|Recently Accepted Publications (page 8) September 2021|
This addresses USDA-ARS Research Goal: Crop plants with enhanced water and input-use efficiencies
Abdelrahman, M.A.; Emadeldin, Y.; Rohila, J.S.; Karthikeyan, R. Impact of Genetic Improvements of Rice on Its Water Use and Effects of Climate Variability in Egypt. Agriculture 2021, 11(9): 865. https://doi.org/10.3390/agriculture11090865 (goes outside ARS)
Natural resources are limited for crop production and there is a need to use marginal agricultural lands and reduced water resources to sustain rice production to feed the world. Genetic improvements and the release of improved rice varieties will aid in meeting this challenge. Egypt relies only upon the Nile River for all of its freshwater supply. To remain competitive in rice production, rice breeders have aggressively improved Egyptian rice varieties for reduced water requirements. We analyzed data for the last two decades to understand the impacts of climate variables, improved cultivars, and various cultivar substitution scenarios as a case study in productivity trends. In general, rice acreage and total production have decreased over time. An in-depth analysis of data demonstrated that while some late maturing varieties had greater yield, early maturing varieties had higher water productivity (i.e. the amount of water used to produce a ton of rice). Using a classical cultivar substitution analysis it was found that improved cultivars (e.g., Giza179, Sakha 107) that were of short duration (days to maturity = 122) and were higher yielding (9.26 metric ton/ha) were capable of providing higher net savings on water (795.55 thousand m3) compared to the average of the popular cultivars. In addition, the typical weather pattern in Egypt is characterized by more precipitation during off-season than during the growing season. Using autoregressive distributed lag (ARDL) model, long-term and short-term effects of certain climate variables on rice production were analyzed and results demonstrated that on- and off- season precipitation had mainly long-term impacts, but relative humidity during the rice growing season had greater short-term impacts possibly due to affecting physiology of the plant via vapor pressure deficit. Overall, the results indicated that short duration and higher yielding varieties could be one of the effective ways to increase rice production by using less irrigation water.
Pictured: (b) location of the Nile River Delta in northern Egypt; and (c) the study areas in the rice-growing areas.