Soil and Plant Interactions

fa تعیین تبخیر-تعرق و ضریب گیاهی کاملینا (Camelina sativa L. Crantz) در شرایط کم‌‌آبیاری و سطوح مختلف شوری با استفاده از لایسیمتر در گلخانه Determination of Evapotranspiration and Crop Coefficient of Camelina (Camelina sativa L. Crantz) Under Deficit Irrigation With Different Salinity Levels by Using Lysimeter in Greenhouse رشد گیاهان در شرایط تنش Plant growth under stressful conditions پژوهشي Research به‌منظور تعیین تبخیر-تعرق و ضریب گیاهی کاملینا در مراحل مختلف رشد در شرایط بدون تنش (بدون کمبود آب و شوری) و تنش (تحت تنش شوری و خشکی)، آزمایش گلدانی به‌صورت فاکتوریل (با سه فاکتور آبیاری، شوری و مرحله رشد) در قالب طرح کاملاً تصادفی با سه تکرار در گلخانه‌ای با پوشش پلاستیکی انجام شد. تیمارهای آبیاری شامل W1 ،W0 و W2 به‌ترتیب 100، 75 و 50 درصد تأمین نیاز آبی و تیمارهای شوری آب شامل S2 ،S1 ،S0 و S3 به‌ترتیب 0/7، 4، 8 و 12 دسی‌زیمنس بر متر بودند. نتایج نشان داد که مقدار کل تبخیر-تعرق کاملینا طی 61 روز دوره رشد در گلخانه برابر 245 میلی‌متر بود. با افزایش شوری آب آبیاری، تبخیر-تعرق دوره مذکور در تیمارهای W0S2 ،W0S1 و W0S3 نسبت به تیمار شاهد (W0S0) به‌ترتیب 9، 21 و 32 درصد کاهش یافت. در شرایط آبیاری کامل (100% نیاز آبی) با آب غیرشور (بدون تنش شوری)، مقادیر میانگین ضریب گیاهی در مراحل ابتدایی، توسعه، میانی و انتهایی دوره رشد به‌ترتیب برابر 0/45، 0/9، 1/35 و 0/5 به‌دست آمد. ضریب گیاهی کاملینا در مراحل اولیه، توسعه، میانی و انتهایی رشد در تیمار W2S3 نسبت به تیمار شاهد به‌ترتیب به‌میزان 44، 60، 64 و 54 درصد کاهش یافت. با توجه به کاهش کمّی و کیفی منابع آب زیرزمینی در دشت ممنوعه بحرانی کاشمر، پیشنهاد می‌شود ضریب گیاهی کاملینا نسبت به شوری آب آبیاری و کم‌آبی، اصلاح گردد. Abstract In order to determine the evapotranspiration and crop coefficient of camelina in different growth stages under normal (i.e. without water shortage and salinity) and stressful conditions (i.e. under drought and salinity stress), a pot experiment was conducted as factorial in the form of completely randomized design with three replications. Three irrigation treatments including 100 (W1), 75 (W2) and 50% (W3) water requirements and four salinity levels including 0.7 (S1), 4 (S2), 8 (S3) and 12 dS m-1 (S4) were used in greenhouse with plastic cover. The results showed that cumulative evapotranspiration of camelina during growth stage (i.e., 61 days) was 245 mm in the greenhouse. By increasing irrigation water salinity, camelina evapotranspiration decreased by 9, 21 and 32% in W0S1, W0S2 and W0S3 treatments, respectively, when compared to control (W0S0). Under irrigation with fresh water and without salinity stress, crop coefficient was identified 0.45, 0.9, 1.35 and 0.5 for initial, development, mid and final growth stages, respectively. Increasing irrigation water salinity from 0.7 to 12 dS m-1 and decreasing irrigation water by 50%, decreased camelina crop coefficient by 33 and 46% respectively, into quadruple growth stages. Due to the quantitative and qualitative reduction of underground water resources in the forbidden plain of Kashmir, it is suggested to modify the plant coefficient of camelina in relation to irrigation water salinity and water scarcity. Background and Objective: Camelina (Camelina sativa L. Crantz) is an oilseed crop that is currently being commercially produced as a feedstock for biodiesel in semi-arid areas (Hunsaker et al., 2011). Camelina seed consists of about 43% oil in dry matter. The contents of unsaturated fatty acids in the oil are 30‒40% linoleic acid and 15% oleic acid (Zubr, 2003). Crop evapotranspiration (ETc) and precipitation are major factors that control the water requirements of crops. Quantification of ETc for a type of crop in any region and season is necessary for proper design of irrigation systems, crop water balance studies and seasonal irrigation water management (Okechukwu and Mbajiorgu, 2020). The most common method for computing ETc is through the crop coefficient (Kc) approach. The Kc is the ratio of crop evapotranspiration (ETc) to reference evapotranspiration (ET0) (Shukla et al., 2014). Considering that ETc and crop coefficient are necessary for estimating of crop water requirement and improvement of irrigation scheduling in any region, the objective of this study was to determine the ETc and crop coefficient of camelina in greenhouse conditions. The novelty aspect of this research in comparison with the past researches was to determine the ETc and crop coefficient of camelina by applying saline water and deficit irrigation during the experiment. Methods: Three irrigation treatments including W0, W1 and W2 (providing 100, 75 and 50% crop water requirement, respectively) and four salinity levels of irrigation water including S0, S1, S2 and S3 (0.7, 4, 8 and 12 dS m-1, respectively) were