There is a growing body of rigorous, quantitative, independent empirical research on the impact of various ICT-based advisory services on farmers’ welfare. While much of the early evidence was largely anecdotal, fortunately we are now in a world where there is some data detecting what works and what doesn’t. A few key studies, from across the globe, that immediately come to mind are:

From India: Rob Jensen has looked at the adoption of mobile phone by fishermen in south Indian state of Kerala (http://qje.oxfordjournals.org/content/122/3/879.abstract). I have looked at the impact of market information systems on prices received by soybean farmers in Madhya Pradesh (http://www.aeaweb.org/articles.php?doi=10.1257/app.2.3.22). Similarly, Fafchamps and Minten have looked at impact of SMS based market information systems on the choices that farmers make about where to buy and sell. There is evidence from Sub Saharan Africa: Muto and Yamano have looked at the impact of mobile phone usage by Ugandan farmers of maize and banana (http://ideas.repec.org/a/eee/wdevel/v37y2009i12p1887-1896.html), and Fafchamps and Aker have looked at mobile phone usage in Niger (http://www.economics.ox.ac.uk/members/marcel.fafchamps/homepage/mobiles). There is evidence emerging from Colombia and Peru as well (http://works.bepress.com/aparajita_goyal/23/).

Developing and disseminating simple low cost 2 min videos showing farmers utilizing a particular ag technology and sharing their experiences, can sometimes lead to powerful effects in terms of higher adoption rates. For instance, look at Digital Green's videos that are "produced by farmers, for farmers, and of farmers." However, it requires strong support of local agricultural extension officers to not only validate and disseminate these innovations widely to the community, but also provide ancillary support to sustain adoption.

Not surprisingly, serious investment is required to build a "sustainable" advisory service for smallholders where:

1. The content is valuable - demand driven, timely, accurate, and relevant

2. The means of delivery is user friendly - via technology that is suitable to the local context, language compatibile and interactive

3. The service is affordable - robust partnerships between advisory service providers and telecom service providers (who are often not the same) are one way to offer subscription to extremely affordable voice and data services at scale to farmers in a country

Through the e-choupal program (http://www.itcportal.com/sustainability/lets-put-india-first/echoupal.aspx), a private company, ITC limited, provided price info and other ag advisory services to soy (and other) famers in India that also facilitated the sale of soybeans by the farmers directly to them making it not only profitable for the private company to implement the program due to more efficient procurement and lower transaction costs, but also profitable for the farmers to use the service due to higher prices.

what other models exist out there of commercially viable e-extension services?

A dynamic firm in Ghana, Prep-eez, is currently building a national electronic extension platform, in collaboration with the government, that will allow information sharing between farmers, agricultural extension officers and agri experts via voice and SMS. The platform has two main components. A comprehensive e-knowledge management website where most of the agronomic content will be created by scientists and published on the portal for users such as field officers, farmer based organizations, NGOs, researchers and policy makers. The second component would involve transmitting relevant content from the knowledge management portal to smart phone enabled agricultural extension officers in the field, and from there to the farmers' mobile phones via voice and sms.

The IVR and audio component provides an opportunity to deliver critical content to farmers in local voice dialect, and the farmer also has the opportunity to contact the nearest extension officer or  call center for further support. It naturally involves the establishment of a call center to handle farmer queries for effective response. There will be regional  e-labs as well that would be expected to help develop extension officers and  farmer's e-learning skills.

Are there examples out there of successfully delivering content to farmers via voice?