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Made available in DSpace on 2022-04-29T12:17:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-01-01 Sewage sludge can be a source of micronutrients, such as zinc (Zn) and nickel (Ni), for Cerrado soils; however, since they are heavy metals, continuous use of this residue requires an evaluation of the dynamics of these elements in the soil/plant system. This study aimed to evaluate the dynamics of Zn and Ni in a soil/plant system regarding extraction methods to determine the quantity of plant nutrients in the soil as well as the soil enzymatic activity in an area treated with sewage sludge for eleven years. Sewage sludge was applied annually in an Oxisol and a crop was sown. The accumulated sewage sludge doses throughout the eleven years of the experiment were 0 as control, 55, 110 and 167.5 Mg ha-1, and corn was the test crop. At 60 days after sowing, corn soil samples were collected from the 0-10 cm layer (for analysis of enzymatic activity) and 0-20cm, 20-40 cm (for analysis of Zn and Ni). The activities of the enzymes urease and dehydrogenase and the extractors Mehlich-1, Mehlich-3 and DTPA were evaluated. The increments of Zn and Ni in the Cerrado Oxisol as a function of sewage sludge application over a long time were small. The Mehlich-3 extractant was the best correlated with Zn and Ni extraction by the corn plants. In the eleventh year of application, sewage sludge was not efficient at supplying Zn to plants. The application of high doses of sewage sludge for a long time affects soil enzymatic activity. Department of Plant Nutrition, Center for Nuclear Energy in Agriculture, University of Sao Paulo, Av. Centenário, 303 Department of Technology, Sao Paulo State University, Access route Prof. Paulo Donato Castellane, s/n. Department of Technology, Sao Paulo State University, Access route Prof. Paulo Donato Castellane, s/n.

Made available in DSpace on 2014-06-11T19:33:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-06-25Bitstream added on 2014-06-13T19:44:31Z : No. of bitstreams: 1 000739777.pdf: 1467417 bytes, checksum: f7af80a0526b2e0314851d2da8912a3d (MD5) Atividades antrópicas têm aumentado a concentração de elementos tóxicos no ambiente, especialmente no solo. Dentre esses elementos, estão os metais pesados, estando o bário (Ba) na lista dos elementos que apresentam risco à saúde humana e cujas informações sobre seu comportamento no solo e nas plantas ainda são muito limitadas. Em assim sendo, objetivou-se, no presente estudo, avaliar a influência do Ba, fornecido por meio de sais com diferentes solubilidades, na nutrição e produção de grãos por plantas de sorgo; conhecer sua distribuição e acúmulo nas diferentes partes das plantas e os possíveis sintomas de toxicidade; conhecer sua fitodisponibilidade e dinâmica no solo e a biodegradação dos restos vegetais e sua liberação para o solo. O experimento, dividido em duas etapas, foi conduzido em casa de vegetação, utilizando amostras de um Latossolo Vermelho coletado a 0-20 cm de profundidade. A primeira etapa foi desenvolvida em delineamento experimental em blocos casualizados com 7 tratamentos [2 fontes de Ba (BaSO4 e BaCl2) em 3 doses (150, 300 e 600 mg kg-1), mais uma testemunha, sem adição de Ba] e 4 repetições. A segunda etapa teve início após o término da primeira, sendo testados 6 tratamentos [S0A0R0= solo dos vasos do tratamento testemunha (T) do experimento da primeira etapa; S0A0R1= T + R (raízes das plantas cultivadas no solo com 300 mg kg-1 de Ba na forma de BaCl2 do experimento da primeira etapa); S0A1R1= T + R + A (parte aérea das plantas cultivadas no solo com 300 mg kg-1 de Ba na forma de BaCl2 do experimento da primeira etapa); S1A0R0= solo dos vasos do tratamento com 300 mg kg-1 de Ba na forma de BaCl2 do experimento da primeira etapa (S300); S1A0R1= S300 + R; S1A1R1= S300 + R + A] em delineamento experimental inteiramente casualizado com 4 repetições. Na primeira etapa, foi realizada amostragem de solo e de folhas diagnósticas (FD) aos 56 dias... Anthropogenic activities have increased the content of toxic elements in the environment, especially in soil. Trace elements, among them barium (Ba), whose informations on soil behavior and plant effects are much reduced, are one of this toxic components. The objective of this study was to evaluate the influence of Ba, supplied as salts of different solubilities, on the nutrition and grain production by sorghum plant; to know the distribution and accumulation in different parts of the plant and possible toxicity symptoms; to know Ba phytoavailability and soil dynamic during plan biodegradation. The experiment was conducted in greenhouse, using samples of Red Oxisol sampled at the t0-20cm depth. The experiment was divided into two steps. The first one was developed using randomized complete block design with seven treatments [2 sources of Ba (BaSO4 and BaCl2) in 3 doses (150, 300 and 600 mg kg-1) and a control] and 4 replications. The second step started soon after the first step and consisted of 6 treatments [SOA0R0= soil from the control of the first step (T); S0A0R1= T + R (roots from the plants cropped in soil that received 300 mg kg-1 Ba as BaCl2in the first step); S0A1R1= T + R + A (aerial part from the plants cropped in soil that received 300 mg kg-1 Ba as BaCl2 in the first step); S1A0R0= soil that receive 300 mg kg-1Ba in the first step (S300); S1A0R1= S300 + R; S1A1R1= S300 + R + A] in experimental design totally randomized and 5 replications. In the first step soil samples and leaves (DL) were taken 56 days after seedlings transplanting (DAT). For whole plant analysis (roots, leaves and culms), grains and dry mass (DM) production the samples were taken 101 DAT. In the second step soil samples were taken at 0, 15, 30, 60 and 90 days after plant addition. Soil samples were analyzed for pseudo-total Ba, Mehlich 3 extracted Ba and its distribution in the soil fractions soluble ...