Ammonium Nitrate Research Articles

Assessment of the presence of nitrates and other chemicals in soil and in maize plants by nitrogen fertilization

The main purpose of this study was to evaluate the effect of nitrogen fertilization, with different levels and type of fertilizers, on the agrochemical evolution of the soil superficial horizon and on nitrates levels in maize leaves in different growth stages (5 leaves, flowering and milk maturity). Two type of nitrogen fertilizers (Ammonium nitrate and Urea) and five nitrogen levels (80 kg/ha; 120 kg/ha; 200 kg/ha and 240 kg/ha) were applied in experimental trails. Filed experiments were conducted at the Agricultural Research and Development Station (ARDS) of Suceava, Romania, during years 2021 and 2022. The pH of the soil in the conditions of fertilization with ammonium nitrate, was acid with values between 4.88—4.65 in the first vegetation stages, and between 4.36—4.3 at the end of the vegetation period. Referring to response of maize plant to the fertilization levels and type of fertilizers showed some influences on chemical content of maize leaves in different growth stages. Concerning the presence of nitrates in maize plants, this study showed that the nitrates contents was highest in the first growth stage of maize plants, particularly when ammonium nitrate fertilizer was used.

The Impact of Bacillus coagulans X3 on Available Nitrogen Content, Bacterial Community Composition, and Nitrogen Functional Gene Levels When Composting Cattle Manure

Nitrogen loss is an unavoidable problem during organic waste composting, while exogenous microbial inoculation is a promising strategy for reducing nitrogen loss and improving compost quality. This study was designed to probe available nitrogen levels, bacterial community composition, and the levels of nitrogen functional genes present when composting cattle manure with or without the addition of Bacillus coagulans X3. Bacterial supplementation was associated with the prolongation of the thermophilic stage and improved maturity of the resultant compost. At the maturity stage, samples to which B. coagulans X3 had been added exhibited significant increases in ammonium nitrogen, nitrate nitrogen, and total nitrogen levels. The dominant bacterial phyla observed in these composting samples were Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteriota, and Chloroflexi. B. coagulans X3 addition resulted in significant increases in relative Firmicutes abundance during the thermophilic and cooling stages while also increasing amoA and nosZ gene abundance and reducing nirS gene levels over the course of composting. Together, these data suggest that B. coagulans X3 supplementation provides an effective means of enhancing nitrogen content in the context of cattle manure composting through the regulation of nitrification and denitrification activity.

Enhancing Phytoextraction Potential of Brassica napus for Contaminated Dredged Sediment Using Nitrogen Fertilizers and Organic Acids.

Dredged sediment contaminated with heavy metals can be remediated through phytoremediation. The main challenge in phytoremediation is the limited availability of heavy metals for plant uptake, particularly in multi-contaminated soil or sediment. This study aimed to assess the effect of the nitrogen fertilizers (ammonium nitrate (AN), ammonium sulfate (AS), and urea (UR)), organic acids (oxalic (OA) and malic (MA) acids), and their combined addition to sediment on enhancing the bioavailability and phytoremediation efficiency of heavy metals. The sediment dredged from Begej Canal (Serbia) had high levels of Cr, Cd, Cu, and Pb and was used in pot experiments to cultivate energy crop rapeseed (Brassica napus), which is known for its tolerance to heavy metals. The highest accumulation and translocation of Cu, Cd, and Pb were observed in the treatment with AN at a dose of 150 mg N/kg (AN150), in which shoot biomass was also the highest. The application of OA and MA increased heavy metal uptake but resulted in the lowest biomass production. A combination of MA with N fertilizers showed high uptake and accumulation of Cr and Cu.

Interactions between halotolerant nitrogen-fixing bacteria and arbuscular mycorrhizal fungi under saline stress.

