Microfield Experiment Research Articles

Effectiveness and Duration of Action of Dolomite Screening Particles Used for Reclamation of Acidic Soils. Empirical Models of the Acidification Process of SodPodzolic Light Loamy Soil (according to Field Experience)

In a long-term 10-variant microfield experiment based on a mediumacidic sod-podzolic light loamy soil, a comparative study of the reclamation properties of the screening of dolomite crumbs stored in dumps, without separation into fractions (SIF), particles of 5–7 and 7–10 mm in size and dolomite flour (DF) prepared from the screening of dolomite when sifting dolomite crumbs with the diameter of the holes is 0/25 mm. The experiment lasts for 14 experimental years. It has been revealed that dolomite particles of 5–7 and 7–10 mm in size are valuable calcareous material. Their use leads to the neutralization of soil acidity already in the year of liming. The higher the dose of application, the greater the reclamation effect. There were no significant differences in the effect of granules of 5–7 and 7–10 mm in size, applied in equivalent doses, on the pH value. The positive effect of liming with meliorant in the amount of 3 and 5 doses of hydrolytic acidity (Ah) did not end after 14 experimental years after reclamation and allowed to postpone the period of repeated (maintenance) liming. The positive effect of using a natural mixture of chalk fractions (SIF) in a scientifically justified dose was inferior to dolomite flour. Clustering of individual variants of the experiment was carried out according to their effect on the рHKCl value for the entire period of the experiment. Linear trends of the averaged dependencies of the acidification process for meliorant particles of various sizes over the entire period of the experiment have been developed. The mechanisms of interaction of dolomite particles with soil in the process of land reclamation are considered.

Morphological and physiological properties of lupine nodule bacteria (Bradyrhizobium lupini) when grown on a typical urban soil.

In the conducted studies, the moorphological and physiological properties of nodule bacteria of lupine were studied. Lupine plants were grown under the conditions of a microfield experiment on a typical medium loamy urban soil. In the study, a pure culture of Bradyrhizobium lupini was isolated. Then, the morphological properties of nodule bacteria cells and the chemical composition of cell membranes of nodule bacteria were determined. The acid resistance and physiological properties of lupine nodule bacteria were also determined, as well as the ratio of Bradyrhizobium lupini to antibiotics. All studies were carried out according to generally accepted methods. The results of the research showed that during the cultivation of lupine on a typical urban soil, nodule bacteria Bradyrhizobium lupini were isolated, which can be characterized as gram-negative, non-spore-forming rods that do not exhibit amylolytic activity. It was revealed that the rhizobia of nodule bacteria are not acid-resistant. Nodule bacteria turned out to be the least resistant to polymyxin, then to levomycetin, and Bradyrhizobium lupini showed the greatest resistance to tetracycline.

Potato yield forecasting based on a fuzzy-possibility model

Potato production is a complex dynamic system that requires ensuring the stability of its functioning in changing, uncertain economic conditions and a scientifically based approach to making effective management decisions. The purpose of the research was to assess and predict potato productivity depending on the level of mineral nutrition and the length of the growing season using expert knowledge and a fuzzy-possibility approach in the conditions of the Republic of Karelia. The experiments were carried out in 2019-2021 on three potato varieties of different early maturity: Udacha, Red Scarlet and Aurora on soddy-weakly podzolic sandy loamy well-cultivated soil. The microfield experiment included two options for applying mineral fertilizers: N80P60K120 и N120P90K180, the variant without fertilizers served as a control. Studies have shown that the application of mineral fertilizers significantly increases the yield of tubers by 10-58%. The yield of potatoes without the use of fertilizers averaged 28.4 t/ha in the experiments. The highest potato yield was obtained on the early variety Udacha (38.4 t/ha) against the background of the use of mineral fertilizers at a dose of N80P60K120. An adequate fuzzy-possibility model (FPM) based on explicit and implicit expert knowledge has been synthesized to predict potato yield. It is shown that the most significant factors in assessing the yield of potatoes of all tested varieties are the level of mineral nutrition (X2) and soil fertility (X5). The synthesized FPM can be used for the planned potato yield under certain external and similar technical and technological conditions.

