Effect of organic inputs in urban agriculture system and their optimization in prospect of poverty alleviation in Senegal West Africa
The aim of this paper is to review the impact of the use of organic manure in the urban agriculture system in Senegal. A multidisciplinary project on urban agriculture was carried out over the last decade in Senegal. We describe the facts and findings of the project regarding the use of wastewater organic manure as crop fertilizer. Organic inputs in urban agriculture in Senegal can be summed up into two distinct types. The first type is related to the use of wastewater, characterized by its heavy organic matter content in that it decomposes over time or is processed by a water treatment station using a refining system (Wastewater is known to have high organic matter content that can boost soil fertility and plant growth). The second type, which is the main one, is related to the use of organic manure from composting system or livestock. This cultural practice is influenced by many factors. The Niayes agroecosystem is affected by the incursion of marine water in the ground water. The result of this is an increasing salinity and poor yield affecting farmers’ income. To circumvent this constraint, Senegalese farmers have realized that the use of organic fertilizers such as livestock and poultry droppings and groundnut hulls could reduce the salinity and increase soil fertility. Most farmers rely on this type of manure because it is cheap and enhances soil fertility.
At the agronomic level, results suggest that the use of some organic fertilizers can reduce plant susceptibility to pests. Besides, organic fertilizers can improve fruit shelf life and allow gardeners to sell their produce in the market over longer periods.
However, there are some other aspects that need to be taken into account before optimizing this practice. The use of these organic inputs (manure and wastewater) is not without costs. Both types of organic fertilizers have repercussions on soil and groundwater chemistry. Moreover, public health is threatened. Wastewater is full of heavy metals, plant parasitic nematode worms (such as eelworms) and opportunistic pathogens (such as coliform bacteria, whose presence indicates that other pathogenic organisms of faecal origin may be present). Microbial studies carried out in our project suggest that the use of wastewater and organic fertilizers could affect public health and contaminate ground water. It has also been shown that vegetables grown using these methods are not washed from the collecting point to the market (especially lettuce and other vegetables that are eaten raw). Considering all these facts, policies should be formulated to protect environmental and public health.
Although wastewater and organic fertilizers seem to increase farmers’ incomes, safety measures should be taken to avoid ill health. A sensitizing program should be planned to inform all the sectors that are involved in these activities.
Auteur(s) : NIASSY S., AND DIARRA K
Pages : 1-22
Année de publication : 2012
Revue : Organic Fertilizers: Types, Production and Environmental ImpaOrganic Fertilizers: Types, Production and Environmental Impact
N° de volume : Chapitre 1
Type : Livre
Mise en ligne par : DIARRA Karamoko