Studying the Impact of Climate Change on the Evapotranspiration and Water Use Efficiency of Wheat Crop in Iraq


  • Saadi Sattar Shahadha College of Energy and Environmental Sciences, Al-Karkh University of Science, Baghdad, Iraq
  • Suhair L. Zeki Ministry of Water Resources, Iraq
  • Riyadh M. Salih National Center for Water Resources Management, Ministry ofWater Resources, Baghdad 10045, Iraq
  • Ahmed H. Salim National Center for Water Resources Management, Ministry of Water Resources, Baghdad, Iraq
  • Ibrahim A. Dawood Ministry of Water Resources, Iraq


Finding appropriate adaptation strategies to climate change in Iraq become necessary, especially, regarding the growth and productivity of strategic crops by focusing on modern irrigation systems. This study aims to discover appropriate field irrigation strategies to adapt to climatic changes in terms of high air temperature and low relative humidity. The study was conducted at Al-Raeeid Research Station during the winter season of 2020-2021. The land was divided into sprinkler and surface irrigation. In this study, the Root Zone Water Quality Model (RZWQM2) was used. Three different modeling scenarios were applied which are normal weather data, increasing the temperature by 2 degrees, and increasing the temperature by 2 degrees with decreasing the relative humidity by 0.2. The modeling was performed independently for each scenario. The results showed that the actual evapotranspiration increased under the sprinkler irrigation for the T and T&H climate scenarios by 2% and 4%, respectively, and under the surface irrigation, the evapotranspiration increase was 4% and 11% for climate scenarios of T and T&H, respectively. The yield of wheat under the sprinkler irrigation system decreased by 6% and 14% under the influence of T and T&H scenarios, respectively. The results also showed a decrease in the water use efficiency of wheat by 7% and 17% under the influence of T and T&H scenarios, respectively, for sprinkler irrigation. Whereas, for the surface irrigation system, the water use efficiency decreased by 6% and 9% under the influence of T and T&H scenarios, respectively.


Adamo, N., AL-Ansari, N., Sissakian, V. K., Knutsson, S., and Laue, J., (2018), Climate change: Consequences on Iraq’s Environment. Journal of Earth Sciences and Geotechnical Engineering. 8 (3), 43-58.

Ahmad, S., G. Abbas, Z. Fatima, R. Khan, M. Anjum, M. Ahmed, M. Khan, C. Porter and G. Hoogenboom. ,(2017), Quantification of the impacts of climate warming and crop management on canola phenology in punjab, pakistan. Journal of Agronomy and Crop Science 203: 442-452.

Ahuja, L., Rojas, K. W., & Hanson, J. D. (Eds.), (2000), Root zone water quality model: modelling management effects on water quality and crop production. Water Resources Publication.

Ali, H.Z., M.S. Hameed, A.A. Abdulrahman and H.M. Saood,(2020), First report on fusarium brachygibbosum isolate fir 16_its isolated from iraqi wheat plant. Journal of Ecological Engineering 21.

Allen, R. G., Clemmens, A. J., Burt, C. M., Solomon, K., and O'Halloran, T., (2005), Prediction Accuracy for Project Wide Evapotranspiration Using Crop Coefficients and Reference Evapotranspiration, Journal of Irrigation and Drainage Engineering, Vol. 131, No. 1, pp. 24-36.

Anex, R., L. Gu and M. Helmers, (2018), A metric for evaluating the ability of the rzwqm model to project the impact of climate change.

Brooks, R., Corey, T., (1964), Hydraulic Properties of Porous Media. Hydrology Papers. Colorado State University.

Burt, C. C., Mutziger, A. J., Allen, R.G., and Howell, T. A., (2005), Evaporation

Research: Review and Interpretation, Journal of Irrigation and Drainage

Engineering, Vol. 131, No. 1, pp. 37-58

Cameira, M., R. Fernando, L. Ahuja and L. Ma.,( 2007),Using RZWQM to Simulate the fate of nitrogen in field soil–crop environment in the mediterranean region. Agricultural Water Management 90: 121-136.

Daba, K., T. D. Warkentin, R. Bueckert, C.D. Todd and B. Tar’an, ( 2016), Determination of photoperiod- sensitive phase in chickpea (Cicer arietinum L.). Front. Plant Sci. 11:478.

Daham, A., D. Han, W. Matt Jolly, M. Rico-Ramirez and A. Marsh, ( 2019), Predicting vegetation phenology in response to climate change using bioclimatic indices in iraq. Journal of Water and Climate Change 10: 835-851.

