The bio fertilizer (NPKB) was processed by mixing PK rock fertilizers with an earthworm compound enriched in N by inoculation with the selected free-living bacteria (NFB 10001) in accordance with Lima et al. (2010). The analysis of the earthworm compound showed: pH 7.95; organic carbon (100.7 g kg−1); total N (8.6 g kg−1); total S (2.98 g kg−1); and total P (1.12 g kg−1).
The rock bio fertilizer (PKB) and the organic bio fertilizer (OB) were mixed in a proportion of 1:4 (PKB: OB), inoculated with free-living bacteria (NFB 10001) and incubated for 30 days. The NPKB was analyzed (Embrapa, 2009) and showed: pH (H2O) = 5.9; total N = 19 g kg−1; available P = 20 g kg−1 and available K= 19.9 g kg−1. The bio protector (NPKP) represents the bio fertilizer (NPKB) inoculated with Cunninghamella elegans (UCP 542), which are fungi that contain chitosan in their cellular wall(Franco et al., 2004). The fungus C. elegans was purified in Petri dishes with potato dextrose agar (PDA) grown for 10 days at 28 ◦C. The monosporic culture of C. elegans was obtained by growing the Mucorales fungus in Potato - Dextrose(BD) and using 2000 mL Erlenmeyers flasks (containing 1000 mL) that were shaken (180 rotations per minute) for 96 h at 28 ◦C. The culture was diluted in distilled water (20 L−1) that was applied by manual irrigation For the production of the bio protector (NPKP),the NPKB from PK rocks were mixed with the earthworm compound and incubated for 30 days, and the chemical analyses at the final period of incubation showed: pH = 6.4, total N = 20 g kg−1; available P = 21 g kg−1 and available K= 19 g kg−1