Influence of sewage sludge biochar and Priestia sp. on soil fertility

Influência do biocarvão de lodo de esgoto e Priestia sp. na fertilidade do solo

This study aimed to evaluate, after the period of soil incubation with biochar, the influence of the interaction between sewage sludge biochar and Priestia sp. on soil fertility. The experiment was carried out in Campina Grande, PB, Brazil, using 4 doses of biochar (0, 5, 10 and 15 t ha^-1) and 4 doses of Priestia sp. (0,1.5 × 10⁶, 1.5 × 10⁷, 1.5 × 10⁸ CFU mL^-1), in a completely randomized design with 3 replicates, totaling 48 experimental units, containing 350 grams of soil. After 104 days of soil incubation with the treatments mentioned above, biochar x Priestia sp. (after mineralization), soil samples were collected from the experimental units and chemically analyzed. Biochar significantly influenced all chemical variables evaluated. Priestia sp. affected most variables, except for electrical conductivity, sodium and calcium. The interaction between biochar and Priestia sp. influenced phosphorus, pH, magnesium and hydrogen + aluminum contents. In general, the single effects of biochar and Priestia sp. promoted increases in carbon and calcium contents in the soil. The interaction between the factors favored the increase in available phosphorus and variations in pH, keeping it within a range suitable for nutrient availability, evidencing the potential of the combination for improving soil fertility.

Keywords:
Microorganism; Pyrolysis; Soil properties.