Efficiency of application of nitrogen fertilizers and biological products on spring wheat

The research was carried out in order to study the new biologics’ effect based on rhizosphere microorganisms on the yield and the spring wheat grain’s quality. The work was carried out in 2018-2020 in the Ulyanovsk region on leached heavy loam chernozem in a microfield experiment in vessels without a bottom with an area of 0.018 m2. The experiment’s scheme: Background 1: Р45К4 (control); Background 1+ Strain KL-10; Background 1+ Strain 17-1; Background 1+ Rhyzoagrin; Background 2: N45Р45К45; Background 2+ Strain KL-10; Background 2 + Strain 17-1; Background 2 + Rhyzoagrin; N45Р45К45. It was discovered that pre-sowing inoculation of spring wheat seeds with new biological preparations based on associative rhizobacteria’s strains increases grain weight by 19…22 %. The increases from the Rhyzoagrin biologics’ using on Р45К45 as a standard averaged 66 g/m2 (+13 % to Background 1), from strain KL-10-98 g/ m2 (+19 %), strain 17-1 - 113 g/m2 (+22 %). Based on NPK-one of the most common in pollination, which contains a biological product based on nitric oxide 17-1 - 80 g / m2 (+15 %). The maximum yield obtained from N90-789 g/ m2 (+51 %), from N45-647 g/m2 (+ 24 %), that is comparable to 17-1 (636 g/m2). The raw protein’s collection increased from the introduction of N90 to 80 % as a result of exposure to nitrogen nutrition, crop production, from the biological products’ usage or N45 - by 25…32 %. The nitrogen fertilizers’ using and biologics positively affected the accumulation of nitrogen consumed in the grain, increasing the nitrogen index (the share of nitrogen accumulated in the grain from its total accumulation in the crop) from 64 % to 71 %, increasing the ammonium nitrate nitrogen’s payback with the grain harvest’s growth by 52 …67 %.

Influence of Diatomite, Zeolite and Bentonite Clay on Agrochemical Indicators Sod-Podzolic Soil and Yield Agricultural Crops

In three-year microfield experiments on sod-podzolic light loam soil, the effect of reclamation doses (3, 6 and 12 t/ha) of siliceous rocks (diatomite, zeolite and bentonite clay) on the main agrochemical properties of the soil and crop productivity in the grain link of the crop rotation of winter wheat-spring barley-seed peas was studied. Among other positive effects, a significant effect of diatomite was found in reducing the concentration of exchangeable forms of aluminum in the soil (by 0.11 mg-eq/100 g), increasing the content of exchangeable forms of magnesium (by 0.33 mg-eq/100 g) and phosphates of soil solution (by 225%). Against the background of the influence of diatoms, barley gave the greatest increase in grain yield (by 38%) and straw (by 29%). The most significant effect of zeolite was revealed in a decrease in the actual, metabolic and hydrolytic acidity of the soil (a decrease of 1.11, 0.48 pH units and 0.33 mg-eq/100 g), as well as the concentration of exchange compounds of calcium (an increase of 17.7 mg-eq/100 g), magnesium (by 12.0 mg-eq/100 g) and potassium (by 46%). The introduction of zeolite rock contributed to the greatest increase in the yield of grain (by 32%) and straw (by 23%) of barley. The most significant influence of bentonite clay was established on the indicators of actual soil acidity (their decrease by 0.65 pH units), the content of exchangeable aluminum (decrease by 0.19 mg-eq /100 g) and phosphates of soil solution (increase by 175%). The introduction of clay contributed to the formation of the greatest increase in grain yield (by 33%) and straw (by 19%) of seed peas.

Changes in Mn availability and soil acidity in <em>Albic Retisol</em> limed with dolomite screenings of various sizes and doses: a long-term microfield experiment in the north-western Russia

Liming of acidic soils is associated with various processes in the soil, including the availability of nutrients for plants. The vector and extent of these changes depend, inter alia, on the type of lime material and the doses used. Particularly, excessive liming can trigger a deficiency of manganese for crops. A long-term microfield experiment (13 test years) was carried out on Albic Retisols reclaimed with the dolomite particles of various sizes as a by-product of stone processing quarries. Ten treatments including various sized dolomite particles and their combinations, as well as traditional limestone flour on the background of NPK fertilizer were studied for the changes in soil acidity indicators (exchangeable acidity, pH; hydrolytic acidity, Hy; total acidity, Htot) and manganese availability. The amount of acidic components passing into the extract of 1N KCl was insufficient to reveal a dependency between the exchangeable acidity and the content of mobile manganese in the soil of most treatments limed with dolomite particles of various sizes. However, the relationship between the content of mobile Mn in soils and the value of hydrolytic acidity was proved by paired linear regressions. Regardless of the dose and size of dolomite particles added, the soil was highly and moderately supplied with plant available manganese during the entire study period.

