Effect of application of microelements on nitrogen nutrition of parsley, yield and quality of greens and roots

The article presents the results of vegetation-field studies (for 2018-2020) to study the effect of trace elements on the yield and quality of greens and root crops of parsley on heavy loamy chernozems on loess-like loams. A soil mixture was poured into the vessel at the rate of 10 kg of heavy loamy chernozem. Microelements were introduced into the soil in an amount: boron – 1.0 mg; zinc – 2.5 mg; copper – 0.5 mg; manganese – 5.0 mg; molybdenum – 1.0 mg; cobalt – 1.0 mg; iodine – 2.0 mg of active ingredient per kilogram of soil. In the prepared soil, 100 parsley seeds were sown in vessels at the beginning of May. Trace elements were aplicated in the form of an aqueous solution of salts 20 days before chemical analyzes. Molybdenum in the form of ammonium molybdenum (0.05 % solution), manganese – in the form of manganese sulfate (0.6 %, solution) and boron – in the form of boric acid (0.15 % solution). The experiments were carried out in triplicate. Collecting greens was carried out when the plants reached a height of 20–25 cm, leaving petioles 2 cm high from the head of the root crop. The results of the research found that microelements: boron, copper, manganese, molybdenum and cobalt on chernozem on average over two years contributed to an increase in seed germination by 1.2–1.3 %, and the introduction of iodine into the soil slightly reduced seed germination. Parsley shoots appeared together, which was also influenced by the water–air properties of the soil. At the same time, the plants were well leafy and had a darker green color of the leaves, increased the productivity of greens and parsley root crops. In the variant where organic fertilizers were applied to the soil under the predecessor, the microelements increased the yield. This is due to the fact that organic fertilizers were introduced under the previous crop, when decomposed in the soil, they provide the plants with microelements. The increased yield of parsley root crops was obtained from the introduction of molybdenum and a double dose of copper. An increased yield of root crops compared to the control (without feeding) was obtained, respectively: cobalt – 151 g, double dose of copper – 135 g, copper – 108 g and zinc – 106 g. Thus, the use of trace elements for parsley in order to obtain high yield and quality marketable products are best used on poor soils of these elements.

Biotechnology of Newly Created Bacterial Composition for Siloing Based on Lactic Acid Bacteria

Peculiarities of high-quality silage production are the use of biological products based on lactic acid bacteria. The composition of such starters varies greatly according to the use of bacterial cultures, so among the starters available on the market, the range of their effectiveness is also different. It is very common to use a one-sided approach to the choice of bacterial components, which in combination with imperfect production technology have low preservative activity. The study of combined preparations, which combine homo- and heterofermentative types of lactic acid fermentation, allows to stabilize the preservative properties throughout the ensiling time, and increase the aerobic stability of the silage after access of oxygen. Aim. Development of biotechnology of bacterial preparation for corn ensiling, optimization of cultivation conditions of newly created bacterial composition, and selection of cryoprotectants for its lyophilization. Methods. The combined preparation was created on the basis of heterofermentative strain Lactobacillus buchneri 3806 combining it in two- and three-strain compositions with other representatives of lactic acid bacteria, which are characterized by obligate homofermentative and facultative heterofermentative types of metabolism. Optimization of the environment and technological parameters was carried out using a central-compositional plan, further statistical analysis of the obtained data and determination of optimal values of input parameters according to the created mathematical model of optical density response. The effectiveness of the selected protective media was tested for the survival of bacteria after lyophilization. Results. The most effective bacterial composition was found during experiments: L. buchneri 3806, Enterococcus faecium C-8-12, L. plantarum 3216. The effectiveness of the obtained composition was tested by laboratory silage of corn. Tests of the drug based on the selected bacterial composition showed an improvement in the chemical composition of the silage compared to the untreated control and treated only with monoculture L. buchneri 3806, namely: there was a decrease in dry matter loss by 2.21% and 2.04%, 22 due to the increase of lactic acid content, and increase of aerobic stability of silage – 341 h against 57 h of the control sample, and 313 h in case of using monoculture. For the obtained bacterial composition, the culture medium of the following composition was optimized: base (hydrolyzed milk with the addition of the following components: monosubstituted potassium phosphate – 2 g/L; 5-aqueous manganese sulfate – 0.05 g/L; 7-aqueous magnesium sulfate – 0.2 g/L; twin-80 – 1.0 g/L); glucose – 19.7 g/L; yeast extract – 7.8 g/L; corn extract – 23.6 g/L; peptone – 9.1 g/L; sodium citrate – 6.6 g/L; sodium acetate – 3,4 g/L. Cultivation of the bacterial composition on an optimized medium made it possible to obtain the maximum biomass yield, at which the optical density was 2.01 units, which is almost twice as much as the value obtained by culturing the same composition in MRS medium. The optimal technological parameters of culturing the bacterial composition were established, namely the best growth was observed at a temperature of 36.4±0.4°C with constant maintenance of the pH value in the culture medium at the level of 6.5±0.1 units. In addition, the optimal composition of the protective medium containing sodium citrate, sucrose and agar was selected, and ensures the survival rate of lactic acid bacteria 98.4% after lyophilization. Conclusions. The newly formed bacterial composition can be used for the production of preparations for corn silage, and tested on other raw materials, in particular on some perennial legumes (alfalfa, clover), and the conditions of its production can be used to scale the technology.

