5. High Water-Consuming Crops Under Control: Case of Rice Crop

In this chapter, we calculated the applied water amount for rice in 2013 growing season and investigated the effect of improved cultivation method on rice national production. Moreover, we graphed maximum temperature in 2040 with cutoff temperature to investigate suitability of growing rice in its current growing areas. Under climate change, with the assumption that potential rice production will be reduce by 11 %, its production was assessed in 2020, 2030 and 2040 under traditional and improved cultivation method. The effect of the reduction in the cultivated rice area under climate change was quantified, as well as using potential saved water to cultivate additional area with maize. The results indicated that changing cultivation method from traditional method to cultivation on wide furrows saved a large amount of irrigation water. The saved irrigation amounts were invested to cultivate 309,911 hectare of maize on raised beds, or 371,893 hectare under drip system, which will increase maize production. The results also showed that in 2020, 2030 and 2040 water requirements for rice under traditional planting will increase and consequently its cultivated area will be reduced. The results also showed that during the growing season of rice in both Alexandria and Demiatte, maximum temperature raised above cutoff temperature for a few days during the growing season. Thus, it is implied that Alexandria and Demiatte will be suitable to grow rice in 2040, with probably low yield losses. However, the effect of maximum temperature above cutoff temperature will be more pronounced in the rest of the studied governorates, which might restrict its cultivation in the future. In 2020, 2030 and 2040, water requirements for rice under wide furrows will increase, compared to its values under current climate. Thus, the amount of saved irrigation water, rice productivity and total production will decrease, compared to its counterpart under wide furrows and current climate. Furthermore, the saved water assigned to be use in maize production will be reduced. Water productivity values for rice grown on wide furrows were higher than its value under traditional method in all governorates, either under current climate or climate change.