Effect of biochar amendment on nutrient fluxes during manure fermentation

Biochar is a charred organic matter often used as a soil amendment. Among other beneficial applications in agriculture belongs to its usage as an additive and bulking agent in composting. The biochar amendment to manure has the potential to reduce greenhouse gas emissions and nutrient leaching during the composting process. Biochar addition reduces NH3 and N2O emissions from manure. Recent studies showed that maximal ammonium sorption occurs on low pyrolysis temperature (400 °C) biochar at near neutral pH (7.0–7.5). Consequential lower NH3 emission is explained due to the greater incorporation of ammonium (NH4+) in organic compounds during microbial utilization of dissolved organic carbon (DOC). Both facts are related to findings that low-temperature biochar have a much higher content of utilizable carbon as well as less low molecular weight (LMW) acids. However, the knowledge of the impact of biochar on the mineralization of manure is still sparse. More studies about the effects of biochar on both nitrification and denitrification processes during composting are needed. The main interest of our studies was the transformation of organic nitrogen during the fermentation process of biochar-amended manure. A small-scale FYM- experiment for monitoring the fermentation of FYM amended by various amounts of biochar was designed and carried out in 50 litters tightly closed barrels. Each of these barrels was filled up with 20 kg of FYM, biochar was added in some barrels in amounts corresponding to particular variants. All variants were prepared in five replicates. The experimental variants were as follows: [1] control FYM; [2] FYM + biochar 40 g.kg-1; [3] FYM + biochar 100 g.kg-1; [4] FYM + biochar 200 g.kg-1. The portion of 17 g of biochar closed in a polyurethane bag was inserted in each barrel containing biochar as a control sorption matrix for monitoring of time-course microbial and chemical enrichment of biochar. These biochar samples served also for monitoring of changes in surface structure and chemical parameters. The fermentation process was run for 6 weeks on a shaded place (stables), a concentration of NH4+ was periodically measured. FYM was sampled at time 0, 13, 27, and 41 days from the start of the experiment. pH values and the dry mass were estimated, chemical analyses of nutrients (N, P, K) were done. Microbial biomass was quantified via qPCR SYBR-green methods for estimation of: 16S rDNA copy number (bacteria), 18S rDNA (fungi), amoA gene copy number (ammonium oxidizing bacteria - AOB). The results showed that amoA copy number and concentration of NH4+ changes indirectly to the increasing amount of amended biochar whereas the nitrogen content is comparable between all variants. Differences in amounts of bacteria, Actinomycetes, and fungi may indicate biochar-mediated changes in utilization of nutrient sources and in mineralization of organic nitrogen and carbon. The abundance of methanogenic microflora (quantified by qPCR) significantly increased during the fermentation process but possible methane formation was putatively mitigated by the addition of biochar, thus the variants amended with high amount of biochar exerted lower methanogen-specific 16S rDNA values. The FYM-biochar fermentation technology is intended to produce superior quality FYM type fertilizer enriched with nutrients (thus reduced production of greenhouse gases should protect nutrition elements from volatilization) and to produce beneficial soil amendment biochar, which might be activated by structural changes mediated during the FYM fermentation via the activity of microorganisms. Thus, the aim of ongoing study is also the development of an efficient method for the bio-activation of biochar. Aknowledgements: The work was supported by the project of Technology Agency of the Czech Republic TH03030319: „Promoting the functional diversity of soil organisms by applying classical and modified stable organic matter while preserving the soil\u27s production properties”

Silver nanoparticles (AgNPs) in urea solution in laboratory tests and field experiments with crops and vegetables

