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Dispersão e condutividade hidráulica em solos de Pernambuco, em resposta à saturação por sódio e à concentração salina da solução / Dispersion and hydraulic conductivity in soils of Pernambuco, in response to sodium saturation and salt solution concentrationPaes, Jefferson Luiz de Aguiar 15 February 2012 (has links)
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Previous issue date: 2012-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / To estimate clay dispersion susceptibility, the water dispersible clay (WDC) is determined in the laboratory. This analysis may not correspond to reality observed in the field, when saline and saline-sodic soils are present, due to the relatively high salt concentration in the soil solution. In addition, results of determinations of saturates hydraulic conductivity (K0) in the laboratory with distilled or deionized water, may also not match the field conditions in these soils. Thus, we determined the dispersed clay (DC) and the K0, in the laboratory using working solutions of different electrical conductivities (EC) in seven representative soils of Pernambuco State, with exchangeable sodium percentage (ESP) set in the range of 5-30%. In the determination of DC was used a factorial arrangement (7x6x5): 7 soils, 6 adjustments in ESP values (5, 10, 15, 20, 25 and 30%) and 5 EC (0, 0.3, 0.6; 0.9 and 1.2 dS m-1). In the K0 assay was used a factorial arrangement (7x3x3): 7 soil, 3 adjustments in ESP values (5, 15 and 30%) and 3 EC (0, 0.6 and 1.2 dS m-1). The adjustment of ESP was performed by saturating the soil with solutions of sodium adsorption ratio (SAR) appropriate. The DC was obtained by stirring a suspension of 400 ml in 500 mL containers, using a Wagner rotary shaker for 16 h, at 50 rpm. The K0 was measured using constant head permeameter. The experimental results show that there was an increase in the values of DC directly related to the increase in ESP and decrease in EC, also resulting in a decrease in the value K0. The response to treatment was more pronounced in soils with higher proportions of active clays compared to those with a strong presence of iron oxides. The presence of more active clay causes reduction in K0 compared to soils with high percentage of oxides. Those soils are more susceptible to K0 variations due to ESP. Also there is a marked influence of water EC used in the analysis or for irrigation. Measurements of WDC and K0, usually associated with problems of infiltration, erosion and deterioration of the soil structure, are generally performed in laboratories with deionized or distilled water, EC close to 0 dS m-1. However, for salt affected soils, the analysis should be carried out with solutions of EC ≠ 0 dS m-1, using values close to the EC of the saturation extract. / Para estimar a tendência à dispersão de argilas, determina-se, em laboratório, o teor de argila dispersa em água (ADA). Essa análise pode não corresponder à realidade no campo em solos salinos e salino-sódicos, em que a solução desses apresenta concentrações relativamente elevadas de sais. Em acréscimo, resultados de determinações da condutividade hidráulica em meio saturado (K0) em laboratório, com água destilada ou deionizada, podem também não corresponder às condições de campo nesses solos. Determinaram-se a argila dispersa (AD) e a K0, em laboratório, utilizando soluções de trabalho de diferentes condutividades elétricas (CE) em sete solos representativos do Estado de Pernambuco, com percentagem de saturação de sódio (PST) ajustada no intervalo de 5-30%. Na determinação da AD, utilizou-se arranjo fatorial (7x6x5): sete solos, seis ajustes nos valores da PST (5, 10, 15, 20, 25 e 30%) e cinco CE (0; 0,3; 0,6; 0,9; e 1,2 dS m-1). No ensaio da K0, usou-se arranjo fatorial (7x3x3): sete solos, três ajustes nos valores da PST (5, 15 e 30 %) e três CE (0; 0,6 e 1,2 dS m-1). O ajuste da PST foi realizado, saturando os solos com soluções de relação de adsorção de sódio (RAS) apropriadas. A AD foi obtida agitando-se 400 mL de suspensão em recipientes de 500 mL, em agitador rotatório Wagner, durante 16 h, a 50 rpm. A K0 foi quantificada por meio de permeâmetros de carga constante. Os resultados experimentais evidenciaram que houve incremento nos valores da AD diretamente relacionado com o aumento da PST e a diminuição da CE na solução de trabalho, resultando também na diminuição nos valores da K0. A resposta aos tratamentos foi mais acentuada nos solos com maiores proporções de argilas ativas frente àqueles com presença marcante de óxidos de ferro. A presença de argilas mais ativas leva à diminuição da K0, quando comparada com solos com maior proporção de óxidos, tornando esses mais susceptíveis a variações de K0, em decorrência da PST, com marcada influência da CE da água eventualmente utilizada na análise ou na irrigação. As determinações da ADA e de K0, geralmente associadas a problemas de infiltração, erosão e degradação da estrutura dos solos, são realizadas em laboratórios com água deionizada ou destilada, de CE próxima de 0 dS m-1; no entanto, para solos afetados por sais, as análises deveriam ser realizadas com soluções de CE ≠ 0 dS m-1, utilizando valores próximos aos do extrato da pasta de saturação.
