CHARACTERIZATION OF BIOGENIC, INTERMEDIATE AND PHYSICOGENIC SOIL AGGREGATES OF AREAS IN THE BRAZILIAN ATLANTIC FOREST

Authors

  • Júlio César Feitosa Fernandes Department of Soils, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ.
  • Marcos Gervasio Pereira Department of Soils, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ.
  • Eduardo Carvalho da Silva Neto Department of Soils, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ.
  • Thaís de Andrade Corrêa Neto Department of Soils, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ.

DOI:

https://doi.org/10.1590/1983-21252017v30n107rc

Keywords:

Aggregate morphology. Forest fragments. Organic carbon. Humic substances.

Abstract

Aggregate formation and stability are related to soil quality, contributing significantly to the carbon storage and nutrient maintenance capacities of the soil. Soil aggregates are formed by two different process: physicogenic, related to moistening and drying cycles and input of organic matter; and biogenic, related to the action of macrofauna organisms and roots. The objective this work was to classify aggregates according to their formation process, quantify and compare organic carbon contents in humic substances and assess the stability of aggregates formed by different processes, in areas with different coverage in the Mid Paraiba Valley, Pinheiral, State of Rio de Janeiro, Brazil. Aggregated soil samples were collected at a depth of 0-10 cm, in a Cambisol (Cambissolo Háplico Tb Distrófico) under four plant covers: secondary forest in advanced (SFAS), medium (SFMS) and initial (SFIS) successional stages and managed mixed pasture (MMP). Aggregates were classified and identified into three morphological classes (physicogenic, biogenic and intermediate). The variables evaluated were mean weight diameter (MWD) and geometric mean diameter (GMD) of aggregates, chemical fractions of organic matter, total organic carbon (TOC) and humic substances: humin (C-HUM) humic acid (C-FAH) and fulvic acid (C-FAF). Biogenic aggregates were found in smaller quantities and showed higher TOC, C-HUM and C-FAH, compared to intermediate and physicogenic aggregates. Thus, biogenic aggregates have potential to be used as soil quality indicators for structured environments, which are able to maintain its intrinsic formation processes.

Author Biographies

  • Júlio César Feitosa Fernandes, Department of Soils, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ.
    Departamento de Solos da UFRRJ
  • Marcos Gervasio Pereira, Department of Soils, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ.
    Departamento de Solos da UFRRJ
  • Eduardo Carvalho da Silva Neto, Department of Soils, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ.
    Departamento de Solos da UFRRJ
  • Thaís de Andrade Corrêa Neto, Department of Soils, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ.
    Departamento de Solos da UFRRJ

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Published

02-12-2016

Issue

Section

Agronomy