Carbon and nitrogen stocks in soil in native forests and pasture in the Pantanal biome, Brazil

• Autor(a) principal: Cardoso, Evaldo Luis
• Data de Publicação: 2011
• Outros Autores: Silva, Marx Leandro Naves, Silva, Carlos Alberto, Curi, Nilton, de Freitas, Diego Antônio França
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Pesquisa Agropecuária Brasileira (Online)
• Texto Completo: https://seer.sct.embrapa.br/index.php/pab/article/view/8475
• topic: deforestation; soil carbon sequestration; humic substances; wetlands; desmatamento; sequestro de carbono; substâncias húmicas; áreas úmidas

The objective of this work was to evaluate the impact of the conversion of native forests into cultivated pasture, and exposure of native pasture to continuous grazing, on the C and N stocks in the soil, in the Brazilian Pantanal wetlands. Three remnants of native forest, three areas with Urochloa decumbens pastures at different ages of formation, and one native pasture submitted to continuous grazing and without grazing for 3 and 19 years were evaluated. Soil samples were collected at 0–10, 10–20 and 20–40 cm depths, with three replications. The conversion of native forests into pastures promoted reduction of organic carbon and microbial carbon stocks in the soil, mainly in cultivated pastures with longer implantation time. However, no alteration in the total N stocks was observed. Carbon stock losses occurred in the three humic fractions but, proportionally, the main losses occurred in the humic and fulvic acid fractions. Cultivated and native pastures under continuous grazing are not capable of accumulating more C in the soil than the natural ecosystems.