Soil salinity negatively affects crop development. Halotolerant nitrogen-fixing bacteria (HNFB) and arbuscular mycorrhizal fungi (AMF) are essential microorganisms that enhance crop nutrient availability and salt tolerance in saline soils. Studying the impact of HNFB on AMF communities and using HNFB in biofertilizers can help in selecting the optimal HNFB-AMF combinations to improve crop productivity in saline soils. We established three experimental groups comprising apple plants treated with low-nitrogen (0 mg N/kg, N0), normal-nitrogen (200 mg N/kg, N1), and high-nitrogen (300 mg N/kg, N2) fertilizer under salt stress without bacteria (CK, with the addition of 1,500 mL sterile water +2 g sterile diatomite), or with bacteria [BIO, with the addition of 1,500 mL sterile water +2 g mixed bacterial preparation (including Bacillus subtilis HG-15 and Bacillus velezensis JC-K3)]. HNFB inoculation significantly increased microbial biomass and the relative abundance of beta-glucosidase-related genes in the rhizosphere soil under identical nitrogen application levels (p < 0.05). High-nitrogen treatment significantly reduced AMF diversity and the relative abundance of beta-glucosidase, acid phosphatase, and urea-related genes. A two-way analysis of variance showed that combined nitrogen application and HNFB treatment could significantly affect soil physicochemical properties and rhizosphere AMF abundance (p < 0.05). Specifically, HNFB application resulted in a significantly higher relative abundance of Glomus-MO-G17-VTX00114 compared to that in the CK group at equal nitrogen levels. The impact of HNFB on the AMF community in apple rhizospheres is influenced by soil nitrogen levels. The study reveals how varying nitrogen levels mediate the relationship between exogenous HNFB, soil properties, and rhizosphere microbes.

Indirect mineral carbonation of recycled concrete aggregate: Enhancing calcium extraction using a packed bed reactor

Mineral carbonation of industrial residues is gaining increasing interest, with the first pilot and industrial-scale applications being implemented. The process offers a low-risk, easily available solution for permanent carbon dioxide storage while concurrently valorising industrial wastes. This work investigates the indirect mineral carbonation of recycled concrete aggregate (RCA), in which calcium is first leached from the RCA into an aqueous ammonium nitrate (AN) solution, followed by carbonation to yield high-purity precipitated calcium carbonate. The study focuses on the first step, calcium dissolution, which traditionally takes place in a stirred batch reactor (SBR). However, SBRs often encounter solubility constraints, leading to low calcium extraction yields. In this investigation, we explore the application of a packed bed reactor (PBR) and demonstrate its superior performance, resulting in a calcium extraction enhancement of 27% to 55% relative to SBRs, across AN concentrations ranging from 0.25 to 2.0 mol/kg, at 25 °C and atmospheric pressure. The PBR’s superior performance can be attributed to the more compact design, enabling longer dissolution times, and to the continuous supply of fresh solvent, effectively reducing solubility limitations. The impact of key operating parameters (AN concentration, liquid flow rate and extraction time) are systemically assessed experimentally, accurately modelled using a shrinking-core model, and illustrated in process performance maps. Furthermore, this research highlights the significance of ammonium nitrate recovery from the wet solids after filtration to ensure the process’s environmental viability. The packed bed reactor (PBR) functions as an integrated filter, facilitating the straightforward recovery of 80% of the trapped ammonium nitrate solution through simple water flushing. In conclusion, the utilisation of PBRs in indirect mineral carbonation presents an innovative and efficient approach for enhancing calcium extraction while addressing environmental concerns through ammonium nitrate recovery. The applicability of PBRs extends beyond recycled concrete aggregates, and could also be successfully applied for other coarse industrial residues such as steel slags.

Monitoring ammonia concentrations in more than 10 stations in the Po Valley for the period 2007–2022 in relation to the evolution of different sources

Regarding secondary aerosols, in addition to the significant contribution of anthropogenic gases such as NOx and SO2, atmospheric ammonia (NH3) plays a crucial role as the primary basic gaseous species capable of neutralizing acidic compounds. This acid–base reaction is responsible for the formation of ammonium nitrate (NH4NO3), constituting up to 60% of PM10 within the Po River basin in Italy. Ion chromatographic analyses performed on offline samples indicate that this secondary inorganic species exhibits minimal concentration variability over the Po Valley because of limited air circulation due to orography and mesoscale air circulation. Therefore, investigating gaseous precursors becomes crucial. From the northern to the southern part of Lombardy—the region at the center of the basin—NH3 emission amounts account for 2.5, 11.1, and 27.7 t/y/km2, mainly due to agriculture and livestock activities (∼97%). To study NH3 temporal and spatial variability, the Environmental Protection Agency of Lombardy Region has been monitoring NH3 concentrations across its territory since 2007, with 10 active monitoring sites. Annual and seasonal cycles are presented, along with a focus on different stations, including urban, low-mountain background, high-impact livestock, and rural background, highlighting the impact of various sources. Measurements indicate that within the Po basin, NH3 concentrations can reach up to 700 µg/m3 (as an hourly average) in proximity to the main gaseous NH3 source. Instrument intercomparisons among online monitors and passive vials, as well as different online monitors, are presented. Therefore, this paper provides crucial data to understand the formation of secondary inorganic aerosols in one of the most important hotspot sites for air pollution.

