted in weedy treatments to supplement the natural weed community. Biomass samples and soil moisture measurements were taken at early bud and full bloom to simulate when these crops would be terminated. Biomass samples from the early bud stage were analysed for total nitrogen content. Green manure biomass production for all species was lower under weedy conditions. Weed biomass in weedy treatments decreased with increasing green manure plant population density for all species. Trapper field pea was the most competitive crop while Indianhead black lentil was the least competitive. Although total plot biomass differed among species and green manure crop density, changes in soil moisture levels were not greatly affected. No significant difference in total nitrogen concentration was found among green manure species. Differences in total nitrogen accumulation occurred because of differences in biomass production. Marginal cost analysis based on green manure seed costs and their nitrogen contribution to the value of subsequent wheat crop yield were used to determine optimum plant population densities. Under weedy conditions field pea and black lentil should be planted at densities of 49-78 and 223-300 plants m-2, respectively. Under weed-free conditions plant population densities for field pea and black lentil could be reduced to 45-60 and 184-223 plants m-2, respectively. No profitable plant population density was determined for chickling vetch when assuming a lower nitrogen contribution under both weedy and weed-free conditions. However, when assuming a higher nitrogen contribution, a profitable plant population density for chickling vetch of 24 plants m-2 was determined under weedy conditions and 32 plants m-2 under weed-free conditions.
22

Determining optimum plant population densities for three annual green manure crops under weedy and weed-free conditions

Lawley, Yvonne 22 December 2004 (has links)
Green manure crops are critical to maintaining soil fertility in organic cropping systems. However, little research has been conducted to address their contribution to weed control. Indianhead black lentil (Lens culinaris Medikus), AC Green Fix chickling vetch (Lathyrus sativus L.), and Trapper field pea (Pisum sativum L.) are legumes developed for use as annual green manure crops in the Northern Great Plains. Currently, no plant population density recommendations exist for these three species when grown as green manure crops under weedy conditions. The objective of this research was to determine the yield-density response of these three species under weedy and weedy-free conditions and to develop plant population density recommendations for use as annual green manure crops. Each species was grown at five plant population densities (10, 24, 64, 160, and 400 plants m-2) with weedy and weed-free treatments. Wild oat (Avena fatua L.) and wild mustard (Brassica kaber (D.C.) L.C. Wheeler) were planted in weedy treatments to supplement the natural weed community. Biomass samples and soil moisture measurements were taken at early bud and full bloom to simulate when these crops would be terminated. Biomass samples from the early bud stage were analysed for total nitrogen content. Green manure biomass production for all species was lower under weedy conditions. Weed biomass in weedy treatments decreased with increasing green manure plant population density for all species. Trapper field pea was the most competitive crop while Indianhead black lentil was the least competitive. Although total plot biomass differed among species and green manure crop density, changes in soil moisture levels were not greatly affected. No significant difference in total nitrogen concentration was found among green manure species. Differences in total nitrogen accumulation occurred because of differences in biomass production. Marginal cost analysis based on green manure seed costs and their nitrogen contribution to the value of subsequent wheat crop yield were used to determine optimum plant population densities. Under weedy conditions field pea and black lentil should be planted at densities of 49-78 and 223-300 plants m-2, respectively. Under weed-free conditions plant population densities for field pea and black lentil could be reduced to 45-60 and 184-223 plants m-2, respectively. No profitable plant population density was determined for chickling vetch when assuming a lower nitrogen contribution under both weedy and weed-free conditions. However, when assuming a higher nitrogen contribution, a profitable plant population density for chickling vetch of 24 plants m-2 was determined under weedy conditions and 32 plants m-2 under weed-free conditions.
23

Pavasarinio vikio būklė ir invazinių krūmų plitimas Palangos botanikos parke / Spring vetch condition and the spread of invasive shrubs in Palanga Botanical Park

