Soils and landscapes as legacies of the sugar industry land use

Abstract

<p>The sugar industry has been widespread in the world for centuries, accumulating huge amounts of production waste. The development of modern technologies for sugar beet processing has led to the abandonment of dumps and sumps; not all of them were remediated later. In Russia, the industrial production of sugar from sugar beets was established in the early 19th century. For the first time, soils and landscapes formed on abandoned sites of sugar production waste in the Chernozem zone of Russia were studied. The distribution and chronological sequence of abandoned sites were identified using space images and field observation. Sugar production wastes discharged into sumps and landfills contained mainly carbonic lime (СаСО3), caustic lime Ca(OH)<sub>2</sub> and organic material, and an admixture of nitrogen, phosphorus potassium and sulfur (about 1-3%). It was revealed that in about 50 years, alkaline soil- geochemical landscapes were formed, which are unusual in the study area. Series of ponds temporarily filled with rainwater – former waste sumps – are covered with dense reed beds (Phragmítes austrális); there, strongly alkaline (pH ≥9), rich in organic matter and bioturbated soils with a thickness of up to 50-60 cm are formed. They can be attributed to Garbic Technosols (Carbonic), but their classification position in WRB needs to be clarified. Reed has spread widely in the surrounding water bodies and rivers; newly formed landscapes enrich waters with nutrients, contributing to their eutrophication. Soil mantle is also complicated by Technosols of industrial sites of sugar factories, soils in the remediated and no-remediated landfills, and soils irrigated with sugar mills' wastewater. All these soils are repositories of large volumes of organic carbon. The study of newly formed soils and landscapes, overgrowing of dumps and sumps is extremely important both for nature conservation and for understanding the seasonal patterns of carbon dioxide emissions from accumulations of organic substances. Integrated soil-geochemical and geobotanical studies of areas affected by the sugar industry can be pioneers, among other things, to expand the horizons of soil and geobotanical classification.</p> <p>The work was financially supported by the Russian Foundation for Basic Research, project № 19-29-05025-mk.</p>

Biological activity of mountain meadow subalpine soils of Central Caucasus

“…The indices of the bulk density characterize the upper horizons (0-10 cm) of mountain meadow soils of the background territories as loose, due to the large number of plant roots and organic matter in the silt fraction [3,5,11,12]. The main reason contributing to the upland soils compaction under pastures is physical activity in the form of intensive grazing.…”

“…Love & D. Love, Betonica macrantha C. Koch., that form dense root mat [3,10,11]. Projective coverage of species is 95-100%.…”

“…The considered mountain soils are characterized by a high content of coarsely dispersed humus (15-20%) and its exceptional reserves in the upper horizons. This specific feature could be described by the climatic conditions of mountain landscapes, which provide constant sufficient soil moisture for the formation of rich meadow vegetation [3][4][5][6][8][9][10][11][12].…”

“…Due to the unfavorable conditions of bedding along the relief, the studied mountain meadow subalpine soils are actively used for natural forage lands -mown lands and pastures [3][4][5]11]. However, long-term unsystematic grazing of livestock leads to the transformation of the vegetation cover and, as a consequence, to the degradation of soil micro-and macrostructure, compaction of the upper soil layer, humus loss and inhibition of biochemical activity.…”

“…However, long-term unsystematic grazing of livestock leads to the transformation of the vegetation cover and, as a consequence, to the degradation of soil micro-and macrostructure, compaction of the upper soil layer, humus loss and inhibition of biochemical activity. As a result of the degradation of the soil and vegetation cover, especially deterioration of the species composition of phytocenoses, the productivity of forage lands decreased in some cases up to ten or more times [3,11].…”