Sauti ya wakulima, "The voice of the farmers", is a collaborative knowledge base created by farmers from the Chambezi region of the Bagamoyo District in Tanzania by gathering audiovisual evidence of their practices using smartphones to publish images and voice recordings on the Internet.

The participants of Sauti ya wakulima, a group of five men and five women, gather every Monday at the agricultural station in Chambezi. They use a laptop computer and a 3G Internet connection to view the images and hear the voice recordings that they posted during the week. They also pass the two available smartphones on to other participants, turning the phones into shared tools for communication. The smartphones are equipped with GPS modules and an application that makes it easy to send pictures and sounds to the Internet. The farmers at Chambezi use them to document their daily practices, make reports about their observations regarding changes in climate and related issues, and also to interview other farmers, expanding thus their network of social relationships.

The farmers at Chambezi not only struggle because of insufficient infrastructure and unreliable markets for their products, but they are also facing the challenges of a changing local climate. Less rains, less underground water and unprecedented threats caused by pests and plant diseases are some of the pressing issues that they have to deal with. However, they know that by sharing their knowledge on how to cope with these problems, they can become stronger and find ways to overcome them. They hope that, by communicating their observations to extension officers and scientific researchers, who can be in remote locations, they can participate in the design of new strategies for adaptation. They want their voices to be heard: they have so much to say.