Management of soil organic matter and carbon storage in tropical fruit crops/Manejo da materia organica do solo e estoques de carbono em cultivos de frutas tropicais

• Published in: Revista brasileira de engenharia agrícola e ambiental 2014-03, Vol.18 (3), p.301
• Main Authors: Guimaraes, Danielle V, Gonzaga, Maria I.S, Neto, Jose de O. Melo
• Format: Article
• Language: Spanish
• Subjects: Agricultural land; Air pollution; Analysis; Carbon content; Citrus; Citrus fruits; Forest soils; Soils
• ISSN: 1415-4366

The main objective of this study was to investigate changes in carbon dynamics and stocks in agricultural soils. Soil samples were collected at 0-10 cm and 10-30 cm depths in two agricultural areas (cultivated with banana (Musa spp.), and cultivated with citrus (Citrus sinensis). A native forest soil was used as a reference and to determine the carbon pool management index. Organic matter was physically fractionated into particulate organic matter (> 53 µm) and complexed organic matter (< 53 µm). Analysis of total organic carbon was run to characterize soil organic matter. Comparing to the native forest soil, the banana cultivation increased the total soil organic carbon content (TOC) in approximately 14% while citrus cultivation reduced the TOC content in about 38%. The cultivated soils reduced the particulate organic matter fraction in more than 50%, showing a higher decomposition rate of the organic residues. The Carbon Management Index values were lower than 1 in all treatments, however the best results were observed for the citrus orchard (116.5). Overall, the change in land use from native forest to fruit crops reduced soil organic matter content, especially its labile fraction, and reduced soil quality. Key words: particulate organic matter soil quality carbon sequestration tropical soils Com este trabalho objetivou investigar as mudancas na dinamica e no estoque de carbono em solos agricolas. Amostras de solo foram coletadas de 0-10 cm e 10-30 cm, em duas areas agricolas (cultivo de banana (Musa spp) e cultivo de citros (Citrus sinensis). Um solo em floresta nativa foi utilizado como referencia e para determinacao do Indice de Manejo de Carbono (IMC). A materia organica do solo (MOS) foi fracionada fisicamente em particulada (MOP, > 53 µm) e complexada (MOC, < 53 µm). O carbono organico total (COT) foi analisado para caracterizar a MOS. Comparando com o solo em mata nativa o cultivo da banana aumentou o teor de carbono organico do solo (TOC) em aproximadamente 14% enquanto o cultivo de citros reduziu o teor de TOC em cerca de 38%. O cultivo de fruteiras reduziu a fracao particulada em mais de 50% mostrando uma velocidade de decomposicao maior dos residuos organicos. Os valores do Indice de Manejo de Carbono foram menores que 1 em todos os tratamentos; entretanto, foram observados os melhores resultados para o pomar de citros (116,5). No geral, a mudanca no uso da terra de mata nativa para culturas de frutas reduziu o teor de materia organica do sol