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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.
1

Nitrogênio, arsênio, bário e estado nutricional de plantas de milho cultivadas em latossolos tratados com lodo de esgoto /

Alvarez Lazo, Ronald. January 2010 (has links)
Orientador: Wanderley José de Melo / Banca: Mara Cristina Pessôa da Cruz / Banca: Cassio Hamilton Abreu Junior / Banca: Antonio Enedi Boaretto / Banca: Marcos Omir Marques / Resumo: O objetivo do trabalho foi avaliar o efeito da aplicação de doses anuais de lodo de esgoto (LE) por dez anos consecutivos, no comportamento das formas de nitrogênio em Latossolos cultivados com milho; no estado nutricional, produção de grãos e matéria seca da planta, nos teores de As e Ba no solo e nos teores de As e Ba na folha e no grão de milho. Dois experimentos foram realizados em Jaboticabal (SP), Brasil, sob condições de campo, em blocos ao acaso em Latossolo Vermelho eutroférrico (LVef) e Latossolo Vermelho distrófico (LVd). Os tratamentos foram aplicações de LE (5, 10 e 20 Mg ha-1, b.s.) e uma testemunha (sem LE e com fertilização NPK). O teor médio de N-total apresentou decréscimo com o aumento da profundidade, e aumentou por efeito das doses de LE nos dois solos. Há movimentação do N-NO3 - para as camadas inferiores do solo no LVd. O teor de N-NH4 + no LVef e LVd mostrou comportamento irregular com o incremento da profundidade, predominando sobre o N-NO3 - até a camada 0,60-0,80 m de profundidade no LVef. Dependendo do LE utilizado, tipo de solo e da dose aplicada o LE provocou incrementos no teor de B, Mg, Mo e Zn acima da faixa considerada adequada para o milho. No LVd houve diferença entre tratamentos no teor de As e Ba no solo com decréscimo da concentração com o aumento da dose de LE. Houve diferença entre tratamentos no teor de Ba extraível pelo Mehlich 3, e diminuição do teor pelo incremento da dose de LE no LVef e LVd. No LVef o teor de As no grão aumentou por efeito da dose de LE aplicada. Nos dois solos houve decréscimo do teor de Ba no grão por efeito dos tratamentos. Em LVd o teor de As e Ba foliar do T0 difere dos tratamentos com lodo de esgoto, observando-se decréscimo da concentração com o aumento da dose de LE. O As e Ba adicionados aos solos pelo lodo de esgoto não afetou a produção de grãos e matéria seca das plantas de milho / Abstract: The aim of this work was to evaluate the effect of the application of annual dosages of Sewage sludge (Ss) during a period of ten years of experimentation, on soil nitrogen response, the nutritional stage, the grain and dry matter yield of maize plants, the As and Ba contents in soil, leaves and grain of maize. Two experiments were carried out in Jaboticabal-SP, Brazil, in randomized blocks under field conditions, in Typic Eutrothox (TH) and Typic Haplorthox. The treatments were, Ss applications rates (5; 10 and 20 Mg ha-1 DW) and a control (without Ss and with NPK fertilization).The average content of total N showed decrease with the rising of depth and increase with the dosages in both soils. The results showed NO3 --N moving to the lower soil layers, in TH. NO4 +-N content in TE and TH showed uneven behavior with the rising of the soil depth, prevailing over NO3 --N until depth layer of 0,60-0,80 m in TE. Depending of the Ss used, soil type and applied dosage the Ss provoked increasing of B, Mg, Mo, and Zn content over the level considered adequate for corn. There was difference between treatments in soil As content in TH, with concentration decrease by the increase of Ss dosage. Ba content determined in TH was affected by treatments showing content decrease by the Ss dosage increase. There was difference between treatments in Ba content extractable by Mehlich 3, and Ba content decrease by increasing of Ss dosage in both soils. In TE As content in corn grain increased by the effect of Ss dosages applied. In both soils decrease of Ba content was found in grain by the effect of Ss treatments. In TH foliar As and Ba content of control treatment differs from Ss treatments, observing decrease of foliar As and Ba concentration by increase of Ss dosage. As and Ba added to the TE and TH by sewage sludge rates didn't affect dry matter and grain yield of maize plants / Doutor

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