Effect of biochar application on production parameters of two cowpea cultivars planted in succession in five soils from the Brazilian semiarid region

Abstract

In a context of the need to improve agricultural production combined with sustainable soil management practices, the present work aimed to assess the effect of increasing doses of biochar on production parameters of two cowpea cultivars planted in succession on five soils from the Brazilian northeastern semiarid region. Soils assessed were Typic Haplustepts, Typic Haplustults, Typic Hapludox, Typic Ustifluvents, and Typic Ustipsamments. Biochar was produced with wood from pruning cashew trees. Biochar doses were 0.0, 3.5, 7.0, and 10.5 t ha−1. Two cowpea cultivars were planted in succession, BRS Potengi in the first cycle and BRS Guariba in the second. The following production variables were assessed: number of grains per pod, average pod length, hundred-grain weight, and grain yield. Experimental data from each cycle were submitted to analysis of variance using the F-test. The effect of biochar doses was assessed by regression analysis. The cowpea production parameters in the first cycle showed an increasing response as biochar dose increased for the five soils. A positive linear response of production variables in the second cycle indicated the residual effect of applying biochar in the soils Haplustults, Ustifluvents, and Haplustepts, which presented the highest response of most variables to biochar in both cycles. The results obtained without fertilization indicate the benefits of using biochar as amendment in soils of the Brazilian semiarid region, at least up to a dose of 10.5 t ha−1.