Enhancing of nitrogen fixation by legumes

¹ Gorsky State Agrarian University, Department of Agriculture, Plant Growing, Crop Breeding and Seed Production, 362040 Vladikavkaz, Russia
² Gorsky State Agrarian University, Department of Ecology and Land Management, 362040 Vladikavkaz, Russia
³ Gorsky State Agrarian University, Department of Production Technology, Storage and Processing of Crop Products, 362040 Vladikavkaz, Russia
⁴ Vladikavkaz Scientific Centre of the Russian Academy of Sciences, The North Caucasian Research Institute of Mountain and Piedmont Agriculture, 363110 Mikhailovskoye, Russia
⁵ Institute of Biochemical Physics named after N.M. Emanuel of the Russian Academy of Sciences, Department of Biology, 119334 Moscow, Russia

^* Corresponding author: bekos37@mail.ru

Abstract

To increase the legumes’ nitrogen fixation, the seeds were treated with a mixture of biopreparations of 4-aminobenzoic acid (PABA) at a concentration of 0.05% aqueous solution, to with adding of “Nikfan” biopreparation in an amount of 0.1% of the solution volume. The seeds of leguminous grasses such as clover and alfalfa were soaked in this mixture, and 10-15 days after emergence of seedlings, foliar feeding of this concentration was carried out. In the phase of budding and the beginning of flowering, plant productivity was accounted and active nodules were counted. We used variants with seed treatment by industrial strains for each culture, as well as without biopreparation treatment, as a control experiment. As a result of the obtained data, it was found that the use of a biopreparations mixture significantly increases the number of nodules, more biological nitrogen is accumulated in the soil, and protein content in the herbage increases. Correlation was established between the number of nodule bacteria and leaf area at the 4^th-5^th internodes in clover and the 6^th-7^th in alfalfa.