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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Water table management for cranberry production on sandy and peat soils Québec

Handyside, Patrick E. January 2003 (has links)
No description available.
42

Effect of water table management on selected physical properties and carbon fractions of a Hoytville soil in Northwest Ohio

Baker, Barbara J. 20 December 2002 (has links)
No description available.
43

A subsurface irrigation experiment on a St. Samuel sandy loam soil /

Hoyningen Huene, Bernhard von. January 1984 (has links)
No description available.
44

A subsurface irrigation experiment on a St. Samuel sandy loam soil /

Hoyningen Huene, Bernhard von January 1984 (has links)
No description available.
45

Desenvolvimento de mudas de pinhão manso (Jatropha  curcas L.) em tubetes e submetidas a diferentes níveis de déficit hídrico. / Development of seedlings of physic nut (Jatropha curcas L.) in plastic tubes and submitted to different levels of water deficit

Cícero Renê Almeida Barboza Júnior 31 January 2012 (has links)
Com a crescente procura por alternativas para suprir energeticamente o mundo, cada vez mais, fontes mais limpas e renováveis estão sendo utilizadas. No Brasil, a produção de óleos vegetais visando a geração de energia (biodiesel) ainda é incipiente. Dentre as diferentes espécies de oleaginosas, o pinhão manso (Jatropha curcas L.) vem se destacando como uma ótima alternativa no fornecimento de matéria prima para a produção de biodiesel. Informações sobre essa cultura ainda são escassas, principalmente no Brasil, onde há pouco tempo foram iniciadas as pesquisas. A necessidade de informações locais também ressalta a importância da pesquisa com o Pinhão Manso. Com base nessas necessidades, o objetivo desse experimento foi analisar a viabilidade técnica da produção de mudas irrigadas de pinhão manso por sistema de subirrigação e desenvolver um sistema automatizado de manejo. O controle da irrigação foi realizado a partir da variação de peso dos tubetes com as mudas, devido a perda de água por evapotranspiração. No processo de controle dos pesos foram utilizadas células de carga, que monitoraram a variação de peso de um conjunto de tubetes denominado conjunto controle. O delineamento experimental foi em delineamento inteiramente aleatorizado, com quatro repetições. Os tratamentos avaliados foram quatro níveis de depleção da máxima capacidade de retenção de água (MCRA) apresentada pelo substrato (T1=20%, T2=40%, T3=60% e T4=80% da MCRA). Para se quantificar os efeitos dos tratamentos foram avaliadas semanalmente as seguintes características das mudas: altura e diâmetro do caule, número de folhas e área foliar, bem como a produção de matéria fresca e seca da parte aérea e do sistema radicular. Os resultados mostram que o tratamento 2 foi o que se destacou dentre os demais, produzindo mudas de melhor qualidade, com maior acúmulo de matéria seca e maior consumo hídrico. / With the growing demand for alternative energy to meet the world, increasingly more clean and renewable sources are being used. In Brazil, the production of vegetable oils aimed at producing energy (biodiesel) is still incipient. Among the different species of oleaginous plants, jatropha (Jatropha curcas L.) has emerged as a great alternative in providing raw material for biodiesel production. Information on this crop are still scarce, especially in Brazil where they recently started research. The need for local information also emphasizes the importance of research with Jatropha. Based on these needs, the aim of this experiment was to analyze the technical viability production of jatropha seedlings irrigated by subirrigation system and develop an automated system management. The irrigation control was carried out from the weight variation of the vials with the seedlings because of water loss through evapotranspiration. In the process of weight control were used load cells, which monitored the weight variation of a set of vials called the control group. The experimental design was the completely randomized with four replications. The treatments were four levels of depletion of the maximum water holding capacity (MCRA) presented by the substrate (T1=20%, T2=40%, T3=60% e T4=80% da MCRA). To quantify the effects of the treatments were evaluated weekly the following characteristics of seedlings: height and diameter of the stem, leaf number and leaf area, and the production of fresh and dry shoot and root. The results show that treatment 2 was what stood out among the others, producing higher quality seedlings with greater dry matter accumulation and increased water consumption.
46

Desenvolvimento de mudas de pinhão manso (Jatropha  curcas L.) em tubetes e submetidas a diferentes níveis de déficit hídrico. / Development of seedlings of physic nut (Jatropha curcas L.) in plastic tubes and submitted to different levels of water deficit

