Humus and nitrogen content of sod-podzolic soil under the influence of biopreparations for potato cultivation

Abstract

In organic potato cultivation technologies, various biopreparations are used, which have a considerable impact on both the growth and development of crops, and on soil fertility indicators, which is especially important for sod-podzolic soils characterised by low potential fertility. The purpose of the study is to establish the changes in humus content and mineral nitrogen in sod-mediumpodzolic loam soil under the influence of biopreparations for the decomposition of white mustard as a cover crop and for the treatment of potato tubers and vegetative potato plants. In a two-factor experiment, the following factors were examined: factor 1: control without a destructor and “Ecostern” destructor at a dosage of 1.2 litres per hectare; factor 2: nine options of biopreparations application, including Agat, Regoplant, Mycohelp, Phytohelp, and Stimpо. Soil samples were collected from the 0-30 cm layer of sod-medium-podzolic sandy loam soil on water-glacial deposits. In them, the total humus content was established by the Tyurin method, and the mineral nitrogen content was calculated as the sum of ammonium and nitrate nitrogen determined potentiometrically. The application of the destructor on the green biomass of the cover crop contributed to an increase in the humus content in the 0-30 cm soil layer, where it ranged from 1.135% to 1.24%, compared to 1.025% to 1.15% in the options without the use of the bio-destructor. A reverse dependence was observed in terms of mineral nitrogen content. In the options with the use of the Ecostern destructor, the mineral nitrogen content was on average 2.09 mg/kg lower compared to the options without the application of the destructor. The highest humus content was observed in option 8, which involved the use of “Phytohelp” for treating potato tubers at a dosage of 1.0 litre per ton and three-fold treatment by “Phytohelp” at a dosage of 1.0 litre per hectare during the vegetation period. In the option without the destructor, the humus content was 1.15% and 1.24% with the application of the Ecostern bio-destructor. It slightly lagged behind option 9 with the “Phytohelp” biopreparations. The materials presented in the study may have practical value for agricultural enterprises engaged in growing organic potatoes to ensure the preservation and reproduction of organic matter in soils