Dissertations / Theses on the topic 'Plants, Effect of nitrogen on'
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1
Zhou, Maoqian 1961. "Nitrogen fixation by alfalfa as affected by salt stress and nitrogen levels." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277231.
Abstract:
The growth and Nitrogen fixation by one low salt tolerant alfalfa (Medicago sativa L.) and two germination salt tolerant selections inoculated with were investigated at two salt levels (0, -0.6 Mpa) and two N rates (1, 5ppm) using a system which automatically recirculates a nutrient solution. The high level of salinity (-0.6 Mpa osmotic potential of culture solution) resulted in substantial reduction in the N fixation percentage and total fixed N. The effect of salinity was more pronounced for later cuttings than for the earlier cutting. The N fixation percentages were substantially decreased by increasing N level and the reduction was enhanced by time. The N treatment levels did not exhibit a significant effect on total fixed N. Cultivars did not differ in either growth or N fixation. However, the interaction of N and salinity significantly decreased the percentage and amount of N fixation.
2
Abraham, Trevor Ian. "Photosynthetic and growth response of C₃ and C₄ subspecies of Alloteropsis semialata to nitrogen-supply." Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1003750.
Abstract:
The greater photosynthetic nitrogen use efficiency (PNUE) of C4 compared with C3 plants may explain the relative success of C4 grasses in nutrient poor environments. This study compared the responses in photosynthetic parameters, leaf nitrogen and biomass allocation between the C3 and C4 subspecies of Alloteropsis semialata supplied soil nitrogen at three levels. Photosynthesis was assessed by means of CO2 response curves and the leaf nitrogen content assayed. Plants were destructively harvested, leaf areas determined and the dry biomass of functional plant components was measured. Results confirmed that the higher PNUE of C4 plants allowed them to accumulate more biomass than C3 plants at the high nitrogen level, despite smaller leaf areas. The greater productivity of C4 plants enabled them to invest more in storage and sexual reproduction than in leaves when compared to the C3 plants. In contrast the C3 plants invested biomass in less efficient and more nitrogen demanding leaves and bigger root systems. PNUE and photosynthetic rates were not significantly affected by nitrogen-limitation in either subspecies and the major response was a decrease in biomass accumulation and an increase in biomass allocation to roots. This altered root to shoot ratio was accompanied by a lowered allocation to sexual reproduction in the C4 subspecies, but an unaltered allocation to leaves, while in the C3 subspecies there was a decrease in leaf allocation. In a further experiment, the C4 subspecies was supplied three levels of nitrogen provided as nitrate, or alternatively as ammonium plus nitrate, and leaves were excised to within 5 cm of the ground at the start of treatment. Prior to flowering, photosynthesis was assessed by means of CO2 response curves and the plants were destructively harvested. Leaf areas and the dry biomass of functional plant components were determined, and at levels of nitrogen supply higher than those found in savanna soils the rate of photosynthesis was increased. Leaf re-growth was reduced by severe nitrogen limitation and co-provision of nitrate and ammonium had no significant effect other than increased tillering. Both subspecies of Alloteropsis semialata are adapted to nutrient poor environments and maintain photosynthetic rates by reducing leaf area. The C4 subspecies is likely to show greater resilience in disturbance-prone environments by exploiting its higher PNUE to allocate greater resources to storage and sexual reproduction, while the C3 subspecies is usually found in environments with closed canopies which favour vegetative growth, and allocate greater resources to leaves and roots.
3
Cepeda, Jose de los Angeles 1955. "Nitrogen fixation by alfalfa as affected by osmotic potentials and measured by nitrogen-15 techniques." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276591.
Abstract:
One low salt tolerant alfalfa (Medicago sativa L.) cultivar and two germination salt tolerant alfalfa selections were compared for growth and N fixation at four salinity levels (0, -0.3, -0.6 and -1.2 Mpa). In the first experiment a Hoagland's solution at 5 ppm-N was used; in the second experiment the solution had a 1 ppm-N concentration and supplemental light was used. No significant differences were found among the cultivars. This provides additional support that germination salt tolerance is not necessarily related to salt tolerance for growth. Nitrogen fixed to the first harvest was 61, 48, 49, and 27% of the total shoot N for plants in the control, -0.3, -0.6, and -1.2 Mpa solutions, respectively. At the second harvest, N fixation percentages were 94, 89, 80, and 57% for the corresponding salinity levels which showed significant reduction in N fixation at -0.3 Mpa. The evaluation of N fixation was by 15N techniques.
4
Papadopoulos, Anastasios K. "Nitrogen and moisture distributions under subirrigated soybeans." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=55520.
Abstract:
A field lysimeter experiment was conducted on a sandy loam soil during the 1990 and 1991 growing seasons. The experiment tested the effects of different watertables on soybean yields, and on moisture distribution and nitrogen concentration of the soil profile. The watertable depths were 40, 60, 80, and 100 centimeters (cm).Yields were measured in terms of number of beans per plant, number of pods per plant, number of beans per pod, and seed protein content at harvest.
Soil samples collected at depths of 30 and 70 cm from the soil surface were analyzed for moisture content and NO$ sb3 sp-$-N and NH$ sb4 sp+$-N concentrations.
The experimental results showed that controlled watertable management increased the yield and decreased soil NO$ sb3 sp-$-N levels. The best results from the watertables tested were found to be at 60 and 80 cm. This is suggested as the range of watertable depths that should be maintained for optimum soybean production.
5
Campos, Felipe Girotto [UNESP]. "Annona emarginata (Schltdl.) H. Rainer 'araticum-de-terra-fria' cultivada com variação de nitrogênio: produtividade e perfil químico dos voláteis foliares." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/127598.
Abstract:
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000846843.pdf: 2165230 bytes, checksum: ab9198f9a55c917b25a89ffa7ed83969 (MD5)A espécie Annona emarginata (Schltdl.) H. Rainer 'araticum-de-terra-fria' possui grande potencial como porta-enxerto para o híbrido atemoia (Annona cherimola Mill. x Annona squamosa L.), conferindo resistência contra a broca do tronco, característica dependente de seus metabolismos primário e secundário. O nitrogênio é um elemento essencial na síntese de aminoácidos, proteínas, entre elas, a Ribulose 1,5 - difosfato (Rubisco), ácidos nucleicos, clorofila e metabolitos secundários, entre outros importantes constituintes celulares. Além dessas funções, deve ser considerada sua relação de competição com o CO2 e síntese de terpenos, por agentes redutores e esqueletos carbônicos. Deste modo, o presente estudo objetivou avaliar a influência da variação do nível de nitrogênio na solução nutritiva, na produtividade e composição de voláteis foliares durante o desenvolvimento inicial de mudas de A. emarginata. Para o estudo da produtividade foram avaliadas as trocas gasosas, a atividade das enzimas nitrato redutase, catalase, peroxidade, superóxido dismutase, a peroxidação lipídica, a produção de massa seca de raiz, caule e folhas, área foliar, diâmetro de caule, razão de área foliar, taxa de assimilação líquida, taxa de crescimento relativo, peso específico de folhas, distribuição de massa seca para os diferentes órgãos do vegetal, razão de massa foliar e a composição de voláteis extraídos das folhas. As plantas cultivadas com níveis intermediários de nitrogênio apresentaram maior eficiência de carboxilação e taxa de assimilação de CO2. A atividade da nitrato redutase variou com os diferentes níveis de nitrogênio a que as plantas foram submetidas. No maior nível de nitrogênio utilizado, as plantas com menor produtividade, demostraram competição entre a fixação de nitrogênio, assimilação de CO2 e síntese de terpenos. A atividade das ...
The species Annona emarginata (Schltdl.) H. Rainer 'araticum-de-terra-fria' has great potential as a rootstock for this hybrid atemoya (Annona cherimola Mill. X Annona squamosa L.) conferring resistance to stem borer. This resistance may be related to primary and secondary metabolisms. Nitrogen is an essential element on the synthesis of amino acids, proteins such as Ribulose 1,5 - diphosphate (Rubisco), nucleic acids, chlorophyll, secondary metabolites, and other important cellular constituents. Besides these functions, it should be considered competing relation to CO2 by reducing agents and carbon skeleton. Therefore, the present study aimed to evaluate the influence of variation in the level of nitrogen in the nutrient solution on yield and composition of the leaf volatile during the early development of seedlings of A. emarginata. To study the productivity gas exchange were evaluated, the activities of nitrate reductase, catalase, peroxidase, superoxide dismutase, lipid peroxidation, the dry weight of roots, stems and leaves, leaf area, stem diameter ratio leaf area, net assimilation rate, relative growth rate, leaf specific weight, dry weight distribution to different organs of the plant, leaf mass ratio and the composition of volatiles extracted from the leaves. Plants grown with intermediate levels of nitrogen had higher carboxylation efficiency and CO2 assimilation rate. Nitrate reductase activity varied with different levels of nitrogen that the plants were submitted. In the largest amount of nitrogen, plants with lower productivity, demonstrated competition between nitrogen fixation, CO2 assimilation and synthesis of terpenes. The activity of antioxidant enzymes prevented lipid peroxidation in plants subjected to different levels of nitrogen. Gas exchange, the activity of nitrate reductase and antioxidant enzymes in plants grown with 78.75 and 118.12 mg L-1 N contributed their best ...
6
Campos, Felipe Girotto 1989. "Annona emarginata (Schltdl.) H. Rainer 'araticum-de-terra-fria' cultivada com variação de nitrogênio: produtividade e perfil químico dos voláteis foliares /." Botucatu, 2014. http://hdl.handle.net/11449/127598.
Abstract:
Orientador: Carmen Sílvia Fernandes BoaroBanca: Gisela Ferreira
Banca: Ivan de La Cruz Chacón
Resumo: A espécie Annona emarginata (Schltdl.) H. Rainer 'araticum-de-terra-fria' possui grande potencial como porta-enxerto para o híbrido atemoia (Annona cherimola Mill. x Annona squamosa L.), conferindo resistência contra a broca do tronco, característica dependente de seus metabolismos primário e secundário. O nitrogênio é um elemento essencial na síntese de aminoácidos, proteínas, entre elas, a Ribulose 1,5 - difosfato (Rubisco), ácidos nucleicos, clorofila e metabolitos secundários, entre outros importantes constituintes celulares. Além dessas funções, deve ser considerada sua relação de competição com o CO2 e síntese de terpenos, por agentes redutores e esqueletos carbônicos. Deste modo, o presente estudo objetivou avaliar a influência da variação do nível de nitrogênio na solução nutritiva, na produtividade e composição de voláteis foliares durante o desenvolvimento inicial de mudas de A. emarginata. Para o estudo da produtividade foram avaliadas as trocas gasosas, a atividade das enzimas nitrato redutase, catalase, peroxidade, superóxido dismutase, a peroxidação lipídica, a produção de massa seca de raiz, caule e folhas, área foliar, diâmetro de caule, razão de área foliar, taxa de assimilação líquida, taxa de crescimento relativo, peso específico de folhas, distribuição de massa seca para os diferentes órgãos do vegetal, razão de massa foliar e a composição de voláteis extraídos das folhas. As plantas cultivadas com níveis intermediários de nitrogênio apresentaram maior eficiência de carboxilação e taxa de assimilação de CO2. A atividade da nitrato redutase variou com os diferentes níveis de nitrogênio a que as plantas foram submetidas. No maior nível de nitrogênio utilizado, as plantas com menor produtividade, demostraram competição entre a fixação de nitrogênio, assimilação de CO2 e síntese de terpenos. A atividade das ...
Abstract: The species Annona emarginata (Schltdl.) H. Rainer 'araticum-de-terra-fria' has great potential as a rootstock for this hybrid atemoya (Annona cherimola Mill. X Annona squamosa L.) conferring resistance to stem borer. This resistance may be related to primary and secondary metabolisms. Nitrogen is an essential element on the synthesis of amino acids, proteins such as Ribulose 1,5 - diphosphate (Rubisco), nucleic acids, chlorophyll, secondary metabolites, and other important cellular constituents. Besides these functions, it should be considered competing relation to CO2 by reducing agents and carbon skeleton. Therefore, the present study aimed to evaluate the influence of variation in the level of nitrogen in the nutrient solution on yield and composition of the leaf volatile during the early development of seedlings of A. emarginata. To study the productivity gas exchange were evaluated, the activities of nitrate reductase, catalase, peroxidase, superoxide dismutase, lipid peroxidation, the dry weight of roots, stems and leaves, leaf area, stem diameter ratio leaf area, net assimilation rate, relative growth rate, leaf specific weight, dry weight distribution to different organs of the plant, leaf mass ratio and the composition of volatiles extracted from the leaves. Plants grown with intermediate levels of nitrogen had higher carboxylation efficiency and CO2 assimilation rate. Nitrate reductase activity varied with different levels of nitrogen that the plants were submitted. In the largest amount of nitrogen, plants with lower productivity, demonstrated competition between nitrogen fixation, CO2 assimilation and synthesis of terpenes. The activity of antioxidant enzymes prevented lipid peroxidation in plants subjected to different levels of nitrogen. Gas exchange, the activity of nitrate reductase and antioxidant enzymes in plants grown with 78.75 and 118.12 mg L-1 N contributed their best ...
Mestre
7
Anderson, Annette. "The effects of acetolactate synthase (ALS) inhibiting herbicides on the growth, yield, nodulation and nitrogen fixation of selected legumes." Title page, contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09pha545.pdf.
Abstract:
Bibliography: leaves 251-268. The main aim of this thesis is to determine the effects of sulfonylurea residues and in-crop usage of selected ALS-inhibiting herbicides on the growth, yield, nodulation and nitrogen fixation of legumes under alkaline conditions. Reviews literature concerning ALS-inhibiting herbicides, nitrogen fixation and the effects of herbicides on legumes, rhizobia, nodulation and nitrogen fixation; Glasshouse trial investigating the effects of flumetsulam on biomass and nodulation of chickpea; Field trail investigating the effects of sulfonylurea residues and 'in crop' usage of flumetsulam on medic shoot biomass and seed yield and the effects of chlorsulfuron residues and 'in crop' usage of flumetsulam and imazethapyr on chickpea shoot biomass, grain yield and nitrogen fixation; develops methodologies for experiments investigating the effects of ALS-inhibiting herbicides on nodulation of chickpea.
8
Al-Rawahy, Salim Ali. "Nitrogen uptake, growth rate and yield of tomatoes under saline conditions." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184894.
