Solos do Projeto Xingó: caracterização e limitações ao uso com agricultura irrigada

• Autor(a) principal: FERNANDES, Luiz Augusto Costa
• Data de Publicação: 2005
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRPE
• Texto Completo: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5209
• topic: Agricultura irrigada; Projeto Xingó; Irrigated land; Xingó Project; AGRONOMIA::CIENCIA DO SOLO

Soil research aiming irrigated land use have great importance in the semiarid Sertão zone of Sergipe state. With this purpose, four soil profiles were characterized and classified along a topossequence, including two Regolithic Nesols, a Planosol and a Luvisol. The objectives were to evaluate soil potential for irrigated land use and to produce information to improve the Brazilian System of Soil Classification. Soil morphological, chemical, physical and mineralogical characterization was carried out according to methods recomended by Embrapa (1999). The first profile, classified as solodic Psamitic Regolithic Neosol is a deep soil related with the highest and preserved position of the relief. It was considered suitable for irrigated land use, with good drainage and low risk of salinization, despite the low natural soil fertility and water availability. The second soil profile, a leptic, sodic, fragipanic, Eutric Regolithic Neosol is related to the mid slope positions and has low natural soil fertility. It was considered unsuitable for irrigated land use due to its small depth to the impermeable bedrock. The third studied soil classified as typic Ortic Natric Planosol is unsuitable for irrigated land use and related to the lowest positions of the relief. The presence foa shallow barrier zone (27cm) which restrict the clownward movement of water is the main limitation, resulting in watertable is the main limitation, resulting in watertable formation and high susceptibility to erosion. Profile four was classified as sodic-salic Orthic Cromic Luvisol and is relate with the occurrence of the Mulungu unit bedrocks. The low hidraulic condutivity, together with an exce’s of soluble salts and high exchangeable sodium percentage make this soil unsuitable for irrigation, despite its high natural fertility. The Regolithic Neosol (profile 1) was adequately classified in the Brazilian System of Soil Classification, while the other three profiles were not, the Planosol, at the order level, and the Neosol (profile 2) and Luvisol, at the subgroup level. To overcome this problems a modification in the definition of the planic B horizon and the inclusion of new subgroups for Luvisols and Regolithic Neosols were suggested