Impact of coffee biochar on carbon, microbial biomass and enzyme activities of a sandy soil cultivated with bean.

ARGEMIRO P. MARTINS FILHO,JENIFER S.A. DA SILVA,ERIKA V. DE MEDEIROS,ANTÔNIO C.D. ANTONINO,JOSÉ ROMUALDO S. LIMA,RÔMULO S.C. MENEZES,JULYANA B. DE OLIVEIRA,CLAUDE HAMMECKER,DIOGO P. DA COSTA,GUSTAVO P. DUDA

doi:10.1590/0001-3765202120200096

Abstract

Biochar has been used to reuse the agro-industrial wastes and improve soil quality. Several studies have been carried out to show the impact of biochar on physical and chemical soil attributes. However, there are still gaps regarding the effects on as microbial biomass and enzymatic activities that are important to determine sensitive indicators to evaluate changes in management practices. The objective of this study was to assess the effect of two biochars on the chemical, microbial biomass carbon, and the enzymatic activities in an Entisol cultivated with bean. We evaluate two types of coffee biochar: ground and husks, four doses (4, 8, 12, and 16 Mg ha-1) and control. All treatments received organic fertilization with cow manure. Husks biochar increase the soil pH, Ca, and K, also contributing to the reduction of toxic aluminum contents and raising the concentrations of P labile. The treatments that received ground biochar showed higher soil organic carbon, microbial biomass, β-glucosidase, and fluorescein diacetate. Biochar produced from coffee residues increased sandy soil quality. We showed the first report on the beneficial impact of coffee biochar on enzymatic and microbiological quality of sandy soil cultivated with the bean.

Highlights

The waste generated by the agro-industry can be used as sources of organic matter for the soil or transformed into biocarbon, which can improve soil quality for a longer time than fresh organic matter
The Heig45 of bean plants was not affected by the interaction between biochar and doses applied to Sandy Entisol
The biochars delayed the elongation of the plants, mainly the coffee grounds (CG), which differed from the effect of the coffee husk (CH) biochar (Table II)

Summary

Introduction

The waste generated by the agro-industry can be used as sources of organic matter for the soil or transformed into biocarbon, which can improve soil quality for a longer time than fresh organic matter. Biochar is a stable solid carbonaceous material of fine granularity with high carbon content (70% - 80%), and its properties depend on raw materials used on production process (Zhang et al 2013) It is a pyrolysis product of organic matter such as crop residues, husk, manure, wood debris, various grasses and other agricultural, and livestock at a temperature between 300 and 900 °C (Novotny et al 2015). In this sense, the coffee culture has great importance in the world, being one of the primary commodities. One of the possibilities of use to these wastes is the production of biochar (Lima et al 2018)

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Conclusion