Nº 9 (2025)

The phosphate stock of Siberian arable soils reflects the uniqueness of the genetic features of soil formation and the unequal phosphate enrichment of soil-forming rocks of various geomorphological structures. Among the mineral phosphates that serve as the main factors of soil fertility, loosely bound (Ca-P_I) and polybasic forms (Ca-P_II) are of crucial reserve importance for plant nutrition. Siberian arable lands in half of the surveyed area (>10.5 million hectares) are insufficiently supplied with available phosphates to produce sustainable yields of high-quality products. The use of phosphorus fertilizers, having a positive effect on the productivity of field crops, significantly improves the qualitative composition of mineral phosphates in soils. The degree of influence of fertilizers on the fractional composition of phosphates is determined by the type of soil, duration and doses of their application. With the systematic application of fertilizers, the main quantitative changes occur in the first 4 groups of mineral phosphates – the content of P₂O₅ increases by 1.4–2.2 times. Their total share in sod-podzolic and chestnut soils is 15–20%, in chernozems and meadow-chernozem soils it increases to 25–34%.

The article presents the results of long-term studies on the effect of various soil cultivation systems on the content of organic matter. It has been established that the content of organic matter in the soil significantly depends on the level of anthropogenic impact, as well as on the method of primary cultivation. The presented data show a change in the humus content for 2017–2024 from the initial value (2015) using the direct seeding technology (no-till) towards an increase in the 0–30 cm layer by 0.26%, which contributes to the stabilization of the humus state of southern chernozem in the five-field crop rotation system. The productivity of five-field crop rotation crops was greatly influenced by the level of precipitation; in the dry years of 2017, 2019 and 2024, a decrease in productivity by 10, 50 and 28%, respectively, was noted.

Optimization of the use of limited raw materials for the production of phosphorous fertilizers is recognized as the most important problem of our time. Substantiation of the dose and method of application of phosphorus fertilizer (PF), correction of the technology of its application are one of the ways to solve this problem. The effectiveness of the annual and reserve methods of applying PF to soils with different phosphate stocks was compared. The soil is old–arable leached medium-acre chernozem. The soil was sampled in the Central forest-steppe of the Novosibirsk region. on 2 sites, which differed in the composition of the soil-forming rocks and, accordingly, in the amount of phosphate stock. In soil 1, the total phosphorus content was 1.4 times higher than in soil 2, and the Ca-P_III fraction was about 2 times higher with lower Ca-P_II fraction values. The soils are highly humic, with a content of exchangeable potassium up to 140 mg/kg, mobile phosphorus (according to Chirikov) – up to 215 mg/kg. In the vegetation experiment, 5 cycles of spring wheat cultivation were carried out before the earing phase in the KKR-001 artificial climate chamber. Experience options: N₅₀K₅₀ (background), N₅₀K₅₀ + P₄₀ (single use), N₅₀K₅₀ + P_40+40+40 (annual deposit), N₅₀K₅₀ + +P₁₂₀ (stock deposit). The biomass of wheat during the application of P_40+40+40 in cycle 3 was about 20% higher than that of P₁₂₀, so the phosphorus deposited in the reserve was immobilized by the soil. Phosphorus removal in cycles 1 and 2, when adding P₁₂₀ to the reserve, exceeded the other options by about 50%, in cycle 3 it was 30% less than the option P_40+40+40, so the potential for adding phosphorus to the reserve by the end of cycle 3 was exhausted. In cycles 4 and 5, with a significant decrease in the removal of the element, the differences between the variants were leveled. The utilization rate of phosphorus fertilizer was maximal in cycle 1 and decreased significantly (by 2–3 times) in subsequent cycles, regardless of the method of its application and the soil. When studying the effect of fertilizers (1–3 growing cycles), an increase in the phosphorus content in the mobile fractions of the soil was observed, an increase in the number of CFU phosphatemobilizing microorganisms with suppression of phosphatase activity. It was concluded that, regardless of the soil properties, in order to increase the economic efficiency of agrocenosis, it is advisable to apply РF annually (to provide plants with phosphorus), to increase the soil’s phosphorus supply, the studied methods of applying fertilizers were equivalent and ineffective.