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Dinâmica da água e dos nutrientes no sistema de produção integrado gerado pela dessalinização da água de poço do semiárido brasileiro / Dynamics of water and nutrients in the integrated production system generated by desalination of ground water from Brazilian semiaridEduardo Ballespi de Castro Vasconcellos 01 July 2011 (has links)
Foram realizadas análises isotópicas, físicas e químicas na água, no solo e nas plantas do Sistema de Produção Integrado Utilizando Efluentes de Dessalinização, criado pela Embrapa Semiárido, como uma alternativa para a reutilização desses efluentes na produção de alimentos e diminuição do impacto ambiental causado pelo descarte incorreto deste rejeito. O sistema avaliado se localiza no Campo Experimental da Caatinga, na Embrapa Semiárido (Petrolina-PE). Os resultados encontrados quanto à ciclagem dos nutrientes indicaram a ocorrência de uma contínua adição dos cátions Ca+2, Mg+2 , K+ e Na+ no solo durante o experimento, de 199 kg ha-1, 88 kg ha-1, 51 kg ha-1 e 142 kg ha-1, respectivamente. A eficiência de retirada do Ca+2, Mg+2 e Na+ pela Atriplex nummularia foi de 12,1, 4,3 e 23,9%, respectivamente; Ocorreu uma elevada perda de nitrogênio no sistema causado pelo processo de denitrificação, que diminuiu a concentração de nitrogênio em 72% do inicio ao final do sistema, levando este nutriente em quantidades insuficientes para a área agrícola. Estes resultados serão utilizados para indicar caminhos de melhorias no sistema. Ainda, quanto aos resultados isotópicos, foi possível concluir que: a água sofre um fracionamento durante o processo de osmose reversa na ordem de 1,87 para o 18O e 10,3 para o 2H; A água do poço é formada por uma mistura de águas recentes e paleoáguas; A relação 18O vs 2H; possui um coeficiente angular de 4,1, indicando elevada evaporação neste elemento; O solo avaliado possui uma média isotópica de -24 de 13C no solo de caatinga e -20 de 13C na área experimental, indicando uma troca da matéria orgânica desta área por material proveniente da Atriplex, que teve uma razão isotópica média de -13,7 .de 13C. / Isotopic, physical and chemical analysis were performed in water, soil and plants of the \" Integrated Production System Using Wastewater Desalination \", created Embrapa Semiarid, as an alternative to reuse of wastewater for food production and reducing the environmental impact caused by the incorrect disposal of the reject. The evaluated system is located in the Experimental Área Caatinga at Embrapa Semi-Arid (Petrolina-PE). The findings about the cycling of nutrients indicated the occurrence of a continuous addition of Ca+2, Mg+2, K+ and Na+ in the soil during the experiment of, 199 kg ha-1, 88 kg ha-1, 51 kg ha-1 and 142 kg ha-1, respectively. The efficiency of removal of Ca+2, Mg+2 and Na+ by Atriplex nummularia was 12,1, 4,3 and 23,9% respectively; Was observed high loss of nitrogen in the system caused by denitrification process, which decreased the concentration of nitrogen by 72% from beginning to end system, taking this nutrient in insufficient quantities to agricultural area. These results will be used for indicate ways to improve the system. Also, with the isotopic results was concluded that: water undergoes fractionation during the process of reverse osmosis the order of 1,87 to 18O and 10,3 for 2H; The well water is formed by a mixture of recent water and paleoáguas; The relationship 18O vs 2H; has a slope of 4,1, indicating high evaporation of this element; The soil has an average rated -24 in isotopic 13C in savanna soi and -20 of 13C in the experimental area, indicating an exchange of matter of this area of organic material from Atriplex, which had an average isotopic ratio of -13,7 . of 13C.
