Various Forms of Sr in Albic Stagnosoils from the South of Primorskii Region

To assess the concentration level and identify the main phase-carriers of various forms of strontium (Sr), the total content, distribution and concentration of water-soluble forms of the element in Albic Stagnosoils, which composed the bulk of the arable fund of the region under study, were studied. Full-profile soil pits were dug at the long-term fallow, phytoreclamative, and fertilized with mineral and organic fertilizer variants of the experience. The study of the different Sr forms contents was carried out by energy dispersive X-ray fluorescence spectroscopy and atomic absorption spectrometry. The main Sr volume was immobilized in the composition of soil mineral phase in soils of all variants of the experience. The addition of mineral fertilizers to soil was accompanied by an increase in the total content (by 6.4 %) and concentration of water-soluble (by 5,7 times) Sr forms, compared to the soil of fallow, and intensification of Sr sorption by Mn-containing soil compounds. The long-term addition of different types of organic fertilizers contributed to the activation of stable Sr-organic complexes formation. Under a green manure application in conditions of soil solution acidity decrease, the increase in the influence of Ca-containing soil compounds on the distribution of Sr has been shown. The soils of all variants of the experience were characterized by the absence of factors and conditions that contributed to the Sr accumulation in profiles, it was suggested by the lower total Sr content compared to the mean background content for surface soils around the world and to the mean content in agricultural soils in Japan.