Abstract:
Results of two studies are reported here, a greenhouse study and a field study. In the greenhouse study, dry matter yield and nitrogen (total and 15N) uptake of leaves, stems and roots of tomato plants (Lycopersicum esculentum Mill., cv. Columbia) subjected to saline stress by NaCl were studied. The integrated effects of responses of these tissues to salinity on the whole plant basis and levels of Na⁺, Cl⁻ and K⁺ accumulation in these tissues were also studied. The treatments consisted of low (control, 0.3 bar), medium (4.3 bars), and high (8.3 bars) salinity. The saline treatments were prepared by adding NaCl to nutrient solution in sand culture. The plants were 80 days old at the start of the treatments and each was in a pot containing 1.8 kg of quartz sand. The ¹⁵N was provided to plants by adding K¹⁵NO₃ to the pots and the 15N treatment continued with the saline treatments up to 30 days. The plants were harvested at each 5-day interval during the treatment period. Dry matter production and nitrogen (total and ¹⁵N) uptake were significantly lower for saline treatments as compared with the control. Differences in dry matter production and ¹⁵N uptake on whole plant basis appeared in the latter part of the treatment period between the two saline treatments. For most of the parameters studied, the leaves were found to be affected most by salinity, the roots were intermediate in their response and the stems were the least affected by salinity. The effect of salinity on the studied parameters were attributed to osmotic effects and specific ion effects of Na⁺ and/or Cl⁻. A field study with two cultivars--Columbia and Pearson was conducted at the Safford Agricultural Center. Three N treatments were used: 0 kg N/ha, 84 kg N/ha and 168 kg N/ha and two treatments consisting of two water sources--river water with an EC of 1.15 dS/m and more saline well water of EC of 2.21 dS/m. Columbia had a significantly higher yield of tomatoes than Pearson for both water types. The N treatments had no effect on tomato yield apparently due to high residual N remaining in the field from the previous crop. Commercially acceptable fresh market yields were approached with both varieties and waters in spite of moderate salinity and sodium under heavy textural soil conditions, high temperatures and the presence of certain diseases in the area.
9
Ayub, Najma. "The effect of VAM inoculation on interplant ¹⁵N transfer." Thesis, University of Aberdeen, 1991. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU546184.
Abstract:
This thesis reports a study carried out to investigate the involvement of VA mycorrhizas in interplant 15N transfer in a model pasture system and in a model agroforestry system. Two pot experiments were designed to investigate the effect of VAM inoculation on 15N transfer from clover to rye grass in sterile (in the first experiment the sterilisation was by autoclaving and in the second, by gamma-irradiation) and fresh soil. A third pot experiment was designed to investigate the effect of VAM inoculation on 15N transfer from grass and clover to wild cherry seedlings in fresh soil. For these pot experiments donor plant seedlings were labelled with 15N by growing in Hoaglands solution containing K 15NO3 (5 atom % 15N). To study 15 N transfer and its possible mechanisms, plants and soil samples were analysed for 15N, total N (14N + 15N) and P concentrations. Rates of soil nitrogen mineralisation and nitrification, as well as 15N enrichment of available N were also determined to investigate N transfer through soil. There was transfer of 15N from donor to receiver in the simulated pasture system as well as in simulated agroforestry system. The transfer of 15N was increased by VAM inoculation. The transfer of 15N was small in relation to plant nutrition and was not associated with an increase in total N in the receiver plants although P concentrations were generally increased. There was no increase in the soil N fluxes of mineralisation and nitrification associated with enhanced 15N transfer from donor to receiver in the VAM inoculated system. In addition, there was often no increase in the 15N concentration in the soil available N pool of VAM inoculated systems. There was no evidence, therefore, of increased transfer of 15N through the soil in VAM inoculated systems with enhanced 15N interplant transfer, suggesting the likely involvement of VAM fungal hyphae. There was no marked effect on plant growth due to VAM inoculation. The growth of cherry, however, was reduced when grown with grass and this may have been due to N competition between the root systems. The growth of cherry seedlings was reduced to a lesser extent when grown with clover compared to when grown with grass. The findings of this study suggest that VA mycorrhizal hyphae play a part in interplant transfer of nitrogen. Although the study did not demonstrate high rates of 15N transfer in VAM inoculated system, circumstances are discussed where VAM interplant transfer of nutrients may become significant at the single plant, community and ecosystem level. The benefits to man of VAM mediated N transfer may be best realised in land use systems such as pastures having legumes and non-legumes, in mixed cropping of legumes and non-legumes and in an agroforestry system with a legume component, particularly when the soil is deficient in nutrients such as nitrogen and phosphorus.
10
Antunes, Cristiane Leite [UNESP]. "Fertirrigação nitrogenada por gotejamento e época de aplicação foliar de ácido giberélico 'GA IND.3' em alface americana (Lactuca sativa L.)." Universidade Estadual Paulista (UNESP), 2001. http://hdl.handle.net/11449/93828.
Abstract:
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antunes_cl_me_botfca.pdf: 3224894 bytes, checksum: ebe83c98cf65dede1137b2f26b044f56 (MD5)Com o objetivo de avaliar os efeitos do nitrogênio aplicado ao solo, via fertirrigação por gotejamento, e a aplicação foliar do ácido giberélico (GA3), na nutrição e nos componentes de produção da alface tipo americana, cv. 'Lucy Brown', em cultivo protegido, foi efetuado o presente trabalho. O delineamento experimental utilizado foi o de blocos casualizados em esquema de parcelas subdivididas: quatro doses de nitrogênio (60, 120, 180 e 240 kg de N.ha-1), na parcela, e quatro épocas de aplicação de GA3 (0, 40, 55 e 70 DAS - dias após a semeadura), na subparcela. O ácido giberélico foi aplicado com pulverizador costal de CO2, numa concentração única de 20 mg do ingrediente ativo.L-1 de solução, nas subparcelas nas épocas determinadas. Foram realizadas quatro coletas para avaliação dos parâmetros vegetativos e análise de nutrientes, com intervalos de 15 dias, iniciando-se aos 51 DAS (23 DAT- dias após o transplantio) até 96 DAS (64 DAT). Os trabalhos foram conduzidos na área experimental da Fazenda São Manuel, no município de São Manuel - SP. Não foi observada interação entre a aplicação de nitrogênio e o ácido giberélico nos parâmetros vegetativos avaliados, bem como no teor e acúmulo dos macronutrientes. Contudo, houve influência dos fatores de variação de forma independente nos parâmetros ao longo do ciclo. O nitrogênio é extremamente importante no crescimento e acúmulo de matéria fresca na planta de alface tipo americana e pode ser usado em doses maiores quando há disponibilidade de cálcio e potássio. Tendo sido os melhores resultados alcançados com a dose de 180 kg de N. ha-1. O uso do ácido giberélico (GA3), aos 70 DAS (dias após a semeadura) proporcionou os melhores resultados nos parâmetros relativos ao crescimento. Enquanto a época de aplicação aos 40 DAS, promoveu o desenvolvimento intenso do caule, levando a efeitos... .
With the goal of estimating the nitrogen effects applied on the soil, through fertigation by dripping, and the foliar application of gibberellic acid (GA3), in the nourishment and in the components of Crisphead Lettuce production, cv. 'Lucy Brown', in protected cultivation, this paper was done. The used experimental drawing was made of casual blocks in subdivided portions: four doses de nitrogen (60, 120 180 and 240 kg de N.ha-1), in the portion, and four application times of GA3 (0, 40, 55 e 70 DAS - days after sowing) in the subportion. The gibberellic acid was applied with a costal pulverize machine of CO2, in a unique dose of 20 mg.L-1 of the active ingredient, in the subportions in the specific times. Four collects were done for the evaluation of the vegetative parameters and nutrient analysis, with a 15-days recess, beninning on 51 DAS (23DAT) to 96 DAS (64 DAT). The works were managed in the experimental area of São Manuel Farm, in São Manuel County - SP. It wasn't observed interaction between nitrogen application and the gibberellic acid in the evaluated vegetative characteristics, as well as in the tenor and accumulation of macro-nutrients. However, there was na influence of changing factors in na independent way in the parameters along the cycle. The nitrogen is extremely important in the growth and accumulation of fresh material in the Crisphead lettuce vegetable and it can be used in bigger doses when there is availability of calcium and potassium. These have been the best results got with the dose 180 kg of N.ha-1. The usage of gibberellic acid (GA3), on 70 DAS (days after the sowing) provided the best results in the characteristics related to the growth. As long as the application time on 40 DAS, provided the intense satlk growth, conducing to the depreciatory effects, as the plants arranged in layers, a bigger number of external leaves, and a samller accumulation of fresh... (Complete abstract, click electronic address below).
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Darwiche, Amal Omar 1964. "Effect of cytokinin, gibberellin, and nitrogen applications on the growth of eldarica pine seedlings." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/276979.
Abstract:
A greenhouse experiment was conducted over a ninety day period to test the effect of different nitrogen fertilizer regimes and several application rates of compounds with gibberellin and cytokinin activity (GA4/7 and BA, respectively) on the growth and development of Pinus brutia var. eldarica. Nitrogen produced no significant effects and this was attributed to its abundance in the potting medium, to begin with. All levels of growth regulators used showed a highly significant effect on vegetative development. A reduction in root collar diameter, shoot elongation, needle nitrogen content and oven-dry weight, was observed, especially when the medium and high hormonal rates were used. Phytotoxicity increased with the increase in concentration of both chemicals. Ba induced a proliferation of adventitious buds along the stem of saplings, but this was accompanied with rapid new top growth and branching at the top only when BA was applied in conjunction with GA4/7.
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Schievenin, Dimitrio Fernandes 1989. "Regeneração natural sob talhões puros de espécies nativas com diferentes atributos funcionais /." Botucatu, 2016. http://hdl.handle.net/11449/138942.
Abstract:
Orientador: Vera Lex EngelBanca: Antonio Carlos Galvão de Melo
Banca: Giselda Durigan
Resumo: A facilitação e a inibição da regeneração natural por plantações florestais já foram demonstradas em regiões tropicais. Os mecanismos de facilitação e a influência das espécies plantadas na trajetória do sistema em regeneração, no entanto, ainda não estão completamente elucidados. Objetivou-se neste estudo investigar se, a partir das características funcionais das espécies do dossel, há diferenças nos processos de colonização do sub-bosque. O estudo foi realizado na região central do Estado de São Paulo, no município de Botucatu. Foram comparadas quatro espécies arbóreas plantadas há cerca de 80 anos como sombreadoras de cafezais: Anadenanthera colubrina (Vell.) Brenan var. cebil (Griseb.) Altschul (fixadora de nitrogênio); Araucaria angustifolia (Bertol.) Kuntze. (não fixadora); Piptadenia gonoacantha (Mart.) J.F. Macbr. (fixadora); Hymenaea courbaril L. (não fixadora). Todos os indivíduos arbustivo-arbóreos maiores que 0,5 m de altura foram medidos e identificados, em 25 parcelas de 10 x 10 m em cada talhão. O Índice de Área Foliar (IAF) de cada parcela foi determinado ao final da estação chuvosa (março) e ao final da estação seca (Setembro), de modo a detectar diferenças no padrão de sombreamento das áreas. No início da estação seca, foi coletada a serapilheira depositada no piso florestal com auxílio de um gabarito, de modo a verificar sua massa seca e sua influência na densidade e riqueza da regeneração natural. Levantamentos microclimáticos foram feitos durante um semes... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Facilitation and inhibition of natural regeneration through forest plantations have been demonstrated in tropical regions. However, the facilitation mechanisms and its influence on succession trajectory are no so clear. We aimed at investigating whether there were differences amongst colonization processes of the understory, based on functional characteristics of the canopy species. The study site was located in central São Paulo State, Southeastern Brazil. We compared four abandoned forest stands that were used as shaded coffee plantations around 80 years ago: 1) Anadenanthera colubrina (Vell.) Brenan var. cebil (Griseb.) Altschul (nitrogen-fixing); 2) Araucaria angustifolia (Bertol.) Kuntze. (non-fixing); 3) Piptadenia gonoacantha (Mart.) Macbr. (nitrogen-fixing); and 4) Hymenaea courbaril L. (non-fixing). All understory individuals above 0.5 m tall were measured and identified at the species level, in 25 plots of 10 x 10 m in each stand. Leaf Area Index (LAI) was determined inside each plot at the end of the rainy season (March) and at the end of the dry season (September), in order to detect differences in shading pattern among the areas. Ground litterfall was collected in each plot using a 0.25 m² template, in order to assess the dry weight and its influence on natural regeneration. Microclimate data were also collected during six months, to check for differences among stands. The results show high rates of self-recruiting on A. colubrina var. cebil and P. gonoacantha st... (Complete abstract click electronic access below)
Mestre
13
Kana'n, Ghassan Jadou Mousa. "Molecular studies of genes required for nitrate assimilation in fungi and higher plants." Thesis, University of St Andrews, 1997. http://hdl.handle.net/10023/14338.
Abstract:
Nitrate assimilation is an extremely important part of the nitrogen cycle and is carried out by most bacteria, fungi and plants. A relatively short catalytic pathway reduces nitrate to nitrite (via nitrate reductase activity) and then nitrite to ammonium ions (via nitrite reductase activity) which are converted into organic nitrogen by further metabolic pathways. A considerable amount of information is known about the biochemistry, genetics and recently, the molecular biology of these two enzymes. Much less is known about the transport of nitrate and nitrite into cells as well as the synthesis of the molybdenum cofactor needed for nitrate reductase catalytic activity. Research work reported in this thesis focus on these latter two processes in the eukaryotic model organisms. Aspergillus nidulans and to a lesser extent Arahidopsis thaliana. Genetic characterisation of 47 crn mutants shows that there are three additional genes (i.e. to the original identified crnA gene) likely to be involved in nitrate transport. These additional genes are unlinked to each other or to crnA. Although it was shown that the nitrate uptake into cells of these mutants are lower than the wild-type, their exact involvement in nitrate transport requires their molecular cloning. Certain mutations generated in the crnA gene have been investigated at the molecular level and the disruptions in the protein determined. During the genetic studies of crn mutants, two other genes were postulated. The first is chlA, mutation which results in resistance to chlorate (unlike the wild-type) and caesium (like the wild-type). The second is cesA mutation. These latter mutants lead to caesium sensitivity but are chlorate sensitive like the wild-type. These two genes are unlinked to crnA, crnB, crnC and crnD genes. The bases of these phenotypes is unclear and need further investigation. A study of nitrite uptake was undertaken which showed that wild-type A. nidulans has an active nitrite transport system. The activity of this system is repressed by ammonium and is nitrate induced. Mutants which are hypersensitive to chlorate taken up much higher levels of nitrite as compared to wild-type. 2,082 cnx mutants were isolated and 456 of these were classified as cnxA, cnxB, cnxC, cnxE, cnxF, cnxG and cnxH mutants on the basis of phenotypic complementation. No novel cnx genes were found. More importantly a number of temperature -conditional mutants were isolated, 10 mutants were found to be temperature-sensitives and 10 cryo-sensitives. Of the isolated temperature-sensitives 1 located in cnxA, 1 in cnxB, 2 in cnxC, 1 cnxE, 2 in cnxF and 3 in cnxH. Of the crysosensitives 4 in cnxB, 3 in cnxC and 3 in cnxF. These mutants will be particularly useful to relate structure and function when data is forthcoming regarding their protein sequence. Two temperature-sensitive mutants, cnxH255 and cnxH261 showed reduced nitrate reductase thermostability which indicates that the cnxH product could be associated with the NR protein. One of the Aspergillus nidulans genes required for the synthesis of the molybdenum cofactor was isolated using molecular self-cloning transformation approaches. This gene, cnxH, was sequenced at the nucleotide level as well as three mutant alleles (one temperature sensitive and two temperature non-conditional). The results show that the cnxH product is the homologue of Escherichia, coli moaE whose role is in the synthesis of the molybdenum cofactor specifically to convert the large subunit to active converting factor. Sequence analysis of the two non-conditional mutants indicates that such mutants generated stop codons which provides little or no information about the structure / function relationships. The mutation in the temperature-sensitive mutant lead to a glycine insertion at position +443 and it is postulated that this additional amino acid caused the heat liability of the NR enzyme. Studies of cnxH expression show that the cnxH is in very low abundance and not regulated at the transcriptional level at least since similar transcript levels were seen in both nitrate and ammonium grown cells- conditions, which making difference for nitrate reductase activity. Finally attempts at isolating Arabidopsis thaliana cnx genes failed.
