Biochar Yield From Shell of Brazil Nut Fruit and Its Effects on Soil Acidity and Phosphorus Availability in Central Amazonian Yellow Oxisol

Phosphorus is one of the most limiting elements in the amazon soil, requiring low cost alternatives that increase the agronomic efficiency of phosphate fertilizers for satisfactory crop production and biochar has been used as an option for increase soil fertility. The objective of this work was to evaluate the yield and properties of the biochar produced from the shell of Brazil nut fruit at 500 oC, as well as its behavior in the acidity and phosphorus availability from mineral source in Yellow Oxisol. The experimental design was completely randomized in a factorial arrangement (5 × 5) with five doses of biochar (0, 20, 40, 60 and 80 t ha-1) and five doses of P2O5 (0, 100, 200, 300 and 400 kg ha-1) in 20 kg pots. The trial was carried out at 365 days and the yield and properties of the produced biochar were evaluated, as well as the determination of acidity and total and available phosphorus. The biochar produced from feedstock was considered satisfactory, with 59%, which is a good alternative for producers. Aluminum contents were reduced confirming the potential of biochar as a corrective for acidity. Additionally, the amount of total and available phosphorus increased with increasing biochar doses. Thus, not only the feedstock but also the pyrolysis temperature showed hight potencial to improve the amount of phosphorus in the soil and decrease the soil acidity.