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Eficiência da aplicação de níveis da necessidade de gesso na correção de solos salino-sódicosVASCONCELOS, Ricardo Rafael Andrade de 28 September 2012 (has links)
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Previous issue date: 2012-09-28 / The present study had as objective to evaluate the effectiveness of applying different levels of gypsum on saline-sodic soil reclamation and its influence on physical-chemical newly corrected soil characteristics by the gypsum application. The laboratory experiment used PVC columns. The treatments were done in a randomized factorial arrangement block of 2x5 (two soil x five level gypsum of requirement), with five replicates. The levels used were equivalent to 50, 100, 150, 200 and 250 % of gypsum requirement, determined by the modified method Schoonover (Schoonover M-1), incorporated at the first 12,5 cm column of soil. The leachate electrical conductivity (EC), soluble cations and pH were evaluated. In soils were determinate the exchangeabled sodium and the exchangeable sodium percentage (ESP); The EC, soluble cations and sodium adsorption relation (SAR) in the saturation extract; the hydraulic conductivity, infiltration rate, the dispersed clay water and aggregate stability. The application level 100% of the need of plaster, obtained by the method of Schoonover M-1, followed by a water depth correspondent to three pore volumes afforded the correction of soil sodicity (SAR < 13 mmol L-1 and ESP < 15 %). The water depth correspondent to three times the pore volumes corrected salinity of soil was used when the levels of 50 and 100 % of gypsum requirement (EC < 4,0 dS m-1). The use of increasing levels of gypsum for the correction of saline-sodic soils provided greater water infiltration rate of the soil. The level of 100 % of the gypsum requirement in lower degree of dispersion and more stability of aggregates of soils. / O presente trabalho teve como objetivo avaliar a eficiência da aplicação de diferentes níveis de gesso, na recuperação de solos salino-sódicos e sua influência nas características físico-químicas de solos recém corrigidos pela aplicação de gesso. O experimento foi realizado em laboratório, utilizando colunas de PVC. Os tratamentos foram dispostos em delineamento em blocos casualizados com arranjo fatorial de 2 x 5 (dois solos x cinco níveis da necessidade de gesso), com cinco repetições. Os níveis utilizados foram equivalentes a 50, 100, 150, 200 e 250% da necessidade de gesso, determinada pelo método de Schoonover modificado (Schoonover M-1), incorporados aos primeiros 12,5 cm da coluna de solo. Foram avaliados nos lixiviados a condutividade elétrica (CE); os cátions solúveis e o pH. Nos solos foram determinados o sódio trocável e a percentagem de sódio trocável (PST); a CE; os cátions solúveis e a relação de adsorção de sódio (RAS) no extrato da pasta saturada; a condutividade hidráulica; a taxa de infiltração; grua de dispersão e a estabilidade de agregados. A aplicação do nível de 100% da necessidade de gesso, obtido pelo método de Schoonover M-1, seguida de uma lâmina de lixiviação correspondente a três vezes o volume de poros, proporcionou a correção da sodicidade dos solos (RAS < 13 mmolc L-1 e PST < 15%). A lâmina de lixiviação correspondente a três vezes o volume de poros corrigiu a salinidade dos solos quando foram utilizados os níveis de 50 e 100% da necessidade de gesso (CE < 4,0 dS m-1). A utilização de níveis crescentes de gesso para a correção de solos salino-sódicos proporcionaram maior taxa de infiltração de água dos solos. O nível de 100% da necessidade de gesso promoveu menor grau de dispersão e maior estabilidade de agregados dos solos estudados.