14
Foroutan-Pour, Kayhan. "Aspects of barley post-anthesis nitrogen physiology." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22730.
Abstract:
The protein concentration of cereal grains is low and the production of cereal crops with increased grain protein concentrations is desirable. This work investigates the physiological aspects of protein accumulation potential in barley grain. A recently developed perfusion system was used in four experiments conducted in 1993 and 1994. In the field experiment, plants were allowed to take up urea at 15 or 30 mM N, or ethephon at 15 $ mu$ M. Abscisic acid and 2,4-D decreased total seed weight spike$ sp{-1}$. Gibberellic acid and 2,4-D increased seed protein concentration and content, while ABA decreased both of these. Kinetin and abscisic acid treatments resulted in the highest and lowest levels, respectively for flag leaf photosynthesis, stomatal conductance, transpiration and intercellular CO$ sb2$ concentration. Both protein content spike$ sp{-1}$ and seed protein concentration were elevated in plants fertilized with 10.7 mM N via the soil and plants perfused with 30 mM N via the peduncle. Plants receiving treatments of 10.7 mM N from the soil and mixture of 30 mM N and GA$ sb3$ or 2,4-D through the peduncle had increased protein content seed$ sp{-1}$, and the highest seed weight spike$ sp{-1}$, respectively. Peduncle perfusion with 30 mM N increased spike protein concentration and content and grain protein concentration without affecting seed weight spike$ sp{-1}$. Grain protein concentration was increased by peduncle perfusion with ethephon. The perfusion technique worked well under field conditions. (Abstract shortened by UMI.)
15
Tolman, Deborah A. "The influence of plant age and nitrogen rate on nutrient removal from the container medium solution." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/91106.
Abstract:
Adequate nutrient supply to the medium solution of container-grown crops is a major concern to container plant production practices. The extent to which nutrients are removed by the plant from the medium solution of a container, however, has never been demonstrated. Mariogold, Tagetes erecta ‘Inca’ seeds were glasshouse-grown in 500 cc plastic pots containing 1 peat: 1 perlite (v/v) medium and fertilized daily with 200 ppm N as ammonium nitrate. Thirty, 35, 40, 45 and 50 day old plants were subjected to either 20, SO, 80 or 110 ppm N. Medium solutions were tested at hour 0 and 6, and analyzed for N, P and K. Nitrogen removal from the medium solution was greatest by 45 and 50 day old plants at the higher N treatments. Phosphorous and K removal also increased with plant age. Medium solutions were tested and analyzed again, 10 days later. Nitrogen removal, 10 days later, was greatest for 50, 55 and 60 day old plants at the higher N treatments. Phosphorus removal was greatest by 55 and 60 day old plants whereas K removal increased up to day 60 through all age groups. Total N, P and K in the tissue reflected nutrient removal rates; however, no differences in dry weight due to N treatment were detected. In a second experiment, to determine the age at which dry weight is affected by N treatment, plants of one age group were treated with either 10, 30, 50 or 70 ppm N. Shoot dry weights did not differ until day 27 when plants grown at 10 ppm were smaller than for other treatments. As plants aged, higher levels of N were required to prevent growth reduction. These results indicate that age influences the N removal rate from the medium solution of container-grown plants. This relationship affects the amount of N applied to the medium solution to satisfy plant N requirement.M.S.
16
Nelson, J. M., D. A. Dierig, and G. L. Hart. "Effect of Planting Date, Nitrogen Fertility and Postemergence Herbicides on Lesquerella Production." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201436.
Abstract:
Lesquerella is a potential crop plant that produces seeds containing hydroxy fatty acids similar to those in castor beans. An important step in the commercialization of this plant for Arizona farms is the development of an efficient agronomic production system. Research on cultural practices for lesquerella was conducted during the 1991-92 and 1992-93 seasons. Results of planting date experiments indicate that early fall planting dates are superior to late fall or winter dates in terms of dry matter production and seed yield. Lesquerella produced a marked response to nitrogen (N) in tests comparing different N rates. In a postemergence weed control test, several herbicides gave good control of small winter weeds.
17
Yu, Shaobing. "Winter wheat nitrogen management in south coastal British Columbia." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/29888.
Abstract:
Nitrogen is essential to obtain high yields of winter wheat in south coastal British Columbia, which includes Vancouver Island and the lower Fraser Valley. An accurate recommendation for N application is required to keep input costs down for most economical returns and to limit environmental problems related to leaching of excess N. The questions are how much, when and which form of N should be applied to winter wheat. The general objective of this study is to improve our understanding of winter wheat growth and N uptake. This study monitors the soil N supply and characterizes the plant development, dry matter accumulation, and N uptake of winter wheat in South Coastal B.C.. Also, it compares the effectiveness of conventional and intensive crop N management and urea and ammonium nitrate sources of fertilizer N under intensive crop management.
A series of field experiments was conducted in 1986-87 and 1987-88 with winter wheat to evaluate conventional and intensive N management in the area. Additionally, a N source
study was carried out in the latter year to compare ammonium nitrate and urea.
Soil N supply for winter wheat ranged from 52 to 151 kg N/ha through the two years of field experiments at five sites. Available N in the 0-50 cm soil depth varied from 10 to 100 kg N/ha through the growing season in the different treatments. An accurate estimate of N behavior involves N accumulation in the crop. During the early spring until harvest, the crop dry matter yield and N uptake patterns were plotted. The grain yields ranged from 4 to 9 t/ha for the conventional management (75 kg N/ha), and from 4 to 11 t/ha for the intensive crop management (I.CM. 225 kg N/ha) system. Between the conventional and I.CM., there was no significant difference in grain yield but there was in quality, specifically grain protein. Grain protein ranged from 8.2 to 9.7% for the conventional and from 10 to 13.7% for the I.CM. treatment. Also, there was no difference in grain yield or quality between ammonium nitrate and urea fertilized plots at final harvest. However, in the early stage at GS31, crop took up more N from ammonium nitrate (97 kg N/ha) than from urea (75 kg N/ha) and soil mineral N levels with urea were higher than with ammonium nitrate.Land and Food Systems, Faculty of
Graduate
18
McGriff, Terry Lee 1952. "Nitrogen fertility studies on the buffalo gourd (Cucurbita foetidissima) grown as an annual root crop." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277132.
Abstract:
A fertility study was initiated at the Maricopa Agricultural Center in 1984 to determine how nitrogen levels influenced growth, development, and root yield of the potential domesticate, buffalo gourd (Cucurbita foetidissima). Nitrogen had little or no effect upon the following parameters: seedling emergence, early growth rates, specific leaf weights, individual root weights, consumptive water use, canopy organic N content, and nitrate and ash content of all organs. Percent root dry matter and total carbohydrate content dropped linearly as N was increased, whereas canopy dry matter production, root organic N content, petiole nitrate concentration, and leaf area indices exhibited a positive linear response. A quadratic response curve best fitted fresh weight root yields, total root dry matter and carbohydrate production, water use efficiencies, and final plant populations. A modest amount of N (84 kg ha⁻¹) provided maximum yield response in this feral species grown at 405,000 plants ha⁻¹.
19
Ward, Michael Patrick. "Biochemistry, genetics and molecular biology of nitrite reduction in barley." Thesis, University of St Andrews, 1997. http://hdl.handle.net/10023/14341.
Abstract:
Nitrite reduction is the third step of the nitrate assimilation pathway in higher plants and is catalysed by nitrite reductase. The whole-plant barley mutants STA1010, STA2760 and STA4169 accumulate nitrite in the leaf after treatment with nitrate and, like the nir1 mutant STA3999 (Duncanson et al, 1993), lack detectable nitrite reductase cross-reacting material in the leaf and root. STA1010, STA2760 and STA4169 carry a recessive mutation in a single nuclear gene, identified as the Nir1 locus. RFLP analysis of the nir1 mutant STA3999 has allowed the Nir1 locus to be mapped to within 0.3cM of the nitrite reductase apoprotein gene, Nii. Studies to confirm the identity of the Nir1 locus as Nii, by establishing the full-length Nii cDNA sequences from STA3999 and from its wild-type cv Tweed for comparative purposes, were unsuccessful as attempts to isolate a Nii cDNA clone from a barley cv Tweed cDNA library yielded only partial-length Nii clones. These nirl mutants display greatly reduced nitrite reductase activity and increased NADH-nitrate reductase activity in the leaf, as compared to wild-type plants, suggesting a regulatory perturbation in the expression of the Nar1 gene. Northern analysis shows that the nir1 mutants possess nitrite reductase apoprotein (nii) transcript of wild-type size (2.3kb) and at approximately wild-type levels. Since nir1 mutants possess a phenotype that might be anticipated for a Nii mutant, it is likely that the nir1 mutation is present in the nitrite reductase apoprotein gene Nii and affects translation of the nii transcript. Studies of barley wild-type cv Golden Promise have demonstrated that nitrite reductase in leaf tissue is up-regulated by a coaction of nitrate and light which acts, at least partly, at the transcriptional level.
20
Fajri, Abolhassan. "Nitrogen fixation by pasture legumes : effects of herbicides and defoliation." Title page, table of contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phf1755.pdf.
Abstract:
Bibliography: leaves 209-254. Experiments detailed in this thesis, evaluate the impact of various herbicides and herbicide mixtures on the growth, nodulation and nitrogen fixation of annual pasture legumes, the efficacy of the herbicides for weed control, and the potential role of mechanical defoliation to replace herbicides, leading to lower cost and more sustainable farming systems.
21
Antunes, Cristiane Leite. "Fertirrigação nitrogenada por gotejamento e época de aplicação foliar de ácido giberélico 'GA IND.3' em alface americana (Lactuca sativa L.) /." Botucatu : [s.n.], 2001. http://hdl.handle.net/11449/93828.
Abstract:
Orientador: Antônio de Pádua SousaBanca: Roberto Lyra Villas Bôas
Banca: Tarlei Arriel Botrel
Resumo: Com o objetivo de avaliar os efeitos do nitrogênio aplicado ao solo, via fertirrigação por gotejamento, e a aplicação foliar do ácido giberélico (GA3), na nutrição e nos componentes de produção da alface tipo americana, cv. 'Lucy Brown', em cultivo protegido, foi efetuado o presente trabalho. O delineamento experimental utilizado foi o de blocos casualizados em esquema de parcelas subdivididas: quatro doses de nitrogênio (60, 120, 180 e 240 kg de N.ha-1), na parcela, e quatro épocas de aplicação de GA3 (0, 40, 55 e 70 DAS - dias após a semeadura), na subparcela. O ácido giberélico foi aplicado com pulverizador costal de CO2, numa concentração única de 20 mg do ingrediente ativo.L-1 de solução, nas subparcelas nas épocas determinadas. Foram realizadas quatro coletas para avaliação dos parâmetros vegetativos e análise de nutrientes, com intervalos de 15 dias, iniciando-se aos 51 DAS (23 DAT- dias após o transplantio) até 96 DAS (64 DAT). Os trabalhos foram conduzidos na área experimental da Fazenda São Manuel, no município de São Manuel - SP. Não foi observada interação entre a aplicação de nitrogênio e o ácido giberélico nos parâmetros vegetativos avaliados, bem como no teor e acúmulo dos macronutrientes. Contudo, houve influência dos fatores de variação de forma independente nos parâmetros ao longo do ciclo. O nitrogênio é extremamente importante no crescimento e acúmulo de matéria fresca na planta de alface tipo americana e pode ser usado em doses maiores quando há disponibilidade de cálcio e potássio. Tendo sido os melhores resultados alcançados com a dose de 180 kg de N. ha-1. O uso do ácido giberélico (GA3), aos 70 DAS (dias após a semeadura) proporcionou os melhores resultados nos parâmetros relativos ao crescimento. Enquanto a época de aplicação aos 40 DAS, promoveu o desenvolvimento intenso do caule, levando a efeitos... (Resumo completo, clicar acesso eletrônico abaixo).
Abstract: With the goal of estimating the nitrogen effects applied on the soil, through fertigation by dripping, and the foliar application of gibberellic acid (GA3), in the nourishment and in the components of Crisphead Lettuce production, cv. 'Lucy Brown', in protected cultivation, this paper was done. The used experimental drawing was made of casual blocks in subdivided portions: four doses de nitrogen (60, 120 180 and 240 kg de N.ha-1), in the portion, and four application times of GA3 (0, 40, 55 e 70 DAS - days after sowing) in the subportion. The gibberellic acid was applied with a costal pulverize machine of CO2, in a unique dose of 20 mg.L-1 of the active ingredient, in the subportions in the specific times. Four collects were done for the evaluation of the vegetative parameters and nutrient analysis, with a 15-days recess, beninning on 51 DAS (23DAT) to 96 DAS (64 DAT). The works were managed in the experimental area of São Manuel Farm, in São Manuel County - SP. It wasn't observed interaction between nitrogen application and the gibberellic acid in the evaluated vegetative characteristics, as well as in the tenor and accumulation of macro-nutrients. However, there was na influence of changing factors in na independent way in the parameters along the cycle. The nitrogen is extremely important in the growth and accumulation of fresh material in the Crisphead lettuce vegetable and it can be used in bigger doses when there is availability of calcium and potassium. These have been the best results got with the dose 180 kg of N.ha-1. The usage of gibberellic acid (GA3), on 70 DAS (days after the sowing) provided the best results in the characteristics related to the growth. As long as the application time on 40 DAS, provided the intense satlk growth, conducing to the depreciatory effects, as the plants arranged in layers, a bigger number of external leaves, and a samller accumulation of fresh... (Complete abstract, click electronic address below).
