Carbon fractions and stock in response to solid and fluid organomineral fertilizers in highly fertile soils

Juliano Corulli Corrêa,Amanda Zolet Rigo,Álvaro Luiz Mafra,Agostinho Rebellatto,Marco André Grohskopf,Lauri Caetano Ródio

doi:10.1590/s1678-3921.pab2019.v54.00266

Abstract

Abstract: The objective of this work was to evaluate the effect of the application of organomineral and mineral fertilizers to highly fertile soils on the carbon management index (CMI) and carbon fractions and stock. The experiment was carried out on an Oxisol and Inceptisol, under no-tillage, in three crop seasons. The treatments consisted of two organomineral fertilizers and of two mineral fertilizers in solid and fluid forms, besides a control without fertilization. The application of organomineral and mineral fertilizers, in solid and fluid forms, to the different soil classes with high fertility promoted changes in total organic carbon, particulate organic carbon, and carbon associated with minerals, as well as in carbon stocks and the CMI. In the treatments with fluid mineral fertilizer and solid organomineral fertilizer, such changes occurred only in the Inceptisol due to the lower degree of weathering of this soil. The higher values of the CMI, with the fluid mineral fertilizer in the Inceptisol, allow inferring on which would be the best management practice aiming at the increase and maintenance of carbon in the soil-plant system, based on the yield results of wheat, sorghum, and corn, which were similar to those obtained with the other fertilizers.

Highlights

Soil organic matter (SOM) participates in various biological, chemical, and physical soil processes that determine the productive potential of the soil (Mafra et al, 2014)
Methodologies for the evaluation of fertilizer efficiency on Organic carbon (OC) alteration in a short-term include the analysis of particulate organic carbon (POC), carbon associated with minerals (CAM), and subsequent calculation of the carbon management index (CMI) (Conceição et al, 2014; Mafra et al, 2015)
Little change occurred in the total organic carbon (TOC) content in the soil, as a result of the application of organomineral and mineral fertilizers in solid and fluid forms, in the Inceptisol and Oxisol with “constructed fertility” (Table 3), except for the Inceptisol where the fluid mineral fertilizer (MF) increased the TOC content in comparison to the other treatments at 0.0–0.05 and 0.0–0.2 m soil depths

Summary

Introduction

Soil organic matter (SOM) participates in various biological, chemical, and physical soil processes that determine the productive potential of the soil (Mafra et al, 2014). Organic carbon (OC) is the main constituent of SOM which is influenced by the soil class characteristics and soil management system (McCarthy et al, 2008), including the fertilization practice, with both inorganic and organic fertilizers (Corrêa et al, 2018a). The application of fertilizers promotes changes in the OC fractions in the soil in medium and long-term tillage systems (Karhu et al, 2012), whereas, in short-term ones, such increases may or may not occur (Wu et al, 2004; Šimon, 2008). Methodologies for the evaluation of fertilizer efficiency on OC alteration in a short-term include the analysis of particulate organic carbon (POC), carbon associated with minerals (CAM), and subsequent calculation of the carbon management index (CMI) (Conceição et al, 2014; Mafra et al, 2015)

Objectives

Methods

Results

Conclusion