نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه زراعت و اصلاح نباتات، دانشکده کشاورزی، دانشگاه یاسوج
2 استاد- دانشگاه یاسوج
3 عضو هیأت علمی گروه زراعت و اصلاح نباتات دانشگاه یاسوج
4 دانشگاه یاسوج
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objectives: Canola (Brassica napus L.) is an oilseed crop, which due to the high percentage and quality oil, extending of its cultivation is of interest. Nitrogen is one of the most important nutrients and the key factor to achieve optimal yield in rapeseed. Considering nitrogen leaching in the soil and resulted environmental pollution, the use of biofertilizers, especially nitrogen-fixing bacteria, play an important role in enhancing nutrient uptake and nitrogen use and uptake efficiencies. Therefore, the aim of this research was to investigate the improvement of absorption of macronutrients and nitrogen efficiency indicators under the influence of chemical and biological nitrogen fertilizer management.
Materials and methods: A field experiment as split plots based on a randomized complete block design with three replications was conducted at the research station of the Faculty of Agriculture, Yasouj University located in Deshtrum in 2019. The main factor was nitrogen fertilizer at 6 levels (zero, 25, 50, 75, 100 and 125 kg ha-1 of pure nitrogen from the urea source) and the sub factor was biofertilizer containing Azotobacter and Azospirillium bacteria at two levels (application and non- application). The uptake of nitrogen, phosphorus and potassium nutrients in seeds and shoot was measured and the nitrogen efficiency indices were calculated.
Results: The highest seed nitrogen, phosphorus and potassium percentage obtained from the combined application of nitrogen fertilizer + bacteria. The combined application of chemical and biological nitrogen fertilizer increased grain yield. The highest seed yield (8790.60 kg ha-1) was obtained in the treatment of 125 kg ha-1 of nitrogen and the application of biofertilizer. The nitrogen use efficiency decreased with the increase of nitrogen levels, and the maximum (40.92 kg ha-1) was obtained from the treatment of no application of bacteria and also nitrogen. The nitrogen uptake efficiency increased significantly with the use of nitrogen fertilizer and the use of bacteria. The maximum nitrogen remobilization (89.79%) was obtained from the application of 125 kg ha-1 of nitrogen and no application of biofertilizer, and the lowest was obtained from the treatment of no application of nitrogen and application of biofertilizer (74.46%).
Conclusion: Considering the superiority of the 125 kg ha-1 of nitrogen along with biofertilizer in terms of seed yield and percentage of absorbed nutrients, it seems that these amounts of nitrogen fertilizer with the use of biofertilizer are recommendable to achieve proper yield in the examined and also similar areas. Also, the results showed that for most of the investigated traits, applying biofertilizer could reduce the consumption of chemical nitrogen fertilizer by supplying some part of the nitrogen (ca. 50 Kg/ha) needed by canola.
کلیدواژهها [English]
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