TILLAGE OF DARK GRAY FOREST SOIL AND FORMATION OF SYMBIOTIC APPARATUS IN ROOT SYSTEM OF VETCH

Abstract

There was analyzed the effect of moldboard and nonmoldboard tillage techniques applied during three crop rotations on forming the symbiotic apparatus in the root system of such a grain-legume crop as vetch. Investigations were carried out on dark gray forest soil in Northern Trans-Ural Region. It has been found that during the early growing period, nonmoldboard tillage helps the symbiotic apparatus in vetch to be formed more intensively (by 17.0-18.3 percent for tubercle weight and 7.8-9.0 percent for their number) than plowing does against the background of both applying fertilizers and without them. However, because the period favorable in moisture and density of the topsoil for forming and functioning of tubercles is short, the regularity found does not result in improved nitrogenous nutrition of a subsequent crop at nonmoldboard tillage. The application of mineral fertilizers delayed the formation of tubercles reducing their weight by 24.7-29.8 percent and their number by 15.1-16.7 percent.