Potash State of the Soil and Crop Productivity when Applying Mineral Fertilizers and Plant Residues

In micro-field experiments conducted on gray forest soil, changes in the forms of potassium under the influence of mineral fertilizers and plant residues were studied. It is shown that the soil potassium contained in a water-soluble and easily exchangeable form varied widely. In the conditions of 2012, when applying K60 on the background of nitrogen and phosphorus, the content of water–soluble potassium increased by about 2 times compared with the control, and the content of light-exchange potassium increased by 4 times. In the case of embedding plant residues in the soil, the potassium content in the water–soluble form increased by 2 times, light-exchange – by 2.5 times, respectively. The content of exchangeable potassium changed little in the variants, the changes affected the non-exchangeable form to a greater extent. In particular, the content of non-exchangeable potassium in 2018 decreased by 1.5–2.0 times compared to 2012, which required the creation of a more reliable basis for obtaining objective information about the state of the potash fund of the soils of the forest-steppe zone. Under the influence of K-fertilizers in combination with plant residues, plant productivity stabilized, and at the same time a positive balance of potassium in the soil was formed.

NITROGEN FERTILIZERS ROLE IN GRAIN CROPS PRODUCTIVITY IN SOUTH-EAST KAZAKHSTAN

Seeking to improve the efficiency of nitrogen fertilizers for grain crops led to conducting this study on developing methods using 15N in 2015–2017 at the Kazakh Research Institute of Agriculture, Almalybak Village, Almaty Region, Southeastern Kazakhstan. Nitrogen use efficiency using the stable isotope 15N in microfield experiments revealed that the assimilation of nitrogen fertilizers by grain crops largely depends on the norms, timing, fertilization method, and varietal parameters of the concerned crop. Based on morphophysiological methods of monitoring plant development conditions, the nitrogen fertilizers’ role based on the development has been affirmative, with the optimal timing of their application also determined. Results show that grain crops use nitrogen productively with partial application at the beginning of tillering and tubing, respectively, and stages III and V of organogenesis. With the use of nitrogen fertilizers, the significant varietal differences were evident. The help of an isotope label established the accurate nitrogen utilization coefficients of fertilizers based on the options ranging from 14.7% to 32.2%. Using the isotope method provides an opportunity for further development of practicing the most efficient techniques of applying fertilizers, which is an imperative method for determining the effectiveness of nitrogen fertilizers.

Sizes and Ratios of Organic Carbon Pools in Gray Forest Soil under Long-Term Application of Mineral and Organic Fertilizers

Soil organic matter (SOM) is proposed to subdivide into structural and process pools. Structural pools include particulate organic matter (CPOM) and mineral-associated organic matter (CMAOM), and process pools include microbial biomass (Cmic) and potentially mineralizable organic matter (C0). The studies were carried out in a long-term microfield experiment on gray forest soil (Luvic Retic Greyzemic Phaeozems (Loamic)). Mineral (N 90–360, P2O5 75–300 and K2O 100–400 kg/ha) and organic (fresh cattle manure from 25 to 100 t/ha) fertilizers in increasing doses were applied annually for 9 years. The increasing in soil organic carbon (Corg) stocks from NPK and manure was 5–10 and 38–83%, respectively. The application of extreme doses of manure (700 to 900 tons/ha in 9 years) led to saturation of the soil with organic carbon. SOM pools sizes decreased in the sequence CMAOM CPOM C0 Cmic, amounting to 7.91–12 g/kg (50–84% of Corg), 0.76–12 g/kg (8–50%), 0.32–1.71 g/kg (2.8-13.7%) and 0.09-0.56 g/kg (0.8-3.7%), respectively. CPOM pool size depended mainly on the dose of mineral and organic fertilizers, and CMAOM depended on the duration of fertilizer application. Both Cmic and C0 pools increased with the manure dose and decreased with the NPK dose. The long-term manuring did not produce a cumulative accumulation of C0 in the soil. It is emphasized that the separation of structural and process pools can be used for monitoring of SOM quality and functions.

