Storage duration and temperature affect pathogen load, heavy metals, and nutrient levels in faecal derived fertiliser

There are debates regarding the safety of faecal derived fertiliser (FDF) due to notions that harmful substances may persist at undetectable levels. A major concern is the recolonisation of indigenous pathogens and nutrient changes while undergoing storage. Abiotic factors such as duration and temperature on indigenous pathogen re-growth and nutrient during FDF storage have received little research attention. In this study, we assess the effect of varying storage temperature conditions and duration on indigenous E. coli re-growth and NPK changes of different FDF (enriched co-compost, NECo and co-compost, Co) during storage. A 2 × 3 × 6 factorial design was used with factors: fertiliser, temperature, and duration. The factorial had 36 experimental conditions in a completely randomised design with three replications. FDF samples were collected monthly for 6 months and analysed for pH, EC, organic carbon, N, NH4-N, NO3-N, P, K, E. coli, and total coliform. Findings show storage temperature and duration did not affect indigenous E. coli re-growth and total N in stored NECo and Co. However, NH4-N concentrations of NECo decreased between 27% and 55% with increasing duration of storage at lower temperatures (5°C and 25°C). The significance of this study for the FDF industry is that it is safe after storage and longer storage do not necessarily influence nutrient losses in stored FDF. Future studies are recommended to investigate the effect of moisture on stored FDF.This work was supported by Sue White Fund for Africa –Cranfield University; International Water Management Institute; GCRF Q

Assessing consistency in the aerobic co-composting of faecal sludge and food waste in a municipality in Ghana

Background: A faecal sludge (FS) co-composting study assessed the extent of consistency in compost characteristics between and within batches. The study focused on the consistency of the co-composting process by measuring the variability of key parameters. Method: The set up consisted of 12 FS and food waste (FW) co-composting piles in three successive batches (1, 2 and 3). Consistency was assessed in the three successive batches of co-composted FS and food waste (FW). Within batches, consistency was assessed in each of them by dividing it into four separate replicate piles. Characteristics of interest were E. coli, as well as selected physico-chemical parameters (pH, EC, Mg, Ca, N, NH4-N, NO3-N, P, avail. P, and K) and heavy metals (Se, Fe, Cd, Cu, Hg, Ni, Pb and Cr). Data were subjected to analysis of variance (ANOVA) using SPSS. Result: Results show that, E. coli levels were not consistent between the successive batches during the entire co-composting process. While variations between batches were only observed for EC and nutrient parameters, variations were evident for several measured characteristics within batches. The measured coefficient of variations (CVs) within batches ranged between 0–125% and 3–111% for heavy metals and nutrients, respectively. Conclusion: In conclusion, there was less consistency in nutrients between successive batches and CV within batches was wide. Consistency levels for E. coli may not be an issue if pathogen inactivation is complete. Recommendation: It is recommended that a threshold value be created for determining what is an acceptable level of variation in FS co-composting.Sue White Fund for Africa. International Water Management Institut

Crops and farmers’ response to application of fecal sludge derived - Fortifer™ in different agro-ecological zones in Ghana

Fecal sludge (FS)-derived fertilizer material, Fortifer™ was used in farmers’ field to cultivate different crops under varying soil and agro-climatic conditions in Ghana. The aim was to (1) create awareness among smallholder farmers for widespread use of Fortifer™ (2) observe the response of crops to Fortifer™ application by farmers in different agro-ecological zones (3) obtain farmers feedback on the FS-derived product to enhance further dissemination across the country. In total 95 farmers in six locations participated in the farmer-led pilots. Fortifer™ containing up to 3.0% nitrogen, 3.6% phosphorus, 1.3% potassium and 44.3% organic matter was applied to tomato, rice, maize and pepper in comparison to inorganic fertilizers at recommended rates. Subsequently, farmers’ perception of, and willingness to use the product were studied. Crop yield was significantly higher (p = 0.05) in the Fortifer™ plots compared to the inorganic fertilizer plots for all the selected crops. Yield was 12% higher for tomato, 27% for rice and maize and 30% for pepper under the Fortifer™ plots. Farmers indicated that, nutrient content was the most important factor they consider when making fertilizer purchasing decision

Data: Storage duration and temperature affect pathogen load, heavy metals, and nutrient levels in faecal derived fertiliser

This dataset describes the changes in nutrient characteristics and pathogen in two types of stored faecal derived fertiliser over a period of time.</p

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

Purpose: Faecal sludge (FS) has been co-composted with many organic solid wastes globally. Agricultural wastes, such as oil palm empty fruit bunches (EFB) and cocoa pod husks (CPH), have received very little research attention as far as combining with FS is concerned. This study aimed at co-composting these wastes at different ratios to produce safe compost for use as soilless medium for raising tomato transplants. Methods: Dewatered FS (DFS) was mixed with shredded EFB 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 physicochemical parameters and pathogens were monitored every fortnightly and 3 weeks, respectively. Results: Maximum temperatures obtained ranged 46.8–54.5 °C. Though these temperatures were lower than sanitizing temperatures prescribed by USEPA, no E. coli was found in any of the piles at the end of composting. The ratio 2DFS:2EFB:1CPH was found to be the safest formulation and hence was used to grow tomato under greenhouse conditions. Tomato seeds were sown in three different growing media: 100% FS-based compost, 100% rice husk biochar, and 50% FS-based compost–50% rice husk biochar mix. Conclusion: Results showed that FS-based compost was a suitable growing medium for tomato. Further studies into the optimal rate and frequency of application of compost teas on tomato are recommended