Agronomic efficiency of fermented composts in organic fertilization management of butterhead lettuce and green leaf lettuce

Abstract

ABSTRACT This work aimed to evaluate the agronomic efficiency of fermented composts formulated with brewery waste (RC) with castor bean bran (FM) or Gliricidia sepium leaf bran (FG) in the fertilization of butterhead lettuce and green leaf lettuce grown in succession. The experimental design was in randomized blocks in a 2x5 factorial scheme, consisting of two fermented composts and five N doses (0, 50, 100, 200, and 400 kg/ha). The composts were formulated by combining 60 RC+40 FM and 60 RC+40 FG considering the % of dry matter after moisture correction. We verified that the phytotechnical performance of the butterhead lettuce, in relation to fertilization, is influenced by the applied dose; no difference regarding the composts was noticed, though. The doses of 272.2 and 248.71 kg/ha of N enabled the maximum yield of 78.01 and 87.79 t/ha, respectively, 60 RC+40 FM and 60 RC+40 FG. The fermented compost containing FM, in the range of the stipulated doses, showed a residual effect on the main phytotechnical traits of the green leaf lettuce, and the magnitude of the effect is directly proportional to the dose applied in the previous crop.