• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Atributos ed?ficos e aduba??o nitrogenada em cana de a??car em tabuleiros costeiros: respostas a sistemas de colheita com e sem queima da palhada / Edaphic attributes and nitrogen fertilizitation in sugarcane on coastal tableland region: response to harvesting system with and without previous burning of straw

OLIVERA, Ana Paula Pessim de 27 February 2013 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-11-09T17:37:20Z No. of bitstreams: 1 2013 - Ana Paula Pessim de Oliveira.pdf: 984469 bytes, checksum: 8daf942927a119ee9cb7fe02201b5631 (MD5) / Made available in DSpace on 2018-11-09T17:37:20Z (GMT). No. of bitstreams: 1 2013 - Ana Paula Pessim de Oliveira.pdf: 984469 bytes, checksum: 8daf942927a119ee9cb7fe02201b5631 (MD5) Previous issue date: 2013-02-27 / CAPES / To evaluate the impacts of trash management on soil quality and sugarcane production in the Brazilian region of coastal tableland three studies were conducted and are presented in distinct chapters. In the first chapter, a literature review, the results of research with sugarcane and changes in biological, chemical and physical soil properties, in response to trash management and their relationship with soil quality, are presented. In general, the data suggest that harvesting without burning affects positively the soil properties and improves soil quality. However, the studies are not sufficient to inform about the effect of mechanical harvesting without burning of trash in the tableland soils. In the second chapter they were evaluated the effect of N fertilization of green sugarcane on the stalk productivity, the trash accumulation, the relationship between the number and weight of stalks, the extraction and accumulation of nutrients in the fresh stalks and trash, and the sugarcane technological quality. This study was conducted in the LASA distillery, in Linhares municipality, Esp?rito Santo State, with ratoon cane, varieties RB86 7515 and RB91 8639, in a Xanthic Udult soil. The experiment was set in a randomized blocks design with the control (without N) and four treatments with N applied as ammonium sulphate (80, 100, 120, and 160 kg N ha-1) in four replicates. The N had a significant effect on stalks productivity. The relationship between the number and weight of stalks was significant for the dosages of 80 kg N ha-1 (both varieties) and 100 kg N ha-1 (only the RB91 8639 variety). There was significant effect of N rates on the cane technological quality only in the second cycle studied. The extractions of N, P and K were significant for the N levels. The third chapter is a simulation study conducted with the APSIM-Sugar cropping systems model, based on data from the log-term experiment (duration of 23 years) in the municipaliy of Linhares-ES. This study had as goal to investigate the impact of trash management after harvesting on sugarcane production and the long-term fate of N contained in trash. The objectives were: to investigate if the model was capable of reproducing the trends of the major N pools (cane yields and soil organic carbon) in the long term experiment; and using the parameterized model to evaluate how the relationship between N fertilizer and yield (and losses of N to the environment) varies with the trash management. The trash management systems conditions simulated were: retention of trash at harvest (100 %, GCTB); half retention of trash at harvest (50%); and burnt cane trash. The N fertilizer management system was simulated by varying N fertilizer application from 0 to 240 kg ha-1 (in 40 kg ha-1 increments) rates on the ratoon crops. The cane yield and soil organic C responded positively to the trash management systems (GCTB and half GCTB), but the magnitude of the response is dependent on N-fertilizer applied on crops. Half removal of trash might reduce the extent of yield increasing potential. When the trash deposition is a recent practice, additional N fertilizer is required by the crop, to avoid yield reduction caused by the N immobilization. The simulations also indicated that the average environmental losses of N were greater from trash retained systems for all rates on N fertilizer applied. / Para avaliar o impacto do manejo da palhada sobre a qualidade do solo e produ??o de cana-de-a??car na regi?o dos Tabuleiros Costeiros, tr?s estudos foram conduzidos e s?o apresentados em cap?tulos. No primeiro cap?tulo, em forma de revis?o de literatura s?o apresentados os resultados de pesquisas com cana-de-a??car e altera??es nas propriedades biol?gicas, qu?micas e f?sicas do solo em resposta ao manejo da palha, e sua rela??o com a qualidade do solo. Do conjunto de dados, se infere que a colheita sem queima com manuten??o da palha altera positivamente as propriedades ed?ficas e melhora a qualidade do solo. Por?m, os estudos s?o insuficientes para suprir informa??es sobre o efeito da colheita mec?nica e sem queima da palhada da cana sobre os solos de tabuleiro. No segundo cap?tulo foram avaliados, os efeitos da aduba??o nitrogenada, em cana crua, sobre a produtividade de colmos, ac?mulo de palhada, rela??o entre n?mero e peso colmo, extra??o e ac?mulo de nutrientes nos colmos frecos e na palhada, e sobre a qualidade tecnol?gica da cana de a??car. O estudo foi realizado na destilaria LASA no munic?pio de Linhares-ES, com cana soca, variedades RB 867515 e RB 918639, em ARGISSOLO AMARELO. Os tratamentos consistiram de cinco doses de N-Sulfato de am?nio (sem N, 80, 100, 120 e 160 kg de N ha-1), arranjados em desenho experimental de blocos casualizados com quatro repeti??es. Houve efeito significativo de doses de N sobre produtividade de colmos. A associa??o entre n?mero e peso de colmos foi significativa para 80 kg N ha-1 (ambas as variedades) e 100 kg ha-1 (para a variedade RB91 8639). Houve efeito significativo das doses de N sobre a qualidade tecnol?gica da cana apenas no segundo ciclo de cultivo estudado. As extra??es dos nutrientes N, P e K mostraram signific?ncia para as doses de N. O terceiro cap?tulo, relata um estudo de simula??o conduzido com o APSM-Sugar cropping systems model, com dados de um experimento de campo de longa dura??o (cerca de 23 anos) em Linhares-ES. Este estudo se prop?s a investigar o impacto do manejo da palhada ap?s a colheita sobre a produtividade da cana e o destino em longo prazo do N contido na palha. Os objetivos foram: investigar se o modelo foi capaz de reproduzir as tend?ncias de maiores ?pools? de N (rendimento de cana e C org?nico no solo) no experimento de longa dura??o; e usar o modelo parametrizado para investigar como a rela??o entre o N-fertilizante e rendimento (e perdas de N para o ambiente) varia com o manejo da palhada. As condi??es de manejo da palha simuladas foram: 100% e 50% da palhada retida ap?s a colheita; e palhada queimada. O manejo da aduba??o foi simulado para variar com as doses de N de 0 a 240 kg ha-1 (com incrementos de 40 kg ha-1) em cana soca. O rendimento de cana e o C org?nico do solo foram bem representados pelo modelo. O rendimento de cana respondeu positivamente aos sistemas de manejo da palhada (100% e 50% de reten??o), mas a magnitude da resposta depende da aduba??o nitrogenada. A remo??o de 50% da palha pode reduzir o efeito de rendimento potencial. Quando a deposi??o da palhada ? pr?tica recente, N adicional ? requerido pela cultura para evitar redu??o do rendimento causada pela imobiliza??o do N. As simula??es tamb?m indicam que as perdas ambientais de N foram maiores nos sistemas com cana crua para todas as doses de N.

Page generated in 0.1014 seconds