Dependence of soil microbiota in apple tree plantations on moisture level and agrotechnical methods

Abstract

Studies were conducted in the I. V. Michurin Federal Scientifi c Center and in its Middle Russian branch. For the fi rst time in the North-Eastern part of the Central black earth region, researches are being conducted to study the microbiota of the soil in the garden of pome crops. The aim of this research was to study the micromycetic composition of the soil in the agrocenosis of a multifactorial experience of an intensive apple orchard. Soil samples were taken in the space between rows and near-stem stripes on the sodding, in the space between rows and near-stem stripes on the fallow land. Experimental conditions: 1) control (natural conditions); 2) optimal moisture (irrigation, soil moisture 80 %); 3) waterlogging (irrigation, soil moisture 120 %). As a result of the conducted research, the dependence of the number of phytopathogenic and saprotrophic populations on the elements of agrotechnology was shown. The maximum number of the population was marked in the near-stem stripes on the fallow land and the minimal number was marked in the near-stem stripes on the sodding. The eff ect of moistening on the number of soil micromycetes was revealed. 80 % moisturized sodded space between rows and near-stem stripes, space between rows on fallow land at a humidity of 120 %, and near-stem stripes with 80 % moisture contained a high number of phytopathogens in relation to natural conditions. The greatest species diversity of the soil mycobiota was observed in the sodded near-stem stripes. A strong correlation was established from reverse close (r = -0.98) to positive close (r = 0.83) in relation to the phytopathogens and saprotrophs in the sodded row spacing; in the soil of the sodded near-stem stripes – from close negative (r = -0.90) to close positive (r = 0.92). It was noted that soil mites did not tolerate the over moistened soil, nematodes, on the contrary, were activated in soils with a humidity of 80 % and 120 % in sodded row spacing. The correlation between nematodes and soil mites in all variants remained strong (r = 0.86-0.97), closer in the control. The number of micromycete organisms in the soil was determined by a modifi ed fl otation method. In the course of research, 1 ml of distilled water was added at one of the stages, instead of a 0.1 % solution of potassium pyrophosphate; on the other, 29 ml of 0.1 % potassium pyrophosphate solution was added instead of 29 ml of distilled water.