Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-26T20:13:29Z
No. of bitstreams: 1
2014 - Deyvid Diego Carvalho Maranh?o.pdf: 3511156 bytes, checksum: 353d33c1ec8bd59e0324501bd6a5033a (MD5) / Made available in DSpace on 2017-05-26T20:13:29Z (GMT). No. of bitstreams: 1
2014 - Deyvid Diego Carvalho Maranh?o.pdf: 3511156 bytes, checksum: 353d33c1ec8bd59e0324501bd6a5033a (MD5)
Previous issue date: 2014-03-20 / CAPES / Calcareous soils represent a significant portion of agricultural areas of the planet; commonly have high contents of calcium, magnesium, carbonates, associated with high pH values. In general, although there is little information about their attributes, they are located in areas with great potential for agricultural use. This study aimed to evaluate aspects involved in the genesis of calcareous soils of the Bambu? Group in the municipalities of Lavandeira and Aurora, southeast of Tocantins state, using morphological, physical, chemical and mineralogical attributes, and to compare methods for analytical evaluation ofthis soil attributes. Mostly, these soils havea low degree of pedogenetic development, highlighting the pedogenic processes of melanization and calcification, as well as high levels of silt fraction, which are related to the occurrence of siltstones layers associated with the limestone. From the evaluations, it is suggested that the carbonate character or calcic horizon must be included in the large group level in the class of Luvissolos H?plicos in the Brazilian System of Soil Classification. In this study, the profil P4 of toposequence T2 showed high calcium carbonate content, but were classified as "?rtico" respectively; thus omitting a feature of great importance in the management aspect. This attribute should be emphasized in the classification, since it influences the soil pH, available phosphorus content and micronutrients. The use of the suffix "r" should be reviewed in the Manual for Soil Description and Sampling in the Field, as this suffix has been used exclusively to the horizon and / or layer C, omitting this feature to other horizons, as it is featured in profile P1 of toposequence T2. As for the analytical methods, the phosphorus (P) determination more efficiently to calcareous soilsuses a buffered alkaline solution extraction (Olsen et al., 1954), and the use of acidic nature extractors (Mehlich 1) may overestimate the values of available phosphorus. Moreover, the method for determining calcium carbonateequivalent, with the changes proposed by Donagemma et al. (2011), quantified higher concentrations of calcium carbonate (CaCO3), suggesting that other methods have underestimating the CaCO3 content of the samples. As for the particle size analysis of fine earth, the usage of sodium hydroxide as chemical dispersant was more efficient in determining the clay fraction, with better dispersion of this fraction compared to the sodium hexametaphosphate solution. In contrast, the method for organic carbon measurement proposed by Yeomans and Bremner (1988) was more efficient, when compared to the method of Donagemma et al. (2011), as shown by the values similar to the ones obtained from elemental analysis (CHNS-O) in samples pretreated with an acid solution. / Os solos calc?rios representam uma parcela significativa das ?reas agr?colas do planeta; comumente, apresentam elevados teores de c?lcio, magn?sio, carbonatos, associados a elevados valores de pH. De modo geral, embora haja poucas informa??es acerca de seus atributos, est?o em ?reas de grande potencial para a utiliza??o agr?cola. Esse estudo teve como objetivo avaliar aspectos envolvidos na g?nese de solos calc?rios do Grupo Bambu?, nos munic?pios de Lavandeira e Aurora, sudestedo estado do Tocantins, a partir de atributos morfol?gicos, f?sicos, qu?micos e mineral?gicos, bem como comparar m?todos anal?ticos para avalia??o de atributos desses solos. Majoritariamente, esses solos apresentaram baixo grau de desenvolvimento pedogen?tico, destacando-se os processos pedogen?ticos de melaniza??o e calcifica??o, al?m de elevados teores da fra??o silte, o que est? relacionado ? ocorr?ncia de l?minas de siltitos associadas ao calc?rio. A partir das avalia??es realizadas, sugere-se que o car?ter carbon?tico ou horizonte c?lcico devem ser inclu?dos no n?vel de grande grupo na classe dos Luvissolos H?plicos do Sistema Brasileiro de Classifica??o de Solos. Neste estudo, os perfis P1 e P4 da topossequ?ncia T2 apresentaram elevados teores de carbonato de c?lcio, por?m foram classificados como ?L?tico? e ??rtico?, respectivamente, omitindo-se essa caracter?stica que ? de grande relev?ncia no aspecto de manejo. Esse atributo deve ser ressaltado na classifica??o, visto que ? determinante do pH, teor de f?sforo e de micronutrientes dispon?veis. A utiliza??o do sufixo ?r? deve ser revista no Manual de Descri??o e Coleta de Solo no Campo, pois esse sufixo tem sido de uso exclusivo para o horizonte e/ou camada C, omitindo essa caracter?stica para os demais horizontes, assim como caracterizado no perfil P1 da topossequ?ncia T2. Quanto aos m?todos anal?ticos, o m?todo de determina??o de f?sforo (P) mais eficiente para solos calc?rios faz uso de uma solu??o extratora alcalina tamponada (Olsen et al., 1954), sendo que a utiliza??o de extratores de natureza ?cida (Mehlich-1) pode superestimar os teores de P dispon?vel. Por outro lado, o m?todo de determina??o de carbonato de c?lcio equivalente, com altera??es da metodologia proposta pela Donagemma et al. (2011), quantificou maiores teores de carbonatos de c?lcio (CaCO3), sugerindo que os demais m?todos t?m subestimando os teores de CaCO3 das amostras. Quanto ? an?lise granulom?trica da terra fina, o hidr?xido de s?dio, como dispersante qu?mico, mostrou-se mais eficiente na determina??o da fra??o argila do solo, por ter proporcionado maior dispers?o dessa fra??o, quando comparado ? solu??o de hexametafosfato de s?dio. Em contrapartida, o m?todo de determina??o de carbono org?nico proposto por Yeomans e Bremner (1988) mostrou-se mais eficiente em compara??o ao m?todo da Donagemma et al. (2011), apresentando valores mais pr?ximos dos obtido na an?lise elementar (CHNS-O) em amostras pr?-tratadas com solu??o ?cida.
| Identifer | oai:union.ndltd.org:IBICT/oai:localhost:jspui/1690 |
| Date | 20 March 2014 |
| Creators | MARANH?O, Deyvid Diego Carvalho |
| Contributors | Pereira, Marcos Gervasio, Mazur, Nelson, Pereira, Marcos Gervasio, Fontana, Ademir, Valladares, Gustavo Souza |
| Publisher | Universidade Federal Rural do Rio de Janeiro, Programa de P?s-Gradua??o em Agronomia e Ci?ncia do Solo, UFRRJ, Brasil, Instituto de Agronomia |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFRRJ, instname:Universidade Federal Rural do Rio de Janeiro, instacron:UFRRJ |
| Rights | info:eu-repo/semantics/openAccess |
Page generated in 0.0033 seconds