The evaluation of compost and biocompost based on sewage sludge (SS) produced by various methods as fertilizer for spring grain crops showed that the use of fertilizers in the first year of operation improved the acid-base properties of the soil, increased the content of mineral nitrogen and mobile phosphorus in the arable soil layer. The standardized application of compost and biocompost based on organic fertilizers ensured reliable yield increases and did not lead to contamination of soil and grain with heavy metals.

The possibility of using ultrafine silver forms as biocidal components of new generation pesticides has been studied. The effect of ultrafine silver particles and its ionic forms on the growth of Triticum aestivum L. has been studied. The effects of ionic forms were evaluated using the example of chelate – glycinate and silver nitrate. Ultrafine silver particles were obtained by the “green synthesis” method by reacting silver nitrate with quercetin and adding a 5% ammonia solution. The sizes of Ag nanoforms have been confirmed by the dynamic light scattering method. It was shown that small amounts of ultrafine silver particles did not have a depressing effect on germination and biochemical parameters of plants. Silver nitrate at a concentration of 8.493 × 10^–4 g/l slowed down the growth and development of Triticum aestivum, and the effect of silver glycinate on vital, morphometric, and biochemical parameters of the culture correlated with its content in solution. The concentration of 8.427 × 10^–3 g Ag+/l almost completely suppressed the germination of wheat, and when it decreased to 1.053 × 10^–3 g Ag+/l, the negative effect of glycinate weakened. Nitrates, chelates and ultrafine Ag particles showed pronounced fungicidal and bactericidal effects, which, against the background of the absence of phytotoxicity of the metal nanoform, indicated the prospects of its use for pre-sowing seed treatment. From the economic side, the low concentration of ultrafine particles in the solution will help reduce the cost of the final product.

In a field experiment conducted in 2022–2024 at the All-Russian Research Institute of Corn in the Stavropol Territory, the effectiveness and phytotoxic effect of the post-emergence herbicide Milagro Plus, MD on hybrids and corn lines was studied. Experimental options: 1 – control without herbicides, 2 – Milagro Plus (1.0 l/ha). The high sensitivity of weeds to the active ingredients of the drug has been established. 21 days after application, 77.0% of weeds died from the action of the Milagro Plus herbicide over an average of 3 years. The decrease in the number of dicotyledonous weeds was 68.6%, monocotyledonous – 88.6%, with a decrease in the above-ground mass by 75.5 and 94.1%. By the end of the growing season, corn control without chemical weed killing was heavily clogged, with an average of 42.3 plants growing per 1 m² in 2022–2024 weeds weighing 960 g/m². In the Milagro Plus herbicide experiment, weed death was 75.4%. The decrease in the number of dicotyledonous plants over an average of 3 years was 76.6%, monocotyledonous – 73.2%. The total vegetative mass of weeds decreased by 92.3% compared to the control, the mass of dicotyledonous weeds decreased by 93.1%, and monocotyledonous weeds decreased by 86.5%. The response of hybrids and lines to the use of the herbicide over the years of the study was mixed. In 2022, lightening of the upper leaves or their bases was noted in the Mashuk 140 hybrid, the maternal form of Alpha M and 4 lines (CL 6M, RD 2144, RG 298 MV, RM 146). In 2023, a greater number of studied hybrids and maize lines showed lightening of the base of the upper leaves, whereas in 2024. No signs of the herbicide’s effects on corn plants have been recorded.

