Soil and land use in the Brazilian Amazon.

Abstract

On the basis of the Brazil Soil Map and the current Brazilian Soil Classification System, thirteen major representative soil classes of the Brazilian territory can be distinguished. These classes (viz., Latossolos, Argissolos, Alissolos, Cambissolos, Chernossolos, Geissolos, Luvissolos, Neossolos, Espodossolos, Nitissolos, Planossolos, Plintossolos and Vertissolos) are subdivided into different soil types according to morphological characteristics and physical, chemical and mineralogical properties separating them into more homogeneous units. The characteristics of these soil classes are given, including some of the most expressive attributes that define and differentiate them, as well as some aspects of their extension, geographical distribution and correlation with other classification systems, such as Soil Taxonomy and the World Soil Reference Base, are generalized. In order to understand the land use patterns, a brief history of the occupation of Amazon soils as a whole is reported, as well as the technologies and available tools for the accomplishment of those studies.

Changes in Soil Physical and Chemical Properties in Long Term Improved Natural and Traditional Agroforestry Management Systems of Cacao Genotypes in Peruvian Amazon

“…Ash deposits after burning of biomass help to fertilize the soil by rapidly releasing mineral nutrients such as Ext. Ca, Mg, P and K for crop use [ 68 , 72 , 73 , 74 , 75 ]. These favorable changes in the extractable soil nutrients due to conversion of forest system through slash and burn methods is known to persist for at least six years [ 74 ].…”

“…K increased among 20 to 60cm depth due to burning of vegetative matter ( Fig 4 ), similar to the Ext. P and for the same reasons [ 68 , 72 , 73 , 74 , 75 ]. The Ext.…”

Land use and vegetation cover on native symbionts and interactions with cowpea

“…In Legal Amazon, most areas without original native vegetation were converted to pastures (Mendonça-Santos et al, 2006), altering the natural cycling of nutrients and organic matter in the superficial soil layers, previously in equilibrium (Boddey et al, 2003). These alterations also directly impact on soil microbiota, with reflex on the growth of the plants, making them more dependent on processes mediated by microorganisms .…”