used. The experiment was carried out as factorial (with three factors including salinity, irrigation water and growth stage) in a form of completely randomized design with three replicates. For determining the ETc and crop coefficient, 36 pots were used as weighing microlysimeters. Soil moisture status in the microlysimeters was monitored through weighting. Before each irrigation event, lysimeters and their content were weighted and then water content needed to reach the soil water content to field capacity, was calculated. The ET0 in greenhouse conditions was estimated by planting grass in the two same pots. Results: In all treatments, daily variations of ETc during the growth period showed that by initiating the development stage, ETc increased rapidly, at midseason stage reached to maximum value and then decreased at the end of growth stage. The accumulated ETc for camelina during the growth season was 245 mm in the normal conditions (i.e., no salinity and drought stress).  In all of the irrigation treatments, ETc decreased by increasing the irrigation water salinity. The ETc decreased by 9, 21 and 32% respectively, in W0S1, W0S2 and W0S3 treatments compared to the normal conditions. The results also indicated that quadruple distinct growth stages were identified for the seasonal changes in Kc. In the first stage (initial), the Kc-ini values had a higher dispersion due to the effect of soil evaporation, when the ground cover values were low. In the second stage (crop development), the daily Kc values increased and the maximum values were observed when the plants reached maximum cover coincided with the initial mid-season stages. In the third stage (mid-season), the Kc-mid values were high and more or less constant. In the fourth stage (late season), as leaves began to age and senescence, there was a continuous decrease in daily camelina Kc until it reached to a lower value at the end of the growth period denominated Kc-end. In this study, the average crop coefficient values for camelina in normal conditions were determined to be 0.45, 1.35 and 0.50 during the initial stage, mid-season, and late season stages, recpevtively. Camelina crop coefficient at the initial, development, middle and final growth stages for the W2S3 treatment decreased by 44, 60, 64 and 54%, respectively, compared to the W0S0 treatment. Conclusions: The findings revealed that by increasing irrigation water salinity to 4, 8 and 12 dS m-1, ETc decreased to 223, 193 and 166 mm, respectively. Besides, by increasing water irrigation salinity to 12 dS m-1 (without drought stress), crop coefficient at initial stage, development stage, midseason and late season decreased to 0.35, 0.6, 0.85 and 0.32, respectively. Considering the decrease in quality and quantity of groundwater resources in most regions of Iran especially in Kashmar plain, it is suggested to determine the crop coefficient of camelina under different drought and salinity conditions.   References: 1. Hunsaker, D.J., French, A.N., Clarke, T.R., El-Shikha, D.M., 2011. Water use, crop coefficients, and irrigation management criteria for camelina production in arid regions. Irrig. Sci. 29, 27–43. 2. Okechukwu, M.E., Mbajiorgu, C.C., 2020. Determination of crop coefficients and spatial distribution of evapotranspiration and net irrigation requirement for three commonly cultivated crops in South-East Nigeria. Irrig. Drain. 69(4), 743–755. 3. Shukla, S., Shrestha, N.K., Jaber, F.H., Srivastava, S., Obreza, T.A., Boman, B.J., 2014. Evapotranspiration and crop coefficient for watermelon grown under plastic mulched conditions in sub-tropical Florida. Agric. Water Manag. 132, 1–9. 4. Zubr, J., 2003. Qualitative variation of Camelina sativa seed from different locations. Ind. Crops Prod. 17(3), 161–169. تبخیر-تعرق, تنش خشکی, تنش شوری, گلخانه, مراحل رشد. Evapotranspiration, Drought stress, Salinity stress, Greenhouse, Growth stages. 19 35 http://jspi.iut.ac.ir/browse.php?a_code=A-10-2137-1&slc_lang=fa&sid=1 Mahdi Mokari مهدی مکاری mehdimokari@gmail.com https://orcid.org/0000-0001-6419-4068 Yes Department of Water Engineering, Kashmar Higher Education Institute, Kashmar, Iran گروه علوم و مهندسی آب، مرکز آموزش عالی کاشمر، کاشمر، ایران Amir Hossein Ghaderi امیرحسین قادری amir.hossin.gh1373@gmail.com https://orcid.org/0000-0001-7223-236x No Department of Water Engineering, Kashmar Higher Education Institute, Kashmar, Iran گروه علوم و مهندسی آب، مرکز آموزش عالی کاشمر، کاشمر، ایران Javad Alaei جواد علایی javad.alaei1374@gmail.com https://orcid.org/0000-0001-9124-0357 No Department of Water Engineering, Kashmar Higher Education Institute, Kashmar, Iran گروه علوم و مهندسی آب، مرکز آموزش عالی کاشمر، کاشمر، ایران