Barboza Júnior, Cícero Renê Almeida 31 January 2012 (has links)
Com a crescente procura por alternativas para suprir energeticamente o mundo, cada vez mais, fontes mais limpas e renováveis estão sendo utilizadas. No Brasil, a produção de óleos vegetais visando a geração de energia (biodiesel) ainda é incipiente. Dentre as diferentes espécies de oleaginosas, o pinhão manso (Jatropha curcas L.) vem se destacando como uma ótima alternativa no fornecimento de matéria prima para a produção de biodiesel. Informações sobre essa cultura ainda são escassas, principalmente no Brasil, onde há pouco tempo foram iniciadas as pesquisas. A necessidade de informações locais também ressalta a importância da pesquisa com o Pinhão Manso. Com base nessas necessidades, o objetivo desse experimento foi analisar a viabilidade técnica da produção de mudas irrigadas de pinhão manso por sistema de subirrigação e desenvolver um sistema automatizado de manejo. O controle da irrigação foi realizado a partir da variação de peso dos tubetes com as mudas, devido a perda de água por evapotranspiração. No processo de controle dos pesos foram utilizadas células de carga, que monitoraram a variação de peso de um conjunto de tubetes denominado conjunto controle. O delineamento experimental foi em delineamento inteiramente aleatorizado, com quatro repetições. Os tratamentos avaliados foram quatro níveis de depleção da máxima capacidade de retenção de água (MCRA) apresentada pelo substrato (T1=20%, T2=40%, T3=60% e T4=80% da MCRA). Para se quantificar os efeitos dos tratamentos foram avaliadas semanalmente as seguintes características das mudas: altura e diâmetro do caule, número de folhas e área foliar, bem como a produção de matéria fresca e seca da parte aérea e do sistema radicular. Os resultados mostram que o tratamento 2 foi o que se destacou dentre os demais, produzindo mudas de melhor qualidade, com maior acúmulo de matéria seca e maior consumo hídrico. / With the growing demand for alternative energy to meet the world, increasingly more clean and renewable sources are being used. In Brazil, the production of vegetable oils aimed at producing energy (biodiesel) is still incipient. Among the different species of oleaginous plants, jatropha (Jatropha curcas L.) has emerged as a great alternative in providing raw material for biodiesel production. Information on this crop are still scarce, especially in Brazil where they recently started research. The need for local information also emphasizes the importance of research with Jatropha. Based on these needs, the aim of this experiment was to analyze the technical viability production of jatropha seedlings irrigated by subirrigation system and develop an automated system management. The irrigation control was carried out from the weight variation of the vials with the seedlings because of water loss through evapotranspiration. In the process of weight control were used load cells, which monitored the weight variation of a set of vials called the control group. The experimental design was the completely randomized with four replications. The treatments were four levels of depletion of the maximum water holding capacity (MCRA) presented by the substrate (T1=20%, T2=40%, T3=60% e T4=80% da MCRA). To quantify the effects of the treatments were evaluated weekly the following characteristics of seedlings: height and diameter of the stem, leaf number and leaf area, and the production of fresh and dry shoot and root. The results show that treatment 2 was what stood out among the others, producing higher quality seedlings with greater dry matter accumulation and increased water consumption.
47

Water management effects on potato production and the environment

Satchithanantham, Sanjayan January 2012 (has links)
Potatoes (Solanum tuberosum) were grown in a fine sandy loam soil in southern Manitoba in a three-year field study comparing four water management treatments: No Drainage with No Irrigation (NDNI), No Drainage with Overhead Irrigation (NDIR), Free Drainage with Overhead Irrigation (FDIR), and Controlled Drainage with Subirrigation (CDSI). The objectives of the study were (i) to evaluate the effect of the four treatments on yield and quality of potatoes, (ii) to evaluate the effect of water management on the environment, (iii) to estimate the shallow groundwater contribution to potato water requirement, and (iv) to simulate the shallow groundwater hydrology using the DRAINMOD and HYDRUS 1-D model. Subsurface drains were installed at 0.9 m depth and at spacings of 15 m (FDIR) and 8 m (CDSI). Subirrigation was done by pumping water back into the tiles through the drainage control structures. Overhead irrigation was carried out using a travelling gun. Water table depth, soil water content, drainage outflow, nutrient concentration in drainage water, irrigation rate, weather variables, potato yield and quality parameters, and biomass were measured. Compared to the NDNI treatment, the potato yield increase in the other treatments ranged between 15-32% in 2011 and 2-14% in 2012. In 2011, potato yield from FDIR was higher than CDSI (p = 0.011) and NDNI (p = 0.001), and yield from NDIR was higher than NDNI (p = 0.034). In 2012, potato yield was higher in FDIR in comparison to NDNI (p = 0.021). In 2012, the NDIR gave higher dark ends (p = 0.008) compared to other treatments. Under dry conditions, up to 92% of the potato crop water demand could be met by shallow groundwater contribution. Compared to free drainage, controlled drainage was able to lower the nitrate export by 98% (p = 0.033) in 2010 and by 67% (p = 0.076) in 2011, and the phosphate export decreased by 94% (p = 0.0117) in 2010. A major part of the drainage flow and nutrient export took place between April and June in southern Manitoba. DRAINMOD was able to accurately predict the shallow groundwater hydrology for this particular research site.

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