Desempenho agronômico de biocarvões tratados com AL ou MG

Abstract

Due to the low efficiency of phosphate fertilization, especially in tropical conditions, allied to the high rates of P fixation in very weathered soils and the high polluting potential of aquatic environments by P, it is desirable to develop technologies capable of recovering this element from eutrophic environments or wastewater and reuse it in agriculture. Some studies have shown a high potential for P recovery with the use of biochar submitted for metal doping treatments. The objective of this work was to evaluate the agronomic efficiency of biochars modified with MgCl2 and AlCl3 as phosphate fertilizers. An experiment was carried out in a greenhouse using biochars enriched with P as phosphate fertilizers in successive cultivation of corn (26 d) and soybean (23 d), at doses of 50 and 200 mg/dm-3 P for each fertilizer and comparing them those with the commercial source triple superphosphate (ST), seeking to evaluate the agronomic efficiency of these materials. To evaluate the availability and diffusivity, a colorimetric test was performed in order to capture the diffusive radius of each material. The BMg was the treatment that presented the greatest agronomic efficiency in the successive cultivation of corn-soybean, corroborating the result of the colorimetric test, in which it was possible to visualize the transmission radius similar to the ST, and the high values of extractable P.