The Effect of the Solution Flow and Electrical Field on the Homogeneity of Large-Scale Electrodeposited ZnO Nanorods.

In this paper, we demonstrate the significant impact of the solution flow and electrical field on the homogeneity of large-scale ZnO nanorod electrodeposition from an aqueous solution containing zinc nitrate and ammonium nitrate, primarily based on the X-ray fluorescence results. The homogeneity can be enhanced by adjusting the counter electrode size and solution flow rate. We have successfully produced relatively uniform nanorod arrays on an 8 × 10 cm2 i-ZnO-coated fluorine-doped tin oxide (FTO) substrate using a compact counter electrode and a vertical stirring setup. The as-grown nanorods exhibit similar surface morphologies and dominant, intense, almost uniform near-band-edge emissions in different regions of the sample. Additionally, the surface reflectance is significantly reduced after depositing the ZnO nanorods, achieving a moth-eye effect through subwavelength structuring. This effect of the nanorod array structure indicates that it can improve the utilization efficiency of light reception or emission in various optoelectronic devices and products. The large-scale preparation of ZnO nanorods is more practical to apply and has an extremely broad application value. Based on the research results, it is feasible to prepare large-scale ZnO nanorods suitable for antireflective coatings and commercial applications by optimizing the electrodeposition conditions.

Improving the elements of cultivating technology for Sarepta mustard (Brassica juncea L.) on leached blackearth of Western Ciscaucasia

Increasing interest among agricultural producers in Sarepta spring mustard as a promising, multi-purpose crop requires improving the elements of its cultivation technology to obtain consistently high yields. The current study was carried out in 2021–2022 on the experimental fields of the central experimental base of the FSBSI “FRC “All-Russian Scientific Research Institute of Oil Crops by the name of Pustovoit V. S.”. The purpose of the research was to study and scientifically substantiate individual elements of the technology (sowing time, seed sowing rate and level of mineral nutrition) for Sarepta mustard’s cultivation on seed productivity of the crop grown on leached blackearth (chernozem) of Western Ciscaucasia. There has been established that the highest yield (1.42 t/ha) and oil yield (0.60 t/ha) of the crop is obtained at an early sowing time (the first term (early) is in the 2nd decade of April) with a minimum seed sowing rate (1.3 million units/ha). Sarepta spring mustard’s single feeding of with ammonium nitrate at a dose of N60 in the seedling phase has helped to obtain maximum yield of 2.08 t/ha and 0.87 t/ha of oil. But the largest oil content in seeds (47.1 %) was identified in the variant with the application of nitrogen fertilizer at a dose of N30 fractionally in equal parts, i.e. in the stages of germination (N15) and booting (N15). Foliar treatment of Sarepta spring mustard with helium mixtures (Micro gel at a dose of 1 l/ha and Brassica gel at a dose of 2 l/ha) in the booting stage allowed obtaining the highest yield of 1.85 t/ha, with 47.9 % of oil in seeds and 0.80 t/ha of oil yield.