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Efeito da irrigação com efluente de esgoto rico em sódio em propriedades químicas e físico-hídricas de um Argissolo e produtividade de capim Tifton 85 no município de Lins / Effect of irrigation with sodium rich sewage effluent in chemical, physical and hydraulic properties of an Ultisol and productivity of Tifton 85 Bermudagrass at Lins municipality-SP-BrasilSilva, Aijânio Gomes de Brito 30 April 2013 (has links)
O uso de efluente de estação de tratamento de esgoto (EETE) na agricultura irrigada pode ser uma estratégia alternativa de fornecimento de água e nutrientes para culturas agrícolas. Entretanto se realizado por longos períodos pode adicionar grandes quantidades de sódio ao solo o que poderia levar a degradação de suas propriedades e impacto em aspectos agronômicos de capim Tifton 85. Esse trabalho consistiu de dois objetivos: i) avaliar os efeitos da irrigação com efluente rico em sódio durante mais de oito anos em propriedades químicas e físico-hídricas de um Argissolo Vermelho. Para isso foram estabelecidos três tratamentos avaliados nas profundidades de 0,05-0,15 (P1), 0,25-0,35 (P2) e 0,70-0,80 m (P3): SI - cultivo de capim sem adubação e sem irrigação; A100 - cultivo irrigado com água de abastecimento sódica e adubado com 520,0 kg ha-1 ano-1 de nitrogênio; E66 - cultivo irrigado com EETE e adubado com 343,2 kg ha-1 ano-1 de nitrogênio. Foram determinados: pH do solo (em água e CaCl2), condutividade elétrica do extrato aquoso do solo (CE1:1), concentração de sódio (Na+), potássio (K+), cálcio (Ca2+), magnésio (Mg2+), alumínio (Al3+), carbono (C) e nitrogênio (N) do solo, com posterior cálculo de soma de bases (SB), capacidade de troca catiônica (CTC), saturação por bases (V) e percentagem de sódio trocável (PST); densidade do solo (?), argila dispersa em água (ADA), condutividade hidráulica do solo saturado (Ksat), curva de retenção da água no solo (CR), porosidade do solo (?) e distribuição do tamanho dos poros; ii) avaliar os efeitos da irrigação com efluente rico em sódio durante mais de oito anos em aspectos agronômicos de capim Tifton 85. Para alcançar o segundo objetivo foi estabelecido além do SI, A100 e E66, mais quatro tratamentos: A0 - cultivo de capim sem adubação e irrigado com água de abastecimento sódica; E0, E33 e E100 - cultivo de capim irrigado com EETE e adubado com 0, 171,6 e 520,0 kg ha-1 ano-1 de nitrogênio, respectivamente. Foram determinados: produtividade de massa seca estacional (MS-Estacional), anual (MS-Anual) e acumulação estacional e anual de nitrogênio (N-MS), potássio (K-MS) e sódio (Na-MS) no tecido vegetal de capim Tifton 85. Houve alterações nas propriedades químicas e físico-hídricas do solo em função dos tratamentos e profundidades. Na P1 o E66 aumentou a CE1:1, a densidade do solo, o conteúdo de água residual e diminuiu a concentração de Mg2+ e conteúdo de água de saturação. Já o A100 reduziu a concentração de K+ e Mg2+, o conteúdo de água de saturação e aumentou a densidade do solo e o conteúdo de água residual. Na P2 o E66 aumentou o pH-H2O e a CE1:1, o conteúdo de água de saturação e o conteúdo residual. O A100 aumentou o pH-H2O, o Na+, o PST, a argila dispersa em água, o conteúdo de água de saturação e o conteúdo residual e diminuiu o C e N. Na P3 o E66 aumentou apenas o pH-H2O e o conteúdo de água residual e reduziu o conteúdo de água de saturação. O A100 aumentou o conteúdo de água de saturação, o conteúdo de água residual e a mesoporosidade. As propriedades do solo da P2 parecem ser as mais afetadas pelos efeitos do sódio decorrentes, principalmente, do uso de irrigação com água sódica. As produtividades de MS e acumulação de N-MS e K-MS foram superiores nos tratamentos E66, E100 e A100 e não foram reduzidas ao longo destes anos. A acumulação de Na-MS foi proporcional à produtividade, mas o capim passou a acumular um pouco menos sódio. Na estação chuvosa a MS de capim representou cerca de 72% da MS-Anual, sendo influenciada fortemente pelo período de estacionalidade. / The use of treated sewage effluent (TSE) in irrigated agriculture can be an alternative strategy to supply water and nutrients to crops. However if applied for long periods of time, it can add large amounts of sodium to the soil, resulting in soil properties degradation and impacts on agronomic aspects Tifton 85 Bermudagrass. The objectives of this work were: i) evaluate the effect of irrigation with sodium rich effluent for more than eight years on