Issue 4 (6)-2024

Abstract. The article presents the results of the description of soil profiles of two sites in JSC Moskovskoye, Ryazan District, Ryazan Region, water-physical properties, and constructs a preliminary simulation model for the rational use of alluvial soil in the Central floodplain of the Oka River.

Problem and purpose. To obtain initial data on the alluvial soil of the Central floodplain of the Oka River, two sites were selected: No. 1 was under meadow vegetation and No. 2 was under corn for agricultural purposes. The purpose of the work was to study the structure of the alluvial soil profile of the Central floodplain of the Oka River and to create a simulation model of its rational use. Research began in September 2024.

Methodology. To study the soil morphology, pits were dug at two sites according to the guidelines of V.D. Naumov et al. "Soil Morphology" and OST 56-81-84 "Field Soil Research. Procedure and Methods of Carrying Out Work, Basic Requirements for Results." Weather conditions in 2024 were characterized by hot and dry summer. Research began in September 2024, when heat supply was higherthan the long-term average one (average monthly t = +17° C), and there was no precipitation.

Results. The description of soil profiles of two plots No. 1 under meadow vegetation and No. 2 under corn was given. Its zonal features in the form of an unexpressed humus horizon, layered alluvium, gleying of the lower horizons were revealed. The description of the soil profile on plot No. 2 under corn was used to create a model aimed at the rational use of regional soil resources.

Conclusion. Alluvial loamy meadow soil of the Central floodplain of the Oka River of JSC Moskovskoye was regularly flooded for about 2-3 weeks. Zonal features of the soil were well-developed turf, unclear humus horizon and its lumpy structure, presence of iron spots, stratification of alluvium, wet transitional horizon with the smell of silt, signs of gleying. Compared with the data of 1995, the soil of the surveyed area was characterized by deterioration of water-physical properties. To predict its further condition, a preliminary simulation model of the surveyed area was built in JSC Moskovskoye.

Abstract.

Problem and purpose. The fact of climate change over recent decades is no longer disputed by scientists. The warming trend across Russia suggests that conditions for crop cultivation are becoming more favorable, leading to expectations of expanded arable land and increased yields. However, these forecasts often overlook land suitability in terms of soil and terrain. The aim of this research was to address this gap.

Methodology. The study entailed the assessment of land suitability in the Russian Arctic (north of 60° latitude) for the cultivation of winter wheat, spring barley, winter rye, grain maize, sunflower for seeds, and potatoes, taking into account soil, terrain, and climate under scenarios predicting the climate will become optimal for these crops. Spatial scenarios were constructed using GIS, and land suitability was evaluated based on the maximum limitation rule.

Results. The greatest increase in suitable land areas is expected in Yakutia, Arkhangelsk Oblast, and the Komi Republic, while the least impact of climate change is predicted for Leningrad, Magadan, and Murmansk Oblasts.

Conclusion. Although climatic shifts in the Russian Arctic are expected to improve conditions for agricultural cultivation, significant expansion of arable land for the widely used crops by 2100 is unlikely due to unfavorable soil and terrain conditions.

Abstract.

Problem and purpose. Bacterial blight caused by the pathogen Xanthomonas euvesicatoria pv. allii poses a serious threat to agriculture, leading to significant yield losses in Allium crops. Given the broad host range among Allium species and the importance of timely pathogen detection, the aim of this study was to examine host selectivity and the reproducibility of the PCR method for detecting X. euvesicatoria pv. allii among various Allium species using AVR and PIL primers.

Methodology. Seeds of five Allium species—onion (Allium cepa), chives (Allium schoenoprasum), fragrant onion (Allium ramosum), Welsh onion (Allium fistulosum), and leek (Allium porrum)—were selected for study. Strains 0377 and 0419 of X. euvesicatoria pv. allii were used to inoculate plant material. DNA extraction and qPCR were performed to assess pathogen prevalence and the reproducibility of the method across various bacterial concentrations.

Results. Both strains (0377 and 0419) showed no distinct host specificity among the five Allium species, regardless of bacterial concentration. The PCR method demonstrated high reproducibility with AVR and PIL primers, with relative standard deviations below 2% across repeated tests by different operators and equipment.

Conclusion. The results indicate the lack of narrow host specificity of X. euvesicatoria pv. allii among Allium species and confirm the high accuracy and reproducibility of the PCR assay for pathogen detection. These findings can support improved monitoring and control methods for this phytopathogen’s spread.

Abstract. Based on the experimental results obtained in September, a data bank was compiled, which will subsequently form the basis of scientific work on the comprehensive study of the alluvial soil of the Central floodplain of the Oka River.

