Crescimento e produção de feijão-caupi (Vigna unguiculata L. Walp) em função do efeito residual de carvão vegetal e pó de serra em Latossolo Amarelo distrófico da Amazônia Central

Abstract

The objective of this study was to evaluate the potential of the residual effect of biochar and sawdust as a chemical conditioner, source of nutrients and acidity corrective culture of cowpea in Yellow Latosol from Central Amazon. To this end samplings in 0-10, 10-20, 20-30, 30-40 and 40-50 cm were performed and also was made in laboratory analysis of P, K, Ca, Mg, Al, Zn, Mn and Fe. The experimental desing consisted of four blocks of four plots with four subplots, each subplot in 5 rows of cowpea were planted. The experimental design was based on the residual effect of charcoal and sawdust made in 2006 , maintaining the same experimental design of randomized blocks (4 blocks) in a split plot , the main plot (0 , 40 , 80 and 120 t ha-1 of biochar) and the sub -plots doses of 0 , 40 , 80 and 120 t ha-1 of sawdust were applied . The results show that the nutrients in the soil had higher levels when applied to combination of 120 t ha-1 biochar + 120 t ha-1 of sawdust, the exchangeable acidity has not significantly changed by the treatments tested but was reduced with the combination of 120 t ha-1 of biochar + 40 t ha-1 sawdust . There was no difference between treatments for plant biomass of cowpea, but for grain production the best combination was 120 t ha-1 biochar + 80 t ha-1 sawdust. Therefore the residual effect of biochar and sawdust enhanced the availability of nutrients and grain production with the combination of 120 t ha-1 of biochar + 120 t ha-1 of sawdust.