Search

The water footprint (WF), based on irrigation water quality, is important as a decision-making tool for crop selection based on the comparative advantage of water consumption and yield to maximize agricultural water productivity and sustainably improve water use efficiency. This paper presents a generic link between climate variability and water footprint. To support this link, a case study is presented for wheat and maize in different agro-climate zones in Egypt. In this study, the three agro-ecological zones, Nile Delta, Middle Egypt, and Upper Egypt, were selected to represent three different microclimates. The climate data were analyzed to estimate reference evapotranspiration (ETo) and calculate crop water use (CWU) for wheat and maize from 2015 through 2019. Cultivated area and yield data were analyzed during the study period. Water footprint (WF) was calculated for old land (clay soils) and new lands (sandy soils) in three climate regions based on blue and grey water. Green water was excluded due to negligible rainfall depths in Egypt. The results showed that the mean values of WF for maize were 1067, 1395, 1655 m3/ton in old land and 1395, 1634, 2232 m3/ton in new land under the three climate regions, respectively, while it was 923, 982, 1117 m3/ton in old land and 1180, 1258, 1452 m3/ton for wheat in new land for the three regions, respectively. The results show that the crop water use fluctuated over regions due to climate variability where the CWU values were 6211, 7335, 8007 m3/ha for maize and 4348, 4825, 5774 m3/ha for wheat in the three regions, respectively. The results show an 11% and 33% increase in maize and an 18% and 29% increase in wheat CWU in Middle and Upper Egypt regions comparing to what was observed in Nile Delta due to an increase in solar radiation, temperature, and wind speed. The Egypt mean value of wheat water footprint was 1152 m3/ton and mean value of maize water footprint was 1563 m3/ton. The data clearly show the effect of microclimate variability on WF and irrigation requirements between regions. The methodology and results from this study provide a pathway to help the policy makers to mitigate climate change impacts on crop yield and to enhance water resources management in major crop production regions by redistribution of the cropping patterns based on the comparative advantages of each crop within each region. The crop choices relative to the soil water retention characteristics could also contribute to the moderation of microclimate, which affects ETo and ETc and the water footprint. [ABSTRACT FROM AUTHOR]

Raised beds (RB) are hailed as means to mitigate the problem of excessive irrigation. However, their adoption and impacts in Egypt are not well-documented. This paper is based on survey data collected from a sample of 691 wheat fields drawn from three major wheat-producing provinces of Egypt. Using area-weights for upward aggregation, we estimated that 19.3% of total wheat area in the three provinces is cultivated with raised beds. We applied the endogenous switching regression model to analyze the socioeconomic, biophysical, and environmental impacts of RB. Model results showed that the adoption of RB led to a 937 kg/ha (12.79%) increase in yield, a US$77.60/ha (9.47%) increase in gross margins, an 824.63 m3/ha (15.05%) reduction in irrigation water application, 16.7% reduction in seeding rate, 5.56% increase in water productivity, and an 11.80% reduction in downside yield risk. Adoption of RB didn't have significant effect on soil salinity and quantities of fertilizer and labor inputs. These results show that RB can provide panacea to several interrelated socioeconomic, biophysical, and environmental problems associated with irrigation. The policy implication of our findings is that Egypt and other similar countries can benefit from embracing RB as part of the technology packages promoted by their national agricultural extension systems. The benefits to these countries will increase if they invest more on research for adapting and perfecting the RB technology including its mechanization and its efficacy in soil salinity management. • The use of raised beds (RB) is expanding in Egypt which is now at 19%. • Adopters of raised beds are reaping sizeable gains in yields and gross margins. • Raised beds are good technology options for reducing irrigation water. • RB increase yield stability and reduce the probability of below-average yields. [ABSTRACT FROM AUTHOR]