The broad adoption of improved farming practices can substantially reduce the number of people at risk of undernourishment; for example, the adoption of nitrogen-efficient crop varieties alone can reduce the risk to more than 120 million people. However, adoption of improved practices remains very low, even in areas where projects have heavily promoted them. Positive change will only come about when barriers to adoption – financial, institutional and policy constraints – are better understood and removed. This is Info note number 2 of 3 drawn from The State of Food and Agriculture 2016. Climate change, agriculture and food security. For sources and more detail, please refer to the complete report (available at www.fao.org/3/a-i6030e.pdf). The Info note 1 (http://www.fao.org/3/a-i7084e.pdf) presents the main contents of the report and discusses the changes needed in agriculture in order to respond to the challenge of climate change. The Info note 3 (http://www.fao.org/3/a-i7086e.pdf) addresses the policies, institutions and financing needed to address climate change in agriculture.