Author(s)

Fernanda Tunes Villani¹, Gyovanni Augusto Aguiar Ribeiro¹, Ecila Mercês de Albuquerque Villani², Wenceslau Geraldes Teixeira³, Fatima Maria de Souza Moreira⁴, Robert Miller⁵, Sonia Sena Alfaia⁶

¹Departamento de Química e Meio Ambiente, Instituto Federal de Educação, Ciência e Tecnologia, Manaus, Brazil.
²Universidade Federal de Viçosa, Viçosa, Brazil.
³Departamento de Solos, Embrapa Solos, Empresa Brasileira de Pesquisa Agropecuária, Rio de Janeiro, Brazil..
⁴Departamento de Ciência do Solo, Universidade Federal de Lavras, Lavras, Brazil.
⁵United Nations Development Program, Brasília, Brazil.
⁶Coordenação de Tecnologia e Inovação, Instituto Nacional de Pesquisas da AmazÔnia, Manaus, Brazil.

Slash and burn cultivation systems carried out by many farmers in the Amazon region lead to changes in biogeochemical cycles of nutrients. To assess the extent of the impact of shifting cultivation on the soil in a floodplain portion of this region, samples of an Inceptisol surface layer (0 - 5 cm) under primary forest (FP), secondary forest at an advanced stage of recovery (FS), secondary forest at an initial stage of recovery (CAP), agroforestry (SAF), plantations (R?) in indigenous communities and small farmers, and pasture (PAS) in the Upper Solim?es region, Amazonas, were subjected to analysis of chemical composition during the wet (May) and dry (October) seasons, 2007. Soils were fertile with levels of P, K, Ca and Mg above those generally found in Amazon soils. Microbial content did not vary significantly in the systems studied in the wet season, but there was a reduction of around 60% with the change of season, except for soils with SAF. Ammonium nitrogen was predominant in all systems and seasons studied. Nitrate content was higher in R? soil, in two seasons, and lower in PAS. The type of management adopted by farmers in the region’s indigenous agroforestry systems resulted in small changes in P, K, Mg, MBC and mineral-N levels, independent of soil moisture.

Traditional Agriculture, Soil Management, Primary and Secondary Forests, Pasture, Inceptisol

Tunes Villani, F. , Aguiar Ribeiro, G. , Albuquerque Villani, E. , Geraldes Teixeira, W. , Souza Moreira, F. , Miller, R. and Sena Alfaia, S. (2017) Microbial Carbon, Mineral-N and Soil Nutrients in Indigenous Agroforestry Systems and Other Land Use in the upper Solimões Region, Western Amazonas State, Brazil. Agricultural Sciences, 8, 657-674. doi: 10.4236/as.2017.87050.