Growth and development of Alfalfa depending on the type of nitrogen nutrition

Marina Yu Kozyreva,Larisa Zh Basieva,Khetag M Khetagurov,Al-Azawi Nagham Majeed Hameed,Alda Kh Chibirova,D Solovyev,G Burygin

doi:10.1051/bioconf/20202303007

Abstract

Mineral and symbiotrophic types of nitrogen nutrition of plants were compared in experiments with the blue-hybrid alfalfa. Variants with seed inoculation by high-mountain strains of nodule bacteria (In-1800 and N30+In) had the maximum height of plants during all experimental years (40-70 cm), which is explained by the better nitrogen provision of plants. At the same time, the effect of the mineral forms of nitrogen appeared only in the year of sowing at the beginning of the growing season to the first mowing, in the future the differences between these options were neutralized. The foliage intensity of plants was in the range of 41.4-54.8%, increasing due to the improved availability of biologically bound nitrogen in plants. Mineral forms of nitrogen reduced plants’ foliage coverage in all experimental years, however, this decrease was noted only in the initial periods of vegetation. The maximum indicators of foliage coverage were noted in the In-1800 variant. By the end of the third year of crops use, the plant stand density was 980-1100 thousand units/ha, and the total thinning of alfalfa crops reached 45-51%. At the same time, the symbiotrophic type of nitrogen nutrition made it possible to significantly increase the competitiveness of plants, which ultimately affected the persistence of the crop density.

Highlights

The relevance of the study of legumes and, in particular, of alfalfa, is determined by their high nutritional and important agricultural value [1,2,3]
Plants and microorganisms must be studied as a single system, as they are interconnected by numerous bonds formed in the course of evolution that respond to any changes in the biocenosis [10,11]
The objects of the research were: the blue-hybrid alfalfa (Medicago varia Mart.), standard Vega 87 variety, cultivated in the North Caucasus region, and local races of nodule bacteria of the Sinorhizobium genus, which we selected from the rhizospheric part of alfalfa plants at various altitudes in the environmental conditions of the Republic of North Ossetia-Alania [12,13]

Summary

Introduction

The relevance of the study of legumes and, in particular, of alfalfa, is determined by their high nutritional and important agricultural value [1,2,3]. Crops of perennial legumes are of particular value in Russia due to implementation of a federal law on organic production and transition to organic farming. High requirements for soil fertility in organic farming determine the widespread use of legumes and their unique ability to fix molecular atmospheric nitrogen in symbiosis with rhizospheric microorganisms [4,5,6]. The activation of processes and an increase in the volumes of symbiotic nitrogen fixation require researchers to study the factors limiting this process in each agroclimatic region and the impact of resource-saving, environmentally friendly methods in more detail [7,8,9]. The insufficient, as well as the excess supply of plants with life supporting factors negatively affects initially their growth and development, and subsequently – their productivity

Methods

Results

Conclusion