chemical, physical and hydraulic properties of an Ultisol. For this were established three treatments (WI - growing grass without fertilization or irrigation ; FW100 - irrigation with sodic fresh water supply and fertilized with 520.0 kg ha-1 year-1 nitrogen; E66 - irrigation with TSE and fertilized with 343.2 kg ha-1 year-1 nitrogen) The effects were evaluated at different depths (D1: 0.5-0.15, D2: 0.25-0.35 and D3: 0.70-0.80 m), determining: soil pH (in water and CaCl2), soil electrical conductivity of the aqueous extract (EC1:1) sodium concentration (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), aluminum (Al3+), soil carbon (C) and soil nitrogen (N), with subsequent calculation of sum of bases (SB), cation exchange capacity (CEC), base saturation (V) and exchangeable sodium percentage (ESP); bulk density (?), water dispersible clay (WDC), saturated hydraulic conductivity (Ksat), soil water retention curve (SWRC), soil porosity (?) and pore size distribution. Another objective was to evaluate the effect of irrigation with sodium rich effluent for more than eight years on agronomic aspects of Tifton 85 Bermudagrass. In addition to WI, FW100 and E66 treatments were established another four treatments (FW0 - growing grass without fertilizer and irrigated with sodic water supply; E0, E33 and E100 - growing grass irrigated with TSE and fertilized with 0, 171.6 and 520.0 kg ha-1 year-1 nitrogen, respectively) and determined the productivity of seasonal dry matter (Seasonal-DM), annual (Annual-DM) and nitrogen (N-DM), potassium (K-DM) and sodium (Na-DM) seasonal accumulation and annual in the plant tissue of Tifton 85 Bermudagrass. There were changes in chemical, physical and hydraulic soil properties as a function of treatments and depths. In the D1 the E66 treatment increased CE1:1, the bulk density, the residual water content and decreased the concentration of Mg2+, water content at saturation. FW100 reduced the concentration of K+ and Mg2+, the water content at saturation and increased soil bulk density and residual water content. In the D2, the E66 treatment increased pH-H2O and CE1:1, the water content at saturation and residual water content. The FW100 increased pH-H2O, Na+, ESP, water dispersible clay , the content of water saturation and residual contents and decreased C and N. In the D3 the E66 only increased the pH-H2O and residual water content and reduced water content saturation. The FW100 increased the water content at saturation point, residual water content and mesoporosity. The soil properties of D2 aparently are more affected than other depths by the effects of sodium, mainly from the use of irrigation water with sodium. The DM, N-DM and, K-DM were higher in the treatments E66, E100 and FW100 and there were not observed reductions over the years. The accumulation Na-DM was proportional to productivity, but the grass began to accumulate less sodium. In the rainy season the grass DM accounted for approximately 72% of Annual-DM, being strongly influenced by seasonality period.
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Efeito da irrigação com efluente de esgoto rico em sódio em propriedades químicas e físico-hídricas de um Argissolo e produtividade de capim Tifton 85 no município de Lins / Effect of irrigation with sodium rich sewage effluent in chemical, physical and hydraulic properties of an Ultisol and productivity of Tifton 85 Bermudagrass at Lins municipality-SP-BrasilAijânio Gomes de Brito Silva 30 April 2013 (has links)
O uso de efluente de estação de tratamento de esgoto (EETE) na agricultura irrigada pode ser uma estratégia alternativa de fornecimento de água e nutrientes para culturas agrícolas. Entretanto se realizado por longos períodos pode adicionar grandes quantidades de sódio ao solo o que poderia levar a degradação de suas propriedades e impacto em aspectos agronômicos de capim Tifton 85. Esse trabalho consistiu de dois objetivos: i) avaliar os efeitos da irrigação com efluente rico em sódio durante mais de oito anos em propriedades químicas e físico-hídricas de um Argissolo Vermelho. Para isso foram estabelecidos três tratamentos avaliados nas profundidades de 0,05-0,15 (P1), 0,25-0,35 (P2) e 0,70-0,80 m (P3): SI - cultivo de capim sem adubação e sem irrigação; A100 - cultivo irrigado com água de abastecimento sódica e adubado com 520,0 kg ha-1 ano-1 de nitrogênio; E66 - cultivo irrigado com EETE e adubado com 343,2 kg ha-1 ano-1 de nitrogênio. Foram determinados: pH do solo (em água e