Segetal complex – pioneer stages of syntrophic communities in the Meshchovskiy Opole of the non-Chernozem Zone of Russia

Federation Abstract. In the conditions placor soil Meshchovskiy Opole the Central economic region of the Nonchernozem zone of the Russian Federation on agro-gray forest middle loamy soils defined by the main species composition of segetal complex field agrophytocenoses in the structure of five fields grain and grain-grass crop rotation in the limit of syntaxon Stellarietea mediae R. Tx. et al. ex von Rochow 1951. The combinations of weed and field species specific to field crops are established and the influence of minimization of basic tillage is shown, including No-till, and applying calculated norms of mineral fertilizers (NPK) on the dynamics of the species composition and number of the main components of the segetal complex is shown. The original synanthropic plant communities on the fallow lands of Meshchovsky Opole develop from the segetal complex of previous agrophytocenoses. The core of the cenoflora is represented by 104 species of higher herbage plants from 29 families. Synanthropic communities have a low species saturation – 8 species per 100 m 2 and a projection coverage of 57.6%. In acesite territories the advantage is given to the types of anemochory edificatory. Phytomass of secondary phytocenoses without comprehensive measures to improve their floristic composition cannot be used for bulk feed


Introduction
Field community segetal species are formed in specific agro-climatic conditions and depending on between the cenofloras floristic regions, agricultural crops, structure of crop rotation, intensification of agricultural technology and level of environmental and economic development entity, developing floristically impoverished local segetal complexes, but with a relatively constant set of species, one of the regular causes of the declining productivity of arable land.
Modern adaptive landscape systems of agriculture are aimed at regulating the number of segmental price elements in agrophytocenoses at a level below their economic threshold of  burlutskyvalery@gmail.com harmfulness [1][2][3][4][5]. The floral composition of pioneer communities developing on fallow lands is diverse and varies from the previous segetal complex, a set of crops on arable land, and the ecological and soil conditions of the area. The analysis of successional variability of naturally formed vegetation cover on a temporarily abandoned arable land removed from active agricultural turnover is of scientific and practical significance for assessing the economic potential and developing technologies for their targeted accelerated development [6][7][8].

Materials and methods
Research on the floristic composition of weed-field communities was conducted in 1999-2019 at the Kaluga research Institute of agricultural in biologized five-field crop rotation (total area -4950 m 2 , area of 1 plot -110 m 2 , repeatability -3 times, location-tiered) with varying degrees of saturation of the structure with leguminous and leguminous perennial grasses: crop rotations without complete fallow -30% (Pisum sativum L.

Results and discussion
In agrophytocenoses, synanthropic field communities classified by J Braun-Blanquet [9,10], derivatives were formed in the syntaxon limit Stellarietea mediae R. Tx. et al. ex von Rochow 1951. The core of the complex was determined by the types presented by us in descending order of their projective coverage:   In the link of crop rotation legumes -winter cereals, the use of basic shallow tillage (disking-BDU-2.5) contributed to an increase in weed infestation of crops on average in one field by 52%, and the technology (direct seeding) No-till (RAPID A600)by 65%, relative to the annual plow up (PLN-3-35) -28 copies/m 2 . The application of mineral fertilizers (NPK) in the norms calculated using the full balance method increased the participation of components of the segetal complex by 6 ... 15% in the structure of agrophytocenoses.
Communities of fallow period were assigned to syntaxons to the class Stellarietea mediae The community was presented agrobiological groups of grasses (55%), cereals (25%), legumes (15%), spore (10%) and sedge-juncaceae (5%). Cenoses with adventive participation were more variable in productivity and quality of biomass, the yield was 1.5 times higher than that of native plants [11,12]. The number of species in communities was due to the diversity of the segetal complex, and its increase was due to the possibility and availability of immigration of diasporas. Species abundance was determined by the prevailing groups. Mutually complementary relationships appeared between cereals and legumes, herbs, and spores, sedge-juncaceae in other combinations -antagonistic (Table 2). In the motley grass group Compositae the proportion species was 20% and 5 advents (Erigeron annus (L.) Pers., E. canadensis L., Galingosa parviflora Cav., Matricaria discoidea DC., Solidago gigantea Ait.). Share of species Amaranthaceae, Chenopodiaceae Convolvulaceae, Fumariaceae, Hypericaceae, Onagraceae, Papaveraceae, Violaceae was low -6,4% (Fig. 2).

Conclusion
The