Biochar of Bamboo Influencing the Availability of P From Different Phosphate Sources in Dystrophic Yellow Oxisol of Amazon

The residual biomass of leaves and branches of fast returning species, such as bamboo, are the most promising for biochar production, and could be used as an excellent soil conditioner to recuperate degraded areas, stock carbon and recycling nutrients. The experiment was carried out on greenhouse condition as completely randomized design, under a factorial arrangement (3×3), been three pyrolysis condition (400 ºC, 500 ºC and 600 ºC), applied at 40 t ha-1 and three phosphate sources- Nature Phosphate (NP), Simple Superphosphate (SS) and Triple Superphosphate (TS) (100 kg ha-1 as P2O5), during one year with four crop rotation of cowpea and corn. The presence of biochar, independently of pyrolysis temperature, allowed value of shoot dry matter highest in the first two crops rotation and the P contents in the soil were increased up to third crop, however, it is showing statistic difference only in the soil after the two cowpea crops, in which the interaction showed similar behavior between the more soluble source (TS) and the less soluble source (NP). The concentrations of foliar P were similar between the two cowpea crops, thus in the corn crops the concentrations of foliar P were higher in the second crop and showed significance in the two crops. The presence of biochar modified the nature behavior of the phosphate sources, becoming similar P availability.