CaCl2), condutividade elétrica do extrato aquoso do solo (CE1:1), concentração de sódio (Na+), potássio (K+), cálcio (Ca2+), magnésio (Mg2+), alumínio (Al3+), carbono (C) e nitrogênio (N) do solo, com posterior cálculo de soma de bases (SB), capacidade de troca catiônica (CTC), saturação por bases (V) e percentagem de sódio trocável (PST); densidade do solo (?), argila dispersa em água (ADA), condutividade hidráulica do solo saturado (Ksat), curva de retenção da água no solo (CR), porosidade do solo (?) e distribuição do tamanho dos poros; ii) avaliar os efeitos da irrigação com efluente rico em sódio durante mais de oito anos em aspectos agronômicos de capim Tifton 85. Para alcançar o segundo objetivo foi estabelecido além do SI, A100 e E66, mais quatro tratamentos: A0 - cultivo de capim sem adubação e irrigado com água de abastecimento sódica; E0, E33 e E100 - cultivo de capim irrigado com EETE e adubado com 0, 171,6 e 520,0 kg ha-1 ano-1 de nitrogênio, respectivamente. Foram determinados: produtividade de massa seca estacional (MS-Estacional), anual (MS-Anual) e acumulação estacional e anual de nitrogênio (N-MS), potássio (K-MS) e sódio (Na-MS) no tecido vegetal de capim Tifton 85. Houve alterações nas propriedades químicas e físico-hídricas do solo em função dos tratamentos e profundidades. Na P1 o E66 aumentou a CE1:1, a densidade do solo, o conteúdo de água residual e diminuiu a concentração de Mg2+ e conteúdo de água de saturação. Já o A100 reduziu a concentração de K+ e Mg2+, o conteúdo de água de saturação e aumentou a densidade do solo e o conteúdo de água residual. Na P2 o E66 aumentou o pH-H2O e a CE1:1, o conteúdo de água de saturação e o conteúdo residual. O A100 aumentou o pH-H2O, o Na+, o PST, a argila dispersa em água, o conteúdo de água de saturação e o conteúdo residual e diminuiu o C e N. Na P3 o E66 aumentou apenas o pH-H2O e o conteúdo de água residual e reduziu o conteúdo de água de saturação. O A100 aumentou o conteúdo de água de saturação, o conteúdo de água residual e a mesoporosidade. As propriedades do solo da P2 parecem ser as mais afetadas pelos efeitos do sódio decorrentes, principalmente, do uso de irrigação com água sódica. As produtividades de MS e acumulação de N-MS e K-MS foram superiores nos tratamentos E66, E100 e A100 e não foram reduzidas ao longo destes anos. A acumulação de Na-MS foi proporcional à produtividade, mas o capim passou a acumular um pouco menos sódio. Na estação chuvosa a MS de capim representou cerca de 72% da MS-Anual, sendo influenciada fortemente pelo período de estacionalidade. / The use of treated sewage effluent (TSE) in irrigated agriculture can be an alternative strategy to supply water and nutrients to crops. However if applied for long periods of time, it can add large amounts of sodium to the soil, resulting in soil properties degradation and impacts on agronomic aspects Tifton 85 Bermudagrass. The objectives of this work were: i) evaluate the effect of irrigation with sodium rich effluent for more than eight years on chemical, physical and hydraulic properties of an Ultisol. For this were established three treatments (WI - growing grass without fertilization or irrigation ; FW100 - irrigation with sodic fresh water supply and fertilized with 520.0 kg ha-1 year-1 nitrogen; E66 - irrigation with TSE and fertilized with 343.2 kg ha-1 year-1 nitrogen) The effects were evaluated at different depths (D1: 0.5-0.15, D2: 0.25-0.35 and D3: 0.70-0.80 m), determining: soil pH (in water and CaCl2), soil electrical conductivity of the aqueous extract (EC1:1) sodium concentration (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), aluminum (Al3+), soil carbon (C) and soil nitrogen (N), with subsequent calculation of sum of bases (SB), cation exchange capacity (CEC), base saturation (V) and exchangeable sodium percentage (ESP); bulk density (?), water dispersible clay (WDC), saturated hydraulic conductivity (Ksat), soil water retention curve (SWRC), soil porosity (?) and pore size distribution. Another objective was to evaluate the effect of irrigation with sodium rich effluent for more than eight years on agronomic aspects of Tifton 85 Bermudagrass. In addition to WI, FW100 and E66 treatments were established another four treatments (FW0 - growing grass without fertilizer and irrigated with sodic water supply; E0, E33 and E100 - growing grass irrigated with TSE and fertilized with 0, 171.6 and 520.0 kg ha-1 year-1 nitrogen, respectively) and determined the productivity of