A simple field experiment which provided free fertilizer to female rice farmers in southern Mali was conducted to measure how farmers chose to use the fertilizer, what changes they made to their agricultural practices, and the profitability of this set of changes. First, a census of female farmers in 23 selected villages was conducted, in which one woman per household was randomly sampled, and a baseline survey was conducted. Detailed information was collected on agricultural activities, other economic activities, assets, consumption, expenditures, etc. A total of 383 women who had cultivated rice in the agricultural season prior to the survey constituted our sample frame for the experiment. The experiment had two treatment groups: those who received the full recommended quantity of fertilizer per hectare, and those who received half of the recommended quantity per hectare. Farmers in the control group received no fertilizer. Teams were sent to the villages to distribute the fertilizer to women in the treatment groups. A short, 30-minute explanation on how to use the fertilizer was provided - no other training or monitoring was provided. A few months after the fertilizer distribution, a follow-up survey was conducted that focused on input use. A second follow-up survey was conducted immediately after the harvest to measure output.