Mestre
22
Jablonski, Leanne M. "Reproductive response to elevated CO2 : the roles of vegetative carbon storage, nitrogen and seed traits." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34646.
Abstract:
This study focused on the reproductive response to elevated CO2 of plants possessing below-ground storage. I tested the hypotheses that under elevated CO2: (1) Plants with greater non-foliar storage capacity win show more reproductive response and (2) The altered foliar physiology of carbon (C) and nitrogen (N) use will cause increases in seed number and quality. Carbon dioxide treatments of High (650 muL L-1) and Ambient (360 muL L-1) were used in a controlled environment, simulated growing season, and in a natural pasture community. Hypothesis 1 was tested experimentally using four Raphanus varieties that differed in hypocotyl and leaf sizes. N fertilization and harvest times were used to obtain a range of root:shoot ratios. Enhancements in vegetative leaf area rather than the hypocotyl predicted reproductive responsiveness to CO 2. However, after three years of CO2 exposure in the pasture, hypocotyl-storing Taraxacum officinale responded strongly in vegetative biomass which correlated with inflorescence size and number. Fitness was enhanced four-fold, while the leaf-storing Plantago major produced more ramets and had only a two-fold fitness increase. Hypothesis 2 was tested by examining the C and N physiology underlying the vegetative organs and seeds of the pasture plants. Under elevated CO2, photosynthesis increased two-fold and senescence was delayed. Total plant C:N ratio did not differ, suggesting N acquisition increased. N similarly limited seed number in all cases suggesting an unchanged Physiology of N use in reproduction. While morphology constrained total biomass response, provisioning to seeds increased as shown by higher seed mass and number and decreased variability in number and mass. In all cases, leaf mass increase under high CO2 corresponded with fitness increase. Phenology constrained response to CO 2 as there was no plasticity in flowering day in Raphanus and Plantago, while there were flowering delays but greater seed maturation rate in Tar
23
Rocha, Kassiano Felipe 1989. "Dinâmica do nitrogênio em rotações de forrageiras com milho /." Botucatu, 2017. http://hdl.handle.net/11449/152127.
Abstract:
Orientador: Ciro Antonio RosolemBanca: Luis Ignacio Prochnow
Banca: José Antonio Quaggio
Banca: Heitor Cantarella
Banca: Eduardo Mariano
Resumo: Forrageiras do gênero Urochloa podem alterar a dinâmica do N no solo, afetando processos microbiológicos do ciclo do N, sua disponibilidade no solo e perdas no sistema. O objetivo do trabalho foi avaliar o efeito do cultivo de Urochloa ruziziensis, Urochloa brizantha e Panicum maximum na dinâmica do N no solo, ou seja, potencial de nitrificação, atividade de microrganismos amonificantes, nitrificantes e fixadores de N, bem como possíveis rotas de saída de N do sistema por lixiviação de N-NO3-, emissão de N-N2O e volatilização N-NH3 e o seu efeito no milho cultivado em sucessão, bem como na recuperação do N-fertilizante pela cultura. Foi conduzido um experimento em um Nitossolo Vermelho distroférrico de textura argilosa. Foram utilizadas as forrageiras U. ruziziensis cv. Comum, U. brizantha cv. Marandú, e P. maximum cv. Tanzânia. Na cultura do milho foram aplicadas as doses de 0, 70, 140 e 210 kg N ha-1, sendo a dose de 140 kg N ha-1 enriquecida com 15N. As gramíneas forrageiras permaneceram na área por 11 meses (outubro/2014 a setembro/2015) quando foram dessecadas e o milho foi semeado em semeadura direta. O processo de amonifição não é diminuído no solo cultivado com U. ruziziensis, mas o milho cultivado após esta espécie produz menos em relação a U. brizantha e P. maximum. Em sistemas de produção de alta resposta a N, o cultivo de U. ruziziensis, U. brizantha e P. maximum, mesmo com a adição de até 210 kg ha-1 de N, não diferem em potencial de provocar perdas de N por lixi... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Forages of the Urochloa genus can change the soil N dynamics, affecting microbiological processes of the N cycle, their availability in the soil and losses in the system. The objective of this work was to evaluate the effect of the cultivation of Urochloa ruziziensis, Urochloa brizantha and Panicum maximum on N soil dynamics, that is, nitrification potential, activity of ammonificant, nitrifying and N fixers microrganisms, as well as possible loses routes by N-NO3 - leaching, N-NH3 volatilization and N-N2O emission and its effect on corn grown in succession, as well as N-fertilizer recovery by the crop. An experiment was carried on a clayey Typic Rhodustult in a fatorial design 3x4 in randomized blocks with three forages species and four N doses in four replications. Were used the forage species U. ruziziensis cv. Common, U. brizantha cv. Marandú, and P. maximum cv. Tanzânia. In the corn crop, the doses of 0, 70, 140 and 210 kg N ha-1 were applied, and the dose of 140 kg N ha1was enriched with 15N. Forage grasses remained in the area for 11 months (October/2014 to September/2015) when they were desiccated and corn was sown in no-tillage. The ammonification process isn't decreased in soil cultivated with U. ruziziensis, but corn yield, after this species, is lower than after U. brizantha and P. maximum. In high-N response systems, the cultivation of U. ruziziensis, U. brizantha and P. maximum, even with 210 kg ha-1 of N, don't differ in potential to cause N lossesby N-NO3 - leaching, N-NH3 volatilization and N-N2O emission. The N-fertilizer recovery applied on corn was only 35%, indicating that 65% of the N used by corn cames from soil N and thus having high dependence on the dynamics of forage grasses on the availability of N in integrated production systems. Evidence that BNF is occurring in production systems with U. ruziziensis, U. brizantha and P. maximum, increasing the ...
Doutor
24
Lotfollahi, Mohammad. "The effect of subsoil mineral nitrogen on grain protein concentration of wheat." Title page, table of contents and summary only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phl882.pdf.
Abstract:
Copy of author's previously published work inserted. Bibliography: leaves 147-189. This project examines the uptake of mineral N from the subsoil after anthesis and its effect on grain protein concentration (GPC) of wheat. The overall objective is to examine the importance of subsoil mineral N and to investigate the ability of wheat to take up N from the subsoil late in the season under different conditions of N supply and soil water availability. Greenhouse experiments investigate the importance of subsoil mineral N availability on GPC of wheat and the factors that contribute to the effective utilisation of N. The recovery of N from subsoil, the effect of split N application on GPC and short term N uptake by the wheat at different rooting densities are also studied.
25
Sena, Virley Gardeny Lima. "Sequestro de carbono e eficiência do uso de nutrientes pelo milho em plantio direto sobre palha de leguminosas arbóreas /." Botucatu, 2019. http://hdl.handle.net/11449/182276.
Abstract:
Orientador: Juliano Carlos CalonegoCoorientador: Emanoel Gomes de Moura
Banca: João Paulo Gonsiorkiewicz Rigon
Banca: Gustavo Pavan Mateus
Banca: Iraê Amaral Guerrini
Banca: Emerson Guerrini
Resumo: Nas proximidades da região amazônica, trópico úmido maranhense, sobretudo na região centro norte do Estado, há condições edafoclimáticas que divergem de outras regiões do Brasil e impossibilitam o avanço da agricultura. A elevada pluviosidade somada às altas temperaturas em solos altamente intemperizados, predispostos a coesão e de baixa fertilidade natural dificultam o uso de técnicas comuns tais como aração e gradagem, uma vez que estas compactam ainda mais o solo impedindo o crescimento das raízes das culturas e a absorção dos nutrientes. Neste sentido, dois experimentos foram conduzidos em sistema de plantio direto na palha de leguminosas arbóreas em aleias no município de Brejo - MA e avaliados nos anos de 2016 e 2017. O solo de ambas as áreas foi classificado como Latossolo Amarelo Distrocoeso. Foi cultivado a cultura do milho nos dois experimentos e nos dois anos estudados. O objetivo do primeiro experimento foi avaliar a influência da cobertura do solo com a leguminosa arbórea Gliricidia sepium sobre a fertilidade do solo, o estímulo ao acúmulo de carbono orgânico do solo, a eficiência agronômica e de recuperação do nitrogênio e produtividade da cultura do milho. No segundo experimento, o objetivo foi avaliar o efeito da matéria orgânica sobre os atributos físico-químicos do solo, sequestro de carbono e os fatores que interferem na produtividade da cultura do milho. Observou-se que o uso de biomassa de leguminosas arbóreas como cobertura do solo associada a fertilizaç... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: In the vicinity of the Amazonian region, humid tropical Maranhão, especially in the central north of the state, there are edaphoclimatic conditions that diverge from other regions of Brazil and make it impossible to advance agriculture. The high rainfall combined with the high temperatures in highly weathered soils, predisposed to cohesion and low natural fertility make it difficult to use common techniques such as Ploughing and Harrowing since they further compact the soil, preventing the growth of the roots of the crops and absorption of nutrients. In this sense, two experiments were conducted under no - tillage system in the tree legume straw in alley cropping in the municipality of Brejo - MA and evaluated in the years 2016 and 2017. The soil of both areas was classified as Utisol. The maize crop was grown in both experiments and in the two years studied. The objective of the first experiment was to evaluate the influence of soil cover with the leguminous tree Gliricidia sepium on soil fertility, the stimulation of soil organic carbon accumulation, agronomic and nitrogen recovery efficiency and maize crop productivity. In the second experiment, the objective was to evaluate the effect of organic matter on soil physical-chemical attributes, carbon sequestration and factors that interfere in maize crop productivity. It was observed that the use of biomass of tree legumes as soil cover associated with fertilization via inorganic fertilizers increased soil carbon sequestration and the agronomic and nitrogen recovery efficiency. In addition, the addition of legume biomass to the soil resulted in improvements in the physical-chemical attributes of the soil and increased productivity of the maize crop. These conservationist systems of soil management allow to intensify production,minimize soil degradation and promote the sustainability of agriculture in the humid tropics
Doutor
26
Candian, Joara Secchi 1991. "Doses e épocas de aplicação de torta de mamona na produção, características físico-químicas e teores de macronutrientes em couve-flor sob manejo orgânico /." Botucatu, 2018. http://hdl.handle.net/11449/153788.
Abstract:
Orientador: Antonio Ismael Inácio CardosoBanca: Roberto Lyra Villas Bôas
Banca: Santino Seabra Júnior
Banca: Pedro Jovchelevich
Banca: Jackson Mirellys Azevêdo Souza
Resumo: A couve-flor, comparada a outras brássicas, é a mais exigente em solos férteis e com alto teor de matéria orgânica. O nitrogênio pode ser perdido facilmente no solo, seja por volatilização ou por lixiviação, sendo indicado que seu fornecimento ocorra juntamente com a aplicação de materiais ricos em matéria orgânica, parte no plantio e parte em cobertura. Diante do exposto, objetivou-se com este estudo avaliar o efeito das doses e épocas de aplicação de torta de mamona em cobertura na produção, características físico-químicas e acúmulo de macronutrientes na cultura da couve-flor em manejos orgânicos. Foram realizados dois experimentos um no município de São Manuel, SP, e o outro em Botucatu, SP. Em São Manuel, SP foram estudados 14 tratamentos, em esquema fatorial 3 x 4 + 2, sendo três doses de torta de mamona (2150, 3225 e 4300 kg ha-1), combinadas com quatro parcelamentos em cobertura (¼ + 2/4 + ¼; 1/3 + 1/3 + 1/3 e 1/3 + 2/3 e 2/3 + 1/3), além de duas testemunhas (sem adubação em cobertura e com adubação inorgânica). Em Botucatu, SP, foram 10 tratamentos, em esquema fatorial 3 x 3 + 1, sendo três doses de torta de mamona (1290, 2580 e 3870 kg ha-1) combinadas com três épocas de aplicação em cobertura (única aos 30 ou aos 45 dias após o transplante (DAT) e parcelada aos 30 e 45 DAT), além de uma testemunha (sem adubação em cobertura). Os experimentos foram no delineamento experimental de blocos ao acaso, com quatro repetições. Foram analisadas as seguintes características: c... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Currently, conventional cauliflower cultivation is still predominant; however, cultivation in alternative systems, such as organic, has been growing. Compared to other brassicas, it is the most demanding in fertile soils with a high content of organic matter. Nitrogen and potassium are the most accumulated nutrients in cauliflower. Nitrogen can be easily lost in the soil, either by volatilization or by leaching, and it is indicated that its supply occurs along with the application of materials rich in organic matter, part in planting and part in cover. In view of the above, this study aimed to evaluate the effect of doses and times of application of castor bean cake on yield, physical-chemical characteristics and accumulation of macronutrients in cauliflower crop in organics managements. Two experiments were carried out, one in the municipality of São Manuel, SP, and the another in Botucatu, SP. In the experiment 1 (São Manuel, SP), 14 treatments were studied in a 3 x 4 + 2 factorial scheme, with three doses of castor bean (2150, 3225 and 4300 kg ha-1), combined with four installments (¼ + 2/4 + ¼; 1/3 + 1/3 + 1/3; 1/3 + 2/3 and 2/3 + 1/3), besides two controls (without cover fertilization and with inorganic fertilization). In experiment 2 (Botucatu, SP), 10 treatments were used, in a 3 x 3 + 1 factorial scheme, three castor bean doses (1290, 2580 and 3870 kg ha-1) combined with three installments (one application at 30 or at 45 days after transplanting (DAT) and parceled at 30 and 45 DAT), in addition to one control (no fertilization in coverage). The experiments were in a randomized complete block design, with four replications. The following characteristics were analyzed: cycle (DAT), number of leaves, inflorescence diameter and height, inflorescence fresh matter weight and fresh matter weight of the vegetative part (stem and leaves), pH, titratable acidity (TA), acid ascorbic acid (AA) ...