seasonal dry matter (Seasonal-DM), annual (Annual-DM) and nitrogen (N-DM), potassium (K-DM) and sodium (Na-DM) seasonal accumulation and annual in the plant tissue of Tifton 85 Bermudagrass. There were changes in chemical, physical and hydraulic soil properties as a function of treatments and depths. In the D1 the E66 treatment increased CE1:1, the bulk density, the residual water content and decreased the concentration of Mg2+, water content at saturation. FW100 reduced the concentration of K+ and Mg2+, the water content at saturation and increased soil bulk density and residual water content. In the D2, the E66 treatment increased pH-H2O and CE1:1, the water content at saturation and residual water content. The FW100 increased pH-H2O, Na+, ESP, water dispersible clay , the content of water saturation and residual contents and decreased C and N. In the D3 the E66 only increased the pH-H2O and residual water content and reduced water content saturation. The FW100 increased the water content at saturation point, residual water content and mesoporosity. The soil properties of D2 aparently are more affected than other depths by the effects of sodium, mainly from the use of irrigation water with sodium. The DM, N-DM and, K-DM were higher in the treatments E66, E100 and FW100 and there were not observed reductions over the years. The accumulation Na-DM was proportional to productivity, but the grass began to accumulate less sodium. In the rainy season the grass DM accounted for approximately 72% of Annual-DM, being strongly influenced by seasonality period.
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Assessing Amendment Treatments for Sodic Soil Reclamation in Arid Land EnvironmentsUdy, Sandra 01 December 2019 (has links)
Plugged and abandoned well pads throughout the Uintah Basin face reclamation challenges due to factors including a harsh climate, invasive species, and high salt loads. Finding ways to alleviate soil sodicity could improve soil reclamation success. Gypsum, sulfur, activated carbon, and Biochar are being applied to improve soil parameters negatively impacted by sodicity, but the direct impact of these amendments on Uintah Basin soils is still largely unknown. The aim of this study was two-fold. (1) Evaluate the effectiveness of gypsum, sulfuric acid, Biochar, activated carbon, and combinations of these amendments in reducing the impact of soil sodicity of the Desilt and Conglomerate soils by measuring amendment impact on percent dispersion, saturated hydraulic conductivity, crust bulk density, infiltration, and crust formation. (2) Compare a crust bulk density method using ImageJ to the clod wax density method and a modified linear extensibility percent equation to the linear extensibility percent equation to assess whether the novel methods can be used to accurately measure and calculate soil crust bulk density and shrink swell potential while reducing human error and analysis time.
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Characterizing Salinity Tolerance in Greenhouse RosesSolis Perez, Alma R. 2009 May 1900 (has links)
Among ornamental plants, roses (Rosa L.) are considered the most
economically important, being among the most popular garden shrubs, as well
as the favorite cut flowers sold by florists. In the past roses have been classified
as fairly salt-sensitive, however, recent nutrition studies suggest that they may
actually tolerate moderate to relatively high salinities. The general objective of
this research was to reassess the limits of tolerance to salinity of roses and the
influence of the rootstock used, to determine the ameliorative properties of
supplemental Ca2+ on the response to salt stress, and to establish the influence
of Na+- and Cl--counter ions on the detrimental effects caused by these
salinizing elements.
The NaCl or NaCl-CaCl2-salinity tolerance limit for greenhouse roses,
although greatly influenced by the rootstock, was between 12 and 15 mmol.L-1.
Plants grafted on ?Manetti? sustained their productivity/quality characteristics for
longer time periods, tolerated greater salinity concentrations, and accumulated
less Cl- and Na+ in leaves of flowering shoots than those grafted on ?Natal Briar?,
confirming the greater ability of the former rootstock to tolerate salt stress.
Supplementing the saline solution with 0-10 mmol.L-1 Ca2+ (as CaSO4) did
not alleviate the harmful effects caused by NaCl-salt stress (12 mmol.L-1) on the
productivity and quality responses of roses.
