عنوان مقاله [English]
Background and objectives: Increasing the use of chemical fertilizers in order to increase yield can over time have adverse effects on soil and environment and the reduction of consumption of these fertilizers in sustainable agriculture is necessary. EM contains selected species of microorganisms, including dominant populations of lactic acid bacteria and yeasts, and a small number of photosynthetic bacteria, octanomists that are compatible with each other. These microorganisms improve soil structure, manage organic matter and complete the cycle of elements, and can reduce dependence on fertilizers and chemical pesticides. The increase of protein activity and plant photosynthesis capacity, plant growth, root development, flowering, fruit harvesting, and the improvement of food availability and its better absorption by the plant are due to the benefits of using this biological fertilizer. The aim of this study was to investigate the effects of nitrogen application with Urea fertilizer source and bio-fertilizer EM on nutrient uptake by leaf and yield of strawberry Parous cultivar.
Materials and methods: This experiment was carried out as split plot based on randomized complete block design with three replications at the University of Mohaghegh Ardebili University during the years 2016-2015. Treatments consisted of nitrogen as urea fertilizer at three levels (50, 100 and 150 kg.ha-1 pure nitrogen) and EM bio-fertilizer using two methods of application (foliar and soil with irrigation water) at concentrations of 0, 1, 2 and 3%. In this research, the elements of nitrogen, potassium, phosphorus, sodium, magnesium, calcium, manganese, magnesium and iron of leaves and fruit yield were measured.
Results: According to the results, application of EM fertilizer had a significant and positive effect on all measured traits. The 2% EM treatment with the highest concentration was 2.04% and the control plants had the least leaf nitrogen content with 1.42%. The highest amount of phosphorus was obtained with 1.99, 1.93 and 1.67 mg.kg-1, respectively, with 2, 1 and 3% treatments and the leaves of control plants with the lowest content of 26.2 mg.kg-1 of phosphorus were lowest. The amount of potassium at 1% level was 46.18 at 2 level 45.95 and 44.86 mg.kg-1 in 3%, which was in a statistical group and the control plants had the least amount of potassium. The same trend was observed in the elements of calcium, iron, zinc and manganese. The highest fruit yield was obtained in plants treated with 2% and 3% EM (respectively 185.2 and 176.75 g per plant, respectively). Plants leave Nitrogen content treated with 150 kg of urea fertilizer was 2.9% higher than other concentrations. The amount of potassium, phosphorus, zinc and manganese in leaf and yield of plants treated with 100 kg.ha-1 was higher than other levels of urea fertilizer. Based on the results of the comparison of averages, the application of urea crop 100 kg.ha-1 with EM and 2 and 3% respectively with 141 and 139 mg.kg-1 produced the highest amount of magnesium in the leave.
Conclusion: Generally, it can be concluded that application of EM bio-fertilizer with both spraying and soil methods can improve plant growth, yield and nutrient uptake by roots of strawberries. The best and the most suitable nitrogen concentration in terms of fruit yield and leaf elements were 100 kg / ha.