نوع مقاله : مقاله پژوهشی

نویسندگان

• طالب نظری ¹
• مجتبی بارانی مطلق ²
• اسماعیل دردی پور ²
• رضا قربانی نصرآبادی ³
• سمیه سفیدگر شاهکلایی ⁴

¹ دانشجوی دکتری گروه علوم خاک، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران

² دانشیار گروه علوم خاک، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران

³ استادیار گروه علوم خاک، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران

⁴ فارغ التحصیل دکتری گروه علوم خاک، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران

چکیده

در این پژوهش، تأثیر کاربرد خاکی، محلول­پاشی و مصرف همراه با آب آبیاری اسید هیومیک بر ویژگی­های رشد رویشی و فراهمی آهن و فسفر در گیاه کلزا (رقم هایولا 308) مورد بررسی قرار گرفت. بدین منظور، آزمایشی در قالب طرح کاملاً تصادفی با 10 تیمار در 4 تکرار به صورت گلدانی به اجرا درآمد که تیمارها شامل مصرف خاکی اسید هیومیک در سه سطح (1، 2 و 4 گرم بر کیلوگرم خاک)، محلول­پاشی در سه سطح (0/1، 0/2 و 0/4 درصد)، همراه با آب آبیاری در سه سطح (1000، 2000 و 4000 میلی‌گرم در لیتر) و تیمار شاهد (بدون اسید هیومیک) بود. نتایج نشان داد که اثر نحوه کاربرد و سطوح مختلف اسید هیومیک بر ویژگی­های رشد رویشی به‌جز تعداد برگ معنی­دار شد. بیشترین وزن‌ تر برگ و ساقه به ترتیب با میانگین 3/43  و 5/92 گرم در گیاه در تیمار 2000 میلی­گرم در لیتر مصرف همراه با آب آبیاری دیده شد. نتایجنشان داد که بیشترین غلظت آهن کل ساقه و دانه به‌ترتیب با میانگین 85 و 25/321 میلی­گرم بر کیلوگرم مربوط به تیمار 2000 میلی­گرم در لیتر مصرف همراه با آب آبیاری اسید هیومیک بود. همچنین تیمار 0/4 درصد محلول­پاشی اسید هیومیک بیشترین غلظت آهن کل در برگ با میانگین 245/46 میلی­گرم بر کیلوگرم مربوط را داشت. بیشترین غلظت فسفر در برگ، ساقه و دانه نیز به­ترتیب با میانگین 0/4، 0/72 و 0/897 درصد مربوط به تیمار 2000 میلی­گرم بر لیتر مصرف همراه با آب آبیاری اسید هیومیک بود. نتایج حاصل از یافته­ها نشان داد که هر سه روش استفاده از اسید هیومیک موجب افزایش ویژگی­های رشد رویشی و فراهمی آهن و فسفر در گیاه کلزا نسبت به شاهد شدند اما درمجموع تیمار 2000 میلی­گرم در لیتر مصرف همراه با آب آبیاری اسید هیومیک از دو روش مصرف خاکی و محلول­پاشی اسید هیومیک مؤثرتر بود. 

کلیدواژه‌ها

• آهن
• اسید هیومیک
• فسفر
• کلزا
• رشد رویشی

عنوان مقاله [English]

Comparison of soil, foliar and fertigation application of humic acid on growth parameters and availability of iron and phosphorous of canola

نویسندگان [English]

• T. Nazari ¹
• M. Baranimotlgh ²
• E. Dordipour ²
• R. Ghorbani nasrabadi ³
• S. Sefidgar Shahkolaee ⁴

¹ Ph.D Student, Department. of Soil Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran

² Associate Professor, Department. of Soil Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran

³ Assistant Professor, Department. of Soil Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran

⁴ Ph.D Graduated, Department. of Soil Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran

چکیده [English]

Introduction One of the most important needs in crop planning is the evaluation of different systems of plant nutrition. plant nutrition in a correct way can preserve the environment and increase efficiency of agricultural inputs. Humic acid contains many nutrients that increase the soil fertility and soil organic matter content and thus affect plant growth and yield. In the present study, the effect of soil and foliar application as well as fertigation application of humic acid on iron and phosphorous availability of canola (Hyola 308) was evaluated.
Materials and Methods The soil was air-dried and ground to pass through a 2-mm sieve and then was analyzed to determine soil physical and chemical properties using standard methods. A greenhouse experiment was carried out with 10 treatments in four replications. Treatments include humic acid soil application at three levels (1, 2 and 4 g.kg^-1 soil), foliar application at three levels (0.1, 0.2 and 0.4%) and three fertigation levels (1000, 2000 and 4000 mg L^-1) and control). Soil application in the form of humic acid powder and in cropping time based on the soil weight of the pots and for spraying and use along with irrigation water, each of the spraying and together with irrigation water levels is divided into three equal parts and in three stages (plant establishment, stem elongation and flowering). At the end of growth period (for 139 days), vegetative growth indices were determined and then plants were harvested and stem and leaves were separated. Phosphorous content in plant extracts was measured by molybdate vanadate method (yellow method) and iron concentration in the samples was determined by atomic absorption (AAS-Unicam-919). Statistical analysis was conducted via SAS software and mean comparisons carried out by LSD test at 5% probability level.
Results and Discussion Results show that the application methods and the different levels of humic acid had significant impacts (p < 0.01) on the all parameters but they had no significant effects on the numbers of leaves. The maximum leaf fresh weight was 4.34 gr per plant which obtained water irrigated treatments with 2000 mg/lit. However, there was no significant difference between water irrigation with 4000 and 2000 mg/lit humic acid concentrations. Besides, maximum leaf dry weight was 0.37 gr in the plant that was water irrigated with 4000 mg/lit, however there was no significant difference between water irrigation with 4000 and 2000 mg/lit humic acid concentrations. Also, the maximum stem dry and fresh weight was 5.92 and 1.53 gr which observed in water irrigated with 2000 mg/lit. The application methods and the different levels of humic acid had significant impact (p<0.01) on the content and absorption of Fe and P excluding the Fe content in the root. The maximum Fe content in stem and seed were 321.25 and 85 mg/kg was observed in the treatment of humic acid with water irrigation of 2000 mg/lit. Also, in the treatment of spraying with 0.4 % of humic acid, the maximum of Fe concentration (245.46 mg/kg) was obtained. The humic acid molecules can pass from the cell membranes and cause iron reduction in the Apoplast and increase the availability of Fe. Because of the reduction effect of humic acid on the availability and accumulation of Fe in the plant tissue, increasing in the Fe absorption with humic acid treatment is observed. The increase in the accumulation of Fe by humic material might be due to the releasing phenolic material in the root rhizosphere. The maximum P concentration in the leaf, stem and seed were 0.40, 0.72 and 0.897 respectively that was observed in the treatment of water irrigation with 2000 mg/lit with humic acid. Due to the availability of phosphorus and other nutrients for wheat, humic acid increases the plant yield in the reproductive stage of seeding.
Conclusion Results of the study show that humic acid can ameliorate the negative effect of a large amount of phosphorus on iron availability. In fact, humic acid, due to providing nutritional balance for the plant, prevents negative effects caused by the high amounts of specific elements such as phosphorus. Also, the results showed that all three humic acid application methods increased vegetative growth parameters, and iron and phosphate availability for canola plant compared to control. But in general, 2000 mg/L acid humic with irrigation water was more effective than two methods of soil and foliar application.

کلیدواژه‌ها [English]

• Canola
• Humic acid
• Iron
• Phosphorous
• Vegetative growth