Recent Notes to broadcasters on water management were included in Farm Radio Weekly issue #257 (August 2013, http://weekly.farmradio.org/2013/08/19/notes-to-broadcasters-water-management/ )
“Farmers boost yields, income with small-scale irrigation systems” (Issue #215, September 2012) raises the topic of irrigation systems. It is available through this link: http://weekly.farmradio.org/2012/09/03/farmers-boost-yields-income-with-small-scale-irrigation-systems-international-water-management-institute/ 
The phrase “irrigation scheme” can conjure up visions of immense government-built structures or elaborate equipment on large-scale farms. But small-scale, farmer-run irrigation schemes can be accessible and innovative.
Past Farm Radio Weekly stories have looked at small-scale irrigation methods and how they can help farmers boost their food security and income:
-Zimbabwe: Irrigation schemes bring hope for women in Insist district (FRW 193, March 2012): http://weekly.farmradio.org/2012/03/19/zimbabwe-irrigation-schemes-bring-hope-for-women-in-insiza-district-by-zenzele-ndebele-for-farm-radio-weekly-in-zimbabwe/ 
-Zimbabwe: Collecting rainfall in the city (FRW 141, January 2011): http://weekly.farmradio.org/2011/01/17/zimbabwe-collecting-rainfall-in-the-city-ips/ 
-Senegal: Drip irrigation boosts dry season production (FRW 30, July 2008): http://weekly.farmradio.org/2008/07/28/senegal-drip-irrigation-boosts-dry-season-production-christian-science-monitor/ 
-Kenya: Rainwater harvesting improves rural livelihoods (FRW 15, March 2008): http://weekly.farmradio.org/2008/03/17/1-kenya-rainwater-harvesting-improves-rural-livelihoods-various-sources/ 
Farm Radio International has published a number of scripts on water topics, including irrigation. You can browse them at: http://www.farmradio.org/archived-radio-scripts/?scriptcat=water 
You may wish to develop a program that looks at appropriate irrigation options for farmers, especially if you broadcast to areas where water is scarce. Try to find farmers or farmers’ groups with successful irrigation activities. Present a range of examples − from simple ideas like using watering cans to conserve water, to larger-scale initiatives like river diversion schemes. Research the advantages and disadvantages of each, and explain that different irrigation techniques suit different situations.
Consider what information farmers need when planning to irrigate their farms. For example, is a watering can all that is needed? Do farmers have the financial resources to invest in drip irrigation? Can water be pumped from a stream? How? Is it feasible to invest in rainwater or surface water harvesting? You might want to interview irrigation specialists who can outline some of the many technical factors to consider.