Search

The paper analyzes an array of scientific literature data in the field of studying methods for increasing microbial diversity of agricultural soils. The variety of biological products used in agriculture has been studied. Some biological products approved for use in the Russian Federation are given. The importance of hub species for the biodiversity of the rhizobiome of plants has been revealed. Approaches to obtaining of high-efficiency bioproducts are considered. The necessity of creating biological products to restore the microbial diversity of agricultural soils using hub species is substantiated.

In this study, contamination levels and ecotoxicity in 29 urban soils in two medium-sized Finnish cities, Lahti and Joensuu were evaluated. It was established that Cd concentration exceeded the natural background level in all soils tested. The estimated number of soil samples contaminated with Pb, Ni, Cu and Zn was 1, 3, 1 and 23 respectively. The total content of polyaromatic hydrocarbons (⅀16PAH) was analyzed in urban soil samples. It was found that in soils ⅀16PAH ranged from 23.78 to 831.42 ng*g-1 (Lahti) and from 14.38 to 1173.95 ng*g-1 (Joensuu). No correlation was found between the levels of total metals and total PAHs. Ecotoxicity was analyzed by bioassay of elutriate using Paramecium caudatum (R = 0.75). The ecotoxicity index levels (LID10) ranged from 1 to 40. A strong correlation was observed between total metal content and soil ecotoxicity levels.

Biochar is a product of oxygen-free thermal decomposition of biomass and refers alternative fertilizers. Data on the carbon footprint of agricultural products obtained using different types of biochars are not enough to date. The purpose of this study was to compare the carbon footprint of wheat of the grade "Yoldyz-Elita", grown using mineral fertilizers "Diamofoska" and biochar. Biochar was received from chicken manure, the pyrolysis process was at 400ºC, for 2 hours. Biochar was added in an amount of 30 t/ha, mineral fertilizers "Diamofoska" in an amount of 300 kg/ha, respectively. Calculations the carbon footprint included data on fuel consumption and N2O emission from mineral fertilizers, CO2 emission from soil (respiration activity), data on C fixation in biomass of wheat plants and in biochar. It was demonstrated that the use of biochar led to an increase in total soil carbon by 28% by the end of the field experiment. The application of biochar led to an increase in wheat yield by 2.5 times that was similar to the yield with application of mineral fertilizers. It was found that the main contribution to the carbon footprint of wheat was the respiration activity of the soil (up to 95%). The volume of CO2 from fuel used by agricultural machinery was insignificant (0.5% of the total CO2 emissions), soil cultivation with mineral fertilizers increased CO2 emissions by 3%. The use of biochar as an organomineral fertilizer led to a 79% decrease in the carbon footprint of wheat. Thus, biochar from chicken manures may be recommended to reduce the carbon footprint of wheat.

Amendment of soil with biochar instead of mineral or organic fertilizers might be one of techniques wich reduce carbon dioxide emissions into the atmosphere. The effect of biochar based on chicken manure on the biomass and respiratory activity of agricultural soil microorganisms was evaluated in lab conditions at normal (average climatic norm for the vegetation season in central Russia, 15 °C) and elevated (25 and 35 °C) temperatures. It was shown that the introduction of 10% biochar by mass did not lead to an increase emission of CO2 from the soil relative to the control at 15 °C for 60 days of the experiment. An increase in temperature caused an increase in carbon dioxide emissions from the control soil by 35% and 91% and a decrease in moisture by 24% and 42% at 25 and 35°C, respectively. Microbial biomass increased in the control soil by 32% at 25°C and decreased by 34% at 35°C. Soil amendment with biochar led to the leveling of the effect of elevated temperatures on all three parameters. Thus, biochar made from chicken manure allowed one of the characteristics of soil fertility to be preserved and did not lead to the loss of greenhouse gases.

The purpose of this work was to evaluate the possibility of increasing the CO2 sequestration of hemp in the conditions of urban growth in central Russia by introducing non-traditional fertilizers from agricultural waste. For this, an experiment was carried out on the cultivation of industrial hemp, including the application of fertilizers (biochar, compost, a mixture of biochar and compost). Morphometric indicators, biomass, and chlorophyll content were measured. The absence of a significant effect of fertilizers on morphological (the length of the ground part, the length of the root, biomass) and physiological (chlorophyll content) characteristics was established. Based on the data of the “Register of Green Spaces”, the area of green spaces in Kazan was determined, which can be occupied by hemp (landscaping along roads, sanitary protection zones) – 630.8 hectares. It has been established that it is most expedient to plant hemp using biochar, since this method allows additional carbon sequestration and reduces CO2 emissions from transport by up to 4% per growing season.CO2 is a greenhouse gas with a minimal Global Warming Potential (GWP), however, its contribution to climate change is high due to the large mass of emissions. At the same time, at the moment there are technologies for capturing CO2. However, there is not enough information in the literature about the use of supersequestrator plants such as industrial hemp (Cannabis sativa L., 1753) in large cities to reduce the carbon footprint, and there is practically no data on how sequestration can be increased through the use of various fertilizers, for example biochar.

Sustainable agriculture involves the maximum use of the resource potential of the earth, with the constant renewal of the fertility of the ecosystem. One method of transition to sustainable agriculture is the use of biological control agents, which include biosurfactants. We assessed the possibility of using crude biosurfactants obtained from Bacillus subtilis H1 and Pseudomonas aeruginosa PAO1 as dressing agents for untreated wheat seeds and the presence of seed germination stimulating properties. It was shown that crude rhamnolipids obtained from Pseudomonas aeruginosa PAO1 inhibited the area occupied by fungal mycelia at a concentration of 500 mg/l. Surfactin, derived from Bacillus subtilis H1, inhibited fungal growth at a concentration of 100 mg/L. Stimulation of germination of wheat seeds by 1.9 and 2 times was determined by rhamnolipid at a concentration of 500 mg/l and surfactin at a concentration of 100 mg/l for 168 hours of germination. The use of biocontrol agents is a promising method that can improve product quality while reducing the negative impact on the environment.

