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The article shows the results of long-term studies aimed at assessing the formation of ameliorative regime of natural-anthropogenic complexes in Kalmykia. Initial parameters have been presented for models of forming the water-salt regime of the irrigated agricultural landscapes with their comprehensive amelioration in semi-desert and desert areas of Kalmykia. The influence of water-salt regime of soils on the productivity of saltmarsh bluegrass and alfalfa has been studied, and the threshold of salt tolerance for these crops has been defined. The technology of recovering re-salinized irrigated land with the use of reclaimer crops has been developed, which makes it possible not only to rehabilitate the soils that are adverse due to re-salinization, but to obtain extra quality forage as well.

Rice growing requires highly destructive and highly invasive field management negatively affecting soil biota and its functions. We aimed to compare taxonomic and functional trait compositions of soil macrofauna at different stages of rice cropping cycles in the three temperate rice-growing regions in Russia. Samples were collected in 2016 at four different biotopes in each region: flooded rice paddies; upland crops planted one year after flooded rice; rice paddy bunds; and relatively undisturbed seminatural control grasslands. Collected soil macrofauna were allocated to different traits according to their feeding preferences, vertical distribution, mobility and flood tolerance. The lowest macrofaunal abundance across all regions was observed in rice paddies. Cultivation of upland crops after paddy flooding consistently decreased the abundance of resident macrofauna, but not that of mobile soil macrofauna. In the upland crops, the abundance of belowground and mobile belowground macrofauna was significantly higher than that in control grasslands. The abundance of aboveground phytophages was significantly lower in the upland crops than in control sites. Flood-associated taxa showed low colonization ability after the paddies were drained. In contrast, representatives of other traits recorded in flooded fields increased their abundance at the next stage of crop rotation, demonstrating high resilience within an entire rice-growing system, including bunds. This finding indicates a high potential of seminatural grasslands and especially bunds as sources of rapid restoration of soil macrofauna functional diversity in rice-growing agroecosystems, thus maintaining the sustainability of soil food webs in the rice paddies.

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