برآورد مقدار پتانسیل و شکاف بهره ‏وری آب در تولید گندم‌آبی در ایران

ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﺿﺮورت ﺑﻬﺒﻮد ﺑﻬﺮه وری آب در ﺑﺨﺶ ﮐﺸﺎورزی،ﻫﺪف اﯾﻦ ﭘﮋوﻫﺶ ﺑﺮآورد ﻣﻘﺪار ﭘﺘﺎﻧﺴﯿﻞ و ﺷﮑﺎف بهره وری آب در ﺗﻮﻟﯿﺪ ﮔﻨﺪم آﺑﯽ در اﯾﺮان اﺳﺖ . ﺑﺮای ﺗﻌﯿﯿﻦ ﭘﺘﺎﻧﺴﯿﻞ ﺗﻮﻟﯿﺪ ﮔﻨﺪم از روش ﺗﻮﺻﯿﻪ ﺷﺪ ه‌ ﻓﺎﺋﻮ در ﻧﺸﺮﯾﮥ 33 و ﺑﺮای ﺗﻌﯿﯿﻦ ﺗﺒﺨﯿﺮ ﺗﻌﺮق ﭘﺘﺎﻧﺴﯿﻞ از ﻧﺸﺮﯾ ﮥ 56 ﻓﺎﺋﻮ و ﺑﺮای ﺑﺮآورد ﺗﺒﺨﯿﺮ ﺗﻌﺮق واﻗﻌﯽ از راﺑﻄ ﮥ ﻋﻤﻠﮑﺮد و ﺗﺒﺨﯿﺮ-ﺗﻌﺮق اﺳﺘﻔﺎده ﺷﺪ. ﻋﻤﻠﮑﺮد واﻗﻌﯽ از آﻣﺎرﻧﺎﻣﻪ ﻫﺎی وزارت ﺟﻬﺎد ﮐﺸﺎورزی اﺳﺘﺨﺮاج ﮔﺮدﯾﺪ. ﺷﮑﺎف ﻋﻤﻠﮑﺮد و ﺑﻬﺮه وری آب از ﺗﻔﺎوت ﻣﻘﺪار واﻗﻌﯽ و ﭘﺘﺎﻧﺴﯿﻞ ﺑﻪ دﺳﺖ آﻣﺪ. ﺗﻔﺎوت ﺷﺎﺧﺺ ﻋﻤﻠﮑﺮد و بهره وری ﭘﺘﺎﻧﺴﯿﻞ و واﻗﻌﯽ ﺑﻪ ﻋﻨﻮان ﺷﮑﺎف شاخص ﺑﻪ دﺳﺖ آﻣﺪ. ﻋﻤﻠﮑﺮد ﻗﺎﺑﻞ ﺣﺼﻮل ﺑﻪ ﻋﻨﻮان ﺑﺨﺸﯽ از ﻋﻤﻠﮑﺮد ﭘﺘﺎﻧﺴﯿﻞ در ﻧﻈﺮ ﮔﺮﻓﺘﻪ ﺷﺪ ﮐﻪ ﺑﺮای ﺗﻮﻟﯿﺪﮐﻨﻨﺪﮔﺎن ﻗﺎﺑﻞ دﺳﺘﯿﺎﺑﯽ اﺳﺖ. ﻧﺘﺎﯾﺞ ﺗﺤﻘﯿﻖ ﻧﺸﺎن داد ﺑﺮای دوره‌ زﻣﺎﻧﯽ 1385 ﺗﺎ 1394 ﻣﯿﺎﻧﮕﯿﻦ ﻋﻤﻠﮑﺮد ﻗﺎﺑﻞﺣﺼﻮل و واﻗﻌﯽ ﮔﻨﺪم در ﮐﺸﻮر ﺑﻪ ﺗﺮﺗﯿﺐ 5744 و 2986 ﮐﯿﻠﻮﮔﺮم در ﻫﮑﺘﺎر و ﺷﮑﺎف ﻋﻤﻠﮑﺮدی 2758 ﮐﯿﻠﻮﮔﺮم ﺑﺮ ﻫﮑﺘﺎر اﺳﺖ. ﻣﯿﺎﻧﮕﯿﻦ ﺑﻬﺮهوری ﭘﺘﺎﻧﺴﯿﻞ و ﺷﮑﺎف ﺑﻬﺮهوری ﺑﻪ ﺗﺮﺗﯿﺐ 1/02 و 0/09 ﮐﯿﻠﻮﮔﺮم ﺑﺮ ﻣﺘﺮﻣﮑﻌﺐ اﺳﺖ. ﺑﺎ ﺷﻨﺎﺳﺎﯾﯽ ﻣﺆﻟﻔﻪﻫﺎی اﺻﻠﯽ اﯾﺠﺎدﮐﻨﻨﺪه‌ ﺷﮑﺎف ﻋﻤﻠﮑﺮد و ﺑﻬﺮه وری آب و ﻣﺪﯾﺮﯾﺖ ﻣﻨﺎﺳﺐ زراﻋﯽ در ﻫﺮ اﻗﻠﯿﻢ ﯾﺎ اﺳﺘﺎن ﻣﯽﺗﻮان ﺷﮑﺎف ﻫﺎی ﻣﻮﺟﻮد را ﮐﺎﻫﺶ داده ﯾﺎ ﺑﺮﻃﺮف ﮐﺮد

