Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-11-14T17:13:45Z No. of bitstreams: 1 2013 - Celeste Queiroz Rossi.pdf: 1977299 bytes, checksum: ce171e08be0a2a7e0cf26ac08f9fbd2f (MD5) / Made available in DSpace on 2018-11-14T17:13:45Z (GMT). No. of bitstreams: 1 2013 - Celeste Queiroz Rossi.pdf: 1977299 bytes, checksum: ce171e08be0a2a7e0cf26ac08f9fbd2f (MD5) Previous issue date: 2013-02-26 / CAPES / The accelerated growth of agriculture produces a demand for opening and exploration of new areas. Through government incentives, the migration of sugar cane production reached the Cerrado biome, and this occupation provides a gradual vegetation coverage change. In this context, the aim of this study was to evaluate the effect of sugar cane burning prior to harvesting in the soil organic matter and organic phosphorus in the Goias State Cerrado region. This study was conducted in a chronosequence of 1, 5, 10 and 20 years with straw burning, and application of vinasse in the 20 years area, compared to native vegetation (Cerrado) and pasture areas. The study areas were located in Decal industrial plant in Rio Verde municipality, Goi?s State (Brazil). The soil was classified as an Oxisol with sandy loam texture. Soil samples were taken in pits up to 0.6 m depth. Total organic carbon (TOC), total nitrogen (TN), soil organic matter (SOM) physical and chemical fractionation, and isotopes 13C and 15N were analyzed. Phosphorus chemical fractionation, extracted with NaHCO3, H2SO4 and NaOH, spectroscopic carbon (13C NMR, UV-vis and FTIR) and phosporus (31P NMR) characterization were evaluated. The area with lowest usage time of straw burning had highest Ca and Mg and lowest P and K values. The smallest TOC stocks were observed at the 0-10 cm layer in the sugar cane systems with 1 and 5 years. In general, the highest values of 13C and 15N were observed in the pasture and the lowest values in the Cerrado, with intermediate values in the sugar cane systems. Land use change from Cerrado original vegetation to sugar cane systems resulted in 13C changes, promoting an accumulation of C4 derived carbon plants. Spectroscopic analysis of carbon (13C RMN, UV-vis and infrared) from humic acids carbon showed the same functional groups independent of cane burning harvesting time. At the 0-5 cm depth layer, the aliphatic and carboxylic compounds had the largest contribution compared to the aromatic compounds. The 31P NMR spectroscopy results showed that in the studied areas, the humic acids constitute a readily available source of organic P important for plant uptake, especially in the area that received vinasse. In the areas with 1 and 5 years of harvesting burning sugar cane, the decrease in the accumulation of recalcitrant organic P in the humic acids indicates the usage of the labile-P in the humic substances. / O crescimento acelerado da agricultura gera a necessidade da abertura e explora??o de novas fronteiras agr?colas. Com incentivos governamentais, essa migra??o do setor sucroalcooleiro atingiu o Cerrado, e esta ocupa??o proporciona uma gradativa mudan?a na cobertura vegetal. Neste contexto, o objetivo deste estudo foi avaliar o efeito da queima pr?via para a colheita da cana-de-a??car na mat?ria org?nica e f?sforo org?nico do solo no Cerrado goiano. Foi utilizada uma cronossequ?ncia de 1, 5,10 anos com queima e 20 com queima da palhada e aplica??o de vinha?a, ?rea sob vegeta??o nativa (Cerrado) e pastagem. As ?reas de estudo localizam-se na Usina Decal, em Rio Verde, estado de Goi?s. O solo foi classificado como Latossolo Vermelho Distr?fico de textura franco arenosa. As amostras foram retiradas mediante a abertura de trincheiras at? 60 cm de profundidade. Foram analisados o carbono org?nico total (COT), nitrog?nio total (NT), fracionamento qu?mico e granulom?trico da MOS, 13C e 15N is?topos. A quantifica??o das fra??es de f?sforo foi obtida empregando-se extra??es com NaHCO3, H2SO4 e NaOH, al?m da caracteriza??o espectrosc?pica de carbono (RMN 13C, UV-vis?vel e infravermelho) e f?sforo (RMN 31P). O menor tempo de uso da queima da palhada acarretou em maiores teores de Ca e Mg e menores teores de P e K. Os menores estoques de COT foram verificados na camada de 0-10 cm nos sistemas de cana de 1 e 5 anos. De maneira geral, os maiores valores de 13C e 15N foram verificados na ?rea de pastagem e os menores na ?rea de Cerrado, com valores intermedi?rios para as ?reas de cana. A substitui??o da vegeta??o original de Cerrado para implanta??o de ?reas cultivadas com cana-de-a??car acarretou em mudan?as do 13C, promovendo um ac?mulo de carbono de plantas com ciclo fotossint?tico C4. As an?lises espectrosc?picas de carbono (RMN 13C, UV-v?sivel e infravermelho) dos ?cidos h?micos mostraram os mesmos grupos funcionais independente do tempo de colheita queimada da cana. Na camada de 0-5 cm, a maior contribui??o foi dos compostos alif?ticos e carbox?licos em rela??o aos compostos arom?ticos. Os resultados da espectroscopia de RMN 31P mostram que nas ?reas estudadas os ?cidos h?micos constituem uma reserva importante de P org?nico prontamente dispon?vel e fonte importante para nutri??o das plantas, principalmente na ?rea que recebeu vinha?a. J?, nas ?reas de 1 e 5 anos de cana queimada, a diminui??o do ac?mulo de P org?nico recalcitrante nos ?cidos h?micos indica utiliza??o do P-l?bil das subst?ncias h?micas.