Compost production from Jatropha press cake and compost quality evaluation in Jatropha seedlings

摘要

The aim of the study was to determine the chemical analysis of Jatropha press cake in terms of pH, total N, total P, total C, C/N ratio and others. It was also the objective to determine the behavior of Jatropha press cake in composting in terms of microbial population through composting time and the microbial load changes when press cake was subjected to aerobic or anaerobic composting. In the same manner, the characteristics of Jatropha press cake were determined during aerobic composting when added with nutrients such as nutrient broth or urea. A method using plain composting for 4 weeks and inoculation with Azospirillum spp. derived by enrichment from previously composted press cake, followed by 1-week incubation, was adopted. The study determined the effects of inoculated Jatropha press compost on actual seedlings of Jatropha in pot tests. Initial Jatropha crop tests showed the effectiveness of processed press cake as organic fertilizer and the responsiveness of Jatropha stands to fertilizer addition. Significant increases over the control were noted in Jatropha stem diameter, leaf number and plant height by the addition of Jatropha compost at 1 kg plant(-1) at early growth (35 days after transplanting) and through 77 days of growth.