potential and gap of water productivity in wheat production in iran

extended abstractintroductionwheat has a specific importance and position as the main food and the source of calories (about 45% of the required energy) and protein (about 50% of the required protein). the gap of water productivity in agricultural production has not yet been investigated despite the need to improve water productivity in agricultural productions and the importance of potential of water productivity in the agricultural sector in iran. wheat is the main nutritional material and the main source of calorie and protein which has important and special status in the country among the various products. water productivity is one of the important indices in evaluating the irrigation water use efficiency in the agricultural production. globally, the value of this index has varied from 0.52 kg m-3 to 2.67 kg m-3. in spite of the need to improve water productivity in agricultural production; and the importance of amounts of this index in the agricultural sector, the gap in water productivity for agricultural production has not yet been studied. therefore, the objective of this study was to investigate the wheat-yield gap and to estimate the potential and gap of water productivity in wheat production in iran.methodologythe recommended methods of fao-33 and fao-56 were respectively applied to determine the potential of wheat production and potential evapotranspiration in the country. measured (actual) yields were acquired from documents of agricultural ministry. the gap of yield (and water productivity) was obtained from the difference between actual and potential (or reliable) values. the potential (and actual) of water productivity was achieved from the ratio of yield to the evapotranspiration. the reliable yield was defined as a part of the potential yield that could be achieved by producers. results and discussionwith investigating the wheat-yield gap and to estimate the potential and gap of water productivity in wheat production in iran, the results showed that the reliable and actual yields respectively averaged 6516 and 2905 kg ha-1 with a gap of 3434 kg ha-1 for the period of 1385 to 1394 (2006-2015). now, 36% and 48% of the potential and reliable yields were harvested from wheat farms as an actual yield. the potential and reliable yields; and water productivity in wheat production is influenced by climatic conditions. the highest production gap was estimated from farms with semi- arid climate conditions. the potential productivity and its gap (with water application efficiency of 60%) were 1.04 and 0.52 kg m-3. actual water productivity increases and the gap of water productivity reduce in all regions with enhancing the water application efficiency.conclusionsthis study was conducted with the aim of investigating the wheat-yield gap and to estimate the potential and gap of water productivity in wheat production in iran. findings revealed that wheat farms in the arid and semi-arid climates in the country have a considerable capacity to save irrigation water by improving water application efficiency. the gap in yield and water productivity in wheat production is significantly correlated with the field management. affecting factors on the water productivity gap include irrigation management, tillage practices, sowing time, nutrition and pest management. one of the limitations of this study is the application of the average of several coefficients such as crop coefficient and crop response to water deficit and need to calibration of actual evapotranspiration with field data. therefore, calibration of actual wheat evapotranspiration based on lysimetric data or satellite images as well as analysis or meta-analysis of factors affecting water productivity in wheat production can complement the findings of this study. by identifying the main components affecting the yield gap and water productivity and with appropriate agronomic management in each climate (or province) could reduce the existing gaps.