ارزیابی آب مصرفی، تبخیر-تعرق و بهره‌وری آب گیاه عدس با استفاده از سامانه نیاز آب در شرایط تنش کمبود آب و مصرف کود آهن

تنش کمبود آب یکی از مهم‌ترین تنش‌های محیطی است که بر رشد و عملکرد گیاه عدس (lens culinaris l.) تاثیر نامطلوب دارد. سامانه نیاز آب، سامانه‌ای است که میزان آب مصرفی گیاه را تخمین زده و اطلاعات لازم را در اختیار کاربران قرار می‌دهد. در این پژوهش، آب مصرفی، تبخیر-تعرق و بهره‌وری آب گیاه عدس در شرایط تنش کمبود آب و مصرف کود آهن با استفاده از سامانه نیاز آب بر اساس حل معکوس تابع تولید در بخش دیلمان از توابع شهرستان سیاهکل در استان گیلان در سال های 1397 و 1398 انجام شد. عامل اصلی شامل چهار سطح بدون آبیاری (دیم، i1)، آبیاری تا مرحله گل‌دهی (i2)، آبیاری تا مرحله غلاف‌دهی (i3)، آبیاری در مرحله گل‌دهی و غلاف‌دهی (i4) و عامل فرعی شامل محلول‌پاشی کود نانوکی‌لیت آهن با غلظت 4 در هزار بود که در مرحله‌های گل‌دهی (f1)، غلاف‌دهی (f2)، گل‌دهی و غلاف‌دهی (f3) و قبل از رسیدگی (f4) انجام شد. در مقادیر آب مصرفی، شاخص ریشه میانگین مربعات خطا (rmse) در روش‌های تافته، پاسکوئله و رائس در سال 1397 به‌ترتیب 24.7، 77.3 و 24.3 میلی‌متر و در سال 1398 به‌ترتیب 33.1، 62.9 و 32.2 میلی‌متر بود. این شاخص برای تبخیر-تعرق روزانه در روش‌های تافته، پاسکوئله و رائس در سال اول به‌ترتیب 24.9، 86.7 و 24.7 میلی‌متر در روز و در سال دوم به‌ترتیب 34.4، 67.9 و 33.7 میلی‌متر در روز بودند. به‌طور کلی، نتایج سامانه نیاز آب نشان داد که روش‌های تافته و رائس اعداد نزدیک‌تری به داده‌های اندازه‌گیری شده داشتند و  این دو روش در سامانه می‌توانند به‌عنوان یک روش مناسب در تصمیم‌گیری و تخمین آب مصرفی گیاه عدس برای منطقه مورد مطالعه پیشنهاد شوند.

evaluation of water use, evapotranspiration and water productivity of lentil plant using niazab system under conditions of water deficit stress and iron fertilizer application

