Determination of model parameters of water-nutritional processes in soil for nitrogen compounds

Studies of development of an integrated model that allows calculating the whole range of processes necessary for predicting and managing the water and nutrient regimes of reclaimed soils are considered. Calculated values of the maximum concentrations of nitrate nitrogen in the topsoil during the growing season of plant for Tashkent’s region are shown. Values of field moisture capacity and wilting moisture of the main varieties of irrigated soils are defined.

Fuzzy cognitive modeling of agricultural land productivity in the context of food security

The article deals with the problems of fuzzy cognitive modeling and evaluation of the productivity of reclaimed soils, taking into account the combination of natural-climatic, soil and environmental factors. To construct a fuzzy model, the parameters to be modeled were the coefficient of bioclimatic productivity with a range of variation of 0.5-1.5, and the yield of grain crops, which varied within 10…45 dt/ha for different natural and climatic zones. The theoretical basis for the development of a model of land productivity is the theory of fuzzy inference based on the fuzzy-multiple approach. The main stages of fuzzy modeling using the Mamdani algorithm in interactive mode are presented. An algorithmic representation of the dependence of the integral indicator of the productivity of agricultural land on the value of the yield of grain crops, and the coefficient of bioclimatic productivity is obtained. The constructed fuzzy model allows to obtain estimates of the generalized indicator of agricultural land productivity based on the yield values for the range of values of the bioclimatic coefficient. The constructed model can be used as a part of a system for predicting the level of food security.

Organic matter of soils and technogenic surface formations of residential areas of the city of Perm

On the territory of the left-bank part of Perm, the urban pedocomplexes (UPC) were distinguished as a combination of soil and technogenic surface formations on the same soil-forming rocks within a certain functional zone. Within the UPC, formed on eluvial-deluvial loams and clays in the zone of multi-storey buildings, the surface horizons of soils and TSF (technogenic surface formations) were studied. A change in the zonal trend of humus formation in reclaimed soils was observed as an increase in the content of organic matter, as well as in a change in the type of humus to the humate side. The conservation of zonal features of humus formation in non-purposefully recultivated urban soils and TSF was noted. It manifests in a low or medium content of organic carbon, the formation of a humate-fulvate type of humus. Keywords: URBAN ECOLOGY, URBAN SOILS, URBAN PEDOCOMPLEX, HUMUS, HUMUS TYPE, SOIL PROPERTIES

Spatiotemporal evolution and assembly processes of ammonia-oxidising prokaryotic communities in 1000 years coastal reclaimed soils

Coastal marshes are transitional areas between terrestrial and aquatic ecosystems and vulnerable to climate change and anthropogenic activities. In recent decades the reclamation of coastal marshes remarkably increased and their effects on microbial communities present in coastal marshes have been studied with great interest. However, most of these studies focused on microbial community composition and diversity. The processes underlying functional community assembly and spatiotemporal effect often ignored. Therefore, community structure and assembly mechanisms of ammonia-oxidising prokaryotes in long-term reclaimed coastal marshes have not been studied. Here using qPCR and IonS5TMXL sequencing platform, we investigated spatiotemporal dynamics, assembly processes and diversity patterns in ammonia-oxidising prokaryotes in over 1000 years reclaimed coastal salt marsh soils. The taxonomic & phylogenetic diversity and composition of the ammonia-oxidizers showed apparent spatiotemporal variations along reclamation of soil. The phylogenetic null modelling-based analysis showed across all sites, the archaeal ammonia-oxidising community assembled by deterministic process (84.71%). The ammonia-oxidising bacterial community was formed more by a stochastic process in coastal marshes and at stage 60 years (|βNTI|<2), despite its relatively dominant deterministic process (55.2%). The deterministic assembly process and nitrification activity in reclaimed soils was positively correlated. Archaeal amoA gene abundance were also positively correlated with the nitrification rate. Our study revealed that during the 1000 years of reclamation coastal marshes both ammonia-oxidising communities responded differently to diversity change and assembly processes and nitrification activity. These findings provide a better understanding of how long-term reclamation affect soil N cycling and assembly dynamics of ammonia-oxidising communities.

THE ROLE OF IRRIGATION SUPPLY OF GROUND WATER IN CHANGING THE ENVIRONMENTAL CONDITIONS OF IRRIGATED AREAS

В статье рассматривается взгляд автора и материалы исследований формирования ирригационного питания грунтовых на орошаемых землях и анализ его влияния на изменение экологических условий. Если влияние орошения мелиорируемых почв осуществляется на площади непосредственной реализации мелиоративных мероприятий, то его влияние за счет увеличения инфильтрационного питания грунтовых вод перераспределяется на значительные территории на иерархических уровнях от локального до бассейнового. The article discusses the author's view and research materials on the formation of irrigation nutrition of ground on irrigated lands and the analysis of its impact on changes in environmental conditions. If the influence of irrigation of reclaimed soils is carried out on the area of direct implementation of reclamation measures, then its influence by increasing the infiltration supply of groundwater is redistributed to significant territories at hierarchical levels from local to basin.