Influence of nitrogen stress on nitrate accumulation and yield of lettuce varieties

Relevance. Many authors note the existence of significant genotypic differences in the assimilation of nitrogen and the accumulation of nitrates by lettuce, point to the additive-dominant nature of the inheritance of the trait. The aim of the work was to evaluate the response of lettuce of various cultivars to mineral nutrition stress created against a nitrogen-deficient background (N0) and with an increased dose of nitrogen (N200).Material and Methods. In a microfield experiment on well-cultivated soddy-podzolic soil, a collection of lettuce varieties belonging to the main cultivated variety types was studied. The varieties differed in geographical origin, early maturity and morphological characteristics.Results. Differences in yield between varieties against the background of N200 were 4.5 times, and against the background of N0 – 5.7 times. Against an increased background of nitrogen nutrition, the highest yield – 2.22-2.64 kg/m2 was formed by the following varieties: All the Year, Quedlinburger Dickkopf, Berlin Yellow, Great lakes. Against a nitrogen-deficient background, Azart and Odessa Kucheryavets varieties stood out in terms of yield, which absorbed soil nitrogen better than others. The content of nitrates in lettuce plants of different varieties varied more strongly when grown on the background of N200 and ranged from 10.7 to 13.6 times (on average over 2 years – 11,2 times), on the control of N0 – 33 times. Varieties accumulating maximum NO3 under conditions of excess nitrogen nutrition were revealed. Lettuce Romaine (Lactuca romana) – 353 mg/kg and White paris cus (198 mg/kg) had a low content of NO3. The period of the maximum increase in biomass also corresponded to the maximum decrease in NO3 in plants. Power function equations were calculated to estimate the rate of change in biomass and NO3 content. The results indicate that there may be some scope for NO3 reduction in lettuce through cultivar selection or breeding.

Effect of Long-Term Use of Sewage Sludge and Lime on the Gross Content and Concentration of Mobile Forms of Heavy Metals in Sandy Loam Sod-Podzolic Soil

The long-term dynamics of the gross content and concentration of mobile forms of heavy metals (TM) in the soil of a microfield experiment laid in 1984 on sod-podzolic gleevate sandy loam soil on moraine loam (Vladimir region) is considered. Various large doses of municipal sewage sludge (MSS) and lime (dolomite flour) were introduced as meliorants. Despite the duration of the field experiment, sampling to compare the variants of the experiment on the content of TM in the soil turned out to be insufficiently systematic. Therefore, comparisons were made only on the basis of 3-4 years, and with insufficient comparability of analytical data. As a result, if in some years a significant dependence of the TM content in the soil on the doses of meliorants was obtained, then in the long-term plan, basically we can only talk about trends. From the point of view of contamination of the arable soil layer, it was found that the gross content of Cd, Zn, As was greater than the standard of approximate permissible concentration (APC) in all variants of the experiment (including control); the same is shown for Cu in all variants except control, and for Ni at maximum doses of MSS. Soil contamination in the control appears to be associated with lateral transport. Most of the total Cd and Cu content was extracted with mononormal acids. The content of mobile copper (AAB pH 4.8) (compared with acidsoluble) reacted poorly to the introduction of ameliorants.

Use of natural sorbents for accelerated bioremediation of grey forest soil contaminated with crude oil

Due to the extensive oil extraction and transportation that occurs in oil-producing countries, many lands remain contaminated because of accidental leakages. Despite its low cost and environmentally safe nature, bioremediation technology is not always successful, mainly because of the soil toxicity to the degrading microbial populations and plants. Here we report a three-year microfield experiment on the influence of natural sorbents of mineral (zeolite, kaolinite, vermiculite, diatomite), organic (peat), carbonaceous (biochar) origin, and a mixed sorbent ACD (composed of granular activated carbon and diatomite) on the bioremediation of grey forest soil contaminated with weathered crude oil (40.1 g total petroleum hydrocarbons (TPH) kg−1). Optimal doses of the sorbents significantly accelerated bioremediation of petroleum-contaminated soil through bioaugmentation followed by phytoremediation. The main reason for the influence of the sorbent amendments relied upon the creation of optimal conditions for the activation of hydrocarbon-utilizing bacteria and plant growth due to the reduction of soil toxicity, as well as maintaining an optimal pH and water-air regime in the soil. That happened because of reducing the soil hydrophobicity, increasing porosity and water holding capacity. The content of the TPH in the best samples (2% biochar or ACD) reduced to their local permissible concentration accepted for remediated soils in the Russian Federation (≤5 g kg−1) after two warm seasons compared to that after three warm seasons in the other samples. Although some sorbents decelerated biodegradation of highly condensed polycyclic aromatic hydrocarbons (PAHs, including benzo(a)pyrene) in the soil, the overall risk from the residual contaminants present in the remediated soil and plants was minimized. The final total content of the main PAHs in the sorbent-amended soils did not exceed the maximal permissible levels that are accepted in most EU countries (1000–40,000 μg kg−1), and they did not accumulate in the aboveground phytomass of grasses in dangerous concentrations.