background and objectives the niazab system estimates water consumption at different levels of cultivation based on the latest scientific methods and provides macro information to regional managers. the use of the niazab system in determining the actual amount of water for lentil irrigation was based on the inverse solution of the yield production function. irrigation is essential when lentil plant is growing. water deficit stress is one of the most important environmental stresses that can adversely affect soil properties, plant growth, and productivity of agricultural crops, including lentil. the aim of this study is to evaluate water consumption, evapotranspiration, and water productivity of lentil plant using the niazab system under conditions of water deficit stress and iron fertilizer application.methodologythis research was conducted in daylaman district, siyahkal city, guilan province of iran in 2018 and 2019 as a split plot experiment on the basis of randomized complete block design (rcbd) with three replications. the main plots were comprised of four levels of no irrigation (rainfed, i1), irrigation until flowering stage (i2), irrigation until pod formation stage (i3), irrigation during flowering, and pod formation stage (i4).  the sub-plots consisted of 4% of iron nano-chelate fertilizer applied at flowering stage (f1), pod formation stage (f2), flowering and pod formation stages (f3) and pre-ripening stage (f4).resultsfor water consumption values, the root mean square error (rmse) of the tafteh, pasquale, and raes methods in 2018 was 24.76, 77.27 and 24.35 mm, respectively, and in 2019 it was 33.06, 62.90 and 32.23 mm, respectively. the root mean square normal error (rmsen) in the tafteh, pasquale, and raes methods was 0.11, 0.35, and 0.11 percent in 2018, respectively, and 0.17, 0.32, and 0.16 percent in 2019, respectively. in 2018, the agreement or consistency index (d) of the tafteh, pasquale, and raes methods was 0.95, -0.13, and 0.95 percent, respectively, and the efficiency coefficient (ef) was 0.82, -0.78, and 0.83 percent, respectively. in 2019, the agreement or consistency index (d) of the tafteh, pasquale, and raes methods was 0.88, 0.26, and 0.88 percent, respectively, and ef was 0.59, -0.47, and 0.61 percent, respectively. the coefficient of determination (r2) values ​​for water consumption in the tafteh, pasqualeand, and raes methods varied between 0.74 and 0.85 over the two years. the rmse for daily evapotranspiration of the tafteh, pasquale, and raes methods was 24.9, 86.7 and 24.7 mm/day in the first year, respectively, and 34.4, 67.9 and 33.7 mm/day in the second year, respectively. in daily evapotranspiration, the rmsen in 2018 and 2019 was 0.10 and 0.16 percent in the tafteh method, 0.36 and 0.31 percent in the pasquale method and 0.10 and 0.16 percent in the raes method, respectively. the agreement or consistency index (d) for daily evapotranspiration of the tafteh, pasquale, and raes methods was 0.95, -0.22, and 0.96 percent in the first year, respectively, and 0.88, 0.24, and 0.88 percent in the second year, respectively. the ef was obtained for the tafteh, pasquale, and raes methods in the first year was 0.85, -0.88 and 0.85 percent, respectively and in the second year it was 0.63, -0.44 and 0.65 percent, respectively. the rmse for water productivity and water use efficiency in 2018 was 0.08 and 0.07 mm/day in the tafteh method, 0.27 and 0.25 mm/day in the pasquale method, and 0.08 and 0.07 mm/day in the raes method, respectively, while these values ​​in 2019 were 0.15 and 0.12 mm/day in the tafteh method, 0.25 and 0.23 mm/day in the pasquale method, and 0.14 and 0.11 mm/day in the raes method, respectively. in water productivity, the agreement index (d) and the ef of the tafteh method were 0.38 and 0.92 percent, respectively, in 2018, and 1.56 and 2.43 percent, respectively, in 2019. these indicators in the pasquale method showed 1.32 and 10.82 percent in the first year and 1.60 and 9.39 percent in the second year, respectively. these two indices were 0.41 and 0.03 percent in 2018 using the raes method, respectively, and 1.34 and 1.99 percent, respectively, in 2019. in water use efficiency, the agreement index (d) and ef in the tafteh method were 0.34 and 0.15 percent, respectively, in 2018, and 1.276 and 1.849 percent, respectively, in 2019. these indicators in the pasquale method showed 1.41 and 11.39 percent in the first year and 1.46 and 9.41 percent in the second year, respectively. these two indices were 0.32 and 0.14 percent in 2018 using the raes method, respectively, and 0.98 and 1.55 percent in 2019, respectively.conclusionin general, the results of the niazab system showed that the tafteh and raes methods had numbers closer to the measured data, and these two methods in the system can be recommended as a suitable method for decision-making and estimating the water consumption of lentil plant for the study area.author contributionsconceptualization, a.a.g and a.t; methodology, a.a.g and a.t; performing expriments and measurements, s.m.s; software, a.a.g; n.e.p; and a.t; validation, a.a.g; n.e.p; and a.t; formal analysis, a.a.g and a.t; data curation, s.m.s; writing—original draft preparation, a.a.g; writing–review and editing, a.a.g and a.t; visualization, a.a.g; supervision, s.m.s.; project administration, a.a.g; funding acquisition, all authors have read and agreed to the published version of the manuscript.acknowledgementsthis paper is as part of msc thesis in islamic azad university of lahijan that done in collaboration with researchers from the soil and water research institute (swri). the authors are thankful to the islamic azad university of lahijan.data availability statement data is available on reasonable request from the authors. conflict of interest the authors declare no conflict of interest.ethical considerations  the authors avoided data fabrication, falsification, plagiarism, and misconduct.