Development of organic fertilizers from food market waste and urban gardening by composting in Ecuador

Abstract

Currently, the management of urban waste streams in developing countries is not optimized yet, and in many cases these wastes are disposed untreated in open dumps. This fact causes serious environmental and health problems due to the presence of contaminants and pathogens. Frequently, the use of specific low-cost strategies reduces the total amount of wastes. These strategies are mainly associated to the identification, separate collection and composting of specific organic waste streams, such as vegetable and fruit refuses from food markets and urban gardening activities. Concretely, in the Chimborazo Region (Ecuador), more than 80% of municipal solid waste is dumped into environment due to the lack of an efficient waste management strategy. Therefore, the aim of this study was to develop a demonstration project at field scale in this region to evaluate the feasibility of implanting the composting technology not only for the management of the organic waste fluxes from food market and gardening activities to be scaled-up in other developing regions, but also to obtain an end-product with a commercial value as organic fertilizer. Three co-composting mixtures were prepared using market wastes mixed with pruning of trees and ornamental palms as bulking agents. Two piles were created using different proportions of market waste and prunings of trees and ornamental palms: pile 1 (50:33:17) with a C/N ratio 25; pile 2: (60:30:10) with C/N ratio 24 and pile 3 (75:0:25) with C/N ratio 33), prepared with market waste and prunings of ornamental palm. Throughout the process, the temperature of the mixtures was monitored and organic matter evolution was determined using thermogravimetric and chemical techniques. Additionally, physico-chemical, chemical and agronomic parameters were determined to evaluate compost quality. The results obtained indicated that all the piles showed a suitable development of the composting process, with a significant organic matter decomposition, reached in a shorter period of time in pile 3. At the end of the process, all the composts showed absence of phytotoxicity and suitable agronomic properties for their use as organic fertilizers. This reflects the viability of the proposed alternative to be scaled-up in developing areas, not only to manage and recycle urban waste fluxes, but also to obtain organic fertilizers, including added value in economic terms related to nutrient contents.

Effect of Food Waste Compost (FWC) and its Non-Aerated Fermented Extract (NFCE) on Seeds Germination and Plant Growth

“…Particularly, tomato germination was the most affected by the NFCE, followed by watercress then chili pepper, the latter was negatively impacted by the extract (Table 4). This fact could be explained by the eventual presence of inhibiting substrates when used at high concentrations, especially phenolic compounds and lignin, as the main components in composted plant materials [38]. Indeed, the presence of phenolic compounds in vegetable wastes compost was reported, these are specific phytochemical antioxidants naturally present in practically all plant materials [42].…”

“…The soft rot fungi:Chaetomium, Ceratocystis, and Kretzschmaria deusta can decompose cellulose but degrade lignin slowly and incompletely. Therefore, the regulation and consoil properties and availability of nutrients that would activate the microbial flora[26] [31][34] [38] [39][40]. In 2020, Voběrková et al[2] mentioned high enzymatic activities in FWC, when used alone or supplemented with biochar and sawdust such as deshydrogenases, proteases, β-D-glucosidases, phosphatases and arylsulphatases during 35 days of composts' maturation.…”

The Management of Unsold Food in Outdoor Market Areas: Food Operators’ Behaviour and Attitudes

“…Some studies reported that it is essential to reduce food loss and food waste for the question of food security [75]. This can be done by using the fruit and vegetable waste at a retail and consumer level (supermarkets and food markets) as substrates in bioprocesses [88] to produce organic fertilizers [89,90], as long as this waste is treated correctly to reduce the environmental impact [91]. Compulsory regulation can set some quality standards to reduce waste [92].…”

Perception of the Selected Residents on Household Composting in a Highly Urbanized Area, Manila, Philippines

“…Those biodegradables, you can turn them into fertilizer, Resident G said. According to a study of Jara-Samaniego, et al (2017) [26], composting with gardening pruning wastes have shown their feasibility in terms of matter mineralization and humification where the composts obtained have the suitable characteristics for agricultural use. Furthermore, the composts obtained can be used as an organic fertilizer because they showed absence of phytotoxicity and suitable agronomic properties.…”