Physicogenic and biogenic aggregates under different management systems in the Cerrado region, Brazil

Luiz Alberto Da Silva Rodrigues Pinto,Marcos Gervasio Pereira,Sandra De Santana Lima,Wanderson Farias Da Silva,José Luiz Rodrigues Torres,Igor De Sousa Morais,Robert Ferreira,Sidinei Júlio Beutler

doi:10.36783/18069657rbcs20200114

Abstract

ABSTRACT An important strategy for the sustainable management of Cerrado soils is no-till (NT) systems, which may improve soil properties, particularly aggregation. Soil aggregates can be categorized according to their formation pathways into physicogenic (Phy) and biogenic (Bio). This study aimed (i) to quantify the relative proportion of physicogenic and biogenic aggregates and (ii) evaluate the levels of total organic carbon and their respective humic and physical fractions in the aggregates’ formation pathways. The following managed and unmanaged sites were [...]

Highlights

The Cerrado is the second-largest biome in Brazil, with a variety of land uses that are strongly affected by environmental conditions and anthropogenic activities (Loss et al, 2013)
Physicogenic aggregates predominated in soil samples from all sites in all the layers evaluated (Figure 3)
When analyzing Total organic carbon (TOC) of the management systems in comparison to the reference Cerrado site (RS), it is observed that the lower average values were verified in the management systems regardless of the type of aggregate (Dunnett’s test, p

Summary

Introduction

The Cerrado is the second-largest biome in Brazil, with a variety of land uses that are strongly affected by environmental conditions (e.g., soil acidity and sandy texture in the surface) and anthropogenic activities (e.g., deforestation and fires) (Loss et al, 2013). Soils that present limitations for crop production can be modified by using different management practices. One of the most efficient strategies for improving soil properties and increasing sustainability is using conservationist agriculture approaches, such as no-till systems (NT) (Denardin et al, 2012). Some of the advantages of NT include enhancement of soil organic matter (SOM) content and aggregation (Andrade et al, 2018). Aggregates have various functions in the soil and are directly involved in SOM stabilization, under management systems with little or no soil disturbances. Soil aggregates can be classified according to their formation as physicogenic (formed by physical and chemical processes), biogenic (formed by the action of biological agents) (Bullock et al, 1985) or intermediate between these two classes. The intermediate aggregate can be a physicogenic aggregate linked to a small coprolite or biogenic that has lost its rounded shape (Pulleman et al, 2005)

Objectives

Methods

Results

Discussion

Conclusion