When young maize crops began failing in parts of Kenya earlier this month, the bad news—as well as information about where farmers could get seeds for other crops—spread on many Internet sites, including Facebook, which has 38 million users in Africa.

But it was a mobile platform called iCow—which allows 11,000 farmers and other members to receive livestock-management and other agricultural information—that helped cover the crucial “last mile” to older farmers. When a message from iCow passed along a tip already posted on Facebook about disease-free seeds available from the Kenya Agri Research Institution, that institution was, within two hours, besieged with hundreds of calls. Read More