The role of interspecific competition between species of soil micromycetes (Bipolaris sorokiniana Sacc. Shoem., Fusarium poae (Peck.) Wollenw., F. oxysporum Schltdl., F. equiseti (Corda) Sacc.) on their pathogenicity and aggressiveness towards spring wheat seedlings. A comparative assessment of the degree of influence of culture fluids (CF) of soil micromycetes B. sorokiniana, Fusarium poae, F. oxysporum, F. equiseti during their individual and paired cultivation on the morphological parameters and phytosanitary condition of spring wheat seedlings of the Licamero variety was carried out. The study was carried out in the laboratory using generally accepted methods. All soil phytopathogens were characterized by high pathogenicity and aggressiveness: the decrease in germination under the action of CF of all fungi was significant and reached 16% (F. poae). The suppression of the development of seedlings reached 58.8% (F. equiseti), roots – 40.3% (F. oxysporum), coleoptile – 28.9% (F. poae), the phytomass of seedlings decreased to 53.8% (F. equiseti). The aggressiveness of phytopathogens in terms of the prevalence of root rot symptoms reached 2.9 of the economic threshold of harmfulness (ETH) (B. sorokiniana and F. poae). The pairwise competitive relationships of micromycetes reduced their pathogenicity, the CF of the combination B. sorokiniana + F. oxysporum increased root length by 16.1, phytomass by 23.8%, the combination F. poae + F. equiseti stimulated root development by 22.6, phytomass growth by 40%, the combination F. oxysporum + F. equiseti stimulated root growth by 37.1, phytomass – by 43.8% compared to the control. The increase in the prevalence of root rot symptoms under the influence of CF in pairs of cultivated species reached 32.5 times compared with the control, was expressed in pigmentation and was not accompanied by an increase in harmfulness.

The effect of 6-fields crop rotations in the 6th rotation and permanent sowings of spring durum wheat on their contamination during prolonged use of mineral fertilizers and without their application was studied. In crop rotations with different types of vapors, with appropriate agricultural techniques, a decrease in the contamination of crops by various groups of weeds was noted. The replacement of clean vapors by occupied ones caused a change in the ratio of weeds in the agrocenosis and led to an increase in the number of perennial weeds. The use of mineral fertilizers in crop rotations contributed to an increase in contamination on a fertilized background. In the variants with soil–protective steam, the increase in the contamination of crops for harvesting was 50.2 pcs. on a fertilized background, 49.0 pcs./m² on a non-fertilized background, 61.6 and 66.6 pcs./m² on a sideral steam, respectively. The biological yield of spring durum wheat when cultivated in crop rotations was 2.08–4.32 c/ha on a fertilized background, – 4.31–5.24 kg/ha. Crop yield after sideral steam was 4.32 on a fertilized background, and 5.24 c/ha on a non–fertilized background. The decrease in durum wheat yields in permanent sowing on a fertilized background was primarily due to the high density of the weed component of the agrocenosis.

On the territory of one of the fields of a long-term field experiment with a 4-pole crop rotation (the Lyubertsy experimental field of the NIUIF), the set of properties of soil samples obtained from wells in each plot was analyzed. The undisturbed structure samples were taken 5 cm deep to a depth of 150 cm. In this work, arable and sub-arable layers up to 50 cm were analyzed. In the arable layer, for dry dispersion aggregates >10 mm and for the equilibrium soil density (in spring before tillage), most of the plots were far from optimal, with the best plots being in the first 2 out of 4 field repetitions, and in density in the third. Also, in the arable layer, half of the plots had a low content of exchangeable potassium by Oil content, and the other half (like all plots) – the content of Ca, Mg and the amount of absorbed bases – was very low. Thus. The connection with the long-term application of K-fertilizers for the content of exchangeable potassium in the soil turned out to be not very strict. To obtain a spatial representation of the heterogeneity of soils in the field, the plots were grouped separately for physical, chemical and morphological soil parameters. Spatial ranges for each of the groups have been identified. For physical indicators, the groups of plots were divided mainly according to the indicators of the under–arable layer (the same for morphological ones), and for chemical indicators – according to the indicators of both arable and under-arable layers. A variance analysis of the dependence of average long–term yields on plots of land on experimental options and on grouped soil indicators showed the following decreasing number of shares of influence of factors: experimental options – 54–82%, groups of chemical indicators – 22–31%, groups of physical indicators – 12–14%, groups of morphological indicators – 5.5–5.8%. When the control and NP options were removed, leaving only 8 options with K-fertilizers in order to more clearly identify the influence of soil factors, we got the following number of shares of influence: groups of physical indicators – 37–43%, groups of chemical indicators – 27–35%, experimental options – 19–29%. Variance and regression analyses made it possible to clarify the specific soil indicators most related to the average long-term yield; these turned out to be indicators of the under-arable layer, mainly physical (fractional composition) and the content of exchangeable Ca. Significant regression equations are obtained.