Organic matter content and distribution of Amazonian and "cerrado" latosols

The primary goal of this research was to characterize the Amazonian Latosols (Oxisols) and correlate them to those of the "Cerrado". An area was defined with the aid of soil maps, in the Amazonian and "Cerrado" regions. 78 Yellow Latosols and 184 Red-Yellow Latosols in the Amazonian region, and 123 profiles of Red-Yellow Latosols and 121 Dark-Red Latosols in the "Cerrado" region were studied. These profiles were grouped according to climate, vegetation, and parent material characteristics. It was noted that theorganic matter content of the Amazonian region is higher in the upper horizons. As soil clay content increases, the organic matter content increases. In depth, profiles of Latosols of the "Cerrado" region present a higher organic matter content those of the Amazonia. As rainfall increases organic matter increases in both regions. In the Amazonian vegetation type affects the amount of organic matter in the soil, as well as the materials from the Solimões and Barreiras geological formations. Latosols of the Amazonian region have higher nitrogen contents with C/N lower ratios than those of the "Cerrado" region.

organic matter; amazonian region; latosols

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