بررسی اثر کاربرد سوپرجاذب رطوبتی و تلقیح با قارچ میکوریزا بر جذب عناصر غذایی، کارآیی مصرف آب و عملکرد گیاه سیب‌زمینی (solanum tuberosum) در شرایط کم‌آبیاری

به‌منظور بررسی اثر سوپرجاذب رطوبتی و تلقیح میکوریزایی بر میزان مصرف آب، جذب عناصر غذایی، عملکرد کمّی و کیفی سیب زمینی (solanum tuberosum) آزمایشی به‌صورت طرح استریپ- پلات ‌فاکتوریل (طرح نواری) با طرح پایه بلوک های کامل تصادفی طی سال‌های 98-1397 در مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی همدان به اجرا درآمد. در این تحقیق، مقدار آب آبیاری در سه سطح ( 100 ، 75 و50 درصد نیاز آبی بر اساس تبخیر و تعرق) در کرت های افقی و فاکتور استفاده از سوپر جاذب trawat200a با دو سطح (0 و 80 کیلوگرم در هکتار) و میکوریزادر دو سطح (تلقیح و عدم تلقیح با میکوریزا گونه glomus etunicatum) در کرت های عمودی قرار گرفتند. در طول فصل رشد، درصد کلونیزاسیون ریشه، غلظت عناصر غذایی در اندام های مختلف اندازه‌گیری شد. در مرحله برداشت عملکرد هر کرت توزین، ماده خشک غده اندازه گیری و کارآیی مصرف آب تعیین گردید. نتایج تجزیه واریانس مرکب نشان داد که اثرات اصلی میزان آبیاری، استفاده از میکوریزا و سوپرجاذب در عملکرد غده و درصد ماده خشک آن، میزان جذب عناصر غذایی در ساقه، برگ و در غده معنی دار شد. در مقایسه اثر سال‌های آزمایش صرفاَ در کارآیی مصرف آب تفاوت معنی دار (p≤0.05) مشاهده شد. مقایسه میانگین ها نشان داد که با اعمال کم‌آبیاری (کاهش میزان آب آبیاری) عملکرد کل 8.96 تن در هکتار کاهش پیدا کرد، امّا این کاهش در شرایط تلقیح توام با میکوریزا و با کاربرد پلیمر سوپر جاذب به‌طور معنی‌داری (فقط 4.92 تن در هکتار) کمتر بود. در شرایط کم‌آبیاری متوسط و شدید استفاده از میکوریزا و سوپر جاذب عملکرد کل را در مقایسه با عدم استفاده از آ‌ن‌ها به‌ترتیب حدود 9.5 و 10.15 درصد افزایش داد. همچنین میزان جذب عناصر غذایی (پرمصرف و کم مصرف) در غده و نیز در شاخ و برگ متناسب با کاهش میزان آب آبیاری کاهش پیدا کرد. میکوریزا و سوپرجاذب در افزایش قدرت جذب عناصر غذایی به‌ویژه در شرایط کم‌آبیاری موثرتر عمل کردند. در مجموع، تلقیح با میکوریزا و به‌کارگیری سوپرجاذب در سیب‌زمینی اثرات مثبت و موثری در جذب مواد غذایی و همچنین عملکرد کل در شرایط کم‌آبیاری و به‌ویژه با اعمال کم‌آبیاری شدید داشت.

evaluation the of the effect of application of superabsorbent and mycorrhiza inoculation on nutrient uptake, water use efficiency and yield of potato (solanum tuberosum) plant in deficit irrigation conditions

introduction hamedan province, characterized by an average annual rainfall of less than 340 mm, faces significant limitations in potato production)solanum tuberosum(, primarily due to the scarcity of irrigation water and the occurrence of drought stress during critical growth stages. in order to address these challenges, the utilization of aqueous superabsorbent materials and the inoculation of mycorrhizal fungi have emerged as highly suitable approaches. these methods aim to optimize the utilization of water and soil resources (khadem et al., 2011). previous studies have indicated that the inoculation of arbuscular mycorrhizal fungi in various plant species, apart from potatoes, can reduce the impact of drought stress and enhance nutrient uptake (bolannazar et al., 2007; subramanian et al., 2008). however, limited research has been conducted on the effects of superabsorbents and mycorrhizae, particularly under conditions of moisture stress and deficit irrigation in potato crops. consequently, this experiment aims to investigate the effects of applying these methods under stress conditions.materials and methodsthe experiment was arranged in strip factorial based on randomized complete block design with three replications. three irrigation levels containing optimal irrigation (100, 75 and 50% of water requirement based on evapotranspiration from pan class a) in horizontal plots and factor 2 using trawat200a superadsorbent (0 and 80 kg.ha-1) and four mycorrhiza and superabsorbent levels including no application of these material (control), superabsorbent, mycorrhiza as a bio-fertilizer and their combination were considered as sub plots. the agria potato cultivar was selected. superabsorbent material was applied adjacent to the tubers at planting time. mycorrhizal inoculum containing the active propagules (cfu 120 /g) was inoculated to the tubers. the concentration of nutrients in the shoot and in the tubers were determined by using kjeldahl apparatus for nitrogen (waling et al., 1989), spectrophotometer for phosphorus (jones, 2001), flame photometry for potassium and atomic absorption spectroscopy for iron, zinc, and manganese (ryan et al., 2001). the produced tubers were divided, weighed and counted based on their size in three groups (small, medium and larg). water use efficiency was determined as the amount of dry matter produced per cubic meter of water consumption in different treatments.results and discussionthe results of combined analysis of variance showed that the main effects of irrigation rate, application of mycorrhiza and superabsorbent on tuber yield and percentage of dry matter, nutrient uptake in stem, leaf and tuber were significant. comparison of means showed that with the application of low irrigation and increasing the intensity of water deficiency (reducing the amount of irrigation water), total yield decreased, but this decrease was significantly less in conditions of inoculation with mycorrhiza and the use of superabsorbent polymer. mycorrhiza and superabsorbent increased the absorption of nutrients, especially under severe water deficiency. in this study, there was a significant difference in the uptake of phosphorus and other low-consumption and high-consumption nutrients at normal irrigation levels and stress in mycorrhizal plants, so that their uptake increased in proportion to the increase in stress intensity and in mycorrhizal inoculation conditions. it seems that by creating stress conditions, the ability and efficiency of mycorrhiza in nutrient uptake is increased and thus in the conditions of lack of moisture with the coexistence mechanism in the relationship of the plant more effectively helps the survival and durability of the plant. mycorrhizal fungi can increase the uptake of phosphorus from the soil by increasing the relative water content and ultimately play an effective role in increasing plant growth (krishna et al., 2005). in this study, it was found that the use of superabsorbent in potatoes helps to increase the absorption of nutrients. the reason for this can be increasing the storage capacity of water and nutrients for a long time in the soil, reducing nutrient leaching, rapid and optimal root growth with better nutrient storage and aeration of the soil.conclusionin this study, it was found that the application of superabsorbent and mycorrhiza in potato helps to increase nutrient uptake as well as tuber yield. the positive effects of combined application  of mycorrhiza and superabsorbent on nutrient uptake and yield were more evident especially in conditions of severe water deficiency.acknowledgementswe are grateful for the efforts of dr. bakhtiari and mr. abdolreza mordai in coordinating and equipping irrigation equipment and land preparation.