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  surfaceirrigation systems.

Key words: Best management practices, irrigation, water scarcity