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

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