تاثیر ترکیب یونی محلول‌های غذایی بر رشد، غلظت عناصر غذایی پرمصرف و عملکرد دو رقم ذرت علوفه‌ای (.zea mays l) در کشت بدون خاک

دانسته‌های اندکی در مورد ترکیب یونی محلول غذایی مناسب برای تولید ذرت علوفه‌ای در کشت بدون خاک وجود دارد. بنابراین هدف این پژوهش، انتخاب یک محلول غذایی پایه برای تولید ذرت علوفه‌ای در کشت بدون خاک بود. به این منظور یک آزمایش گلدانی با دو عامل نوع محلول غذایی و نوع رقم ذرت علوفه‌ای به‌صورت فاکتوریل در قالب طرح بلوک‌های کامل تصادفی با چهار تکرار در گلخانه پژوهشی دانشگاه شهرکرد انجام شد. محلول‌های غذایی مورد استفاده عبارت بودند از: 1) محلول غذایی تمام قدرت هوگلند و آرنون، 2) محلول غذایی نیم‌قدرت هوگلند و آرنون، 3) محلول غذایی باری و میلر، 4) محلول غذایی الکساندر و همکاران، و 5) محلول غذایی رواکورا. همچنین ارقام ذرت علوفه‌ای شامل هیبرید سینگل‌کراس 704 و سینگل‌کراس 410 بودند. نتایج نشان داد در هر دو رقم، بیش‌ترین غلظت نیتروژن و فسفر برگ، ساقه و ریشه در گیاهان تغذیه‌شده با محلول غذایی رواکورا مشاهده شد. کاربرد محلول غذایی الکساندر و همکاران منجر به افزایش معنی‌دار غلظت پتاسیم برگ، ساقه و ریشه در مقایسه با سایر محلول‌های غذایی شد. تامین بهینه عناصر غذایی مورد نیاز ذرت توسط محلول غذایی رواکورا منجر به افزایش معنی‌دار ارتفاع گیاه، قطر ساقه، سطح برگ و شاخص سبزینگی برگ شد. در هر دو رقم ذرت بیش‌ترین وزن تازه و خشک شاخساره و کارایی مصرف آب با کاربرد محلول غذایی رواکورا حاصل شد. بر مبنای نتایج این آزمایش، کاربرد محلول غذایی رواکورا برای کشت هر دو رقم ذرت (سینگل‌کراس 704 و سینگل‌کراس 410) در کشت بدون خاک به‌منظور تولید علوفه در شرایط مشابه این پژوهش پیشنهاد می‌شود.

the effect of ionic composition of the nutrient solutions on growth, macronutrients concentration and yield of two fodder maize (zea mays l.) cultivars in soilless culture

little information is available concerning ionic composition of the suitable nutrient solution for fodder maize production in soilless culture. therefore, the aim of this study was to select a basic nutrient solution for production of fodder maize in soilless culture. a pot experiment was carried out as a factorial in a randomized complete block design with two factors of nutrient solutions and cultivar types and four replications in the research greenhouse of shahrekord university. the nutrient solutions were: 1) fullstrength hoagland and arnon, 2) half-strength hoagland and arnon, 3) barry and miller, 4) alexander et al., and 5) ruakura. two maize cultivars of single cross hybrid 704 and single cross 410 were used. the results indicated that in both maize cultivars, the highest concentrations of nitrogen and phosphorus in leaf, stem and root were observed in the plants nourished with ruakura nutrient solution. the application of alexander et al. nutrient solution led to significant increase in potassium concentrations in leaf, stem, and root compared to other nutrient solutions. optimum supply of nutrient requirements of maize with ruakura nutrient solution resulted in significant increase in plant height, stem diameter, leaf area and leaf greenness index. in both maize cultivars, the highest shoot fresh and dry weights as well as water use efficiency were obtained in the plants nourished with ruakura nutrient solution. based on the results, application of ruakura nutrient solution is suggested for the cultivation of both maize cultivars (i.e., single cross hybrid 704 and single cross 410) in soilless culture in order to produce fodder under the conditions similar to this study. keywords: hydroponic, balanced nutrition, vegetative growth indices, water use efficiency. background and objective: sustainable fodder production for feeding livestock is regarded as one of the challenges of agricultural sector in the recent years. one of the recently used methods for fodder production is hydroponic system (i.e., soilless culture). in soilless culture, all essential nutrients are supplied to the plant’s roots by nutrient solution. the factors such as plant species and cultivar type, the type of hydroponic system (open and closed), plant growth stage, edible part of the plant, growing season and weather conditions (temperature, light intensity and day length) are effective in choosing a suitable nutrient solution (1). therefore, choosing the optimum nutrient solution is the fundamental key to success in this cultivation method. considering the lack of sufficient information about ionic composition of the nutrient solution for production of fodder maize in soilless culture, the present study was carried out to select optimum nutrient solution for its production at the greenhouse conditions of shahrekord university. methods: a factorial experiment using randomized complete block design was conducted with the two factors of nutrient solutions and maize cultivars (i.e., single cross hybrid 704 and single cross 410) and four replications in hydroponic culture at the research greenhouse of shahrekord university. the nutrient solutions were: 1) full-strength hoagland and arnon, 2) half-strength hoagland and arnon, 3) barry and miller, 4) alexander et al., and 5) ruakura. maize seedlings were transferred to 10 liter plastic pots containing perlite (with particle size of 0.5 to 5 mm) and were manually fertigated with nutrient solutions on a daily basis. at the end of tasseling stage, plant height, stem diameter, leaf greenness index and leaf area were measured. then, plants were harvested and fresh weights of root, stem and leaf were determined. plant biomasses were dried and dry weights of root, stem and leaf were measured. plant samples were ground and the concentrations of n, p and k were measured in each part. in addition