*2.3. Pearl Millet Yield Data*

To evaluate the variability in pearl millet yield among farmers, we collected yield data from 38 locations representative of the rain gauges shown in Section 2.2. Pearl millet (Okoa variety) was planted in all locations by all farmers under flat cultivation (a common practice by most farmers in the village) and under tied ridges. The tied ridges (in situ) rainwater harvesting practice is among the four soil management strategies recommended as most suitable in semiarid areas [17]. Tied ridges are long, narrow, and elevated strips of land (a ridge) crossed by earthbands within the furrow called ties (Figure 3). The practice is well described in literature [17]. Over 80 farmers across the study area had adopted tied ridge practices at more than 20 spatial rain gauge positions. For each location, we collected yield data from farmers for 2–4 plots with areas of 100 m<sup>2</sup> over two seasons from both flat and tied ridges practices.

**Figure 3.** Tied ridges prepared by different farmers in semiarid Dodoma.
