• 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

Avalia??o do res?duo alcalino do refino de bauxita como condicionador de solos e do estabelecimento de dend? nos tanques de estocagem / Evaluation of red mud as soil conditioner and of the oil palm in stock tanks vegetated with leguminous trees

Moreira, Joventino Fernandes 17 February 2006 (has links)
Made available in DSpace on 2016-04-28T14:58:32Z (GMT). No. of bitstreams: 1 2006-Joventino Fernandes Moreira.pdf: 938643 bytes, checksum: b9ddd1b30c4ea4ca7ccd346032713eb5 (MD5) Previous issue date: 2006-02-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The production of aluminum and alumina generates a great amount of red mud, which is harmful to the environment mainly for its high pH, electric conductivity and concentration of sodium, which restrict plant growth. However, there are some indications that it may be used as a conditioner for acid sandy soils. This work tested a red mud from an alumina production plant by Alumar- S?o Lu?s MA, Brazil as soil conditioner for two acid soil types: sandy and clay soils) and the growth of oil palm hybrids (E. guinensis x E. oleifera) grown in red mud deposition tank vegetated with leguminous trees for 8 years. The red mud was characterized in relation to its physical, chemical and microbial characteristics and tested in two types of soils, a Planossolo and an Argissolo and two bioindicators plants, the grass Brachiaria brizantha and common bean (Phaseolus vulgaris). Bean plants were harvested and brachiaria received a first cut 50 days after planting. A second and third cut were performed in brachiaria 70 and 140 days after the first one. Plant biomass was dried until constant weight and analysed for nutrient content. Number of sprouts of grass was counted at the third harvest. The evaluation of oil palm growth on red mud included eight hybrids between Elaeis oleifera x Elaeis guiinensis from Embrapa Amaz?nia Ocidental. breeding program (C2501, C2301, C2328, C3701, C2801, C7201, RUC13 and RUC 87) 12 months after transplanted to a red mud tank vegetated for 8 years with a mixture of nodulated leguminous trees. Diameter at the base of the plants, top diameter, number of leaves, plant height, diazotrophic bacteria, mycorrhizal fungi and nutrient contents were studied on the oil palm plants. Soil fauna and nutrient availability were evaluated in soils under oil palm and in an area with native species nearby the tanks. The addition of small amounts of red mud to the soils increased soil pH. Addition of red mud decreased plant growth in both soils tested with more deleterious effect on bean than on the grass. However the addition of 5 Mg ha-1 of red mud in the sandy acid soil increased the grass biomass at the last harvest in relation to the control. The evaluation of the oil palm in the tanks indicated that hybrid RUC 87 and C7201 presented larger diameter at soil level, plant height and number of leaves. All cultivars and hybrids showed large population of diazotrophic bacteria in their leaves and mycorhizal infection on roots. Similar richness and density of soil fauna was observed in the red mud below the oil palm to that observed in a soil collect in a secondary forest nearby indicating that the vegetation with leguminous trees is returning the ecological processes toward a sustainable system. / O processo de produ??o de alum?nio e alumina gera grande quantidade de res?duo de bauxita, tamb?m chamado red mud (lama vermelha). Este res?duo ? objeto de preocupa??o para o meio ambiente devido as suas caracter?sticas de alto pH e condutividade el?trica, al?m da elevada concentra??o de s?dio, condi??es estas prejudiciais ao desenvolvimento de plantas, tornando dif?cil o manejo desse material e necessitando de grandes ?reas para seu armazenamento. Por outro lado, alguns estudos t?m sido desenvolvidos com aplica??o desse material na agricultura, visando aumentar o pH e disponibilidade de nutrientes e melhorar a reten??o de ?gua para as plantas em solos arenosos. Esse trabalho foi desenvolvido com o objetivo de avaliar o potencial de uso do res?duo alcalino do refino de bauxita tratado e n?o tratado com ?gua do mar como condicionador de solos. Para isso os materiais foram caracterizados em aspectos f?sicos, qu?micos e microbiol?gicos e comparados quanto a seus efeitos no solo testando-os sobre dois tipos de solos, um Planossolo e um Argissolo e sobre duas plantas bioindicadoras, a braqui?ria (Brachiaria brizantha) e o feij?o comum (Phaseolus vulgaris). Ap?s 50 dias do experimento, as plantas de feij?o foram colhidas e foi feito o primeiro corte da braqui?ria, as plantas foram secas e pesadas, para a an?lise da massa seca. Contou-se tamb?m o n?mero de perfilhos da braqui?ria e nesta foram feitos mais dois cortes, um aos 120 e o ?ltimo aos 190 dias. Al?m dessa avalia??o foi feito um estudo sobre o desenvolvimento de dend? nos tanques de estocagem do res?duo ap?s 8 anos de implanta??o da revegeta??o com leguminosas arb?reas. Foram utilizadas 8 materiais gen?ticos de Elaeis spp (dend?) recomendados pela Embrapa Amaz?nia Ocidental: C2501, C2301, C2328, C3701, C2801, C7201, RUC13 e RUC87 e avaliados o di?metro do c?lo da planta e da copa, o n?mero de folhas, a altura das plantas, a presen?a de bact?rias diazotr?ficas e fungos micorr?zicos associadas ?s plantas de dend?, a fauna de solo e o estado nutricional das plantas e a fertilidade do solo. Os resultados apresentados indicam que os res?duos foram eficientes na eleva??o do pH do solo, j? com pequenas doses. A leguminosa mostrou-se mais sens?vel que a braqui?ria em rela??o ? salinidade provocada pela adi??o dos res?duos, nos dois tipos de solos, sendo que nessa ?ltima, houve aumento de mat?ria seca de parte a?rea em fun??o das doses dos res?duos n?o tratado e tratado com ?gua do mar at? a dose de 5 Mg ha-1, no Planossolo. Na avalia??o do dend? foi observada uma grande quantidade de bact?rias diazotr?ficas e coloniza??o micorr?zica, independentemente do gen?tipo. Os dados indicam tamb?m um melhor desempenho para os gen?tipos RUC87 e C7201 no que se refere ao di?metro do c?lo e da copa, n?mero de folhas e altura das plantas, apresentando uma maior capacidade de estabelecimento destas cultivares em rela??o ?s demais. No que se refere ? fauna do solo na ?rea de dend?, os seus valores de riqueza de grupos e densidade de indiv?duos foram pr?ximos aos valores encontrados em uma mata secund?ria local o que mostra que a revegeta??o com leguminosa est? sendo eficiente em retomar os processos ecol?gicos e o equil?brio do ecossistema.

Page generated in 0.0829 seconds