Nutritional regime and biological activity of soil depending on copper contamination and the role of diatomite as a detoxifier

Relevance. Modern agricultural production is characterized by an increase in anthropogenic impact on agrocenoses, which poses a threat to obtaining environmentally safe crop production. Among the toxicants, heavy metals are particularly dangerous, along with pesticides. Metals, including copper, which play a dual role in the “soil — plant” system, are absolutely necessary for plants and at the same time highly toxic when received in excess quantities, deserve special influence in this regard.Methods. The study of the amounts of copper was carried out in microfield experiments with artificial soil contamination with copper sulfate (CuSO4 · 5H2O) at the level of 2 MPC, 4 MPC and 10 MPC. The soil of the experimental field is medium-loamy leached chernozem, high-siliceous rock diatomite was used as a copper detoxifier at the rate of 5 t/ha. The experimental crop was spring wheat of the Margarita variety selected by the Ulyanovsk Research Institute of Agricultural Sciences. The repetition of the experiment is fourfold, the location of the plots is randomized, the accounting area of the plots is 1 m2.Results. The threshold value of copper, beyond which the biological activity of chernozems significantly decreases in the conditions of the Middle Volga region, is the level of pollution in the amount of more than 4 MPC. The introduction of diatomite into the soil in its pure form was accompanied by an increase in the activity of soil microorganisms, when combined with copper sulfate — a relative decrease. Artificial contamination with copper did not cause significant changes in the content of humus , phosphorus and potassium compounds in the arable layer. It is shown that the copper content in the soil at the level of 10 MPC led to a significant suppression of the activity of soil biota and a decrease in the yield of spring wheat by 0.58 t/ha, or by 29%.

Formation of the yield of oil crops of the Brassicaceae family in the Middle Cis-Urals

The article presents data on the study of the formation of the seed yield of spring oil crops in the conditions of the Middle Cis-Urals. The work is based on the results of a two-factor microfield experiment, where factor A - crops - rape and camelina, factor B - varieties of crops - rape Accord and Podmoskovny, camelina Veles and Yubilyar. The relevance of the study is related to the growing interest in oil crops. The research methodology is generally accepted in agronomy. Camelina was characterized by a faster rate of development, its growing season was 89-109 days, rape - 109-147 days. Morphological and biological features of crops were revealed – a large height of rape plants, their damage by blossom weevil and diamondback moth and the associated lower (50%) survival rate of plants during vegetation; lower seed content (by 44 pcs.) and the formation of smaller seeds (the weight of 1000 seeds was 2.08 g inferior to the same indicator of rape) in camelina. With such a yield structure, camelina had an advantage of 18 g/m2. The crops did not differ in the content of crude protein and fat in the seeds.

Fluxes of 15N, soil nitrogen in sod-podzolic soil in spring wheat crops under inoculation with Rhyzoagrin

In a microfield experiment using a labeled nitrogen 15N fertilizer on sod-podzolic light loamy soil for 11 years during the cultivation of spring wheat and the use of a biological product based on a strain belonging to the genus Agrobakterium radiobakter (strain 204), nitrogen flows in the fertilizer – soil – plant system were studied. The utilization rate of spring wheat labeled with 15N ammonium nitrate averaged 40% of the amount applied. The absolute size of the immobilization in the structure of the labeled nitrogen balance of the mineral fertilizer was 27-30%. Inoculation with Rhyzoagrin does not significantly affect the nitrogen immobilization of the mineral fertilizer. The gaseous losses of labeled nitrogen of the mineral fertilizer were 33% of those applied to the background of the phosphorus and potash fertilizers and decreased with inoculation with Rhyzoagrin to 29%. The use of an integral assessment showed that the agroecosystem functioned in the resistance mode on sod-podzolic light-loamy soil when using mineral nitrogen fertilizer. The dependence of the indicator RI: M, % of the HTC (hydrothermal coefficient) expressed by the equation y = -24, 506x2 + 43,462 x + 15,251 at R2 = 0.7416 is established.