CAN Interceded Oxidative Coupling of β‐Dicarbonyl Compounds to 2‐Aryl/Heteroarylchromenes: A Regio‐ and Diastereoselective Synthesis of Tetrahydro‐benzofuro[3,2‐c]chromenones

AbstractA promising and useful method has been accomplished for regio‐ and diastereoselective synthesis of tetrahydro‐benzofuro[3,2‐c]chromenones through ceric(IV) ammonium nitrate (CAN) mediated oxidative coupling of cyclic/acyclic 1,3‐dicarbonyl compounds to 2‐aryl/heteroarylchromenes followed by a base assisted cyclization. The significant features of the method encircle easy accessibility of the starting materials, high air stability and low toxicity of oxidant CAN, high product yield, operationally simple and eco‐friendly reaction conditions. Trapping of a radical intermediate with radical scavenger TEMPO (detected by LC–MS) from the reaction mixture proved that the oxidative coupling is a radical mediated process.

Effects of Complex Fertilizers on the Properties of Grey Forest Heavy Loamy Soil.

The study's main aim was to evaluate the effects of complex mineral fertilizers on the complex properties of heavy loam soils in the grey forests of Russia in terms of applying individual soil nutrition components from experiments with fodder beets. This study employed a rigorous and systematic approach to accomplish the defined goal. Specifically, the research was conducted within a seven-field crop rotation system, with fodder beets serving as the primary experimental crop. In addition, a model experiment resembling a vegetation trial was undertaken, incorporating seven distinct schemes involving various types of fertilizers. This design facilitated the evaluation of the effectiveness of each fertilizer type. The study results demonstrate that complex fertilizers impact the soil's chemical and biophysical parameters. Soil acidity decreases through the use of complex, high-nitrogen fertilizers. Major chemical nutrients (nitrogen, phosphorus, and potassium) in plant biomass and soil also have a high degree of transition. It is explained by the effects of combining elements on the destruction intensity of the crystalline lattice in the basic structures of potassium, phosphorus, and nitrogen. There is also evidence that complex fertilizers can improve humus quality and replenish its reserves. All the aforementioned impacts of complex fertilizers on the crop contribute to the high productivity and yield of forage beet. The results of the study may help optimize the fertilization process, improve the quality and quantity of agricultural products, as well as increase soil fertility, and reduce the negative impact of agrochemicals on the environment.

Dominant gastrointestinal strongylatosis in sheep in the context of the altitudinal zonation in Dagestan

The purpose of the research is to study the epizootology of the dominant gastrointestinal strongylatosis in sheep in different natural zones of Dagestan.Materials and methods. In 2005–2021, 180 forestomachs of the thin and thick sections of the digestive tract and 600 fecal samples from sheep at the altitude (above 2000 m above sea level) were studied based on dissection results. The study was performed by season among young animals aged up to 1 year, from 1 to 2 years and 3 years and older. The study used methods of complete helminthological dissection per K. I. Skryabin, larvae cultivation in a thermostat at 27 оC, and flotation with a saturated ammonium nitrate solution by Kotelnikov-Khrenov and Berman-Orlov.Results and discussion. Helminth infections are recorded among sheep annually on lowland, moist, steppe pastures of the plains and foothills in various combinations of multiple infections with the prevalence of 11.2–18.7% and the infection intensity of 18.5–186.4 sp./animal. In the mountain zone at altitudes above 2000 m above sea level, the quantitative and qualitative indicators of helminthosis pathogens were sharply limited. On these lands, dicrocoeliosis, monieziosis, larval echinococcosis, chabertiosis, haemonchosis, and nematodirosis were recorded in sheep with the prevalence of 3.2–10.4% and the infection intensity of 2.4–6.3 sp./animal. Gastrointestinal Strongylata dominate in sheep on all types of pastures in the lowland, foothill, and mountain zones: Chabertia ovina, Bunostomum trigоnocephalum, Trichostrongylus axei, T. capricola, T. colubriformis, T. vitrinus, Haemonchus contortus, Nematodirus filicollis, N. helvetianus, N. oiratianus, and N. spathiger.

