Type and quantity of biochar influenced soil microbial activity and carbon priming effect

• Autor(a) principal: Carvalho Junior, José Ilmar Tínel de
• Data de Publicação: 2019
• Outros Autores: Gonzaga, Maria Isidória Silva, Almeida, André Quintão de, Araújo, Jady, Santos, Lúcia Catherinne Oliveira
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Semina. Ciências Agrárias (Online)
• Texto Completo: https://ojs.uel.br/revistas/uel/index.php/semagrarias/article/view/30912
• topic: Black carbon; Waste management; Environmental sustainability.; Carbono preto; Manejo de resíduos; Sustentabilidade ambiental.

Biochar has shown much potential to be used as soil amendment and conditioner as well as an effective alternative to waste disposal. However, the effect of biochar on soil organic matter varies according to the type of feedstock. This study aimed to evaluate the influence of different types and rates of application of biochar on soil microbial activity and on soil carbon priming effect. The incubation experiment was set up as a completely randomized design in a 2 x 5 factorial scheme, with two types of biochar (coconut husk and orange bagasse) and five rates of application (0, 5, 10, 15 and 30 t ha-1), with three replications. Soil microbial activity was evaluated through the concentration of CO2 released from the soil during a period of 130 days. Carbon priming effect was determined based on the CO2 respired in the biochar treated soil and in the control soil. Both biochars increased the total oxidizable carbon in the soil when they were applied at 30 t ha-1, however, the orange bagasse biochar was more effective than the coconut biochar. Coconut biochar increased the cumulative soil microbial respiration at all rates of application during the incubation period, therefore, it contributed to a positive carbon priming effect and should be applied with caution to avoid excessive loss of carbon from the soil. Orange bagasse biochar had little influence on the cumulative CO2 emission, except at 15 t ha-1, which increased soil microbial activity.