Fang, Q.X., L. Ma, D.C. Nielsen, T.J. Trout and L.R. Ahuja, ( 2014), Quantifying corn yield and water use efficiency under growth stage–based deficit irrigation conditions. Practical applications of agricultural system models to optimize the use of limited water 5: 1-24.

Farahani, H. J., & Ahuja, L. R., (1996), Evapotranspiration modeling of partial canopy/residue-covered fields. Transactions of the ASAE, 39(6), 2051-2064.

Food and Agriculture Organization of the United Nations, (1982), Crop Water Requirements, irrigation and drainage. Paper no. 24, FAO, Rome, Italy.

Hall, A. E., 2001, Crop Responses to the Environment, Boca Raton, Florida

Israelsen, O. W. and Hansen V. E.,( 1979),, Irrigation Principles and Practices, 3rd Ed. John Wily and Sons. New York. USA.

Jaradat, A.,( 2003), Agriculture in Iraq: resources, potentials, constraints, research needs and priorities. Journal of food, Agriculture and Environment. 1(2) pp:160

Kahiluoto, H., J. Kaseva, J. Balek, J.E. Olesen, M. Ruiz-Ramos, A. Gobin, K.C. Kersebaum, J. Takáč, F. Ruget and R. Ferrise,(2019), Decline in climate resilience of european wheat. Proceedings of the National Academy of Sciences 116: 123-128.

Karimi, T., C. Stöckle, S. Higgins and R. Nelson, (2018), Climate Change and Dryland Wheat Systems in the Us Pacific Northwest. Agricultural Systems 159: 144-156.

Kristensen, K., K. Schelde and J.E. Olesen, ( 2011) Winter wheat yield response to climate variability in denmark. The Journal of Agricultural Science 149(1): 33-47.

Leisner, C.P. ,(2020), Climate change impacts on food security-focus on perennial cropping systems and nutritional value. Plant Science 293: 110412.

Li, Y., R. Hou and F. Tao, (2020), Interactive Effects of different warming levels and tillage managements on winter wheat growth, physiological processes, grain yield and quality in the north china plain. Agriculture, Ecosystems & Environment 295: 106923.

Liu, H., Y. Liu, L. Zhang, Z. Zhang and Z. Gao,( 2019), Quantifying extreme climatic conditions for maize production using RZWQM in siping, northeast china. International Journal of Agricultural and Biological Engineering 12: 111-122.

Mady, A. A., and Derees, A. H., (2007), Effect of Water Stress and Application of Compost on Water Use Efficiency and Productivity of Cucumber in Plastic House Under Trickle Irrigation System, Misr J. Ag. Eng. Irrigation and Drainage, Vol. 24, No. 1, pp. 182-197.

Meza, F.J. and D. Silva, (2009), Dynamic adaptation of maize and wheat production to climate change. Climatic Change 94: 143-156.

Minati, M.H. and M.K. Mohammed-Ameen, (2019), novel report on six fusarium species associated with head blight and crown rot of wheat in Basra province, Iraq. Bulletin of the National Research Centre 43: 139.

Nimah, M. N., & Hanks, R. J. ,(1973), Model for estimating soil water, plant, and atmospheric interrelations: I. Description and sensitivity. Soil Science Society of America Journal, 37(4), 522-527.

Olesen, J.E., M. Trnka, K.-C. Kersebaum, A.O. Skjelvåg, B. Seguin, P. Peltonen-Sainio, F. Rossi, J. Kozyra and F. Micale, (2011), Impacts and adaptation of european crop production systems to climate change. European Journal of Agronomy 34: 96-112.

Shahadha, S.S., O. Wendroth, J. Zhu and J. Walton, (2019), Can measured soil hydraulic properties simulate field water dynamics and crop production? Agricultural Water Management 223: 105661.

Xiao, D., H. Bai and D.L. Liu, (2018), Impact of future climate change on wheat production: a simulated case for china’s wheat system. Sustainability 10: 1277.

Zhang, X., W. Qin, S. Chen, L. Shao and H. Sun,( 2017), Responses of yield and WUE of winter wheat to water stress during the past three decades—a case study in the north china plain. Agricultural Water Management 179: 47-54.

Zheng, Z., G. Hoogenboom, H. Cai and Z. Wang,( 2020), Winter wheat production on the guanzhong plain of northwest china under projected future climate with simclim. Agricultural Water Management. 239: 106233.