Determining optimal range of reduction rates for nitrogen fertilization based on responses of vegetable yield and nitrogen losses to reduced nitrogen fertilizer application

Vegetable production is commonly accompanied by high nitrogen fertilizer rates but low nitrogen use efficiency in China. Reduced fertilization has been frequently recommended in existing studies as an efficient measurement to avoid large amount of nutrient loss and subsequent nonpoint source pollution. However, the reported responses of vegetable yield and nitrogen losses to reduced fertilization rates varied in a large range, which has resulted into large uncertainties in the potential benefits of those recommended reduction rates. Thus, we constructed the relationship between responses of nitrogen losses and vegetable yield to reduced nitrogen fertilization rates to determine the optimal range of reduction rates for nitrogen fertilization in a proportional form based on data reported in literatures across China's mainland, and evaluated the roles of greenhouse, managing options, and vegetable species on the responses. The relationships were constructed separately for 4 subregions: Northern arid and semiarid, loess plateau regions (NSL), Temperate monsoon zone (TMZ), Southeast monsoon zone (SMZ), Southwest zone (SWZ). The optimal nitrogen fertilizer reduction range for the TMZ, SMZ and SWZ were 51 % to 67 %, 40 % to 66 % and 54 % to 80 %, respectively and no reduction for NSL. Vegetable yields were not be sacrificed when fertilizations were reduced within the optimal ranges. Greenhouse and managing options showed no significant effect on the responses of both vegetable yield and nitrogen losses by the optimal reduction range but vegetable species played a relatively important role on the responses of vegetable yield. This indicated that the optimal reduction rates can be effective on reducing nitrogen loss in both open-field and greenhouse conditions across China's mainland without extra managing options. Therefore, the optimal reduction rates can still serve as a good starting point for making regional plans of nitrogen reduction that help balancing the chasing of high vegetable yield and low nitrogen loss.

Spacing of subsurface poultry litter bands: Influence on maize performance and nitrogen use efficiency

AbstractPoultry litter (PL) is traditionally surface broadcast to no‐till maize (Zea mays L.). PL is nutrient‐dense, and surface‐applied PL nitrogen (N) is vulnerable to losses to the atmosphere and water systems. An application method was developed by USDA‐ARS scientists for shallow subsurface banding PL to reduce ammonia (NH3) volatilization and surface runoff. There is limited information on how this application method will affect conservation and nutrient accessibility in no‐till maize. The objectives were to determine if adjusting PL lateral subsurface band placement in relation to maize rows affects nutrient use and maize yields. Treatments were a nontreated control (NTC), urea ammonium nitrate surface banded (Fert), poultry litter surface broadcast (PLBr), and three subsurface banded PL treatments. The subsurface PL treatments were one (PLSub1), two (PLSub2), or three (PLSub3) bands between maize rows. Treatments receiving N were applied at 180 kg total N ha−1. Nitrogen concentration in V4 aboveground dry matter was higher in PLSub1 than PLSub2. Aboveground dry matter yields for all PLSub treatments were greater than PLBr and comparable to Fert. The PLSub1 and PLSub2 treatments resulted in maize grain yields equivalent to Fert and greater than PLBr and NTC when averaged across years. Few differences were observed in postharvest soil sample nutrient concentrations between PLSub treatments. These results suggest that subsurface banding PL can conserve N and increase no‐till maize yield over traditional surface broadcast PL; however, increasing the frequency of subsurface PL bands did not clearly affect nutrient conservation or accessibility to the maize.

Modeling and simulation on spontaneous detonation of ammonium nitrate explosive induced by sulfide ores.

In this work, the characteristics of the exothermic reaction between ammonium nitrate and sulfide ores were explored using COMSOL Multiphysics. This reaction can cause an increase in temperature within the blast holes of sulfide mines and can potentially induce premature explosions of the explosives. Initially, simulations were conducted to observe temperature variations in blast holes before and after the loading of explosives. Then, the impact of blast hole diameter and initial temperature on the thermal environment was assessed. Subsequent analysis focused on the fluid field's dynamics, examining flow rate changes and the concentration of signature gases produced by the reaction. Additionally, the influence of blast hole diameter on these parameters was evaluated. The results show that the blast hole temperature is positively related to its diameter and initial temperature. When the diameter of the blast hole is 120mm and 165mm, a significant change in flow rate is observed, with a trend of being rapidly increased and then rapidly decreased. The production of NH3 is always found to be greater than that of the other two gases. As for NO and SO2, their production is characterized by an approximate ratio of 1:2. The numerical simulation results can provide important theoretical guidance for the spontaneous detonation of blast hole in sulfide mines.