Nanotechnology and nanomaterials, including silver nanoparticles (AgNPs), are increas-ingly important in modern science, economics, and agriculture. Their biological activity involvesinfluencing plant health, physiological processes, growth, and yields, although they can also be toxicin the environment. A new fertiliser was made based on a urea solution with a relatively low contentof AgNPs obtained by the reduction of silver nitrate V. Laboratory tests were used to assess theeffect of a fertiliser solution containing 10 ppm AgNPs on the germination of agricultural plant seeds(barley, peas, oilseed rape) and vegetables (radish, cucumber, lettuce) and its foliar application onchlorophyll content, stomatal conductance, and seedling biomass. Field experiments were conductedto assess the effect that a foliar application of 15 ppm AgNPs in working liquid had on physiologicalplant parameters and yields of rape and cucumber. The AgNPs in the tested fertiliser reducedinfestation of the germinating seeds by pathogens and positively affected the physiological processes,productivity, and yields of plants. Plant response depended on plant species and habitat conditions.Reduced pathogen infestation of seeds, higher germination energy, increased chlorophyll content andstomatal conductance, and higher seedling masses all occurred under the influence of AgNPs, mainlyin oilseed rape and cucumber, and especially under thermal stress. The beneficial effect of AgNPson the yield of these plants occurred in years of unfavourable weather conditions. The positiveagricultural test results, especially under stress conditions, indicate that fertiliser produced withAgNPs as an ingredient may reduce the use of pesticides and highly concentrated mineral fertilisers.Such a fertiliser is fully in line with the idea of sustainable agriculture. However, research on theeffects that AgNPs and fertiliser have on the environment and humans should continue

Green and non-mechanical method for production of colloidal-size biochar from agriculture waste

Soil is an important source of nutrient and habitat to microflora. During the past 40 years’, the world has lost one-third of its arable land due to an increase in the human population, excessive use of chemical fertilizers, and erosion. There is an urgent need to maintain sustainable approaches in agriculture system. Application of biochar as a soil amendment is a promising approach to improve soil physical, chemical, biological, and hydrological properties. In recent year’s special attention has been focused on pyrolysis condition of biomass, although properties can also be enhanced by the reduction in particle size. Small-size biochar attracts increasing interest due to its unique environmental behavior. This research presents a physical method to modify biochar by ultrasonic radiation to produce colloidal size biochar. Agriculture waste biochar (1 cm) was used as a starting material. We used Malvern sonicator “Hydro 2000MU“ of 20Hz frequency. Biochar (5gram) was added to 100 ml of deionized water and sonicated for 5 hr; after every 15 min of run time, sonicator was stoped for the next 15 min. Please click Additional Files below to see the full abstract

Biochar activated by nutrient- and microorganisms-enriched liquids as a soil amendment

Biochar is very stable in nature and lasts for thousands of years. Biochar addition to soil positively affects the ecosystem, such as soil fertility and biological activity. Adding biochar to soil do not always increases soil activity. Studies have shown that biochar may also have a negative impact on soil microflora. Although biochar provides nutrients and mineralizable carbon to soil microorganism, due to its strong adsorption power, it pulls out soil nutrients away from the soil and may show a negative effect on soil microflora and rhizosphere. Modification of biochar is important to avoid its adverse effects. Physical and chemical modifications are a common method for the activation of biochar. Chemical modification has more advantage than a physical modification in term of porosity, greater surface area, less aromatic compound, and more oxygen-containing group. Chemical modification of biochar requires the use of strong chemicals which increase the risk to environment pollution. In the modern time with the increasing pollution, there is a demand for a low-cost green method to activate biochar, beneficial to the farmers and the environment. Uncommon biological activation of biochar fits in all the above aspects. The specific aim of this study is to develop a low-cost and more environment-friendly method for activation of biochar. For the study, biochar prepared from plant residues was used for activation. Two weeks bathing of biochar was done in liquid enriched with nutrients and beneficial microorganisms. 15 gram of biochar was taken in a sealed polyurethane bag and dipped in each beaker containing nutrients enriched activation liquid and also in a beaker containing distilled water as a control. The variants of the experiment according to a type of used liquid were: [1] Distilled water (non-activated), [2] Medium M9, [3] M9 + Rewital Biogen Pro+ (commercial concentrate of helper soil and plant microorganisms). The activation liquid variant [2] Medium M9, contains dextrose as carbon source, Ammonium chloride (nitrogen), phosphate (phosphorus), sulfur, potassium, and magnesium. The activation liquid of variant [3] was prepared by inoculating medium M9 with Rewital Biogen Pro+ and incubated for three days at room temperature and under intense exposure to air. The activation liquids in a 500-ml bottle were aerated for 14 days at room temperature. Values of pH and glucose concentration were measured at the beginning and the end of the activation. Activated biochar was tested as a soil amendment for its beneficial microbial enrichment in a pot plant growth experiment with lettuce (Lactuca sativa) seedlings. Activated biochar of all three variants was amended to the soil, negative control without biochar amendment was also prepared, sowed with lettuce seeds and grown under white light (20 000 lux) in phytotron (a 12 h photoperiod, temperature 18/22 °C (night/day), relative humidity 70%). After 42-days growth, the plants were harvested, the biomass of plants from all variants compared, and the biological parameters of soil at the beginning and the end of the experiment compared. Biological parameter compared were microbial biomass carbon (MBC), soil dehydrogenase activity (DHA) and soil microbial community abundance was determined by 16S rDNA (bacteria) and 18S rDNA (fungi), amoA gene (ammonium monooxygenase), nxr gene (nitrite oxidoreductase) and nirS gene (nitrite reductase). From the overall result, it can be concluded that the number of bacteria, fungi, and values of microbial carbon and dehydrogenase activity in soil samples of all variants were comparable. The biomass of harvested lettuce seedlings does not show a significant difference. However, a significant increase (more than 2-fold) in the amoA gene were found for soil samples treated with variant [3] . Acknowledgments: The work was supported by the project of Technology Agency of the Czech Republic TH03030319: „Promoting the functional diversity of soil organisms by applying classical and modified stable organic matter while preserving the soil\u27s production properties