Beniušis, Aurelijus 21 June 2010 (has links)
Magistro darbe tiriama į Lietuvos Raudonąją knygą įrašyto pavasarinio vikio būklė, bei invazinių krūmų plitimo ypatumai. Darbo objektas – Palangos botanikos parke augantis pavasarinis vikis (Vicia lathyroides L.) ir aštuoni invaziniai krūmai: guobalapė lanksva (Spiraea chamaedryfolia L.), šermukšnialapė lanksvūnė (Sorbaria sorbifolia (L.) A. Braun), paprastasis ligustras (Ligustrum vulgare L.), baltoji sedula (Cornus alba L.), blizgantysis kaulenis (Cotoneaster lucidus Schltdl.), darželinis jazminas (Philadelphus coronarius L.), baltauogė meškytė (Symphoricarpos albus (L.) S. F. Blake), šluotinis sausakrūmis (Sarothamnus scoparius (L.) W. D. J. Koch). Darbo tikslas – nustatyti pavasarinio vikio būklę ir invazinių krūmų plitimo ypatumus. Darbo metodai. Pavasarinio vikio būklės nustatymui buvo vertinta žydinčių ir derančių vikių kiekis, vegetacijos trukmė, bendrijos įvairovė. Aprašant kiekvienos radavietės medyno sudėtį ir žolinę augaliją, buvo naudojama Braun – Blanquet skalė. Invazinių krūmų plitimo intensyvumo nustatymui buvo vertinta šakninių atžalų plitimo atstumas nuo motininio krūmo, nugenėtų ūglių rudeninis ir pavasarinis žėlimas. Statistinė analizė atlikta naudojant Microsoft Exel skaičiuoklę. Darbo rezultatai. Nustatytos trys pavasarinio vikio augavietės Palangos botanikos parke. Lyginant su senesniaisiais tyrimo duomenimis, pavasarinis vikis aptiktas 3 naujose vietose. Gausiausias pavasarinių vikių padengimas, žiedų ir anksčių skaičius rastas tokiose sąlygose, kur... [toliau žr. visą tekstą] / Master thesis examined the spring vetch condition and the spread of invasive shrub. The object of the study – spring vetch (Vicia lathyroides L.) and eight invasive shrubs: Spiraea chamaedryfolia L., Sorbaria sorbifolia (L.) A. Braun, Ligustrum vulgare L., Cornus alba L., Cotoneaster lucidus Schltdl., Philadelphus coronaries L., Symphoricarpos albus (L.) S. F. Blake, Sarothamnus scoparius (L.) W. D. J. Koch growing in Palanga Botanical Park, The aim of the study – to determine the Vicia lathyroides L. condition and the spread of invasive shrub features. The methods. Spring vetch condition determination was calculated by the density of flowering plants and established their growing time. Description of each finding local stand composition and herbs have been used by Braun – Blanquet scale. Spread of invasive shrubs were evaluated in determining the intensity of root suckers spread of the distance from the parent bush, intensity of shoots spreading after autumn cut. The statistical analysis was performed using Microsoft Excel spreadsheet. The results. There were we found the three habitats of Vicia lathyroides L. in Palanga Botanical Park. To the comparison of the old survey, spring vetch was detected in three new places. Abundant spring vetch cover, flowers and pods appeared in such conditions with adequate lighting, absence of walk trails. Root suckers most intensive spread of Sorbaria sorbifolia (L.) A. Braun, Sarothamnus scoparius (L.) W. D. J. Koch, Symphoricarpos albus (L... [to full text]
24

PASTAGENS DE COASTCROSS-1 CONSORCIADA COM LEGUMINOSAS SOB PASTEJO / COASTCROSS-1 PASTURES MIXED WITH FORAGE LEGUME UNDER GRAZING

Machado, Paulo Roberto 25 February 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this research was to evaluate of three pasture-based systems with bermudagrass (BG) + 200 kg of N/ha; BG + 100 kg of N/ha and common vetch; BG + 100 kg of N/ha + forage peanut. The experiment was carried out from May 2011 to may 2012. Holstein cows receiving 4 kg-daily complementary concentrate feed were used in the evaluation. The actual mean value of forage on offer was 7.2 kg of dry matter/100 kg live weight. Herbage mass, botanical and structural composition, daily dry matter accumulation rate, forage production, disappearance of forage mass and stocking rate were evaluated. Nine grazing cycles were performed during the experimental period (365 days). The mean value of forage production and stocking rate were 21.05; 21.8 and 16.1 t/ha; 5.1; 5.3 and 4.5 animal units/ha/day for respective pasture systems. Superior result were found on BG + 100 kg of N/ha + common vetch and BG + 200 kg of N/ha pasture systems. / Objetivou-se com essa pesquisa avaliar três sistemas forrageiros constituídos por capim bermuda (CB) + 200 kg de N/ha; CB + 100 kg de N/ha e ervilhaca comum e CB + 100 kg de N /ha + amendoim forrageiro. O experimento foi realizado entre maio de 2011 e maio de 2012. Para avaliação foram utilizadas vacas em lactação da raça Holandesa, que receberam individualmente 4 kg/dia de concentrado. A oferta de forragem foi de 7,2 kg de matéria seca /100 kg de peso vivo. Foram avaliadas a massa de forragem, a composição botânica e estrutural, a taxa de acúmulo diário de matéria seca, a produção de forragem e o desaparecimento de massa de forragem e a taxa de lotação. Durante o período experimental (365 dias) foram realizados nove ciclos de pastejo. O valor médio da produção de forragem e a taxa de lotação foram de 21,05; 21,8 e 16,1 t/ha; 5,1; 5,3 e 4,5 unidades animais/ha/dia para os respectivos sistemas forrageiros. Resultados superiores foram encontrados nos sistemas forrageiros constituídos por CB+ 100 kg de N/ha + ervilhaca comum e CB + 200 kg de N/ha.
25

Beitrag von Ackerbohne (Vicia faba L.), Luzerne (Medicago sativa L.) und Saatwicke (Vicia sativa L.) zur Selbstregelung der N-Zufuhr in leguminosenbasierten Fruchtfolgen. / The contribution of faba bean (Vicia faba L.), alfalfa (Medicago sativa L.) and vetch (Vicia sativa L.) to the self-regulation of N input in legume-based cropping systems.

Anthes, Johann 03 February 2005 (has links)
No description available.
26

Hodnocení semenářských vlastností hrachoru lučního a vikve ptačí a jejich uplatnění v trvalých travních porostech. / The evaluation of seed properties of Lathyrus pratensis and Vicia cracca and their employment in permanent grasslands.

KRATOCHVÍLOVÁ, Eva January 2015 (has links)
The theme of the thesis are climbing legumes meadow vetchling (Lathyrus pratensis) and tufted vetch (Vicia cracca). The literature search defines watched kinds of legumes and their occurence in permanent grassland. There is summarized seed growing of legumes because of its problematic production. Legumes are valuable components of grassland especially thanks to fixation of nitrogen and high capacity of proteins. The practical part is focused on observation of floristic compilation of watched locations for three years. Particular locations were compared from the point of view of changes in land management and weather. Pods and seeds of observed kinds were collected and evaluated in single years. Experiments of seed's field germination were done after different period from picking and in case of various treatment.

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