Fecal Sludge Derived Products as Fertilizer for Lettuce Cultivation in Urban Agriculture

Abstract

Fecal sludge (FS) contains a significant amount of plant nutrients. FS (treated/untreated) has been used as soil ameliorant in several countries. Use of FS-based compost on lettuce may meet reservations due to possible microbiological contamination. The objectives of this research are: (1) To determine the fertilizer value of different formulations of sawdust and fecal sludge compost (SDFS) pellets, and (2) to compare the effect of these SDFS formulations with poultry manure, commercial compost, mineral fertilizer, and non-fertilization on lettuce cultivation. The SDFS products were made by enriching, and pelletized with ammonium sulphate, mineral-NPK, or ammonium sulphate + muriate of potash + triple superphosphate. Lettuce was cultivated in a greenhouse and an open field. The result showed that the saleable fresh weight lettuce yield obtained from all SDFS pellets with/without enrichments were higher than those obtained from commercial compost, poultry manure, mineral fertilizer, or no fertilizer. Cultivation in the open field gave higher yields than those in the greenhouse. No helminth eggs were detected in composts or lettuces. Some fecal coliforms were detected in lettuces fertilized with almost all fertilizers tested, including NPK and non-fertilized control. A properly treated fecal sludge-based fertilizer can be a sustainable solution for lettuce production, which helps urban and peri-urban agriculture.

Levels of Lead, Copper, and Zinc in Cabbage (Brassica oleracea sp.) and Lettuce (Lactuca sativa sp.) Grown on Soil Amended with Sewage Sludge

“…e soil at the study site was treated with the sewage sludge. e treatments depended on application rates of the sludge based on recommended nitrogen levels: 160 kg N/ha, 210 kg N/ha, 260 kg N/ha, and 0 kg N/ha (control) for cabbage and 100 kg N/ha, 150 kg N/ ha, 200 kg N/ha, and 0 kg N/ha (control) for lettuce [12][13][14]. e corresponding amounts of sludge (mg) for each of the treatments for the two plants (Table 1) were estimated using equation ( 1) developed by Cooperative Extension Service, University of Purdue, Indiana (https://www.extension.…”

Biological Indicators for Fecal Pollution Detection and Source Tracking: A Review

“…Fecal sludge application may increase soil fertility, especially regarding carbon retention, but retention of bioavailable phosphorus and nitrogen can be low [46]. Furthermore, untreated fecal sludge poses risks to the crops because of pathogens, heavy metals, and toxic levels of ammonia and nitrite; additionally, the intensive fermentation activities within untreated fecal sludge can result in hypoxia in the rhizosphere [47,48]. To avoid these risks, treatment of fecal sludge or wastewater is required before its agricultural reuse.…”