Effects of co-composting of faecal sludge and agricultural wastes on tomato transplant and growth

Purpose Faecal sludge (FS) has been co-composted withmany organic solid wastes globally. Agricultural wastes,such as oil palm empty fruit bunches (EFB) and cocoa podhusks (CPH), have received very little research attention asfar as combining with FS is concerned. This study aimed atco-composting these wastes at different ratios to producesafe compost for use as soilless medium for raising tomatotransplants.Methods Dewatered FS (DFS) was mixed with shreddedEFB and CPH at five different ratios: 1DFS:1EFB,1DFS:1CPH, and DFS:EFB:CPH in ratios of 1:1:1, 2:1:1,and 2:2:1 and composted for 3 months. Select physicochemicalparameters and pathogens were monitored everyfortnightly and 3 weeks, respectively.Results Maximum temperatures obtained ranged46.8–54.5 C. Though these temperatures were lower thansanitizing temperatures prescribed by USEPA, no E. coliwas found in any of the piles at the end of composting. Theratio 2DFS:2EFB:1CPH was found to be the safest formulationand hence was used to grow tomato undergreenhouse conditions. Tomato seeds were sown in threedifferent growing media: 100% FS-based compost, 100%rice husk biochar, and 50% FS-based compost–50% ricehusk biochar mix.Conclusion Results showed that FS-based compost was asuitable growing medium for tomato. Further studies intothe optimal rate and frequency of application of compostteas on tomato are recommended.