بررسی مصرف فسفر و محلول‌پاشی عناصر ریز‌مغذی بر عملکرد علوفه و بذر در دو اکوتیپ یونجه

در تحقیقی سه ساله (1393-1390) اثرات مصرف تلفیقی عناصر فسفر و ریزمغذی‌ (حاوی آهن، منگنز، مس و روی) بر خصوصیات کمی و کیفی بذر و علوفه تولیدی دو اکوتیپ یونجه همدانی و رهنانی، در ایستگاه تحقیقات گلپایگان مورد مطالعه قرار گرفتند. به این منظور از طرح آماری کرت‌های خرد شده در قالب بلوک‌های کامل تصادفی با سه تکرار استفاده گردید که در آن دو اکوتیپ یونجه رهنانی و همدانی به‌عنوان عامل اصلی و تلفیق میزان مصرف کودهای فسفر در سه سطح صفر، 65 و 120 کیلوگرم در هکتار در دو حالت محلول‌پاشی و عدم محلول‌پاشی عناصر ریزمغذی به‌عنوان عامل فرعی به‌صورت تیمار مرکب بررسی گردید. بر اساس نتایج، میانگین عملکرد علوفه تر و بذر در اکوتیپ‌های همدانی و رهنانی بدون اختلاف معنی‌دار به‌ترتیب 35.40 و 34.77 تن در هکتار و 498 و 487 کیلوگرم در هکتار به‌دست آمد. سال اثر معنی‌داری بر عملکرد علوفه تر و خشک، میزان بذر تولیدی و وزن هزار دانه داشت به‌گونه‌ای که حداقل و حداکثر صفات یاد شده به‌ترتیب مربوط به سال اول و دوم بود. بیشترین مقدار علوفه تر تولیدی با مقدار 45.42 تن در هکتار، بیشترین میزان بذر تولیدی با مقدار 689 کیلوگرم در هکتار و بیشترین درصد جوانه‌زنی بذر با میزان 95.12 درصد در تیمار کودی 120 کیلوگرم در هکتار فسفر همراه با محلول‌پاشی با عناصر ریزمغذی حاصل شد. مقادیر یاد شده در تیمار شاهد (بدون کود فسفر و عدم محلول پاشی عناصر ریزمغذی) دارای حداقل مقدار بود.

Investigating the Application of Phosphorus and Spraying of Micronutrients on Forage and Seed Yield in Alfalfa Ecotypes

Introduction;Alfalfa (Medicago sativa L.) is known as the most valuable forage in the world due to its resistance to drought, the high quality of forage and high adaptability, high shelf life and high protein. Desirable nutrition of alfalfa is one of the key factors in the quantity and quality of seed and forage production. In alfalfa production, optimum nutrition is one of the key factors in the growth and development of the product and has a direct effect on the yield of forage and seed. The provision of phosphorus and micronutrient elements of soil in order to balance the nutrients of soil plays an important role in quantitative and qualitative improvement of the product, and it is necessary to carry out a comprehensive research on alfalfa. The purpose of this study was to investigate the effect of different levels of phosphorus and micronutrient fertilizer on quantitative and qualitative yield of alfalfa seed and forage.;Material and Methods;In a threeyear research (20112014), the effects of using phosphorus and micronutrients including iron, manganese, copper and zinc on quantitative and qualitative characteristics of seeds and forage production of alfalfa were studied at Golpayegan Research Station Isfahan province. For this purpose, using a split plot experiment based on a randomized complete block design with three replications, the effect of two alfalfa ecotypes (as the main plot) and 6 levels of phosphorus and micronutrient fertilization (as a subplot) on the yield of seed and forage production was investigated. The main plots were consisted of alfalfa Hamedani (V1) and Rehnani (V2) and sub plots (subtreatment) were included phosphorus (P2O5) at three levels: zero (P0), 65 (P65) and 120 (P120) kg.ha1, and micronutrient elements in two levels of no applied (R0) and micronutrient application as spraying (R1). Parameters were measured, including forage weight, dry forage weight, seed yield, 1000 seed weight and seed vigor percentage. In the first year, there were two cutting for forage and one for seed production, in the second year there were three cutting for forage and one for seed production, and in the third year there were three cutting for forage production and one for seed production.;Results and Discussion;The results showed that there was no significant difference in forage production, seed yield, 1000 seed weight, and percentage of seed vigor between two ecotypes of alfalfa, and the average yield of forage and seed in Hamedi and Rehnani ecotypes was 35.40 and 34.77 ton.ha1 and 498 and 487 kg.ha1 respectively. The year had a significant effect on the yield of fresh and dry forage, seed yield and 1000seed weight. Also, the maximum of these traits were observed in the second year. The effect of the year on vigor seed was not significant. Comparison of means showed that P fertilizer application of 120 kg.ha1 with micronutrient spraying (P120R1) had the highest seed production and increased of 105% compared to control treatment. The application of 120 kg.ha1 phosphorus without micronutrient application was in the next place. The percentage of seed vigor in the treatment of 120 kg.ha1 P, with the micronutrient application (95.1%) was significantly higher than other treatments.;Conclusions;In this threeyear research, the study of the use of phosphorus and micronutrients on fresh and dry forage yield and some quantitative and qualitative characteristics of seed produced in two alfalfa ecotypes was carried out. The results showed that the highest amount of forage production with the amount of 42.45 ton.ha1 and the highest amount of seed produced with the amount of 689 kg.ha1, belonged to the treatment 120 kg.ha1 phosphorus with micronutrient spraying.