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Rawahy, Salim Ali 1951. "EFFECT OF SODIUM-CHLORIDE, SODIUM-SULFATE AND CALCIUM-CHLORIDE SALTS ON NITROGEN AND PHOSPHORUS UPTAKE BY TOMATO PLANTS (SALINITY, OSMOTIC PRESSURE, SPECIFIC ION EFFECT)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/275527.
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Abranches, Jorge Luiz 1984. "Resposta da cultura do café arábica à aplicação de ureia revestida /." Botucatu, 2018. http://hdl.handle.net/11449/152971.
Abstract:
Orientador: Rogério Peres SorattoCoorientador: Marcos José Perdoná
Banca : Adriana Novais Martins
Banca : Marcelo de Almeida Silva
Resumo: Nas condições em que o café arábica (Coffea arabica L.) é cultivado no Brasil, o nitrogênio (N) é o elemento que mais limita as produções, em razão da alta demanda pela cultura e baixa disponibilidade, na maioria dos solos brasileiros, nesse elemento. Através do revestimento dos fertilizantes tradicionais, por resinas sintéticas, orgânicas ou inorgânicas, esses insumos tendem a liberar os nutrientes de forma lenta. Desta forma, uma possibilidade de aumentar a eficiência de aproveitamento dos fertilizantes, e tentar minimizar as perdas de produtividade, é o uso de fertilizantes revestidos. Objetivou-se, com este experimento, estudar a eficiência da ureia revestida em fornecer N para o cafeeiro arábica e seu efeito na nutrição mineral, crescimento vegetativo e produtividade, em comparação a ureia convencional. O experimento foi conduzido no município de Bauru-SP, instalado em agosto de 2014, em uma lavoura de café do cultivar Mundo Novo, IAC 388-17-1, com três anos e meio de idade, em um Latossolo Vermelho Amarelo distrófico (LVAd). Foi adotado o delineamento em blocos casualizados, em um esquema fatorial 3×2+1, testando três doses de N (150, 300 e 600 kg ha-1), duas fontes (ureia revestida e ureia convencional) e uma testemunha (sem aplicação de N), com seis repetições. A ureia revestida utilizada, com 43% de N, é denominada "Kimcoat N®". Cada parcela foi composta por sete plantas. A adubação nitrogenada aumentou o diâmetro do caule, a altura da planta, o número de nós em ramo... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract:In the conditions under which the Arabica coffee (Coffea arabica L.) is cultivated in Brazil, nitrogen (N) is the most limiting element due to the high crop demand and low availability in most Brazilian soils. By coating traditional fertilizers with synthetic, organic or inorganic resins, these inputs tend to release nutrients slowly. Thus, one possibility of increasing the efficiency of fertilizer utilization and trying to minimize productivity losses is the use of coated fertilizers. In this experiment the objective was to study the efficiency of coated urea in providing N for Arabica coffee and its effect on mineral nutrition, vegetative growth, and grain yield, compared to conventional urea. The experiment was conducted in the city of Bauru-SP, installed in August 2014, in a coffee crop of Mundo Novo cultivar, IAC 388-17-1, with three years and middle age, on a dystrophic Yellow Red Latosol (LVAd). A randomized block design was used in a 3 × 2 + 1 factorial scheme, testing three doses of N (150, 300 and 600 kg ha-1), two sources (coated urea and conventional urea) and one control (no application of N), with six replicates. The coated urea used, with 43% N, is referred to as "Kimcoat N®". Each plot was composed of seven plants. Nitrogen fertilization increased stem diameter, plant height, number of nodes in plagiotropic branches, length of branches, leaf N content, SPAD values and crop yield, in the three harvests evaluated. In the edaphoclimatic conditions of the present study, the supply of N for the cultivation of arabica coffee, through the application of coated urea, through the cover, did not prese ...
Mestre
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Stein, Chad M. "Post-fire vegetation in Sierran forests effects on nitrogen fixation, soil nitrogen availability, and water quality /." abstract and full text PDF (free order & download UNR users only), 2006. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1438931.
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Ades, Dennis Raymond. "The role of iron nutrition in regulating patterns of photosynthesis and nitrogen metabolism in the green alga Scenedesmus quadricauda." PDXScholar, 1987. https://pdxscholar.library.pdx.edu/open_access_etds/3649.
Abstract:
The influence of iron nutrition on patterns of photosynthetic behavior, nitrogen metabolism, and fixed-carbon allocation is reported for a common freshwater green alga. Cultures of Scenedesmus quadricauda were grown in Fraquil medium in which iron concentrations ranged from 1.0 μM to 0.01 μM (log 10-6 to 10-8 M, respectively). Carbon 14 and nitrogen uptake experiments were conducted at photosynthetically saturating and subsaturating photon flux densities.
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Brimecombe, Melissa Jane. "The effect of introduced Pseudomonas fluorescens strains on nitrogen dynamics in the rhizosphere of crop plants." Thesis, University of Surrey, 1999. http://epubs.surrey.ac.uk/842952/.
Abstract:
The primary aim of this study was to investigate the effects of seed inoculation with the biocontrol agent Pseudomonas fluorescens strain F113 (producing the antibiotic DAPG) and its modified derivative strain F113G22 (with DAPG production disrupted) on the uptake of nitrogen by pea and wheat plants. Uptake of N by the two plant species was investigated in soil microcosms amended with 15N-labelled fertilisers (urea or ammonium nitrate) or 15N-labelled plant residues. Uptake of fertiliser-N was unaffected by inoculation. However, uptake of N derived from organic residues was enhanced in pea inoculated with either strain. In contrast, uptake of N by wheat was reduced in the presence of either strain F113 or F113G22, suggesting that the effects of these microbial inocula on N-mineralisation in the rhizosphere were dependent on plant species. It was subsequently found that microfaunal populations, especially soil nematodes in the rhizosphere of inoculated pea were significantly larger than those associated with the rhizosphere of non-inoculated controls. In wheat, however, microfaunal populations in the rhizosphere of inoculated plants were lower than those associated with noninoculated controls. These trends were repeated using simple sand microcosms into which soil bacteria and the bacterial-feeding nematode Caenorhabditis elegans were introduced. This suggested that effects on N-mineralisation were mediated by changes in populations of microbial-feeding microfauna. As a possible explanation for the increased nematode populations in the rhizosphere of inoculated pea plants, the nematicidal effects of pea seed exudates on C. elegans were investigated in small-scale sand systems. It was found that exposure to non-inoculated pea seeds reduced the short-term survival of C. elegans as compared to unamended sand, and that survival was greater in the presence of pea seeds inoculated with either strain than non-inoculated seeds, suggesting that nematicidal compounds released by germinating pea seeds were utilised by the P.fluorescens strains. No such effects were observed for wheat.
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Torp, Mikaela. "The effect of snow on plants and their interactions with herbivores." Doctoral thesis, Umeå : Department of Ecology and Environmental Science, Umeå University, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-30444.
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Wang, Dan. "Effects of CO₂ and nitrogen on plant response to heat stress /." Connect to full text in OhioLINK ETD Center, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1225299873.
Abstract:
Dissertation (Ph.D.)--University of Toledo, 2008.Typescript. "Submitted as partial fulfillment of the requirements for The Doctor of Philosophy Degree in Biology (Ecology-track)." Bibliography: leaves 6-9, 29-35, 71-78, 111-118, 149-153.
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Malan, Michelle. "The effect of atmospheric nitrogen deposition on fynbos soils and plants in the Cape Town metropolitan area." Thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/26698.
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Gilabel, Amanda Prado 1991. "Co-inoculação de rhizobium e azospirillum e adubação nitrogenada na cultura do feijão comum /." Botucatu, 2018. http://hdl.handle.net/11449/152913.
Abstract:
Orientador: Rogério Peres SorattoCoorientador: Adalton Mazetti Fernandes
Banca: Dirceu Maximino Fernandes
Banca: José Lavres Junior
Resumo: Devido ao alto custo e baixa eficiência de aproveitamento dos fertilizantes nitrogenados pelas plantas, existe grande interesse em estratégias, como a fixação biológica de N2 (FBN), para a redução da aplicação de nitrogênio (N) inorgânico nas culturas. A co-inoculação consiste na combinação de bactérias do gênero Rhizobium (simbióticas) com as do gênero Azospirillum (associativas), aos quais podem produzir efeito sinérgico proporcionando resultados superiores àqueles obtidos quando utilizadas de forma isolada. O objetivo desse trabalho foi avaliar o efeito da co-inoculação com Rhizobium tropici e Azospirillum brasilense, bem como da adubação nitrogenada de semeadura, no crescimento, nodulação, nutrição mineral e produtividade de grãos do feijoeiro comum. Foram conduzidos dois experimentos em condições de campo, durante as safras "das águas" e "da seca" do ano agrícola 2016/2017; e um experimento em condições de casa de vegetação durante o período de janeiro a março de 2017, no município de Botucatu-SP. Em todos os experimentos, o delineamento utilizado foi em blocos casualizados, com quatro repetições. Foram estudadas nove formas de inoculação/co-inoculação e aplicação de N em cobertura [1: controle absoluto (sem inoculação e sem N em cobertura); 2: 60 kg ha-1 de N em cobertura em V4; 3: inoculação com R. tropici 2,5 × 106 células semente-1; 4: inoculação com A. brasilense 5,2 × 104 células semente-1; 5: inoculação com A. brasilense 2,5 × 105 células semente-1; 6: inoculação ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Due to the high cost and low use efficiency of nitrogen (N) fertilizers by plants, there is great interest in strategies to reduce N application in crops, such as biological N2 fixation (BNF). Co-inoculation consists in combination of bacteria of the genus Rhizobium (symbiotics) with those of the genus Azospirillum (associatives), which can produce a synergistic effect, providing higher performance of the plants then those obtained using Rhizobium alone. The aim of this study was to evaluate the effect of co-inoculation with Rhizobium tropici and Azospirillum brasilense, as well as N fertilization at sowing, in growth, nodulation, mineral nutrition, and grain yield of common bean. Two experiments were conducted under field conditions in "spring" and "summer-fall" growing seasons of the 2016/2017 harvest, and an experiment under greenhouse conditions during the period from January to March of 2017, in Botucatu-SP, Brazil. In all experiments, the design was in randomized blocks, with four replications. Nine forms of inoculation/co-inoculation and topdressing N application were studied [1: absolute control (without inoculation and without topdressing N ) 2: 60 kg ha-1 of topdressing N in V4; 3: inoculation with R. tropici 2.5 × 106 cells seed-1; 4: inoculation with A. brasilense 5.2 × 104 cells seed-1; 5: inoculation with A. brasilense 2.5 × 105 cells seed-1; 6: inoculation with A. brasilense 5.0 × 105 cells seed-1; 7: co-inoculation R. tropici + A. brasilense 5.2 × 104 cells seed-1; 8: co-inoculation R. tropici + A. brasilense 2.5 × 105 cells seed-1; 9: co-inoculation R. tropici + A. brasilense 5.0 × 105 cells seed-1], combined with the application or not of 20 kg ha-1 of N at sowing furrow. Under greenhouse conditions, the N supply at sowing or topdressing reduced the number and dry matter of nodules and increased N concentration and accumulation in the common bean shoot. Nitrogen application...
Mestre
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Grohskopf, Marco André 1988. "Interação entre fósforo e nitrogênio em fertilizante organomineral /." Botucatu, 2017. http://hdl.handle.net/11449/152480.
Abstract:
Orientador: Dirceu Maximino FernandesCoorientador: Juliano Corulli Corrêa
Banca: Roberto Lyra Villas Bôas
Banca: Juliano Carlos Calonego
Banca: Paulo Cesar Teixeira
Banca: Rosemary Marques de Almeida Bertani
Resumo: A adubação é dentre as práticas agrícolas a de maior relevância para estabelecer novos patamares de produção, com ênfase para as inovações em fertilizantes. O objetivo do trabalho foi avaliar o efeito da interação entre fósforo (P) e nitrogênio (N) em fertilizante organomineral a base de cama de aves no sistema solo-planta em Latossolo Vermelho Distroférrico. Três experimentos foram realizados em delineamento inteiramente casualizado, onde o primeiro (experimento 1) foi conduzido em casa de vegetação, com os tratamentos correspondentes ao equivalente a cinco doses crescentes de P (0, 20, 40, 60 e 80 kg ha-1) em interação com cinco doses crescentes de N (0, 50, 100, 150 e 200 kg ha-1); o segundo experimento (experimento 2) de incubação em placas de petri foi realizado em condições de laboratório, com os tratamentos constituídos de sete doses de P (0, 1,3, 1,8, 2,5, 3,8, 5 e 10 mg/placa) com a dose de interação de N fixa em 5,5 mg/placa para avaliar a mobilidade e disponibilidade do N inorgânico (N-NH4+ e N-NO3-); e, o terceiro experimento (experimento 3) foi realizado em condições semelhantes ao experimento 2, com os tratamentos constituídos de sete doses de N (0, 4,4, 8,8, 11,7, 17,5, 24,8 e 32,1 mg/placa) com a dose de interação de P fixa em 8,8 mg/placa para avaliar a disponibilidade e difusão do P. No experimento 1, foram realizados três cultivos sequenciais de milheto com 40 dias de crescimento cada para determinar a produção de biomassa seca e os teores de P e N. Após ca... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Fertilization is the most important agriculture practice to stablish new production levels, highlighted on fertilizer innovations. The aim of this research was to evaluate the effect of phosphorus (P) and nitrogen (N) interaction rates on organomineral fertilizer from poultry litter into the soil-plant system in a Typic Hapludox (Oxisol). Two experiments were carried out in a completely randomized design, where the first one (Experiment 1) was conducted in greenhouse, with treatments corresponding to the equivalent of five increasing doses of P (0, 20, 40, 60 e 80 kg ha-1) in interaction with five increasing doses of N (0, 50, 100, 150 e 200 kg ha-1); and the second experiment (Experiment 2) in petri dishes incubation was conducted under laboratory conditions, with the treatments consisting of seven concentrations of P (0, 1,3, 1,8, 2,5, 3,8, 5 e 10 mg kg1 ) with the N interaction dose fixed in 5 mg kg-1 to evaluated the mobility and availability of inorganic N (NH4 + -N e NO3 --N) and, seven concentrations of N (0, 4,4, 8,8, 11,7, 17,5, 24,8 e 32,1 mg kg-1) with the P interaction dose fixed in 8,8 mg kg-1 to evaluate the availability and diffusion of P. In experiment 1, three sequential millet crops were performed with 40 days of growth each to determine the shoot dry biomass yield and P and N contents to calculate the accumulation. After each cultivation were collected the soil into the pots for analysis of P and N forms. In experiment 2, for the P and N analysis were sampled in petri dishes, the soil in concentric cylinders with different distances from the deposition central point of fertilizers granules (0−7,75; 7,76−13,5; 13,51−25,5; and 25,51−43 mm) in five incubation times (7, 14, 21, 28 and 35 days). There were interaction effects of phosphorus×nitrogen (P×N) with fertilization by organomineral fertilizers, with more pronounced effects on plants than on soil. The highest ...
