51
simulated the effect of application of 80% of full irrigation to faba bean grown in
clay soil under surface irrigation and they found that this amount of water saving
reduced yield by 5%.
– Barley: Ouda et al. (2007) indicated that omitting the last irrigation for barley at
maturity stage reduced yield by 10%, whereas this percentage was reduced to 6%
under spraying with MgCO 3 as an anti-transpirant compound during vegetative
stage and omitting the last irrigation at maturity stage.
– Onion: Taha et al. (2019) indicated that saving 20% of the applied water to onion
grown under sprinkler system in sandy soil reduced yield by 8%. Zayton (2007)
studied the effect of skipping the last irrigation on the applied irrigation water
and the yield of onion. He found that 20% of the applied irrigation water was
saved and 15% the yield was lost. Ouda et al. (2010d) simulated the effect of
applying 80% of full irrigation to onion grown in clay soil under surface system,
where onion yield losses were 5%.
3.8.2 Effect of Deficit Irrigation on Summer Crops
3.8.2.1 Maize
Maize is another important crop in Egypt, where its consumption is higher than its
production. Azab (2016) indicated that 15% yield losses for maize could be occurred
under skipping the second irrigation (25 days after germination). Kubota et al.
(2016) compared between the effect of conventional irrigation interval for maize
grown in clay soil under surface irrigation (14 days) and prolonged irrigation
interval on maize yield and they found that water saving was 8% with almost no
yield losses under prolonged irrigation interval. Taha and Ouda (2016) indicated
that application of deficit irrigation to maize grown in sandy soil under drip system
and fertigation in 80% of irrigation time, where 14% saving in the applied water
resulted in 12% yield losses. Whereas, fertigation in 60% of irrigation time resulted
in saving the same amount of irrigation water with higher yield losses, namely 17%.
The low percentage of yield losses under fertigation in 80% of irrigation time was
resulted from increasing fertilizer use efficiency. El-Sherif and Ali (2015) indicated
that the yield of maize grown in silty clay soil under surface irrigation was reduced
by 14%, when irrigation water was reduced by 10%. Abd El-Halim (2015) compared between the applied water to maize cultivated on conventional furrows and
maize cultivated on alternative furrow irrigation every 14 days. He found that using
alternative furrow irrigation resulted in saving 7% of the applied irrigation water
with only 2% yield losses.
Karrou et al. (2012) indicated that 30% saving in the applied irrigation to maize
under surface irrigation in clay soil resulted in 8% yield losses. Abou Kheira (2009)
reported that yield losses in maize cultivated in loamy clay soil using surface drip
system was 4% under 11% water saving, whereas, 13% saving in the applied irrigation water under furrow irrigation using gated pipes resulted in 18% yield losses.
3 Egypt Faces Water Deficiency, and Food Insufficiency
simulated the effect of application of 80% of full irrigation to faba bean grown in
clay soil under surface irrigation and they found that this amount of water saving
reduced yield by 5%.
– Barley: Ouda et al. (2007) indicated that omitting the last irrigation for barley at
maturity stage reduced yield by 10%, whereas this percentage was reduced to 6%
under spraying with MgCO 3 as an anti-transpirant compound during vegetative
stage and omitting the last irrigation at maturity stage.
– Onion: Taha et al. (2019) indicated that saving 20% of the applied water to onion
grown under sprinkler system in sandy soil reduced yield by 8%. Zayton (2007)
studied the effect of skipping the last irrigation on the applied irrigation water
and the yield of onion. He found that 20% of the applied irrigation water was
saved and 15% the yield was lost. Ouda et al. (2010d) simulated the effect of
applying 80% of full irrigation to onion grown in clay soil under surface system,
where onion yield losses were 5%.
3.8.2 Effect of Deficit Irrigation on Summer Crops
3.8.2.1 Maize
Maize is another important crop in Egypt, where its consumption is higher than its
production. Azab (2016) indicated that 15% yield losses for maize could be occurred
under skipping the second irrigation (25 days after germination). Kubota et al.
(2016) compared between the effect of conventional irrigation interval for maize
grown in clay soil under surface irrigation (14 days) and prolonged irrigation
interval on maize yield and they found that water saving was 8% with almost no
yield losses under prolonged irrigation interval. Taha and Ouda (2016) indicated
that application of deficit irrigation to maize grown in sandy soil under drip system
and fertigation in 80% of irrigation time, where 14% saving in the applied water
resulted in 12% yield losses. Whereas, fertigation in 60% of irrigation time resulted
in saving the same amount of irrigation water with higher yield losses, namely 17%.
The low percentage of yield losses under fertigation in 80% of irrigation time was
resulted from increasing fertilizer use efficiency. El-Sherif and Ali (2015) indicated
that the yield of maize grown in silty clay soil under surface irrigation was reduced
by 14%, when irrigation water was reduced by 10%. Abd El-Halim (2015) compared between the applied water to maize cultivated on conventional furrows and
maize cultivated on alternative furrow irrigation every 14 days. He found that using
alternative furrow irrigation resulted in saving 7% of the applied irrigation water
with only 2% yield losses.
Karrou et al. (2012) indicated that 30% saving in the applied irrigation to maize
under surface irrigation in clay soil resulted in 8% yield losses. Abou Kheira (2009)
reported that yield losses in maize cultivated in loamy clay soil using surface drip
system was 4% under 11% water saving, whereas, 13% saving in the applied irrigation water under furrow irrigation using gated pipes resulted in 18% yield losses.
3 Egypt Faces Water Deficiency, and Food Insufficiency