Caracterização da matéria orgânica leve e manta orgânica em uma topossequência na ilha de Algodoal/Maiandeua-PA

Abstract

Soil organic matter comprises a wide variety of humic compounds (humic substances) and non-humic compounds (organic blanket, fragment of roots and decomposing organisms, etc ...). It is considered a complex, composed of plant and animal residues, in continuous replacement and chemical, physical and biological transformation, giving the soil the characteristics of a dynamic system. The light fraction of organic matter (LOM) consists mainly of plants, but animal waste and microorganisms may also be present in various stages of decomposition. In turn, the organic blanket (OC) is not considered soil organic matter because it covers the surface; however, due to its importance in the cycling of nutrients and formation of humus, this layer is considered an integral part of the soil profile. The present work aims to analyze the production and chemical composition (N, e, Ca, Mg, and P) of the MO and the MO in AlgodoallMaiandeua sites and relate them to each soil type (Sodic Fulvic Neosol, Spodosol, Distrofic Yellow Argissolo, Distrofic Fulvic Neosol, Eutrofic Fulvic Neosol). The collections were performed in a 1370 m long topos sequence. For MOL and soil chemical analysis material was sampled at depths of 0-5 in, 5-10 in, 10-20 in. The organic blanket was collected at the same locations where the soils were collected. The data analyzed show, in general, a directly proportional variation in the macronutrient and micronutrient contents between the organic blanket and the soil, with the exception of eu, which showed an inverse behavior. In general, the nutrient contents were higher in the organic matter, and it is estimated that these high contents are being increased by the microbial biomass and excrement of the mesofauna, among others. The CLM and MO presented higher production in profiles P4 and P4A (Spodosol), based on this production it is possible to observe that the analyzed elements follow in general a proportional relation to the amount of CLM and MO produced.