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Beche, Eduardo. "Caracteres agronômicos e fisiológicos associados ao progresso do melhoramento genético de trigo no Brasil." Universidade Tecnológica Federal do Paraná, 2013. http://repositorio.utfpr.edu.br/jspui/handle/1/465.
Abstract:
CNPqConhecer os processos responsáveis pelo avanço do progresso genético do rendimento de grãos é uma etapa essencial para o desenvolvimento de cultivares mais produtivas. Os objetivos do estudo foram: a) Avaliar a duração dos subperíodos de desenvolvimento de cultivares de trigo brasileiros, lançados entre 1940 e 2009, e quantificar a importância de cada fenofase sobre o rendimento de grãos e seus componentes. b) Caracterizar, fisiologica e agronomicamente, cultivares de trigo desenvolvidos entre 1940 e 2009, a fim de identificar critérios de seleção mais efetivos à continuidade do progresso genético de melhoramento no Brasil. c) Caracterizar cultivares antigos e modernos brasileiros, lançados em diferentes décadas, quanto à eficiência do uso do nitrogênio e seus componentes. Dez cultivares de trigo brasileiros, antigos e modernos, foram avaliados em ensaios de competição, em duas safras agrícolas (2010 e 2011); na safra agrícola de 2011 um ensaio foi conduzido em casa de vegetação, com quatro doses de nitrogênio (0, 60, 120 e 180 kg N ha-1). Comparou-se a duração dos subperíodos, caracteres agronômicos e fisiológicos (trocas gasosas) e caracteres da eficiência do uso do nitrogênio (EUN). O melhoramento reduziu a fase de semeadura a antese e aumentou a fase de enchimento de grãos, contribuindo com o aumento da massa de mil grãos. Os genótipos modernos tiveram o subperíodo de espigueta terminal a antese aumentado (0,68 a 1,35 graus dias ano-1) ao longo dos anos, contribuindo com o incremento do número de grãos por espigueta, número de grãos por espiga, peso seco de espiga em antese e índice de fertilidade da espiga. O incremento de rendimento de grãos foi de 29 kg ha-1 ano-1, com um ganho genético de 0,92% ano-1 no período de 1940 e 2009. O progresso genético para rendimento de grãos foi principalmente relacionado ao incremente do índice de colheita, número de grãos e rendimento biológico, que foram alcançados pelo aumento da condutância estomática e da taxa fotossintética em pré e pós-antese e redução da estatura de planta. A eficiência de absorção de nitrogênio (EAN) foi positivamente associada com a eficiência do uso do nitrogenio (EUN) na ausência de adubação nitrogenada. A eficiência de utilização do nitrogenio (EUtN) e a EAN foram positivamente associadas a EUN nas doses elevadas de N. Os cultivares mais recentemente disponibilizados para cultivo (Quartzo, CD 117, BRS Tangará, BRS 220, BRS 208 e BRS Guamirim) foram mais eficientes no uso do nitrogênio e mais tolerantes a baixas doses em comparação ao grupo formado pelos cultivares BRS 179, BR 23, Toropi e Frontana.
Knowledge the processes responsible for the progress of genetic gain in grain yield in wheat plant is an essential step for the development of high yield cultivars. The aims of the study were: a) Evaluate the duration of developmental phases in wheat cultivars and quantify the importance of each phase on grain yield and its components. b) characterize physiological and agronomically wheat cultivars released in different decades, to identify selection criteria for continued improvement of genetic progress in Brazil. c) Characterize Brazilian wheat cultivars developed in different decades for the nitrogen use efficiency (NUE). Ten wheat cultivars released from1940 to 2009, were examined for two years in a competition essay (2010 and 2011) and in 2011 an essay in green house was conducted with four nitrogen rates (0, 60, 120 e 180 kg N ha-1). We compared the duration of periods, agronomic and physiological traits (gas exchange) and nitrogen use efficiency (EUN) characters. The Breeding reduced time to anthesis and increased the grain filling, contributing to the increase in thousand kernel weight. The modern cultivars had the period terminal spikelet to anthesis increased (0,68 to 1,35 degree days year-1) over the years, contributing to the increase in the number of grains per spikelet, number of grains per spike, spike dry weight at anthesis and spike fertility index. The increase in grain yield was 29 kg ha-1 yr-1, with a genetic gain of 0,92% yr-1 from 1940 to 2009, this is largely related to the increased of harvest index, number of grains m-2 and biological yield, which were achieved through improving stomatal conductance and photosynthetic rate in pre and post-anthesis and reduced in plant height. The nitrogen uptake efficiency (NUpE) was positively associated with nitrogen use efficiency (NUE) in the absence of fertilization. Nitrogen utilization efficiency (NutE) and NUpE were positively associated with NUE in higher N. The modern cultivars (Quartzo, CD 117, BRS Tangará, BRS 220, BRS 208 and BRS Guamirim) were more efficient in the use of nitrogen and more tolerant to low N input compared to the group formed by BRS 179, BR 23, Toropi and Frontana.
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Pivetta, Laércio Augusto [UNESP]. "Ciclagem do nitrogênio relacionada ao sistema de produção." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/132163.
Abstract:
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000851992.pdf: 1315382 bytes, checksum: f1e0b3c6239228aceaa5d9a87e506ffa (MD5)O conhecimento de como o manejo do solo influencia na dinâmica do nitrogênio (N) em longo prazo pode fornecer bases para desenvolver sistemas de produção que otimizem a ciclagem deste nutriente. Objetivou-se com este trabalho avaliar o efeito de sistemas de manejo, com plantas de cobertura e escarificação, em rotação com a cultura da soja, no balanço e ciclagem do N e na produtividade da soja. O experimento vem sendo conduzido desde 2003, em um Nitossolo Vermelho distroférrico, estruturado, de textura argilosa. O experimento foi delineado em blocos casualizados, em esquema de parcelas subdivididas, com quatro repetições. As parcelas foram constituídas pelas culturas de inverno triticale (X Triticosecale) e girassol (Helianthus annuus), e as subparcelas pelos manejos de primavera, milheto (Pennisetum glaucum), sorgo forrageiro (Sorghum bicolor) e crotalária júncea (Crotalaria juncea), além da escarificação, que foi realizada em 2003 e 2009, também na primavera. Na safra de verão foi cultivada a soja (Glycine max), em todas as subparcelas. A ciclagem e o balanço do N foram estudados por determinações de N-total e estoque de N no solo, massa de matéria seca e acúmulo de N da palhada e da parte aérea das culturas, produtividade e exportação de N pelas culturas de outono/inverno e da soja, saídas de N por lixiviação de NO3- e emissão de NH3 e N2O, além da quantificação das entradas de N no sistema via deposição atmosférica, pulverização de defensivos e sementes. As saídas de N oscilaram entre 1,2 a 3,3, 8,2 a 8,9 e 12,2 a 50,4 kg ha-1 ano-1 para emissão de N2O, volatilização de NH3 e lixiviação de NO3-, respectivamente. As culturas de outono/inverno pouco se diferenciaram na ciclagem de N no sistema solo-planta. Os manejos de primavera se diferenciaram mais na lixiviação de NO3-. Apesar de a crotalária apresentar maior perda de N por lixiviação, devido ao ...
The knowledge of how soil management acts upon N cycling in long term can provide bases to develop crop production systems that optimize the cycling of this nutrient. The objective of this research was to assess the effect of soil management systems, using cover crops and chiseling in rotation with soybean on N cycling and balance. The experiment has been carried out since 2003, on a clayey Rhodic Nitosol. The experimental design was a randomized complete block design, in a split‑plot arrangement, with four replicates. Plots consisted of the fall-winter crops, triticale (X Triticosecale) and sunflower (Helianthus annuus), and subplots of the spring managements, pearl millet (Pennisetum glaucum), forage sorghum (Sorghum bicolor) and sunn hemp (Crotalaria juncea), besides chiseling in 2003 and 2009, at the spring too. Soybean (Glycine max) was grown in the summer. The N cycling and balance were studied by determinations of soil total-N and N storage, dry mass and N accumulation of crops and its residues, grain yield and N exportation by fall-winter crops and soybean, N outputs by NO3- leaching and NH3 and N2O emission, besides N inputs by atmospheric deposition, pesticide spraying and seeds. Losses of N ranged from 1.2 to 3.3, 8.2 to 8.9 and 12.2 to 50.4 kg ha-1 year-1 as N2O, ...
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Pivetta, Laercio Augusto 1986. "Ciclagem do nitrogênio relacionada ao sistema de produção /." Botucatu, 2015. http://hdl.handle.net/11449/132163.
Abstract:
Orientador: Ciro Antonio RosolemBanca: Rogerio Peres Soratto
Banca: Monica Sarolli Silva de Mendonça Costa
Banca: André Cesar Vitti
Banca: Paulo César Ocheuze Trivelin
Resumo: O conhecimento de como o manejo do solo influencia na dinâmica do nitrogênio (N) em longo prazo pode fornecer bases para desenvolver sistemas de produção que otimizem a ciclagem deste nutriente. Objetivou-se com este trabalho avaliar o efeito de sistemas de manejo, com plantas de cobertura e escarificação, em rotação com a cultura da soja, no balanço e ciclagem do N e na produtividade da soja. O experimento vem sendo conduzido desde 2003, em um Nitossolo Vermelho distroférrico, estruturado, de textura argilosa. O experimento foi delineado em blocos casualizados, em esquema de parcelas subdivididas, com quatro repetições. As parcelas foram constituídas pelas culturas de inverno triticale (X Triticosecale) e girassol (Helianthus annuus), e as subparcelas pelos manejos de primavera, milheto (Pennisetum glaucum), sorgo forrageiro (Sorghum bicolor) e crotalária júncea (Crotalaria juncea), além da escarificação, que foi realizada em 2003 e 2009, também na primavera. Na safra de verão foi cultivada a soja (Glycine max), em todas as subparcelas. A ciclagem e o balanço do N foram estudados por determinações de N-total e estoque de N no solo, massa de matéria seca e acúmulo de N da palhada e da parte aérea das culturas, produtividade e exportação de N pelas culturas de outono/inverno e da soja, saídas de N por lixiviação de NO3- e emissão de NH3 e N2O, além da quantificação das entradas de N no sistema via deposição atmosférica, pulverização de defensivos e sementes. As saídas de N oscilaram entre 1,2 a 3,3, 8,2 a 8,9 e 12,2 a 50,4 kg ha-1 ano-1 para emissão de N2O, volatilização de NH3 e lixiviação de NO3-, respectivamente. As culturas de outono/inverno pouco se diferenciaram na ciclagem de N no sistema solo-planta. Os manejos de primavera se diferenciaram mais na lixiviação de NO3-. Apesar de a crotalária apresentar maior perda de N por lixiviação, devido ao ...
Abstract: The knowledge of how soil management acts upon N cycling in long term can provide bases to develop crop production systems that optimize the cycling of this nutrient. The objective of this research was to assess the effect of soil management systems, using cover crops and chiseling in rotation with soybean on N cycling and balance. The experiment has been carried out since 2003, on a clayey Rhodic Nitosol. The experimental design was a randomized complete block design, in a split‑plot arrangement, with four replicates. Plots consisted of the fall-winter crops, triticale (X Triticosecale) and sunflower (Helianthus annuus), and subplots of the spring managements, pearl millet (Pennisetum glaucum), forage sorghum (Sorghum bicolor) and sunn hemp (Crotalaria juncea), besides chiseling in 2003 and 2009, at the spring too. Soybean (Glycine max) was grown in the summer. The N cycling and balance were studied by determinations of soil total-N and N storage, dry mass and N accumulation of crops and its residues, grain yield and N exportation by fall-winter crops and soybean, N outputs by NO3- leaching and NH3 and N2O emission, besides N inputs by atmospheric deposition, pesticide spraying and seeds. Losses of N ranged from 1.2 to 3.3, 8.2 to 8.9 and 12.2 to 50.4 kg ha-1 year-1 as N2O, ...
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Horner, Emily Renee. "THE EFFECT OF NITROGEN APPLICATION TIMING ON PLANT AVAILABLE PHOSPHORUS." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1211932436.
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Tavares, Ana Emília Barbosa 1983. "Manejo da adubação nitrogenada na produção e qualidade de frutos e sementes de abobrinha-de-moita /." Botucatu, 2018. http://hdl.handle.net/11449/154382.
Abstract:
Orientador: Antonio Ismael Inácio CardosoBanca: João Nakagawa
Banca: Hélio Grassi Filho
Banca: Cristiaini Kano
Banca: Pâmela Gomes Nakada Freitas
Resumo: Objetivou-se avaliar o efeito de doses e parcelamentos da adubação nitrogenada em cobertura na produção e teor de macronutrientes de frutos imaturos de abobrinha-demoita. Foram conduzidos dois experimentos, com treze tratamentos, no esquema fatorial 4x3+1, com quatro doses de nitrogênio em cobertura (62,5; 125,0; 187,5; 250,0 kg ha-1 de N), três parcelamentos (1 6 ⁄ + 1 3 ⁄ + 1 2 ⁄ ; 1 4 ⁄ + 1 2 ⁄ + 1 4 ⁄ e 1 3 ⁄ + 1 3 ⁄ + 1 3 ⁄ ) e um tratamento sem adubação em cobertura (dose zero), com quatro repetições. Os experimentos 1 e 2 foram conduzidos no ano de 2014 e 2015, respectivamente. Foram avaliados número de frutos total e comercial por planta, produção (g planta-1) total e comercial, comprimento, diâmetro e massa média de fruto comercial. Apenas no experimento 2 foi avaliado o teor de macronutrientes nos frutos. No experimento 1, o parcelamento 1 4 ⁄ + 1 2 ⁄ + 1 4 ⁄ proporcionou maior número de frutos total e comercial. No experimento 2, o aumento das doses nos parcelamentos 1 6 ⁄ + 1 3 ⁄ + 1 2 ⁄ e 1 3 ⁄ + 1 3 ⁄ + 1 3 ⁄ proporcionou incremento linear na produço de frutos total e comercial. A ordem decrescente de teores de macronutrientes nos frutos imaturos, foi de K>N>P>Ca>Mg>S.
