*2.1. Study Area*

This study was conducted in the central Ethiopian highlands at two experimental sites: Affesa in Dangila district and Alefa in Bure district (Figure 1). Affesa (36.83◦ N, 11.25◦ E) and Alefa (37.06◦ N, 10.62◦ E) sites are located about 80 km and 150 km southwest of Bahir Dar, respectively. The elevation of Affesa site ranges from 2132 to 2219 m above MSL, whereas Alefa site elevation ranges from 1983 to 2033 m above MSL. Both Dangila and Bure districts are categorized under moist sub-tropical regions. Dangila has an average annual rainfall of 1578 mm and a mean annual temperature of 17 ◦C [42], whereas, the mean annual rainfall and temperature in Bure ranges from 1386 mm to 1757 mm and 14 ◦C to 24 ◦C, respectively [43]. Based on soil laboratory analysis, clay soil is the dominant soil texture in Affesa (46% clay and 36% silt) and the soil type in Alefa is dominated by loam soil (44% sand and 29% silt). The dominant rainfed crops in both Dangila and Bure districts include maize, millets (sorghum: *Sorghum bicolor* L., or pearl millet: *Panicum sp*.), barley (*Hordeum vulgare* L.), teff [*Eragrostis tef* (Zucc.) Trotter], and wheat (*Triticum aestivum* L.), [44]. While, onion, potato, cabbage, pepper, tomato, and garlic are the dominant irrigated vegetables in both Dangila and Bure district [22,45]. In the Affesa site, farmers used to practice irrigation using river sources, whereas groundwater use was limited to domestic purposes in both sites due to lack of access to affordable water-lifting technology.
