*Alefa site*

CA was the treatment and CT was the control in which each participant was involved in both (CA and CT) practice with overhead irrigation (hose). A total of 10 replicates (i.e., farmers) were used. The size of each plot was 100 m<sup>2</sup> (Figure 2a), which then equally divided; 50 m2 for each management (i.e., randomly assigned to CA and CT). The 100 m<sup>2</sup> plot has 10 beds with 30 cm furrows in between (i.e., 70 cm by 10 m bed size and 30 cm by 10 m furrow size). The experimental plots are not evenly distributed, approximately the distance between the plots ranges from 300 m to more than 1 km. CA was evaluated against CT for their impacts on water productivity, crop growth characteristics, and yield. *Affesa site*

Drip irrigation was the treatment, and overhead irrigation (hose) was the control in which each participant was involved in both drip and overhead irrigation under CA practice (Figure 2b). A total of 10 replicates (i.e., farmers) were used each having 100 m2 plot size. The size of each plot was equally divided; 50 m2 for each management (i.e., randomly assigned to drip and overhead irrigation). Similar to Alefa, the 100 m<sup>2</sup> plot has 10 beds with 30 cm furrows in between. In this case, drip irrigation was evaluated against overhead irrigation for their impacts on water productivity, crop growth characteristics, and yield. Besides, maize-forage vetch (*Vicia* sp.) inter-cropping (500 m<sup>2</sup> in size as shown in Figure 2c) was introduced during the rainy season (i.e., 250 m2 with CA and another 250 m2 with CT practice at random) to provide an alternative source of mulch for conservation practice and simultaneously evaluate the effect of CA on rainfed maize productivity.

(**c**) CA versus CT under (rainfed)

**Figure 2.** Experimental design: (**a**) conservative agriculture (CA) versus conventional tillage (CT) both under overhead irrigation using hose, (**b**) drip versus overhead irrigation using hose both under CA, (**c**) CA versus CT intercropped with forage vetch under rainfed maize production

> A total of 20 farmers participated in this on-farm experiment: 10 farmers in Alefa and 10 farmers in Affesa. A series of discussions were conducted with the local government and community leaders to select potential farmers for this research. Farmer's willingness to participate in this research was confirmed through a focus group discussion. The availability of shallow groundwater, a 100 m<sup>2</sup> plot for vegetable production, and a 500 m2 plot for maize-forage production that was close to the household or at a walking distance was considered as additional criteria as a home gardening principle [48] to identify potential farmers. On the 100 m<sup>2</sup> vegetable plot, a total of 10 beds (70 cm by 10 m) were prepared with 30 cm furrows in between. Farmers produced various vegetables (garlic, onion, cabbage, and potato) in the dry season (2018 to 2020) with irrigation. Each farmer used a solar MajiPump to extract water from shallow groundwater well to an elevated (about 1.5 m high from the ground) water storage tank (1000 L in size). Water was then applied to the plots from the water storage tanks through gravity using the drip system or overhead using a hose, depending on the experimental design. In the rainy season, farmers grew maize, and then inter-crop forage vetch after the maize reaches the maturity stage. The vetch forage production uses partly rainfall and then residual moisture from the rainy season. The variety of seeds for the vegetables, maize, and forage vetch was the same for all farmers.
