and soil samples were collected.

Table 1 presents the timeline of the intervention. In March 2015, the team collected yield expectations and field activities to date. Farmers were divided into 26 strata based on their location and agro-climatic conditions.<sup>16</sup> Individual randomization was done at the stratum level and announced at the end of the March survey.<sup>17</sup> A first mid-line survey was carried out in August 2015 focusing on labor inputs and agricultural practices to date during the growing season of the intervention. We also collected administrative data on fertilizer purchases from our partner agro-dealer. A second mid-line survey was fielded in October 2015, just before the harvest, to measure yield expectations and to record agricultural activities since the first mid-line. In January 2016, we collected yield data for the 2015 growing season. Finally, we collected further information on grain sales from the 2015 harvest in June 2016. In May 2017, 2 years after the experiment, we went back for a final end-line survey to collect information on practices for the 2017 growing season, which allow us to measure persistence. As a result, we have a panel on agricultural practices and input use for the years 2014, 2015 and 2017 and yield information for 2014 and 2015.

To be considered for the farmers had to cultivate maize in at least one eligible program, hectare of owned or rented land (and in no more than 15 hectares), had to be between 18 and 70 years old and had to sow maize in the 2015 growing season. We have consistent panel data on agricultural practices in 2014, 2015 and 2017 for 678 farmers and they comprise the core sample for the study.<sup>18</sup> Table 2 provides summary statistics for the study sample of 678 farmers and their registered plots. Panel A reports farmer characteristics. Incomes were low by Mexican standards with an average self-reported annual income of 29,414 pesos (US$ 2,200). Panel B of Table 2 for all farmers and column 1 of Appendix Table A3 for farmers in the control group, report the agricultural practices at baseline. Farmers cultivate about 2 plots and an average total area of 5.7 hectares. In 2014 (the year before the intervention) fertilizer use in their registered plot was near universal (97%) with farmers carrying out 1.6 fertilizations on average though only 6% fertilized at sowing. Average self-reported yields were about 2 mt/ha and about half sold maize in the market. Only 6% had used agricultural extension services in the past and only 15% had paid for a soil analysis.

> 16 Specifically, study farmers came from 54 localities ( _localidades_ ) of which 29 were quite small and thus merged with the closest _localidad_ using distance between centroids from INEGI’s geographic databases. If there were ties, we chose to merge _localidades_ with the closest altitude. Two of the small _localidades_ were merged into one to give us a total of 26 clusters. The median cluster had 21 farmers, the 25th percentile had 15, and the 75th had 32.

> 17We note that with individual level randomization, there could be spillovers across farmers in different treatments. We study the potential spillovers in Section 5.2.

> 18We lack data for some farmers because they did not sow maize in a particular year (less than 5%), or because they could not be located for the interview. Appendix Table A2 column 1 shows that attrition was not differential across experimental arms.

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