Nettle is most often studied as a spinning plant, as a source of biochemicals and environmentally safe fungicides. Major studies are mostly conducted on natural samples and plant populations. Prospects for the use of plant biological resources of stinging nettle (Urtica dioica L.) from the Cretaceous south of the Central Russian Upland to create cultivars for a wide range of applications are considered. The aim of the study is to investigate the productivity of fresh weight and its biochemical composition in the variety of stinging nettle Avicenna, created on the basis of the initial material selected in the Belgorod region of Russia and patented in 2019, and new promising cultivars UD 32/06 and UD 12/16. The experiments were carried out by the split plot method with full randomization in four replicates. The cultivars UD 32/06 and UD 12/16 reliably surpass the Avicenna cultivar in the collection of fresh mass weight by 16.6–22.7% and 23.1 to 27.8%, dry weight by 11.4–28.7% and 1.9–32.7%, and seeds by 19.7–32.0% and 23.2–40.0% accordingly. Analysis of variance showed a significant effect of the factor “Cultivar” on the productive traits “Fresh weight yield” (strength influence 87.2%), “Dry weight yield” (strength influence 43.9%), and “Seed yield” (h2x = 61.6%). The content of crude protein in dry weight of the Avicenna and new varieties is 21.1–24.2%, crude fat: 2.5–4.2%, fiber: 12.0–14.8%. High content of ascorbic acid, calcium, phosphorus, iron, and zinc were observed in all material tested. It is concluded that the biological resources of the wild-growing forms of Urtica dioica L. from the European south of Russia are a valuable source material for obtaining varieties, and varieties with high productivity of the aboveground mass and stable seed productivity. The obtained research results prove the usefulness of nettle cultivation.

We evaluated the stability of perennial legume and cereal grass species in artificial plant communities on permanent anti-erosion watercourses in the agroecosystems of the Belgorod region with active development of linear soil erosion. In the conditions of steppe and forest-steppe zones of the Belgorod region on permanently grassed watercourses in 2017-2019. varieties of perennial leguminous and cereal grasses: ‘Krasnoyaruzhskaya 1’ and ‘Krasnoyaruzhskaya 2’ (Medicago varia), ‘Kazatsky’ (Trifolium pratense), ‘Olshanka’ and ‘Ivica’ (Festuca arundinacea), ‘Streletsky’ and ‘Stepnyak’ (Lolium perenne)) obtained using local genetic material were studied. All varieties showed their resistance in agro-ecosystems with active development of linear erosion in the forest-steppe and steppe zones. Projective cover on watercourses in the steppe zone in all variants of experience was on average 83,4 %, in the forest-steppe zone - 86,3 %. In the third year of the tests on permanently irrigated watercourses in the steppe zone, the share of cereal and legume grass species was quite high and varied from 88 % in the variant M. varia + Onobrychis arenaria to 92 % in the variants M. varia + Bromopsis inermis and O. arenaria. In the forest-steppe zone, the share of cereal and legume grass species varied from 86 % in the variant L. perenne to 94 % in the variant L. perenne + B. inermis.

Unique plant communities that are com plementary to the cretaceous substrate tend to be formed on the cretaceous outcrops of southern European Russia. They are characterized by a wide spread of calciphilous species of higher plants, including endemic ones. Under these conditions, stable plant aggregations are created by the species that are able to populate substrates being toxic to most plants. The study was conducted in order to examine the nitrogen status o f soils and sub-soils under endemic calciphilous species: M atthiola fragrans Bunge, Hyssopus cretaceus Dubjan. and Andorsace koso-poljanskii Ovcz. The research tasks included a comparative analysis of the dynamic changes in the content of organic m atter carbon, total nitrogen, easily hydrolysable nitrogen, nitrate nitrogen, and nitrification capacity of soils and sub-soils in the course of vital processes of the species under study. It has been found that during the ten-year period of the experiment for M. fragrans Bunge, H. cretaceus Dubjan significantly increases the num ber of particles of <1 mm 594 ARTICLE INFORMATION:

Worldwide, about 12x10 6 ha of arable land are destroyed and abandoned annually due to soil erosion. This problem is very serious for Krasnogvardeiskiy district, which is most eroded district (72.7% eroded lands) in the Central Chernozem Zone (CCZ) of Russia. Under the leadership of the academician of Russian Academy of Agrarian Sciences O.G. Kotlyarova the landscape agricultural systems (LASs) were mastered throughout the Krasnogvardeisky district (132 thousand ha). Our investigations showed that the purpose for which LASs were created is reached. Obtained results showed that it is possible to prevent erosive losses and to raise soil fertility. Restoration of soil fertility is presented in terms of increasing of crops productivity-on 25%. Transformation of a landscape basis has increased the general biological capacity of territory more than twice and exchangeable biological capacity by 32%. All these facts have raised assimilability of the transformed territory that allows to consider it, unlike traditional, not as source СО 2 in atmosphere, and as fixed carbon tank which capacity can reach 0,71 t/ha. In turn the intensification of substances circulation leads to increasing of plant production efficiency. Excess is from 14% (productivity of labour expenses) to 43.2% (use efficiency of PAR). In intensively mastered agricultural district (arable lands more than 80%) agroecosystems have been formed, allowing besides its basic function: soil preservation, steady reception of agricultural production, to carry out also the major biospheric function -increasing biological variety, creation of a favorable inhabitancy for live organisms, including human.