Problem and purpose. Obtaining reliable research results is one of the main tasks of scientific experiments, which can be confirmed by statistical and mathematical methods. Mathematical modeling of processes is one of such methods, which is based on differentiated equations. Alluvial soil occupies small territories in the north-east of Ryazan region, its study is fragmentary. At the same time, the alluvial soil of the Central floodplain of the Oka River is used in agricultural production in JSC Moskovskoye, Ryazan District, Ryazan Region. The purpose of the research was to model the inhibition of the number of microorganisms in the alluvial soil of the central floodplain of the Oka River.

Methodology. The mathematical model included the values of the toxic to living organisms’ concentration of Cd in the soil, being one of the priority metal pollutants, soil temperature and humidity, cellulolytic microorganisms, protease activity and total microbial population. The research began in September, which was characterized by warm and dry weather, which made it possible to collect a bank of initial data. The research methodology was generally accepted. The Hinshelwood model, the Andicks model, and the Kolpikov model were used for modeling. The response surfaces were built in Statistika 10 computer program.

Results. Taking into account the studies conducted after the end of the growing season of the agricultural crop - silage corn and the natural process of gradual attenuation of the activity of soil microorganisms, the results allowed us to model the process of inhibition of microflora. Thus, the concentration of mobile cadmium was slightly below the MAC (-12%), the heat and moisture supply was optimal for microorganisms, protease activity, cellulose destruction and species diversity of the microbiocenosis were low. The obtained data were introduced into differentiated equations and models of inhibition of the number of microorganisms in the alluvial soil of the Central floodplain of the Oka River were obtained.The coefficient of microbiological activity was less than 1.The use of this model, describing the short-term stabilization process and subsequent inhibition of the number of microorganisms from the concentration of Cd in the soil under these influencing factors (soil temperature and moisture, protease activity, cellulose destruction), did not contradict the actual laboratory data.

Conclusion. The soil temperature was above the average long-term indicators. Under these conditions, soil microorganisms developed well and their number was 14.7 million CFU / g. The decomposition of flax was below 10%, which was characterized by the Zvyagintsev scale as very weak. Protease activity was also low. Priority for the region were 4 heavy metals, the concentration of which in Ryazan region was higher than the standards. The Cd content did not reach maximum values, but was elevated, which also affected the number of microbiotas.

Abstract.

Problem and purpose. The number of elements of mineral nutrition in plant organs is related to their content in the root zone. [1,2,3,4,5]. The change in the chemical composition of plant organisms is associated with the use of various forms of nitrogen fertilizers, which do not affect the accumulation of phosphorus in organs or increase or decrease its amount, which activates the adsorption of phosphorus anions in combination with nitrogen in the form of a cation [1]. The purpose of the study is to study the effect of nitrogen and phosphorus nutrition on the yield and quality of onions.

Methodology. In vegetation experiments with onion-seed of the Sturon variety (sand culture), plants were grown in 8-liter vessels containing pure quartz sand. The variant included 10 vessels (40 bulbs), the repetition was threefold. Nutrient salts were introduced in dissolved form with concentrations of nitrogen/phosphorus – 25/5 mg/l, 50/15 mg/l, 100/25 mg/l, 150/35 mg/l and 300/50 mg/l.

Results. The best yield indicators (211 g/vessel) were shown by the concentration of nitrogen/phosphorus – 300/50 mg/l. The phosphorus/nitrogen concentration of 50/300 mg/l lowered the dry matter level to 16.55%. High concentrations of nitrogen and phosphorus significantly reduced the degree of sugars in the bulbs. A high amount of sugars (15.28%) was established at the nitrogen/phosphorus level – 25/25 mg/l. An increase in the concentration of nitrogen/phosphorus in the substrate reduced the amount of ascorbic acid in the organs of the onion. The increase in phosphorus levels in leaves and bulbs was at high nitrogen concentrations regardless of phosphorus concentrations in the substrate. Phosphorus concentrations lowered the level of potassium and calcium in the leaves and calcium in the bulbs. The potassium level in the bulbs did not change under the influence of concentrations of both nitrogen and phosphorus.

Conclusion. An increase in the yield of onions is associated with the dependence of the nitrogen concentration on the phosphorus concentration, i.e. there is a synergism of ions, so an increase in nitrogen concentration is directly proportional to an increase in phosphorus concentration. An increase in nitrogen concentration with a reduced phosphorus concentration contributed to an increase in the yield of onions, and then its decrease. Different nitrogen concentrations at optimal phosphorus concentrations significantly increased yields. A change in the concentration of nitrogen or phosphorus in plant tissues entailed a change in the content of other nutrients in them, as well as the biochemical composition of the bulbs. A balanced increase in the concentration of both nitrogen and phosphorus in the nutrient solution contributed to an increase in its accumulation by both leaves and bulbs. A change in the concentration of nitrogen or phosphorus in plant tissues entailed a change in the content of other nutrients in them.