CO2 emission and physiological aspects of sugarcane ratoon as interactive functions of nitrogen and silicon applications

Sugarcane is the primary renewable energy source in Brazil, necessitating efficient and sustainable production practices. This study assessed the impact of nitrogen sources and their combination of silicon as foliar application on carbon dioxide (CO2) emissions and physiological characteristics of sugarcane cultivated in tropical environment. The experiment was conducted using the second sugarcane ratoon (variety CTC-04), as 2x5 factorial design, with two sources of N-fertilizer (urea and calcium ammonium nitrate - CAN, association with DMPSA − 3,4-dimetilprirazol succínico, nitrification inhibitor) and different silicon concentrations such as 0, 150, 300, 450, and 600 g ha−1. Photosynthetic leaf gas exchange, water use efficiency, pigments, CO2 emissions (ECO2), ammonium and nitrate levels in the soil were observed. The results were subjected to analysis of variance using the F test along with polynomial regression and mean comparison tests. Using urea as a source of nitrogen, there was an increase in internal CO2 concentration of the plants by 19% in relation to treatment with calcium ammonium nitrate association with DMPSA (CAN + DMPSA). Nevertheless, urea increased ECO2 emissions into the atmosphere by up to 15.3% higher compared to CAN + DMPSA application. Foliar application of Si (300 g ha−1) reduced plant transpiration rate (21%), irrespective the source of N-fertilizer utilized. Thus, it is concluded that the use of calcium ammonium nitrate associated with a nitrification inhibitor is an interesting strategy for reducing CO2 emissions, as well as Si is capable of reducing the plant’s transpiration rates, making it efficient in the use of water.

Synergistic effect of composite bacteria on self-healing process of concrete crack

The calcium precipitation activity (CPA) of bacterial strains can vary in response to shifts in ambient conditions. When these conditions become unsuitable, the CPA of bacterial cells may decrease noticeably, potentially compromising the self-healing process. Nonetheless, the synergistic behavior of various bacterial strains can present additional crystallization sites for calcium precipitation and adapt to diverse ambient conditions, thus enhancing microbial-induced calcium precipitation (MICP). In this article, we delve into the interconnected mechanisms involving forty-one bacterial strains, assessing their initial spore concentration ratios and nutritional needs in relation to CPA. Based on CPA considerations, DSM6307 and B6, were selected and combined. Subsequent investigations were carried out to determine the efficacy of self-healing concrete exposed to co-cultured bacterial strains. The mineralization capacity of these combined strains was bolstered using starch and ammonium nitrate as carbon/nitrogen sources, with the ideal initial spore concentration ratio between B6 and DSM6307 established as 4:6. Through visual assessments confirmed that the synergistic effect of B6-DSM6307 can yield repair efficiencies nearing 100% for crack widths between 0.02 mm and 0.2 mm. Furthermore, water permeability and capillary absorption tests on the sample block demonstrated that the repair compound, derived from the composite spore dry powder B6-DSM6307, effectively seals cracks and binds securely. A microstructural evaluation using scanning electron microscope emphasized the prominent presence of calcite crystals, attributed to the metabolic actions of the introduced composite strains within the cracks. The findings presented in this research pave the way for subsequent studies focusing on the incorporation of co-culture bacterial strains into CPA-based engineering strategies.

Contrasting effects of ammonium nitrate on tadpole survival, growth and behavior in two common anuran species

Extensive fertilizer use often leads to an accumulation of chemicals in waterbodies that are in close proximity to agricultural fields. One such commonly used fertilizer, ammonium nitrate, has been shown to negatively affect anuran survival and behavior. We performed experiments on tadpoles of two amphibian species, the Agile frog (Rana dalmatina) and the Common toad (Bufo bufo), to test the effects of different concentrations (0 mg/L, 50 mg/L, 100 mg/L and 200 mg/L) of ammonium nitrate on survival, growth and movement activity. We also examined whether sensitivity to predator cues might be altered in the presence of ammonium nitrate. Finally, we tested for the capacity of the two species to exhibit avoidance behavior. Overall, we found that the Agile frog is more sensitive to ammonium nitrate than the Common toad in terms of survival, growth and movement activity. Sensitivity to predator cues was not affected by the fertilizer for the Agile frog, but was shown to alter the behavior of Common toads, whose movement activity did not decrease in the presence of predator cues. Neither species showed an avoidance behavior. Our results suggest that ammonium nitrate can have significant effects on Agile frog tadpoles through direct toxicological effects on survival and growth, but also through behavioral effects. For Common toads those effects were less obvious, but were nonetheless shown in terms of growth, activity and predator detection.