Biological activity of sod - podzolic sandsand soil with meloriative application of hydrogels

Biological activity of the soil is an indicator characterizing the number of organisms living in the soil, and quantitatively evaluating the results of their vital activity. High biological activity is a factor in increasing soil fertility and its phytosanitary state, achieved by creating optimal living conditions for soil microorganisms: providing nutrients, especially organic matter, moisture, heat and soil aeration. In this paper, we assess the effect of hydrogels of different chemical bases on the microbiological activity of sod-podzolic sandy loam soil. The effect of hydrogels on the microbiological activity of sod-podzolic soil was studied in a microfield experiment in a special installation (“dry place”) under conditions of soil drought and field conditions (Menkovsky branch of the FSBIU API, Gatchinsky district, Leningrad region). The experience was laid with two types of hydrogels (potassium and sodium base) with a single dose (40 g/m2). In the experiment, the indicators of soil biological activity were compared in the following variants: soil - control with the addition of 90 kg ha-1 NPK in the form of an azofoska, hydrogel introduced to a depth of 10–12 cm + N90 P90 K90, hydrogel introduced to a depth of 20–22 cm + N90P90K90. Samples of sod-podzolic sandy loam soil were taken from depths (10–12 cm and 20–22 cm) at the beginning and at the end of the growing season. In the course of the studies, it was found that when the hydrogel is introduced, both in the upper root-inhabited soil layer and in the 20–22 cm layer, favorable conditions are created for the microbiological activity of sod-podzolic sandy loam soil. It has been established that the chemical basis of the hydrogel does not inhibit the activity of the microbial community.

Влияние высоких доз суперфосфата на групповой и фракционный состав фосфатов темно-серой лесной почвы

Abstract. The purpose of the work was to study the effect of high doses of superphosphate on the yield of forage beans and the composition of phosphates in dark gray forest soil. Research methods. The studies were carried out in a microfield experiment. Doses of superphosphate are calculated taking into account the increase in the phosphorus content from medium to very high. The total phosphorus content was determined after calcining the soil, and the mineral group was determined in the natural state of the soil in an extract of 0.2n sulfuric acid, the fractional composition was determined by the method of S. Chang and M. Jackson. Results. High doses of superphosphate (the degree of phosphorus supply is high and very high) without the introduction of nitrogen and potassium fertilizers significantly reduce the productivity of beans. The optimal content of mobile phosphorus is an increased degree of supply (101–150 mg/kg according to Kirsanov). High doses of superphosphate double the total phosphate content in relation to the original soil, mineral phosphates make up 77 %, organophosphates – 22.8–23.3 %. Analysis of the fractional composition of mineral phosphates showed that the use of water-soluble phosphorus fertilizers increases the amount of phosphates of all fractions. The fraction of loosely bound phosphates increases from 5 mg/kg of soil (medium supply) to 14 mg/kg at a very high level. From the total amount of mineral phosphates, calcium phosphates occupy 20–23 %, aluminum phosphates – 12.5–14.9 %. The share of ferrophosphates practically does not change with the dose of superphosphate and is 25.3–25.7 %. The fraction of poorly soluble phosphates is the most significant: with an increased degree of supply, the content of phosphates is equal to 438 mg / kg and increases with a very high degree of supply up to 529 mg/kg of soil, this is 37.1–38.8 % of the total amount of the mineral group of phosphates. The scientific novelty lies in the calculation of the dose of phosphorus fertilizer, taking into account the stepwise transition from one degree of provision to another, from medium to high, high and very high. This approach to calculating the doses of fertilizers makes it possible to differentiate the doses of nitrogen-potassium fertilizers.