Investigation of the Optical, Structural and Compositional Properties of Electrodeposited Lead Manganese Sulfide (PbMnS) Thin Films for Possible Device Applications

The properties of PbMnS semiconductor thin films deposited on fluorine-doped tin oxide (FTO) substrate using an electrodeposition method are investigated to determine their possible device applications. Lead acetate, manganese sulfate, and thiourea were used as precursors for sources of lead, manganese, and sulfur ions respectively. The concentration of lead, manganese, and sulfur ions sources with deposition voltage of 1.8 V was kept constant. The films were deposited using three electrodes system of electrodeposition method by varying deposition time. The films were characterized for optical, structural, morphological, and compositional properties and results showed that the absorbance, refractive index, and optical conductivity of the films are high in the visible (VIS) and near-infrared (NIR) regions but decreases in the NIR. These three properties initially increased with an increase in deposition time up to a time of 70 s which has the highest values of these properties before decreasing to lower values. The transmittance and extinction coefficient of the films are low in both VIS and NIR regions. The bandgap energy of PbS was found to be blue shifted with values of 1.51 eV, 1.54 eV, 1.60 eV, 1.45 eV, and 1.35 eV for the films deposited at 30 s, 50 s, 70 s, 90 s, and 110 s respectively. XRD analysis showed that the films are crystalline with sharp peaks positions indexable to crystalline planes of (111), (200), (211), (220), (311) and (400) with average crystallite size in the range of 16.110 nm to 17.218 nm. Energy-dispersive X-ray spectroscopy (EDX) results showed that the films are composed of lead, manganese, and sulfur but there are some impurity elements present mostly as a result of the substrate used. These properties exhibited by the deposited thin films of PbMnS showed that they can be used for many optoelectronic applications such as photovoltaic cells, sensors, photoconductors, etc.

ISOTHERM OF SOLUBILITY MANGANESE SULFATE - MONOETHANOLAMINE - WATER AT 25 ° C

Solubility in the ternary system manganese sulfate - monoethanolamine - water at 25°C was studied by isothermal method. The equilibrium in the system was controlled by liquid phase analysis. True equilibrium in the system was established within 7 hours. The new compound was isolated in crystalline form and identified by the methods of chemical, graphic, X-ray and thermal analyses. It was found that the new compound is a crystalline substance with an individual set of interplanar distances and line intensities. The formation of the new compound NH2C2H4ON-MnSO4-3H2O which was identified by the methods of chemical, graphic and X-ray analyses has been established. Preliminary agrochemical tests of aqueous solution of the new compound showed its positive properties as a stimulant.

The trace elements influence on the tomato plants heat resistance in arid climate

In the arid conditions of the Astrakhan region agricultural plants heat resistance is one of the important criteria of quality production getting. In this regard, and also taking into consideration the fact that the soils of our region are characterized by a very low content of trace elements in the form accessible to plants, researches were carried out to study the effect of trace elements of copper, manganese and zinc for tomato plants heat resistance. To exclude the trace elements rapid absorption by the soil, plants foliar treatments were used during the growing season with 0.05% solutions of zinc sulfate (ZnSO4), manganese sulfate (MnSO4) and copper sulfate (CuSO4). In the control variant, the plants were sprayed with water. The results showed that tomato plants foliar feeding during the III-V organogenesis stages with 0.05% solutions of zinc sulfate, manganese sulfate and copper sulfate have not got a significant effect on tomatoes growth and productivity. However, the zinc and copper trace elements positively influenced such physiological parameters of plants as the leaf cells hydration, the bound water content in them, the protoplasm viscosity, thereby contributing to the increase in tomato resistance to the adverse effects of high temperatures in the arid climate.

Preparation of nano manganese oxides by H2O2 in-situ oxidation: effect of regulation mechanism on physical and chemical properties

Manganese oxides showed many special physicochemical properties in many fields such as electrochemistry, adsorption and catalysis. They were widely used in cathode materials for lithium batteries, molecular sieves, catalytic materials and adsorbents. In this paper, in situ oxidation of manganese sulfate solution was conducted with H2O2 as oxidant, and the characterization means of XRD, SEM and BET were used. The purpose was to study the effects of different regulation mechanisms on the physical and chemical properties of manganese oxides such as morphology, phase composition, surface properties and specific surface area. The adsorption properties of γ-MnO2 for Co and Ni in manganese ore leaching solution were tested. The results showed as follows. Under alkaline conditions, the main product of manganese sulfate solution oxidized by H2O2 was Mn3O4 spherical particles with a radius of about 50 nm, these particles had micropores or mesopores, the oxidation reaction rate was rapid, and the specific surface area and N2 adsorption capacity changed with the change of reaction conditions.The temperature had a great influence on the micro morphology of the product.The micro morphology was slender nanorod when the temperature was 20℃. With the increase of temperature, the length of nanorod became shorter. When the temperature rises to 50℃, the rod became spherical. When the pH value decreased from 9 to 7, the diffraction peak of each crystal plane in the product Mn3O4 decreased gradually. The diffraction peak of γ-MnO2 appeared when the pH value decreased to 5. All the products were γ-MnO2 when the pH value decreased to 3. With the increase of Mn2+ concentration, the grain size decreased and agglomeration was easy to occur. The optimum conditions were obtained as follows: the temperature was 30℃, pH was 3, reaction time was 90 min, the mole ration of H2O2 to Mn2+ was 1:1, and Mn2+ concentration was 10g/L. Under the optimum conditions, γ-MnO2 with high specific surface area (172.41 m2/g) was prepared. This γ-MnO2 has a good adsorption effect on Co and Ni in manganese ore leaching solution, and the adsorption efficiency could be reached 94.75 % and 95.67 %. This study would provide a reference for the preparation of manganese oxides with different physical and chemical properties.