Comparative analysis of agrochemical, allelopathic and microbiological characteristics of the soil environment for Actinidia arguta (Siebold et Zucc.) Planch. ex Miq. cultivated in Ukraine and two provinces of China

The objective of this study was to evaluate agrochemical, allelopathic and microbiological characteristics of the soil under Actinidia arguta plants cultivated in Ukraine and two provinces of China.
Material and methods. The rhizosphere soil was sampled at 0–15 cm layer under A. arguta plants in the stage of fruit ripening in Ukraine (Kyiv city: North of Ukraine, Forest-Steppe zone, a temperate continental climate) and two provinces of China (Shandong: East China, a temperate monsoon zone; and Heilongjiang: Northeast China, continental monsoon climate). The concentrations of carbon, available forms of macro- and micronutrients, phenolic compounds in the soil samples were determined. pH and redox potential of soil were measured. Soil phytotoxicity was studied by direct bioassay method on cress (Lepidium sativum) root growth. Microbiological analyses of soil samples were conducted.
Results. The dissimilarities in the concentrations of carbon, macro- and micronutrients in the examined soil samples were shown. The reduction conditions (Eh < 400 mV) in the soils under A. аrguta might slow down the humification processes. A similar effect may be caused by mobile forms of organic compounds with allelopathic properties. The redox potential decreased with the increase of pH values. This fact reflects the intensifying of reduction processes. The soil phytotoxicity under A. аrguta reached 20–70 % compared with the control, probably due to the accumulation of phenolic compounds, as well as iron and manganese. In soils under A. аrguta, the relationship between pH, phytotoxicity, and the abundance of main taxonomical and ecotrophic groups of microorganisms was evaluated.
Conclusions. Calcic Luvisols from the M.M. Gryshko National Botanical Garden of the NAS of Ukraine (Kyiv city, Ukraine) and Luvic Chernozems from Jiamusi (Heilongjiang province, China) were determined to be the most favorable for A. arguta cultivation. Salic Solonetz from Harbin (Heilongjiang province, China) and Haplic Luvisols from Linyi (Shandong province, China) had the least suitable soil conditions for A. arguta.