Characterisation and agronomic evaluation of acidified food waste anaerobic digestate products

Raw liquid anaerobic digestate was synthesised into nutrient-dense solid digestates via acidification and evaporation. Acidification retained ammonium in the digestate whilst also donating the anion to free ammonium to form an ammonium salt. Digestate was treated with the addition of sulphuric, nitric, and phosphoric acid resulting in the formation of ammonium sulphate, ammonium nitrate and ammonium phosphate, respectively then evaporated into a solid fertiliser product. FTIR, XRD and SEM-EDS collectively confirm that the addition of acids completely converted the free ammonium in the raw digestate into their respective ammonium salt counterparts. Compounds of potassium chloride, silicon dioxide, calcium carbonate, magnesium ammonium phosphate, sodium nitrate, and sodium chloride were identified in all solid digestate samples. Plant growth and grain yield was higher in urea ammonium nitrate, raw liquid digestate and acidified digestate products compared to control and unacidified solid digestate. Urea ammonium nitrate and ammonium nitrate solid digestate had the highest dry shoot, likely due to the high available nitrogen found in both fertilisers. Overall, acidification and evaporation of liquid digestate can efficiently transform it into a valuable solid fertiliser with a high nutrient density. This process not only has the potential to mitigate handling and storage constraints of low nutrient density digestate in anaerobic digestion facilities but also offers a sustainable alternative to conventional fertilisers.

Development of an oxazole-based cleavable linker for peptides

We report the development of a new oxazole-based cleavable linker to release peptides from attached cargo. Oxazoles are stable to most reaction conditions, yet they can be rapidly cleaved in the presence of single-electron oxidants like cerium ammonium nitrate (CAN). An oxazole linker could be synthesized and attached to peptides through standard solid-phase peptide coupling reactions. Cleavage of these peptide-oxazole conjugates is demonstrated on a broad scope of peptides containing various natural and unnatural amino acids. These results represent the first example of a peptide-based linker that is cleaved through single-electron oxidation. The oxazole is also demonstrated to be a suitable linker for both the release of a peptide from a conjugated small molecule and the orthogonal release of cargo from a peptide containing multiple cleavable linkers. Oxazole linkers could serve as a promising tool for peptide screening platforms such as peptide-encoded libraries.

Experimental warming and nitrogen deposition in clear‐cuts and forest edges: Assessing impacts on plant communities and tree seedling performance

AbstractQuestionsDo nitrogen deposition and climate warming affect tree seedlings and plant communities in different habitats? In these habitats, how do microenvironments, including soil properties and, when applicable, edge effects relate to plant performance?LocationThe University of British Columbia Malcolm Knapp Research Forest, Maple Ridge, British Columbia, Canada.MethodsWe assessed performance of Pseudotsuga menziesii (Mirb.) Franco, Thuja plicata Donn ex D. Don and Tsuga heterophylla (Raf.) Sarg. planted tree seedlings and associated vascular plant communities. Performance of tree seedlings (height) and under vascular plant communities (percent cover) were examined in an experiment with warming (open‐top chambers) and nitrogen deposition (ammonium nitrate applied at 10 kg N ha−1 year−1) treatments applied to subplots in six forest edges and six clear‐cuts (N = 298 total subplots).ResultsIn clear‐cuts, tree seedling height increased with experimental warming and differed among species, and vascular plant cover increased with warming. In clear‐cuts, species identity, not soil variables, was a strong predictor of height, and plant cover was negatively related to pH. In forest edges, edge position and some soil variables were related to height, but not plant cover. There were no interaction effects found between experimental nitrogen deposition and warming.ConclusionsOur results suggest that moderate warming can enhance tree seedling height and understorey vascular plant cover in clear‐cuts in Pacific Northwest coastal ecosystems, but low nitrogen deposition may not have an effect alone or synergistically with warming.