The detrimental effects caused by Na- and Cl-based salinity were greatly
influenced by the composition of the salt mixtures (i.e. their counter ions). Sodium sulfate and CaCl2 were the least harmful salts; NaCl had intermediate
effects, while NaNO3 and KCl were the most deleterious. Among the most
distinguishable effects caused by the more toxic Na+ and Cl- counter ions were
lower osmotic potential (piSS) and greater electrical conductivity (ECSS) of the
salinized solutions, markedly increased uptake and/or transport of either Na+ or
Cl- to the flowering shoot leaves, and altered uptake and/or transport of other
mineral nutrients.
Computations of the saline solutions? chemical speciation revealed that
salts containing divalent ions had lower ionization and exhibited greater ion
associations compared to monovalent ion salts, rendering a lower number in
free ions/molecules in solution which caused greater SS and lower ECSS in
those solutions.
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Groundwater characterisation and disposal modelling for coal seam gas recoveryTaulis, Mauricio January 2007 (has links)
Coal Seam Gas (CSG) is a form of natural gas (mainly methane) sorbed in underground coal deposits. Mining this gas involves drilling a well directly into an underground coal seam, and pumping out the water (CSG water) flowing through it. Presently, CSG is under exploration in New Zealand (NZ); however, there is concern about CSG water disposal in NZ mainly because of the controversy that this activity has generated in some basins in the United States (US). The first part of this thesis studies CSG water from a well in Maramarua (NZ) and compares it to water from US basins. The NZ CSG water from this well had high pH (7.8), alkalinity in the order of 360 mg/l as CaCO₃, high sodium (334 mg/l), bicarbonate (435 mg/l), and chloride (146 mg/l). These ions also occur in US CSG waters, and their concentrations follow the same trend - high sodium, bicarbonate, and chloride with low calcium, magnesium, and sulphate concentrations. Prior to this work, little detailed analyses of CSG water quality variability from a well had been carried out. A Factor Analysis of 33 Maramarua samples was conducted and revealed that about one third of the variations were due to sample degassing, which induced calcium carbonate precipitation - this was supported by experimental work (sample sparging) and geochemical modelling (MINTEQA2). This finding is important for CSG water management because, as calcium concentrations decrease, higher SAR values are generated, and this can cause problems if CSG waters are disposed on land. In the second part, this thesis assesses the potential environmental effects of disposing CSG waters in NZ by formulating management options and a simple wastewater treatment system. This was carried out by studying the ecological response (soils, plant, and aquatic life) resulting from CSG water disposal operations in the US, and by applying relevant salinity and sodicity guidelines to the interaction between soils and CSG waters from Maramarua. This work showed that similar problems are likely to occur in NZ if CSG water disposal takes place without proper controls. Such a study has never been carried out in a region before actual CSG development has taken place, so this work shows how to quantify the effects arising from CSG water disposal prior to full scale production. This can be particularly useful for CSG stakeholders wanting to develop this resource in other regions around the world. A simple treatment system using Ngakuru zeolites has proven effective in reducing the SAR of Maramarua CSG water. Laboratory results indicate that these zeolites work by exchanging sodium cations in the water by other cations contained within the zeolite structure but with slow ion exchange kinetics. The calculated sodium absorption capacity for these natural zeolites ranged from 11.3 meq/100g to 16.7 meq/100g (flow-through conditions without previous regeneration). In addition, these experiments showed that the ion exchange process is accompanied by some dissolution (sulphate, boron, TOC, sodium, calcium, magnesium, potassium and reactive silica), but mainly at the beginning of the treatment process. Nevertheless, using this system, 180 grams of zeolite material were used to treat an initial 1.83 litres of Maramarua CSG water thus reducing potential soil infiltration problems to nil. As more CSG water was treated, the zeolites kept reducing SAR values but at a lesser rate until 4.53 litres of CSG water had been treated. A step-by-step methodology to assess treatment design options for these materials has been developed and will aid future researchers and engineers. This thesis presents the first comprehensive study of CSG water management in NZ. It also presents an ion exchange treatment system using natural zeolites already available in NZ. In conclusion, the research finds that, whether through adequate management or active treatment, CSG waters can be safely disposed without creating major environmental problems, and can even be used in beneficial applications.
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