Wastewater conservation and reuse in quality vegetable cultivation: Overview, challenges and future prospects

摘要

The serious water scarcity experienced across the globe and the desire for sufficient food production all year round to combat hunger, poverty and malnutrition necessitate the need for wastewater reuse in irrigation. Wastewater has varied compositions that affect the growth of different crops positively, they may also be a source of dangerous pollutant. Heavy consumption of vegetables have been encouraged for its nutritional and health advantages. Hence, their production and cultivation have increased globally. While the nutritional advantage of vegetables is appealing, their high susceptibility to harbor and spread pathogenic microbes call for serious concern. Activities such as transportation, improper handling and packaging amongst others are sources of vegetable contamination. Irrigation water and techniques however present greater danger. Agro-industrial wastewater of a ready-to-eat vegetable (RTEv) industry operating a closed system may reintroduce microbes to vegetable gardens. The use of raw domestic wastewater, either black or grey water in vegetable cultivation presents attendant challenges which must be handled with utmost precaution. This review is focused on the dangers associated with the reuse of agro-industrial and domestic wastewater, precautions required as well as possible preventive/reduction measures. The possible dangers associated with "crude irrigation techniques" used in vegetable cultivation in the Southwestern part of Nigeria are presented. This work will no doubt serve as a tool for policy makers and environmentalists in enlightenment and awareness campaigns in educating most rural dwellers who are ignorant of these dangers.