*2.4. Climate Data*

Climatic data (rainfall, maximum and minimum temperature, wind speed, sunshine hour, relative humidity) were collected from the nearby meteorological station, Dangila for Affesa site, and Bure for Alefa site. The CROPWAT 8 model was used to estimate the reference evapotranspiration (ETo) using the Penman-Monteith method [54]. Mean monthly rainfall reaches its maximum value in July (401 mm in Affesa and 301 mm in Alefa), and mean month evapotranspiration reaches its maximum value in April (112 mm in Affesa and 128 mm in Alefa) as shown in Figure 3. Spatial and temporal rainfall variability is high demanding irrigation to prevent crop failure and increase the cycle of crop production [11,55]. Irrigation use for dry season vegetable production in the study sites ranges from October to June.

**Figure 3.** Climatic characteristics (rainfall; Pe, effective rainfall; ETo, reference crop transpiration) at the research sites of (**a**) Alefa and (**b**) Affesa (2018–2020).

Effective rainfall (*Pe*) was determined using the United States Department of Agriculture Soil Conservation Service (USDA-SCS) method [56,57] as shown in (Equation (1)). The

effective rainfall was used later to determine water productivity for each crop under both irrigated and rainfed systems.

$$
\begin{pmatrix}
Pe = 0.8P - 25 & P > 75 \ mm/month \\
Pe = 0.6P - 10 & P < 75 \ mm/month
\end{pmatrix}
\tag{1}
$$

where *Pe* and *P* are effective rainfall and precipitation in mm/month, respectively.