Abstract: We evaluated the effect of nitrogen fertilization rates and plots on yield and macronutrient content of immature fruits of zucchini. Two experiments were carried out, with thirteen treatments, in the factorial scheme 4x3+1, with four nitrogen rates in top (62.5, 125.0, 187.5, 250.0 kg ha-1 of N), three splitting forms ( 1 6 ⁄ + 1 3 ⁄ + 1 2 ⁄ ; 1 4 ⁄ + 1 2 ⁄ + 1 4 ⁄ and 1 3 ⁄ + 1 3 ⁄ + 1 3 ⁄ ) and one treatment without fertilization in top (zero rate) with four replications. Experiment 1 and 2 were conducted in 2014 and 2015, respectively. Total and commercial fruit number per plant, total and commercial production (g plant1), length, diameter and average commercial fruit mass were evaluated. Only in experiment 2 the macronutrient content in the fruits was evaluated. In experiment 1, the 1 4 ⁄ + 1 2 ⁄ + 1 4 ⁄ splitting provided greater number of total and commercial fruit. In experiment 2, the increase of the rates in the 1 6 ⁄ + 1 3 ⁄ + 1 2 ⁄ and 1 3 ⁄ + 1 3 ⁄ + 1 3 ⁄ splitting resulted in a linear increase in total and commercial fruit production. The decreasing order of macronutrient contents in immature fruits was K>N>P>Ca>Mg>S.
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Kraaij, Tineke. "Effects of rain, nitrogen, fire and grazing on bush encroachment in semi-arid savanna, South Africa." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52817.
Abstract:
Thesis (MScFor)--Stellenbosch University, 2002.ENGLISH ABSTRACT: Increases in woody plant density ('bush encroachment') reduce livestock production and biodiversity. By convention, soil moisture, soil nutrients, fire and herbivory are regarded as the principal factors governing the tree-grass ratio of savannas. An experiment with a completely-crossed design was employed to investigate woody seedling (Acacia me/lifera) recruitment near Kimberley, Northern Cape, South Africa, after fire and under conditions of maximum-recorded rainfall, nitrogen addition and grazing. The field experiment was repeated as a garden experiment to determine if the two experiments yield comparable results. Tree germination in the field was extremely low, probably due to below-average natural rainfall in plots that only received natural rain, and insufficient watering frequency in irrigated plots. As a result of low germination, none of the treatments (rain/nitrogen/fire/grazing) had a significant effect on tree recruitment in the field experiment. The duration of the experiment (2000/2001 growing season) was insufficient for the treatments to affect grass composition, although the high rainfall treatment and grazing exclusion significantly improved grass cover and height. The garden experiment showed that frequent watering, no nitrogen addition and grass clipping significantly enhanced tree germination and survival (termed 'recruitment'). There were also significant interactions among rain, nitrogen and grazing in their effects on tree recruitment. The effects of rain on tree recruitment were more pronounced under nitrogen supplementation and vice versa. Similarly, high rain and high nitrogen enhanced the effect of grazing on tree recruitment. It is inferred that above-average rainfall years with frequent rainfall events are required for mass tree recruitment. Tree seedlings can further benefit from space and resources which are made available through grass defoliation. Conversely, nitrogen enrichment improves the competitive ability of the fast-growing grasses relatively more than that of the N2-fixing tree component, thereby suppressing tree recruitment. In contrast to conventional wisdom that grazing alone causes encroachment, it is suggested that there are complex interactions between the abovementioned factors and 'triggering' events such as unusually high rainfall. Contrary to many claims that equilibrium models are inappropriate for explaining savanna dynamics, it was shown that consumer-resource theory has explanatory power for bush-grass dynamics of the savanna studied. The state-space approach that was used facilitated the understanding of savanna dynamics and enabled predictions about the system's response to perturbations. The applicability of consumer-resource theory to semi-arid nutrient-poor savannas confirmed the importance of resource competition in structuring natural systems.
AFRIKAANSE OPSOMMING: Toenames in die digtheid van houtagtige plante ('bosverdigting') verlaag veeproduksie en biodiversiteit. Volgens konvensie word grondvog, grondvoedingstowwe, vuur en beweiding beskou as die belangrikste faktore wat die boom-gras verhouding van savannas bepaal. 'n Volledig-gekruisde ("completely crossed") eksperiment is ontwerp om boomsaad-ontkieming (Acacia mellifera) naby Kimberley, Noord-Kaap, Suid- Afrika, te bestudeer na 'n brand en onder toestande van maksimum-aangetekende reënval, stikstof toevoeging en beweiding. Die veldeskperiment is herhaal as 'n tuineksperiment om vas te stel hoe resultate van die twee eksperimente vergelyk. Boomsaad-ontkieming was uiters laag in die veld, waarskynlik weens ondergemiddelde reënval in persele wat slegs natuurlike reënvalontvang het, en 'n te lae benattingsfrekwensie in die besproeide persele. As gevolg van lae ontkieming in die veldeksperiment, het geen behandeling (reënval/stikstof/brand/beweiding) boomsaad-ontkieming beduidend geaffekteer nie. Die duur van die eksperiment (2000/2001-groeiseisoen) was te kort vir die behandelings om grassamestelling te beïnvloed, alhoewel besproeiing en geen beweiding die grasbedekking en -hoogte betekenisvol verhoog het. Die tuineksperiment het getoon dat boomsaadontkieming en vroeë oorlewing (genoem 'vestiging') betekenisvol verhoog is deur gereëlde benatting, geen stikstof toevoeging en die sny van gras. Daar was ook beduidende interaksies tussen reën, stikstof en beweiding in hul invloed op boomvestiging. Die reënbehandeling het 'n groter uitwerking op boomvestiging gehad onder stikstoftoevoeging en vice versa. Hoë reënval en stikstoftoevoeging het ook die invloed van beweiding op boomvestiging versterk. Die afleiding is dat bogemiddelde reënvaljare met gereëlde reënbuie 'n vereiste is vir grootskaalse boomvestiging. Boomsaailinge kan verder voordeel trek uit die spasie en hulpbronne wat beskikbaar raak wanneer gras ontblaar word. Daarteenoor verhoog stikstofverryking die mededingendheid van die vinniggroeiende grasse meer as dié van die N2-bindende boomkomponent, met die gevolg dat boomvestiging onderdruk word. In kontras met die konvensionele veronderstelling dat beweiding opsigself bosverdigting veroorsaak, word voorgestel dat ingewikkelde interaksies plaasvind tussen die bogenoemde faktore en ander 'sneller-gebeurtenisse', soos buitengewoon hoë reënval. In teenstelling met baie aansprake dat ekwilibrium modelle ontoepaslik is om savanna-dinamika te verklaar, is getoon dat die verbruikers-hulpbron teorie ("consumer-resource theory") oor verklaringsvermoë beskik vir boom-gras dinamika van die savanna wat bestudeer is. Die staat-spasie ("state-space") benadering gebruik, het begrip van savanna-dinamika bevorder en voorspellings moontlik gemaak aangaande die sisteem se reaksie op versteurings. Die toepaslikheid van verbruikers-hulpbron teorie vir semi-ariede, nutriënt-arm savannas bevestig dat kompetisie vir hulpbronne 'n sentrale rol speel in die strukturering van ekologiese sisteme.
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Caglia, Stefania. "Nitrogen Removal in the Pilot Plant ITEST (Increased Technology in Sewage Treatment)." Thesis, KTH, Mark- och vattenteknik (flyttat 20130630), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-171846.
Abstract:
Regions with a cold winter, as in the Baltic countries, have a problem to meet the nitrogen requirement in the Urban Wastewater Treatment Directive 98/15/EC. Especially in the winter season, the temperature of the influent wastewater could arrive also below 10°C and this delays the biological processes that takes place in the wastewater treatment. With the decrease of the temperature, the efficiency of nitrogen removal in the system decreases and leads to a high nitrogen loading in the effluent. The ITEST (Increased Technology and Efficiency in Sewage Treatment) project situated in Hammarby Sjöstadsverk in Stockholm has as its main aim to enhance nitrogen removal, thereby increasing the temperature in the incoming wastewater. The pilot plant ITEST is comprised of two treatment lines, one works with natural temperature influent and the other works at the temperature of 20 °C. In order to warm the incoming water a heating system, using waste heat, is used, leading to save energy. The two test lines were compared analyzing different parameters from January to May 2013. Total nitrogen, nitrate-nitrogen and ammonium-nitrogen concentrations were measured in the incoming water and in the effluent from the two treatment lines. Hence, the efficiency of the nitrogen removal was compared between the reference and the temperature line. In the period where the system was well functioning, the results show a nitrogen efficiency with a maximum of 92 % of removal of total nitrogen for the temperature line compared to only 65 % for the reference line. In the period where the system did not have any troubles the total nitrogen is under 10 mg/l, which is the limit of total nitrogen discharges specified in the Directive. Instead, for the sludge volume and the suspended solids any particular difference can be noticed from the two lines of treatment. In conclusion, in the temperature line can be noticed a great efficiency in nitrogen removal compared to the reference line.
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Lopes, Iza Paula de Carvalho. "Indicadores do estado de nitrogênio da planta, produtividade e biofortificação de tubérculos de batata influenciados por doses de sulfato de magnésio." Universidade Federal de Viçosa, 2014. http://locus.ufv.br/handle/123456789/4636.
Abstract:
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Previous issue date: 2014-07-18Fundação de Amparo a Pesquisa do Estado de Minas Gerais
The aim of this study was to evaluate the effect of magnesium sulphate (MgSO4.7H2O) rates on potato nitrogen status indicators and tuber yield, biofortification, greening and sprouting, Agata cultivar. The experiment was carried out on the field of Universidade Federal de Viçosa from June 7 to September 23th, 2013. The treatments consisted of five magnesium sulfate rates (0, 100, 200, 400 and 800 kg ha-1) pre planting applied with four replications. Plant nitrogen status indicators were evaluated at 21 and 60 days after plant emergence (DAE). Such indicators were SPAD, Dualex, and greenness indices and biomarkers determined in the fourth leaf (length, width, petiole diameter, leaf number, area, fresh and dry matter mass). Also they were determined the biomarkers in the plant organs (stem, leaf and tuber numbers, length and diameter of the main stem, fresh and dry matter mass of leaves, stems, roots and tubers and total plant leaf area). Besides, it was also determined the N content and concentration in the fourth leaf. The fourth leaf, leaves, stems, tubers and roots magnesium (Mg) contents in the dry matter were evaluated at 21 and 60 DAE and the Mg in the tubers was evaluated at end of the harvest, at 88 DAE. Additionally, it was performed analysis of the emergence speed índex (EVI), tuber number, commercial tubers (classes 2 and 3) fresh and dry yield, greening and sprouting of washed and unwashed tubers. Different potato nitrogen status indicators are differently influenced by Mg rates and evaluation time. The highest commercial tuber yield was 40,09 t ha-1 with 800 kg ha-1 of magnesium sulfate which led to 0,904 dag kg-1 of Mg in the fourth leaf dry matter, at 21 DAE. Greenness of tubers yielded from plants fertilized with 800 kg ha -1 of magnesium sulfate, washed or not, were more intense than those from plants without Mg fertilization. After 90 days of storage, increasing magnesium sulphate rates increased linearly the number of sprouted tubers washed and unwashed. It was not possible to biofortify potato tubers using magnesium sulphate rate up to 800 kg ha-1 however, there were Mg "luxury concentration" inductions in leaves, stems and roots of potato plant at early plant development stages.
O objetivo desse trabalho foi avaliar o efeito de doses de sulfato de magnésio (MgSO4.7H2O) sobre indicadores do estado de nitrogênio na planta, produtividade, biofortificação, esverdeamento e brotação de tubérculos de batata, cultivar Ágata. O experimento de campo foi realizado na Horta Nova do Departamento de Fitotecnia da Universidade Federal de Viçosa (DFT/UFV), no período de 7 de junho a 23 de setembro de 2013. Os tratamentos foram constituídos de cinco doses de sulfato de magnésio (0, 100, 200, 400 e 800 kg ha -1) aplicadas em pré - plantio, com quatro repetições. Foram avaliadas, aos 21 e 60 dias após emergência (DAE), características indicadoras do estado de nitrogênio na planta. Tais características foram os índices SPAD, Dualex, intensidade do verde e os bioindicadores determinados na quarta folha (comprimento, largura, diâmetro do pecíolo, número de folíolos, área foliar, massas das matérias fresca e seca) e nos órgãos da planta (número de hastes, folhas e tubérculos, comprimento e diâmetro da haste principal, massas das matérias fresca e seca de folhas, hastes, raízes e tubérculos e área foliar), além do teor e conteúdo de N na massa da matéria seca da quarta folha. Também foram avaliados teor e conteúdo de magnésio (Mg) na massa da matéria seca da quarta folha, folhas, hastes, tubérculos e raízes, aos 21 e 60 DAE e nos tubérculos na colheita final, aos 88 DAE. Adicionalmente foram avaliados o índice de velocidade de emergência (IVE), número, massas das matérias seca e fresca de tubérculos comerciais (classes 2 e 3), esverdeamento e brotamento de tubérculos lavados e não lavados. Diferentes características indicadoras do estado de nitrogênio da batata são diferentemente influenciadas por doses de Mg e por época de avaliação. A maior produtividade comercial foi 40,09 t ha -1 de tubérculos com a aplicação da dose de 800kg ha-1 de sulfato de magnésio que propiciou, aos 21 DAE, a concentração de 0,904 dag kg-1 de Mg na massa da matéria seca da quarta folha. Tubérculos oriundos das plantas do tratamento que recebeu 800kg ha-1 de sulfato de magnésio, lavados ou não, apresentaram maior intensidade de esverdeamento do que aqueles produzidos nas plantas não adubadas com Mg. Após 90 dias de armazenamento, dose crescente de sulfato de magnésio aumentou linearmente o número de brotos de tubérculos lavados e não lavados. Não foi possível biofortificar os tubérculos de batata usando dose de até 800kg ha-1 de sulfato de magnésio, porém, houve indução da concentração de luxo de Mg em folhas, hastes e raízes de batata, no início do ciclo da planta.
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Gould, R. P. "The effects of gaseous sulphur dioxide and nitrogen dioxide on carbon allocation in plants." Thesis, Lancaster University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377896.
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Fernandes, Fabiana Morbi. "Estimativa da necessidade de nitrogênio na cultura da batata com base no índice relativo de clorofila /." Botucatu, 2017. http://hdl.handle.net/11449/151369.
