تأثير زمان برداشت و شوري خاك بر عملكرد كمي و كيفي علوفه پنج رقم يونجه (Medicago sativa L.) در اهواز

تولیدات گیاهی (زراعت، اصلاح نباتات و باغبانی)( مجله علمی کشاورزی)

دوره 40 - شماره 3

نوع مقاله: Original Article
چكيده: جهت بررسي تأثير زمان‎هاي مختلف برداشت بر خصوصيات مختلف ارقام گرمسيري يونجه، آزمايشي در سال زراعي 91-90 به‌صورت كرت‎هاي خردشده در قالب طرح بلوك‎هاي كامل تصادفي با 4 تكرار در شرايط خاك شور با هدايت‌ الكتريكي 7/5 دسي‎زيمنس ‎بر ‎متر در مركز تحقيقات كشاورزي و منابع طبيعي خوزستان اجرا گرديد. كرت‎هاي اصلي ارقام مختلف يونجه شامل مساسرسا، بغدادي، نيك‌ شهري و بمي و زمان‎هاي برداشت در ماه‎هاي شهريور، مهر و آذر (به‌ ترتيب چين تابستانه، پاييزه اول و پاييزه دوم، در مجموع سه‎چين هم‌ چنين مرحله رشدي برداشت بر مبناي 15-10 درصد گل‎دهي براي چين‎هاي تابستانه و چين پاييزه اول و ارتفاع جوانه پاي طوقه (8-6 سانتي‌متر) براي چين پاييزه دوم بود) به كرت‎هاي فرعي تعلق گرفتند. نتايج نشان داد ارقام مورد آزمايش از نظر بيشتر صفات به غير از نسبت برگ به ساقه، غلظت كلسيم و نسبت سديم به كلسيم تفاوت معني‎دار با يكديگر داشتند. بيشترين عملكرد علوفه خشك به رقم بغدادي در چين سوم تعلق داشت (4/93 تن در هكتار). كمترين درصد فيبر گياه در چين سوم (پاييزه دوم) در ارقام بمي و مساسرسا به‌ترتيب با ميانگين‎هاي 21/32 و 21/35 مشاهده شد كه تفاوت معني‎داري با يكديگر نداشتند. بررسي نسبت سديم به كلسيم نشان داد بيشترين و كمترين مقدار اين صفت به‌ترتيب به رقم مساسرسا در چين پاييزه اول و به رقم بمي در چين تابستانه تعلق داشت. بر اساس نتايج اين آزمايش، در ميان ارقام مورد مطالعه، رقم‎هاي مساسرسا و بغدادي و در ميان چين‎ها نيز چين دوم پاييزه وضعيت مناسب‎تري داشتند.
Assessment Effect of Cutting Time and Soil Salinity on Quality and Quantity Forage Yield of Five Alfalfa (Medicago Sativa L.) Varieties under Ahvaz Condition
Article Type: Original Article
Abstract: Background and Objectives: The cutting schedule imposes strong effects on yield and forage quality of alfalfa varieties. In Khuzestan province (south west of Iran), there are many influential factors on alfalfa cutting time such as temperature, sunlight duration, height of water table and amounts of salts in soil. The aim of this research was to evaluate forage production in continuous cuttings of alfalfa varieties in saline soils of Ahvaz conditions.
Materials and Methods: In order to study the effect of cutting time on quantitative and qualitative yield of alfalfa varieties an experiment was carried out as split plots in time, based on randomized complete blocks design (RCBD) with four replications in saline soil (Electrical conductivity=7.5 ds.m-1) at the research farm of Khuzestan Agricultural and Natural Resources Research Center in 2011 and 2012 crop seasons. The main plot included varieties (Mesasirca, Baghdadi, Nikshahri and Bami) and the sub plot included three cutting times (23 Aug., 1 Oct. and 20 Dec.). These cutting times characterized, summer cut, first autumn cut and second autumn cut. Nine traits including Fresh Forage yield, Dry Forage yield, Leaf stem Ratio, Crude protein, Crude fiber, Na concentration in plant, Ca concentration in plant, Na/Ca were determined. Concentrations of Na and Ca in plant were assessed by using flame photometer.
Results: The results of ANOVA showed that genotypes had a significant effect on all of traits, except Leaf Stem ratio, Ca concentration in plan, Na /Ca. The highest dry forage yield (4.93 t.ha-1) and fresh forage yield (15.15 t.ha-1) belonged to Baghdadi in the second autumn cut. The lowest Crude Fiber percentage was owned by Bami in the second autumn cut (21.32%) and Mesasirca in the second autumn cut (21.35%) which did not have a significant difference with each other. The highest amount of Na/Ca trait belonged to Baghdadi in the first autumn cut and the lowest Na/Ca belonged to Bami in summer cut. Baghdadi variety at the second cutting treatment has the highest (0.95%) Na concentration and Nickshahri at summer cutting has the lowest amount of Na (0.44%). Mesasersa (45.9 cm) and Baghdadi (45 cm) varieties had the highest plant height; also, Nickshahri (41.1 cm) and Bami (43.1 cm) had the lowest plant height.
Discussions: Considering results of this research, it is suggested that among varieties, Mesasirca and Baghdadi were the best genotypes and the second autumn cut has suitable conditions for producing of alfalfa high forage quantity and quality.
قیمت : 20,000 ريال