Plant fungal diseases cause up to 15-20% and, in extreme cases, up to 60% yield loss globally. The use of chemical pesticides for the suppression of fungal plant diseases has many negative consequences for the environment. Therefore, new alternatives to suppress fungal pathogens are actively sought. In this present study, biosurfactants produced by the novel strain of Bacillus subtilis H1 were monitored for their ability to inhibit the growth of phytopathogens Fusarium oxysporum f. sp. lycopersici and Alternaria spp in in vitro and in vivo experiments. In the in vitro experiment, the treatment of tomato leaves with a biosurfactant fully inhibited the growth of F. oxysporum, and reduced the growth of Alternaria spp mycelium by 11.5 times at a concentration of 1000 mg/l. In the in vivo experiment, the use of a biosurfactant reduced the degree of damage to tomato and wheat plants, but less than in the in vitro experiment. In the case of tomato leaves infected with F. oxysporum and Alternaria spp and treated with 1000 mg/l biosurfactants, a decrease of 2.6 and 2.1 times was determined relative to infected but intreated leaves. For wheat leaves, the decrease was by 1.6 and 2.0 times, respectively. It can be concluded that biosurfactants produced by B. subtilis H1 are promising to be used for fungal pathogens biocontrol.

The search for new biodegradable fertilizers to increase the productivity of agricultural plants is an urgent task. In this study, a complex microfertilizer was developed based on a chelating agent—glutamic-N,N-diacetic acid (GLDA). The evaluation encompassed assessments of biodegradability and effectiveness in fostering lettuce plant growth in hydroponic and conventional soil settings. The impact on endospheric bacteria, a sensitive indicator, was also examined. Results indicated a 59.8% degradation rate of the GLDA complex on the 28th day. The most notable positive effects were observed in above-ground plant biomass, with a 4.6-fold increase for hydroponics and 1.5 to 1.8-fold increases for root and foliar treatments in soil. In hydroponics, GLDA-treated plants showed 24 and 45 operational taxonomic units (OTUs) for leaves and 272 and 258 for roots (GLDA-treated and control plants). In soil, the OTU counts were 270 and 101, 221 and 111, and 198 and 116 in the leaves and roots of GLDA-treated and control plants (under root and foliar treatments), respectively. Non-metric multidimensional scaling (NMDS) and Indicator Species Analysis (ISA) demonstrated significant distinctions in endospheric communities between substrates (hydroponics and soil) in the presence of GLDA. Importantly, GLDA use simplified the composition of endospheric bacterial communities. [ABSTRACT FROM AUTHOR]

Despite the many papers published on oilfield ecosystems, there is a lack of data about microbial community structure and functioning in many crude oils or oilfields and wells. One of such poorly studied oilfields is supergiant Romashkino situated in Tatarstan (Russia). In the present study, prokaryotic community composition and abundance of functional genes encoding sulfate reduction and rhamnolipid production, was investigated in enrichment cultures of four samples from Romashkino oilfield production wells with different oil/water ratios. The enrichment was conducted under anaerobic conditions, sulfate and nitrate were used as electron acceptors, and acetate – as an electron donor. In enrichment culture A and enrichment culture B, bacteria of the Pseudomonadaceae family predominated with 99% and 93% relative abundance, respectively. In enrichment culture C (obtained on the basis of initial sample contained oil with medium water content) and D (obtained on the basis of initial sample contained oil with very high water content), Pseudomonadaceae were one of the two predominating families, along with Micrococcaceae (enrichment culture C) and Dietziaceae (enrichment culture D). The proportion of dsrA and apsA genes encoding sulfate reduction to 16S rRNA gene copy numbers was quite low and ranged between 0.003% (enrichment cultures A, B) and 0.027% (enrichment culture D). The proportion of rhlB gene encoding rhamnolipid production from the total 16S rRNA gene copy number was 1.10% in sample A and 0.06% in sample B. In enrichment cultures C and D the rhlB gene was not found. [ABSTRACT FROM AUTHOR]

Pyrolysis processes and products have yet to be studied fully, and information about chicken‐manure (CM) pyrolysis is especially poor. In the present study, biochar obtained from two CM samples at different residence times (1–4 h) and peak temperatures (400–800°C) was investigated. It was found that pH ranged between 6.8–10.3 and 6.6–11.6; EC between 1.8–3.9 and 1.2–11.9 mSm/cm; CEC between 30.0–65.6 and 15.2–146.9 cmol/kg; C, N, P, and K contents between 9.5–25.6% and 15.7–61.2%, 0.7–2.8% and 1.5–6.4%, 1.7–2.7% and 2.5–5.6%, 0.9–2.1% and 1.3–3.6%, respectively; ecotoxicity (LID10) towards aquatic organisms between 1–40 and 1–66; germination indices between 189–353% and 54–265%; and surface areas between 0.1–0.7 and 0.1–0.3 m2/cm3 for the second and first samples of CM, correspondingly. The multiobjective optimization method was used to analyse the results obtained and to choose the pyrolysis regimes that result in the biochar with the highest fertilizing ability. [ABSTRACT FROM AUTHOR]