Organic carbon mineralization of the biochar and organic compost of poultry litter in an Argisol

The dynamics of the organic residues added to the soil are closely related to its mineralization rate. Therefore, the present study aimed to evaluate the organic carbon mineralization in soil samples incubated with different doses of biochar and organic compost from poultry litter. Carbon mineralization was evaluated experimentally by measuring the C-CO2 liberated by incubating 200 g of soil mixed with different doses 0, 5, 10, 15, and 20 t ha-1 of both biochar and organic compost for 61 days. The soil microbial activity, and consequently the carbon mineralization, increased with the application of doses of biochar and organic compost from the poultry litter. The highest C-CO2 mineralization was observed in the treatments that received organic compost. The carbon mineralization process followed chemical kinetics with two simultaneous reactions. The greatest amount of released and accumulated C-CO2 was observed in the soil incubated with 15 and 20 t ha-1 of organic compost from the poultry litter. The doses of biochar did not influence the content of mineralized carbon; this behavior was not verified with the use of this compost, whose highest content corresponded to 85.69 mg kg-1, applying 20 t ha-1.