Microbiological and structural quality of Oxisol under pasture renewal systems

Michely Tomazi,Gessí Ceccon,Ricardo Fachinelli,Denise Prevedel Capristo

doi:10.1590/1983-40632021v5168006

Abstract

ABSTRACT The central Brazilian Savanna biome, known as Cerrado, has a vast area of pastures affected by some degree of degradation, where one of the main challenges is incorporating these areas into a crop production system. This study aimed to evaluate the effect of pasture renewal systems on the microbiological and structural quality of a medium-texture Oxisol. A randomized blocks design was adopted, with four replications and eight pasture renewal systems: 1) soybean/off-season maize/soybean; 2) soybean/maize-grass intercropping/soybean; 3) grass for 10 months and then one soybean crop; 4) grass + rattlepod for 10 months and then one soybean crop; 5) grass for 13 months and then one soybean crop; 6) grass + rattlepod for 13 months and then one soybean crop; 7) one soybean crop; 8) original pasture (control). The microbiological quality was assessed based on soil microbial biomass carbon, soil microbial activity, microbial metabolic quotient - qCO2 and activity of the β-glucosidase enzyme; and the structural quality based on the soil structural quality index. The implementation of pasture renewal systems with grass as a single crop (systems 3 and 5) or intercropped with rattlepod (systems 4 and 6) improves the soil microbiological and structural quality. The pasture renewal system beginning with soybean/off-season maize succession (system 1) is not indicated for the medium-texture soil evaluated in this study.

Highlights

In recent decades, advances have been made for agriculture in the Brazilian Savanna, known as Cerrado, a biome that occupies 204 million hectares and corresponds to approximately 24 % of the national territory, a fact that illustrates its importance for the Brazilian agribusiness
The soil microbial biomass carbon (SMB-C) and microbial activity (C-CO2) were higher in the pasture renewal systems 5, 6 and 8, when compared to the system 1; and the other systems did not differ from each other (Table 1)
The β-glucosidase activity values were significantly lower in the system 1, when compared to the systems 3, 4 and 7, without statistically differing from the systems 2, 5, 6 and 8 (Table 1)

Summary

Introduction

Advances have been made for agriculture in the Brazilian Savanna, known as Cerrado, a biome that occupies 204 million hectares and corresponds to approximately 24 % of the national territory, a fact that illustrates its importance for the Brazilian agribusiness. Most of the pasture areas show some degree of degradation; it is important to know the limitations and potential of their soils before they can be incorporated into a crop production system. The purpose of such incorporation is to intensify the agricultural production in the Cerrado without the need to open new areas (Victoria et al 2020). Based on these precepts, pasture renewal systems combined with soil conservation practices, such as the no-tillage system, crop rotation and.

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Results

Conclusion