Amalgam Electrode-Based Electrochemical Detector for On-Site Direct Determination of Cadmium(II) and Lead(II) from Soils

Toxic metal contamination of the environment is a global issue. In this paper, we present a low-cost and rapid production of amalgam electrodes used for determination of Cd(II) and Pb(II) in environmental samples (soils and wastewaters) by on-site analysis using difference pulse voltammetry. Changes in the electrochemical signals were recorded with a miniaturized potentiostat (width: 80 mm, depth: 54 mm, height: 23 mm) and a portable computer. The limit of detection (LOD) was calculated for the geometric surface of the working electrode 15 mm(2) that can be varied as required for analysis. The LODs were 80 ng.mL(-1) for Cd(II) and 50 ng.mL(-1) for Pb(II), relative standard deviation, RSD <= 8% (n = 3). The area of interest (Dolni Rozinka, Czech Republic) was selected because there is a deposit of uranium ore and extreme anthropogenic activity. Environmental samples were taken directly on-site and immediately analysed. Duration of a single analysis was approximately two minutes. The average concentrations of Cd(II) and Pb(II) in this area were below the global average. The obtained values were verified (correlated) by standard electrochemical methods based on hanging drop electrodes and were in good agreement. The advantages of this method are its cost and time effectivity (approximately two minutes per one sample) with direct analysis of turbid samples (soil leach) in a 2 M HNO3 environment. This type of sample cannot be analyzed using the classical analytical methods without pretreatment.O

Immobilization of potentially toxic elements (PTE) by mineral-based amendments: Remediation of contaminated soils in post-industrial sites

In many post-industrial sites, the high contents and high mobility of different potentially toxic elements (PTEs) make the soils unsuitable for effective management and use. Therefore, immobilization of PTE seems to be the best remediation option for such areas. In the present study, soil samples were collected in post-industrial areas in Northeastern Poland. The analyzed soil was characterized by especially high contents of Cd (22 mg·kg−1), Pb (13 540 mg·kg−1), and Zn (8433 mg·kg−1). Yellow lupine (Lupinus luteus L.) and two types of mineral-based amendments were used to determine their combined remediation effect on PTE immobilization. A greenhouse pot experiment was conducted to evaluate the influence of chalcedonite and halloysite on plant growth, chlorophyll a fluorescence, the leaf greenness index (SPAD), PTE uptake, and the physicochemical properties and toxicity of soil. The application of chalcedonite resulted in the greatest increase in soil pH, whereas halloysite contributed to the greatest reduction in the contents of Ni, Pb, Zn, and Cr in soil, compared with the control treatment. The addition of halloysite significantly increased plant biomass. The application of mineral-based amendments increased the ratio of variable fluorescence to maximum chlorophyll fluorescence (Fv/Fm) in yellow lupine leaves. The leaf greenness index was highest in plants growing in soil amended with chalcedonite. The results of this study suggest that mineral-based amendments combined with yellow lupine could potentially be used for aided phytostabilization of multi-PTE contaminated soil in a post-industrial area

