Soil Management in Indigenous Agroforestry Systems ofGuarana (Paullinia cupanaKunth) of the Sateré-MawéEthnic Group, in the Lower Amazon River Region

Abstract

The Sateré-MawéBrazilian indigenous people cultivate the guarana liana in biodiverseagroforests that incorporate many species, mainly trees, and produce food, medicines, fuel andincome. The objective of this study was to evaluate the soil fertility in nineteen indigenous guaranaagroforestry systems (AFSs) compared with areas of adjacent forests in the Andirá–Marau IndigenousLand—an ancestral territory of the Sateré-Mawépeople. Soils in both locations showed low naturalfertility, with levels of most macronutrients below the minimum agronomic reference levels. HigherC and soil organic matter (SOM) content was observed in the forest soils and may be related to greatervegetation cover and higher litter production. However, the maintenance of the average levels of mostnutrients in the soil of the AFSs, at the same level as under the forests, suggests that efficient nutrientcycling is taking place. In these conditions, the management of organic matter seems to be essential tomaintain the productivity of guarana AFSs since levels of C, SOM and organic N were not consideredas low as those of most of the other soil attributes that were evaluated. The high tree diversity in theguarana agroforests, including N-fixing species, may also contribute to efficient nutrient cycling andmaintenance of the soil food web. The results suggest that the addition of limestone, green manurepractices and the reincorporation of organic residues from guarana processing, among other sources,can be a low-cost alternative to improve soil fertility and increase guarana production in the AFSunder study