BEST MANAGEMENT PRACTICES FOR IRRIGATION SYSTEMS IN ARID AND SEMI-ARID LANDS

Abstract

The effects of global climate changes are escalating the negative environmental impacts associated with the changes and the worst hit in terms of water scarcity are the arid and semi-arid lands (ASALs) of sub-Saharan Africa such as Kenya, who continuously face adversities resulting from the intensification of climate conditions, that has resulted for the extremities of more rainfall and more dryness in the region. The water scarcity characterized in the region and the need to ensure that more conservative and sustainable ways of the application of water are employed cannot be overemphasized. This paper reviews the Best Management Practices (BMPs) of irrigation systems which have yielded better results in terms of water management and irrigation systems usage. The methodology employed reviewed the use of irrigation systems as reported in various literatures from two key aspects; the management factors of irrigation systems and the technical irrigation design factors. The BMPs scenario considered include tillage (conservation and no-tillage), irrigation systems (surface, sprinkler and drip). The BMPs are not established rules that override manufacturer’s guidelines for irrigation practices, but are recommendations for practices that have yielded increased agricultural productivity, crop production and minimized any soil or environmental impacts related to the design and operation of irrigation systems. No-tillage practice was found to be the method with the least negative environmental impact on soils ahead of the conventional ridging practice. Findings also reveal that management roles dependent on technical factors played by the farmers are among the best BMPs. The Irrigation Requirement, systems maintenance and Irrigation Scheduling (IS) are the most important BMPs to consider consequently drip irrigation is the most efficient system to use followed by sprinkler then surface irrigation systems.