Agroecossistemas de produção familiar da Amazônia e seus impactos nos atributos do solo

Abstract

The absence of environmental constraints to organic production is the main characteristic of the Amazon, which does not translate into high yields of crops for several successive years when the forest is replaced by agroecosystems. The objective of this study was to evaluate the effect of soil management on the chemical and physical properties of soil by family agriculture, conducted in primitive way. The evaluated forms of use were: agroforestry system, pasture, slash-and-burn agriculture and preserved forest (used as reference), all under Entisol Quartzipsamment. Soil monoliths were collected at 0-5, 5-10, 10-20 and 20-40 cm during two consecutive years (2010/2011 and 2011/2012) in July and January, collecting seven replicates per system. The evaluated soil attributes were: flocculation, aggregates larger than 2 mm, organic matter, acidity, exchangeable cations, phosphorus, base saturation, aluminum and cation exchange capacity. The results indicate that 22 years after the conversion of forest into agricultural ecosystems it is still possible to see the best indicators in managed systems.