Fertilizer circulation and nitrogen balance in the agrophytocenosis of sugar beet when acidizing typical chernozem (study with15n)

The studies were carried out under the conditions of a microfield experiment on typical chernozem (Belgorod region) with two soils (pH 5.0 and 6.5) with the addition of urea (enriched in15N, 17.1 at. %) And effluents from a pig-breeding complex (PSC) at doses of 6 and 12 g N/m2(against the background of phosphate and potash fertilizers, P6K6). The largest amount of nitrogen was consumed by sugar beets with the combined introduction of CCA and urea (25.8 g N/m2). When the soil was acidified to pHsalt 5.0, the consumption of nitrogen in mineral fertilizers decreased by 15-18%, soil ni-trogen – by 21-52%, and waste nitrogen – by 16%. At the same time, the immobilization of nitrogen in the fertilizer decreased by 13-18%, and the loss of gaseous nitrogen compounds increased by 47-108%. The effluent from the pig-breeding complex increased the immobilization of nitrogen in mineral fertilizers (by 38-46%) and reduced gaseous nitrogen losses (by 22-44%). The highest stability and productivity (root crop yield 1654 g/m2, tops yield 239 g/m2) was exhibited by agrophytocenosis on soil with pH 6.5 with the combined application of CCA and urea. When the soil solution was acid-ified to pH 5.0, the yield of beet root crops decreased by 30% and the yield of tops – by 24%. On soil with pH 5.0, fertilizers increased the sugar content in root crops by 0.2-1.3%, on soil with pH 6.5, they decreased by 1.3-2.0%.

ОЦЕНКА ВОЗМОЖНОСТИ ПРИМЕНЕНИЯ ТОРФОДИАТОМИТОВОГО МЕЛИОРАНТА ПРИ РАЗРАБОТКЕ МЕРОПРИЯТИЙ ПО ЭКОЛОГИЧЕСКОЙ РЕАБИЛИТАЦИИ НАРУШЕННЫХ ЭКОСИСТЕМ

One of the main factors determining the transformation of natural technogenic complexes is the storage of large masses of industrial waste on the day surface, and their further transformation leads to a change in geochemical processes in landscapes associated with dumps. Objective. On the basis of the experimental studies performed, to evaluate the effectiveness of the use of peat-diatomite ameliorant in the development of measures for the ecological rehabilitation of disturbed ecosystems. Research methods. The content of copper ions was determined by the atomic absorption method using a Spectr AA-240 FS (Varian Optical Spectr. Instrum, Australia). Mineralization of samples to determine the gross copper content was carried out in concentrated HNO3 using a MARS 5 laboratory microwave system (CEM, USA). The mobile forms of copper were determined in extracts of 0.5 M HNO3 in a ratio of 1:25 (soil: solution). Mine waters of the former Degtyarsky mine with a copper content of 4.61 mg / L were used as a model solution. Technogenic soil for microfield experiments was selected during the summer field research. Peat-diatomite ameliorant own development of “Ekoinnovator”. Research results. According to the results of the analysis of the obtained experimental data, the tendency of the sorption process from 4.61 mg/l to 1.754 mg/l is clearly visible when using "diatomite" as a sorbent, and the introduction of a peatdiatomite meliorant in the composition of which sapropel is also Therefore, using reclamation techniques by introducing mineral and organic fertilizers, it is possible to regulate the mobility of copper ions, and the revealed nature of changes in the amount of mobile copper compounds should be taken into account in the development of environmental protection measures for the ecological rehabilitation of disturbed natural ecosystems.

Screening of Nematicides against the Lotus Root Nematode, Hirschmanniella diversa Sher (Tylenchida: Pratylenchidae) and the Efficacy of a Selected Nematicide under Lotus Micro-Field Conditions

In Japan, Hirschmanniella diversa is an important pest in lotus cultivation in paddy fields and only lime nitrogen is registered for its control. Therefore, additional nematicides are required to control the nematode. The objective of this study was to screen for an effective nematicide. Fourth-stage juveniles and adults of H. diversa sampled from a lotus field were tested in in vitro solution experiments against 37 pesticides that are registered for the pest control of crops in Japan. Carbamate-based benfuracarb, organophosphate-based fenthion, nereistoxin-based cartap hydrochloride and cyanamide showed nematicidal effects against H. diversa. Benfuracarb at 1 μg/mL showed a nematostatic effect on H. diversa in an agar plate assay. Further, H. diversa treated with benfuracarb did not resume activity 7 days post nematicide treatment when transferred to distilled water. Benfuracarb was tested in micro-field experiments, in which H. diversa density and lotus tuber damage levels were monitored. Results showed that benfuracarb reduced H. diversa densities in the roots during the cultivation period in 2012 and consistently reduced damage levels during a five year study period. Thus, benfuracarb is recommended as an effective nematicide to be used for H. diversa control in lotus cultivation.