Abstract:
Orientador: Rogério Peres SorattoCoorientador: Adalton Mazetti Fernandes
Banca: Dirceu Maximino Fernandes
Banca: José Magno Queiroz Luz
Resumo: O nitrogênio (N) é um dos nutrientes extraídos em maior quantidade pela batateira e tem grande impacto no desempenho dessa cultura. A resposta da cultura da batata à adubação nitrogenada é dependente de diversos fatores, o que torna essencial o manejo correto do N, maximizando assim a absorção deste pela planta. Além disso, a aplicação de doses insuficientes ou demasiadamente elevadas de N pode reduzir a produtividade e a qualidade dos tubérculos produzidos e representar prejuízos aos produtores e riscos ao ambiente. Neste sentido, a estimativa da necessidade de N, mediante leituras do índice relativo de clorofila (IRC) nas folhas da cultura, com o clorofilômetro portátil, pode ser uma alternativa viável para tornar o manejo do N mais preciso. Contudo, ainda existe a necessidade de estabelecimento de critérios para a utilização dessa ferramenta na cultura da batata. Dessa forma, os objetivos deste trabalho foram: a) avaliar a correlação entre o IRC, obtido mediante leituras do clorofilômetro portátil, e o teor de N da folha de duas cultivares de batata (Agata e Electra), em diversos estádios de desenvolvimento e b) avaliar qual valor (90% e 95%) do índice de suficiência de N (ISN), calculado com base nas medidas IRC nas folhas em relação ao tratamento referência, é o mais adequado para indicar o momento da adubação nitrogenada em duas cultivares de batata e, consequentemente, proporcionar maior produtividade, qualidade de tubérculos e eficiência de utilização do N aplicado. D... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract:Nitrogen (N) is one of the nutrients extracted in greater quantity by potato and has a great impact on the performance of this crop. The response of the potato crop to the nitrogen fertilization is dependent on several factors, which makes essential the correct management of N, thus maximizing its absorption by the plant. In addition, the application of insufficient or excessively high doses of N may reduce the productivity and quality of the tubers produced and represent damages to the producers and risks to the environment Therefore, the estimation of the need for N, through readings of the relative index of chlorophyll (IRC) in the leaves of the culture, with the portable chlorophyllometer, can be a viable alternative to make N management more accurate. However, there is still a need to establish criteria for the use of this tool in the potato crop. Thus, the objectives of this study were: a) evaluate the correlation between the IRC, obtained by readings of chlorophyll, and the N concentration in leaves of two potato cultivars (Agata e Electra) in various stages of development, and b) evaluate what value (90% or 95%) of N sufficiency index (NSI), calculated based on RCI measures in the leaves regarding the treatment reference, is best suited to indicate the time of N fertilizer in two cultivars potato and hence to higher tuber yields and quality, and N-use efficiency. In the year 2016, during winter season four experiments were carried out in the field conditions, two at Lageado Experimentl Farm (Site 1) and two in a private potato farm (Site 2), both in the municipality of Botucatu. In each site were carried out one experiment with each cultivar. The design used in each experiment will be randomized blocks, with six N managements (M1: 80 kg ha-1 N in the planting furrow + 80 kg ha-1 at 10 days after emergence (DAE) + 80 kg ha-1 at 30 DAE + 80 kg ha-1 at 45 DAE (reference); ...
Mestre
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Ferreira, Tamires Esther 1988. "Decomposição da palha de cana-de-açúcar em área de recolhimento variável sob adubação nitrogenada mineral ou inoculação com bactérias diazotróficas /." Botucatu, 2017. http://hdl.handle.net/11449/151920.
Abstract:
Orientador: Carlos Alexandre Costa CrusciolCoorientador: Nilza Patricia Ramos
Banca: Cristinano Alberto de Andrade
Banca: Raffaela Rossetto
Resumo: A operação de recolhimento da palha de cana-de-açúcar trouxe a oportunidade ímpar de agregar sustentabilidade e renda extra ao setor sucroalcooleiro. Com isto, dúvidas surgiram sobre os efeitos que esta prática ocasionaria ao sistema solo-planta, e quais seriam as necessidades de alteração nas práticas de manejo, principalmente quando se trata da adubação nitrogenada, além de permitir a exploração de tecnologia pouco explorada, como a interação entre planta e microrganismos fixadores de nitrogênio. Neste sentido, o objetivo desta pesquisa foi avaliar a dinâmica de decomposição de quantidades variáveis de palha pela aplicação de adubo nitrogenado mineral ou inoculação com bactérias diazotróficas. Para isto acompanhou-se a decomposição da palha durante a primeira soca da variedade IACSP 95-5000, testando três níveis de recolhimento (36, 64 e 100%), o equivalente à 4.300; 7.400; e 11.500 kg ha-1 de palha mantida em campo e duas técnicas de cobertura: 120 kg ha-1 de nitrato de amônio e a inoculação foliar com a mistura de cinco estirpes bacterianas (Azospirillum amazonense, Gluconacetobacter diazotrophicus, Herbaspirillum seropedicae, Herbaspirillum rubrisubalbicans e Burkholderia tropica). O experimento foi instalado em fatorial 3x2, distribuídos em blocos ao acaso com parcela subdivida no tempo (coletas). Para avaliar a decomposição foi utilizado o método de "litterbags", com coletas regulares aos 0, 101, 180, 235, 285 e 319 dias após a instalação em campo, permitindo o acompan... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The sugarcane straw recovering process brought an unique opportunity to join sustainability and income to sugarcane sector.Thus, doubts arose about the outcome that this practice would have on soil-plant system, and beyond, what would be necessary to change in management system, especially when it comes to nitrogen fertilization, both for amount and source selected, as well as poorly exploited technology using, such the relationship between plant and nitrogen-fixing microorganisms.Therefore, the research aimed to evaluate sucargacane straw levels and its effect on decomposition process by using mineral fertilizer and NBF inoculant. The experiment proceeded by following straw decomposition of IACSP 95-5000 first ratoon, testing three recovering rates (36,64 e 100%), wich represents 4,300; 7,400; and 11,500 kg ha-1 of straw left in the field and two top dressing techniques: 120 kg ha- 1 of ammonium nitrate and leaf inoculation with five bacterial strains (Azospirillum amazonense, Gluconacetobacter diazotrophicus, Herbaspirillum seropedicae, Herbaspirillum rubrisubalbicans and Burkholderia tropica). The experiment was installed in 3x2 factorial arranged in randomized blocks with design scheme of split plot (sampling). The decomposition process was accompanied by litterbags method with sampling at 0, 101, 180, 235, 285 and 319 days after installation wich allowed to determine rate (%) and dry mass of biomass, carbon, structural carbohydrates, lignin, and nitrogen (kg ha-1 ) besides C: N ratio. The C N contents (%) collected from 0-5cm layer was evaluated before harvesting, as well as 0-10 cm, but the last one were sampled from row and crop interrow. The results were submitted to variance analysis with regression and when significant differences were detected, means were compared by Tukey (p <0.05). At the end of the experiment, carbon and straw dry mass constant and decomposition rate ...
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Ottman, M. J., T. A. Doerge, and E. C. Martin. "Late Season Water and Nitrogen Effects on Durum Quality, 1995 (Preliminary)." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/201443.
Abstract:
Durum grain quality is affected by many factors, but water and nitrogen are factors that the grower can control. The purpose of this research was to determine 1) the nitrogen application rate required at pollen shed to maintain adequate grain protein levels if irrigation is excessive or deficient during grain fill and 2) if nitrogen applications during grain fill can elevate grain protein. Field research was conducted at the Maricopa Agricultural Center using the durum varieties Duraking, Minos, and Turbo. The field was treated uniformly until pollen shed when nitrogen was applied at rates of 0, 30, and 60 lbs /acre. During grain fill, the plots were irrigated based on 30, 50, or 70% moisture depletion. In a separate experiment, nitrogen fertilizer was applied at a rate of 30 lbs N /acre at pollen shed only, pollen shed and the first irrigation after pollen shed, and pollen shed and the first and second irrigation after pollen shed. Irrigation had no effect on grain protein level, although increasing nitrogen rates at pollen shed from 0 to 30 and 30 to 60 lbs N /acre increased protein by 1 percentage point. Nitrogen fertilizer application at the first irrigation after pollen shed increased grain protein content from 10.4 to 11.4% and application at the first and second irrigation after pollen shed increased grain protein content further to 11.9% averaged over varieties. Irrigation management during grain fill may not play as large a role in controlling grain protein content as was originally thought except perhaps on heavy soils, and nitrogen fertilizer application during grain fill may not be too late to increase grain protein content.
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Wang, Guangyao (Sam), Kevin Brunson, Kelly Thorp, and Mike Ottman. "Cultivar and Nitrogen Effects on Yield and Grain Protein in Irrigated Durum Wheat, 2012." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2013. http://hdl.handle.net/10150/312150.
Abstract:
The grain yield and nitrogen use efficiency of durum wheat vary in response to genotypic and nitrogen fertilization were studied in field during two growth seasons. The aim of this study was to evaluate the effects the N fertilizer rate on grain yield and quality under irrigated desert conditions in relation to N utilization. Six durum wheat cultivars (Duraking, Havasu, Kronos, Ocotillo, Orita, Topper) were grown in field trails under irrigated regimes at five N levels (0, 65, 110, 160, 240 lbs/acre) in 2010-2011 and six N levels (0, 65, 110, 160, 240, 360 kg ha-1) in 2011-2012 at Maricopa Ag Center. The results showed the varieties and N levels both significantly affected grain yield, grain protein concentration, and nitrogen use efficiency. A simple and rapid method to measure crop N status using SPAD meters was also developed. The results showed that using the differences in SPAD readings between the first and second fully expanded leaves is a useful way to improve effectiveness of SPAD meters in durum wheat N management.
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Haselbauer, Franciele Rechembach. "Produtividade da aveia branca cv. IPR 126 submetida à níveis e formas de parcelamento de nitrogênio em cobertura, com e sem cortes." Universidade Tecnológica Federal do Paraná, 2017. http://repositorio.utfpr.edu.br/jspui/handle/1/2653.
Abstract:
CAPESA intensificação da produção em sistemas integrados de produção, basifica-se na sustentabilidade do mesmo, buscando os melhores arranjos para sustentação de bons resultados. A adubação é de extrema importância para o sucesso na produtividade, sendo a nitrogenada que requer maior atenção na produção, principalmente, de gramíneas. No cultivo de pastagens muitas vezes há um negligenciamento na adubação, sendo maior quando se trata para cobertura. Com base nesta premissa, o trabalho tem o objetivo de encontrar uma resposta para a adubação nitrogenada aplicada na aveia branca, bem como se esta adubação é mais responsiva em doses únicas ou parceladas, em sistema de cortes e para cobertura vegetal. O experimento foi desenvolvido na UTFPR-DV, em delineamento fatorial 2 x 6 (manejo x níveis de nitrogênio), blocos ao acaso, com três repetições e parcelas subdivididas. As parcelas receberam quatro doses de nitrogênio 0, 60, 120 e 180 kg ha-1 de N associados a três formas de parcelamento do fertilizante (aplicação em dose única bem como o parcelamento das doses de 120 e 180 kg ha-1 de N em duas e três aplicações de 60 kg N ha-1 respectivamente). A adubação nitrogenada foi realizada a lanço, sendo a ureia (45% N) a fonte de nitrogênio utilizada. As avaliações realizadas na aveia foram determinação de taxa de acúmulo, matéria seca, taxa de recuperação e eficiência de uso do nitrogênio e teor de proteína bruta. Os dados obtidos foram submetidos à análise de variância e quando verificado significância pelo teste F as médias foram comparadas pelo Teste Tukey a 5% de probabilidade de erro. A taxa de acumulo média variou de 39,36 a 59,42 kg ha-1 de MS para sem cortes e de 41,73 a 62,67 kg ha-1 de MS com cortes. A produção de matéria seca para sem cortes o acumulado variou de 6240 a 10266,67 kg ha-1 de MS nos níveis estudados, com cortes, foi de 4865 a 7593,33 kg ha-1 de MS. A máxima eficiência técnica foi obtida com 149 kg ha-1 de N. A eficiência do uso do nitrogênio decresceu com o aumento dos níveis de nitrogênio. Em geral, a taxa de recuperação também decresceu com o aumento dos níveis de nitrogênio. A proteína bruta variou para as parcelas sem cortes de 12,1 a 16,06% e com cortes de 13,41 a 16,92%. Conclui-se que houve imobilização de nitrogênio aplicado nas maiores doses, sendo mais expressivo nos tratamentos que não receberam cortes. A partir de 120 kg ha-1 de N o parcelamento pode ser interessante quando não se pode ter perda temporal pela imobilização.
The intensification of production in integrated production systems, is based on the sustainability of the same, seeking the best arrangements to sustain good results. Fertilization is of extreme importance for the success in productivity, being nitrogenous that requires more attention in the production, mainly of grasses. In cultivation of pastures there is often negligence in fertilization, being greater when it comes to coverage. Based on this premise, the objective of this work is to find an answer for the nitrogen fertilization applied in white oats, as well as if this fertilization is more responsive in single or split doses, in a system of cuts and for vegetal cover. The experiment was developed in UTFPR-DV, in a 2 x 6 factorial design (management x nitrogen levels), randomized blocks, with three replicates and subdivided plots. The plots received four nitrogen doses 0, 60, 120 and 180 kg ha-1 of N associated to three forms of fertilizer application (single dose application as well as the splitting of doses of 120 and 180 kg ha-1 of N in two and three applications of 60 kg N ha-1 respectively). Nitrogen fertilization was carried out in the haul, with urea (45% N) being the source of nitrogen used. The evaluations carried out in the oats were determination of accumulation rate, dry matter, recovery rate and efficiency of nitrogen use and crude protein content. The data were submitted to analysis of variance and when verified by means of the F test, the means were compared by the Tukey test at 5% error probability. The mean accumulation rate ranged from 39.36 to 59.42 kg ha-1 of DM for uncut and 41.73 to 62.67 kg ha-1 of DM with cuts. The dry matter yield for uncrowded accumulated varied from 6240 to 10266.67 kg ha-1 of DM at the studied levels, with cuts, from 4865 to 7593.33 kg ha-1 of MS. The maximum technical efficiency was obtained with 149 kg ha-1 of N. The efficiency of the use of nitrogen decreased with the increase of the nitrogen levels. In general, the recovery rate also decreased with increasing nitrogen levels. The crude protein varied for the plots without cuts of 12.1 to 16.06% and with cuts of 13.41 to 16.92%. It was concluded that there was immobilization of nitrogen applied at higher doses, being more expressive in treatments that did not receive cuts. From 120 kg ha-1 of N, the splitting can be interesting when there is no temporal loss due to immobilization.