تعیین بهره‌وری فیزیکی آب مصرفی گندم در اقلیم‌های مختلف استان کرمانشاه

با توجه به افزایش جمعیت، تغییرات اقلیمی، کمبود منابع آب، نیاز روز افزون به تولید گندم و تامین غذا، بهبود بهره‌وری آب مصرفی گندم ضروری است. برای بهبود بهره‌وری آب مصرفی اولین گام، شناخت و تعیین مقدار آن می‌باشد. هدف از انجام این پژوهش تعیین بهره‌وری آب محصول گندم در اقلیم‌های سرد، معتدل و گرم استان کرمانشاه می‌باشد. براساس آمار سال زراعی 1400-1399 سازمان جهاد کشاورزی استان کرمانشاه و در اقلیم‌های ذکر شده به‌ترتیب شهرستان‌های سنقر، کرمانشاه و سرپل ذهاب دارای بیش‌ترین سطح زیر کشت محصول گندم بوده و به‌عنوان مناطق انجام پژوهش انتخاب شدند. به منظور انجام پژوهش حاضر 34 مزرعه تحت شرایط زارعین انتخاب و در طول فصل رشد حجم کل آب آبیاری هر یک از مزارع اندازه‌گیری شد. بارش موثر با استفاده از داده‌های نزدیک‌ترین ایستگاه هواشناسی سینوپتیک به مزارع منتخب و رابطه usda تعیین گردید. حجم آب مصرفی هر یک از مزارع منتخب در طول فصل رشد نیز از مجموع حجم کل آب آبیاری و بارش موثر محاسبه شد. پس از برداشت محصول و تعیین عملکرد گندم از تقسیم آن بر حجم آب مصرفی، مقدار بهره‌وری فیزیکی آب مصرفی هر یک از مزارع تعیین شد. سپس داده‌های به‌دست آمده در شهرستان‌های مورد مطالعه با استفاده از نرم‌افزار spss تحلیل آماری شد. نتایج حاصل نشان داد میانگین حجم کل آب آبیاری اندازه‌گیری شده در شهرستان‌های سنقر، کرمانشاه و سرپل ذهاب به‌ترتیب 5204، 5795 و 4236 مترمکعب در هکتار و میانگین حجم آب مصرفی گندم به‌ترتیب 6297، 7737 و 5844 مترمکعب در هکتار به‌دست آمد. میانگین عملکرد محصول گندم در شهرستان‌های ذکر شده‌ به‌ترتیب 5799، 7082 و 4937 کیلوگرم در هکتار حاصل شد. میانگین بهره‌وری فیزیکی آب مصرفی گندم در شهرستان‌های ذکر شده‌ به‌ترتیب 0.97، 0.95 و 0.86 کیلوگرم بر متر‌مکعب به‌دست آمد. بنابراین نتایج نشان داد که مقدار بهره‌وری فیزیکی آب مصرفی گندم در شهرستان سرپل ذهاب کمتر از دو شهرستان دیگر بود که مهم‌ترین دلیل آن کمتر بودن عملکرد گندم در این شهرستان می‌باشد. لذا می‌توان با مدیریت به‌زراعی و به‌نژادی شامل مدیریت تغذیه و کاشت ارقام پربازده در این شهرستان اقدام به افزایش عملکرد و نهایتاً افزایش بهره‌وری فیزیکی آب مصرفی گندم دست یافت.

determining the physical water productivity of wheat in different climates of kermanshah province

introduction wheat is the world's leading agricultural product with the scientific name triticum aestivum l.. it is consumed by 35% of the world's population as the main food source. the cultivation area of this crop worldwide is 219153830 ha, of which about 48% is under irrigation. the wheat cultivation area in iran is 6908545 ha, and about 34.3% of it is under irrigation. the area of irrigated wheat cultivation in kermanshah is about 102236 ha. based on the statistics for the crop year 2021-2022, kermanshah province ranks sixth, fourth, and third in the country in terms of the cultivated area, production volume, and yield of irrigated wheat. wheat is one of the major agricultural products of kermanshah province, and it is cultivated under irrigation in a large area of its lands. therefore, determining wheat's physical water productivity is an important indicator in wheat production planning. considering the increase in population, climate change, water scarcity, and the increasing need for wheat production and food supply, it is necessary to improve wheat water productivity. to improve water productivity, the first step is to assess and determine its amount. unfortunately, there is no accurate information about its amount in kermanshah province, and only information related to the results of research projects in certain conditions is available, which cannot be generalized due to the differences between those conditions and the conditions of farmers' fields. the purpose of this research is to determine the water productivity of wheat crops in the cold, moderate, and hot climates of kermanshah province.materials and methods kermanshah province is located at the geographical longitude of 45° 25ʹ to 48° 6ʹ e and a latitude of 33° 41ʹ to 35° 17ʹ n. kermanshah province, with an area of 24,434.25 km2, covers about 1.5% of the country's area, and its average elevation is 1200 m above sea level. this province generally has three climates: cold, moderate, and hot. based on 2020-2021 agricultural year statistics from the organization of agricultural jahad of kermanshah province, and the cities of sonqor, kermanshah, and sarpol zahab cities, respectively, have the largest wheat-cultivated areas and were selected as the research areas. to carry out the current research, 34 farms were selected under real farming conditions, and during the growing season, the total volume of irrigation water for each farm was measured. effective precipitation was determined using the data from the nearest synoptic meteorological station to the selected farms and the usda method. the volume of water consumed by each selected farm during the growing season was also calculated from the sum of the total irrigation water and effective precipitation. after harvesting the crop and determining wheat yield per hectare, physical water productivity for each farm was determined by dividing the yield by the total water consumed. then, the data obtained in the studied cities were statistically analyzed using spss software.results and discussion the results showed that the average total volume of irrigation water measured in sonqor, kermanshah, and sarpol zahab was 5204, 5795, and 4236 m3 ha-1, respectively, and the average volume of wheat water consumption was 6297, 7737, and 5844 m3 ha-1, respectively. therefore, the total volume of wheat irrigation water in sarpol zahab was 19% and 27% lower than in sonqor and kermanshah, respectively, due to the shorter wheat growth cycle and its growth during the cool months. this resulted in wheat water consumption in this city being 7% and 24% lower than in sonqor and kermanshah, respectively. the average wheat yield in the mentioned cities was 5799, 7082, and 4937 kg ha-1, respectively. the average physical water productivity of wheat in these cities was 0.97, 0.95, and 0.86 kg m-3, respectively. therefore, the results showed that the physical water productivity of wheat in sarpol zahab was lower than in the other two cities, mainly due to the lower wheat yield in this city.conclusion the total irrigation water volume, wheat water consumption, and physical water productivity in the cold, moderate, and hot climates of kermanshah province were determined. the results generally showed that the total irrigation water volume and wheat water consumption in the hot climate were lower than in the cold and moderate climates due to the shorter growth cycle and the wheat growing during cool months. therefore, due to the lower wheat water consumption in a hot climate, it was expected that physical water productivity would be higher compared to the other two climates. however, this was not the case due to the lower wheat yield in hot climates, , resulting in a lower physical water productivity than in the two cold and moderate climates. thus, improving agronomic and breeding management in this city could increase wheat yield and ultimately enhance physical water productivity.