Influence of technological measures of growing on the root system development and symbiotic productivity of sainfoin

Abstract
An important factor in the feed industry intensification is the cultivation of perennial legumes, including sainfoin. The aim of the study was to determine the effect of mineral fertilizers and seed inoculation on the formation of the root system and the symbiotic productivity of different varieties of sainfoin grown on green fodder. Experimental studies were conducted during 2016-2018 on the research field of Forage Production, Land Reclamation and Meteorology Department, located at the NULES of Ukraine "Agronomic Research Station" on typical low-humus chernozem. According to the results of the research, it was established that on average in three years the biggest root mass - at the level of 52.7 t/ha was formed by sainfoin variety Amethyst Donetskyi with providing complete mineral fertilizer in the dose N45P60K90 and presowing seeds inoculation by Rhizotorphin. In plants of the same variant, the most developed symbiotic apparatus was also noted - in the flowering phase, the total number of tubers was 126 units/plant, and their weight was 3.444 g/plant. As a result of a strong root system of plants formation and a well-developed symbiotic apparatus, the amount of biologically fixed nitrogen under crops of sainfoin of variety Amethyst Donetskyi reached 143 kg/ha.