Coffee waste as an eco-friendly and low-cost alternative for biochar production impacts on sandy soil chemical attributes and microbial gene abundance

Cintia Caroline Gouveia Da Silva (1) , Erika Valente De Medeiros (1) , Giselle Gomes Monteiro Fracetto (1) , Felipe José Cury Fracetto (1) , Argemiro Pereira Martins Filho (2) , José Romualdo de Sousa Lima (1) , Gustavo Pereira Duda (1) , Diogo Paes Da Costa (1) , Mário Andrade Lira Junior (1) , Claude Hammecker (3)

1 UFRPE - Universidade Federal Rural de Pernambuco
2 UFV - Universidade Federal de Viçosa = Federal University of Viçosa
3 UMR LISAH - Laboratoire d'étude des Interactions Sol - Agrosystème - Hydrosystème

Biochar is a material produced by the pyrolysis of agro-industrial waste, which has become one of the most promising management tools to improve soil quality. The aim was to determine the effects of incorporating biochar from different coffee wastes in sandy soil, cropped with maize, on soil chemical and microbial attributes. The experiment followed a factorial design 2 × 3 + 1 with two types of biochar, including coffee ground (CG) or coffee husk (CH) in 3 doses (4, 8, and 16 t·ha-1) and a control fertilized solely with bovine manure (3 t·ha-1). The variables analyzed were soil organic carbon, chemical attributes, microbial biomass (C, N and P), soil basal respiration and microbial gene abundance (16S rRNA, 18S rRNA and nifH gene). Most chemical attributes were strongly increased by CH application, while CG at 8 t·ha-1 increased the soil C:N ratio (3.5 times), P (2.1 times) and K+ (7.9 times) and at 4 t·ha-1 increased the C content, microbial biomass C and N (3, 2.1 and 1.6 times, respectively). The application of CG biochar at 16 t·ha-1 showed trend to increase the abundance of bacteria, fungi and diazotrophic genes (11, 10 and 2%, respectively). Contribution of both coffee biochar types, but mainly CH, was more effective than the soil that received organic manure alone. Biochar from coffee wastes is a promising tool to improve sandy soil quality.

Mots clés: biocarbon; 16S rRNA; 18S rRNA; nifH

Domaines: Science des sols

Cintia Caroline Gouveia Da Silva, Erika Valente De Medeiros, Giselle Gomes Monteiro Fracetto, Felipe José Cury Fracetto, Argemiro Pereira Martins Filho, et al.. Coffee waste as an eco-friendly and low-cost alternative for biochar production impacts on sandy soil chemical attributes and microbial gene abundance. Bragantia, 2021, 80, ⟨10.1590/1678-4499.20200459⟩. ⟨hal-03383037⟩