Successful outcome of phytostabilization in Cr(VI) contaminated soils amended with alkalizing additives

This study analysed the effect of three alkalizing soil amendments (limestone, dolomite chalcedonite) on aided phytostabilization with Festuca rubra L. depending on the hexavalent chromium (Cr(VI)) level in contaminated soil. Four different levels of Cr(VI) were added to the soil (0, 50, 100 and 150 mg/kg). The Cr contents in the plant roots and above-ground parts and the soil (total and extracted Cr by 0.01 M CaCl2) were determined with flame atomic absorption spectrometry. The phytotoxicity of the soil was also determined. Soil amended with chalcedonite significantly increased F. rubra biomass. Chalcedonite and limestone favored a considerable accumulation of Cr in the roots. The application of dolomite and limestone to soil contaminated with Cr(VI) contributed to a significant increase in pH values and was found to be the most effective in reducing total Cr and CaCl2-extracted Cr contents from the soil. F. rubra in combination with a chalcedonite amendment appears to be a promising solution for phytostabilization of Cr(VI)-contaminated areas. The use of this model can contribute to reducing human exposure to Cr(VI) and its associated health risks. © 2020 by the authors.Ministerstwo Nauki i Szkolnictwa Wyższego: MNiS

Anticarcinogenic effect of spices due to phenolic and flavonoid compounds-in vitro evaluation on prostate cells

This study shows the effects of spices, and their phenolic and flavonoid compounds, on prostate cell lines (PNT1A, 22RV1 and PC3). The results of an MTT assay on extracts from eight spices revealed the strongest inhibitory effects were from black pepper and caraway seed extracts. The strongest inhibitory effect on prostatic cells was observed after the application of extracts of spices in concentration of 12.5 mg.mL- 1. An LC/MS analysis identified that the most abundant phenolic and flavonoid compounds in black pepper are 3,4-dihydroxybenzaldehyde and naringenin chalcone, while the most abundant phenolic and flavonoid compounds in caraway seeds are neochlorogenic acid and apigenin. Using an MTT assay for the phenolic and flavonoid compounds from spices, we identified the IC50 value of ~1 mmol.L- 1 PNT1A. The scratch test demonstrated that the most potent inhibitory effect on PNT1A, 22RV1 and PC3 cells is from the naringenin chalcone contained in black pepper. From the spectrum of compounds assessed, the naringenin chalcone contained in black pepper was identified as the most potent inhibitor of the growth of prostate cells.O

The role of carbonate-fluoride melt immiscibility in shallow REE deposit evolution

The Lugiin Gol nepheline syenite intrusion, Mongolia, hosts a range of carbonatite dikes mineralized in rare-earth elements (REE). Both carbonatites and nepheline syenite-fluoritecalcite veinlets are host to a previously unreported macroscale texture involving pseudographic intergrowths of fluorite and calcite. The inclusions within calcite occur as either pure fluorite, with associated REE minerals within the surrounding calcite, or as mixed calcitefluorite inclusions, with associated zirconosilicate minerals. Consideration of the nature of the texture, and the proportions of fluorite and calcite present (~29 and 71 mol%, respectively), indicates that these textures most likely formed either through the immiscible separation of carbonate and fluoride melts, or from cotectic crystallization of a carbonatefluoride melt. Laser ablation ICP-MS analyses show the pure fluorite inclusions to be depleted in REE relative to the calcite. A model is proposed, in which a carbonate-fluoride melt phase enriched in Zr and the REE, separated from a phonolitic melt, and then either unmixed or underwent cotectic crystallization to generate an REE-rich carbonate melt and an REE-poor fluoride phase. The separation of the fluoride phase (either solid or melt) may have contributed to the enrichment of the carbonate melt in REE, and ultimately its saturation with REE minerals. Previous data have suggested that carbonate melts separated from silicate melts are relatively depleted in the REE, and thus melt immiscibility cannot result in the formation of REE-enriched carbonatites. The observations presented here provide a mechanism by which this could occur, as under either model the textures imply initial separation of a mixed carbonate-fluoride melt from a silicate magma. The separation of an REE-enriched carbonate-fluoride melt from phonolitic magma is a hitherto unrecognized mechanism for REE-enrichment in carbonatites, and may play an important role in the formation of shallow magmatic REE deposits