Nitrogen Fertilizer Research Articles

Растеж и минерален състав на тютюн Виржиния в отговор на минерално торене и биостимуланти

The influence of mineral fertilization and two biostimulants (microbial inoculant Mycoplant® and protein hydrolysate (PH) Trainer®) on the growth and mineral composition of Virginia tobacco was studied in field and pot experiments on Rendzic Leptosol. The seedlings of the conventional technology (manure+mineral nitrogen fertilizer) had the highest weight and the highest concentration of N and Ca in the above-ground biomass. Biostimulants also had a positive effect on plant weight and the concentration of macro- and micronutrients. Microbial inoculant Mycoplant and PH Trainer increased seedling weight (fresh and dry) by 16.8% - 22.5% and 8% - 12%, respectively, compared to the manure treatment. The microbial inoculant containing AM fungi increased seedling N, P and Mg concentration by 8%, 9% and 13%, respectively, compared to manure treatment. The concentrations of Fe, Mn, Zn and Cu also increased when Mycoplant was applied. The application of a PH-based biostimulant Trainer resulted in higher concentration of N (by 11%) and Mg (by 4%) in seedlings. Leaf area and leaf weight (pot experiment) were positively affected by compound fertilizer application. Biostimulants Mycoplant and Trainer had a weaker positive effect on these indicators. The application of compound NPK fertilizer significantly increased the concentration of N, P and K in the leaves. Biostimulants also improved the uptake of essential nutrients by tobacco plants. The microbial inoculant significantly increased the concentration of Fe in the leaves - by 25.5% compared to the control. The concentration of N was increased by 14.3% when PH Trainer was applied.

Evaluation of Nitrogen Fertilizer Supply and Soil Nitrate Thresholds for High Yields of Foxtail Millet

Foxtail millet is an important cereal crop in the North China Plain. However, excessive nitrogen fertilizer application over the years has led to declining yield and soil quality. This study investigated nutrient management strategies for foxtail millet based on crop yield levels and soil nutrient availability. In a field where targeted fertilization was conducted over six seasons, nitrogen fertilization effects and the dynamics of soil-available nitrogen were monitored continuously for two consecutive years (2022–2023) across five different foxtail millet varieties with varying yield levels. The study aimed to determine the optimal nitrogen application rate for achieving a high yield of foxtail millet, the minimum soil nitrate threshold required to maintain soil fertility, and the effective nitrogen application rate range for sustaining soil-available nitrate levels. Results showed that fertilization significantly affected dry matter weight during flowering, while variety affected dry matter weight at maturity. The average nitrogen application rate for achieving high yield across all five millet varieties was 141.3 kg·ha−1. Specifically, the average nitrogen application rate of nitrogen-efficient varieties achieving high yield (5607.32–5637.19 kg·ha−1) was 151.5 kg·ha−1, while the average nitrogen application rate of nitrogen-inefficient varieties achieving high yield (4749.77–4847.74 kg·ha−1) was 134.5 kg·ha−1. Soil NH4+-N and NO3−-N content increased when nitrogen application rate exceeded 360 kg·ha−1, posing environmental risks. To achieve high yield, soil nitrate levels would be maintained at an average of 17.23 mg·kg−1 (before sowing) and 9.75 mg·kg−1 (at maturity). A relationship between soil nitrate and nitrogen application rate was established: y = 867.5 − 50z (where y represents the optimal nitrogen application rate for high yield (kg·ha−1), and z represents soil NO3−-N content in the 0–20 cm layer before sowing, ranging from 10.0 to 17.35 mg·kg−1), which provided a practical method for nitrogen fertilization to achieve high yield of foxtail millet. In this study, the fertilization strategy was optimized according to soil nutrient level and yield targets, and the nitrogen application rate was controlled within 360 kg·ha−1 based on the soil nitrate nitrogen content, which will be instructive for reducing fertilizer use, maximizing fertilizer efficiency, and increasing yield.

Advancements in fuzzy expert systems for site-specific nitrogen fertilisation: Incorporating RGB colour codes and irrigation schedules for precision maize production in Bangladesh

Advancements in fuzzy expert systems for site-specific nitrogen fertilisation: Incorporating RGB colour codes and irrigation schedules for precision maize production in Bangladesh

Morpho-Physiological and Biochemical Responses in Prosopis laevigata Seedlings to Varied Nitrogen Sources

Nitrogen (N) fertilization promotes morphofunctional attributes that enhance plant performance under stress conditions, but the amount and form supplied modify the magnitude of plant responses. We assessed several morpho-physiological and biochemical responses of Prosopis laevigata seedlings to a high supply of N, provided as either inorganic (NH4NO3) or organic (amino acids). Such N treatments were applied on four-month-old seedlings as a supplement of 90 mg N to a regular supply of 274 mg N plant−1. Nitrogen supply modified biomass allocation patterns between leaves and roots regardless of N form. Increased N input decreased photosynthetic capacity, even when plants had high internal N reserves. Organic N fertilization reduced the N use efficiency, but increased leaf and root amino acid concentrations. Proteins accumulated in stems in plants receiving inorganic N, while the organic N increased leaf proteins. High N supply promoted root starch accumulation irrespective of N form. Nitrogen supply did not directly influence plants’ regrowth capacity. Still, resprouting was correlated to initial root-to-shoot ratios and root starch, confirming the importance of roots as storage reserves of starch for recovering biomass after browsing. These findings have practical implications for designing nutritional management strategies in nurseries to improve seedling performance in afforestation efforts.

Effect of sward species diversity combined with a reduction in nitrogen fertilizer on the performances of spring calving grazing dairy cows

The objective of this study was to evaluate the impact of sward diversification combined with a reduction of chemical nitrogen (N) fertilizer on the performance of spring calving grazing dairy cows within a farm systems experiment. Three farmlets were created; a monoculture of perennial ryegrass (Lolium perenne L.; PRG) fertilized with 250 kg N/ha (PRG-250N), a PRG - white clover (Trifolium repens; WC) sward fertilized with 125 kg N/ha (PRGWC-125N) and a multispecies sward (MSS) comprising of grasses, legumes and herbs also fertilized with 125 kg N/ha (MSS-125N). Each farmlet had its own herd of dairy cows on a total area of 18.7 ha divided into 20 paddocks. Each herd was comprised of pure Holstein-Friesian (HF) and HF Jersey crossbred (JFX) animals and randomly assigned through the 3 treatments. For 3 years (2021 to 2023), the performances of both swards (grass yield, botanical composition, nutritive value) and grazing animals (milk production and composition, body weight (BW) and body condition score (BCS)) were recorded. There were no significant differences in pasture production or sward nutritive value between sward systems and grazing season length was also similar (264 d). On average over the 3 years, PRGWC-125N contained 150 g/kg DM of legumes and the MSS-125N contained 160 g/kg DM legumes, 130 g/kg DM plantain and 40 g/kg DM chicory. Both individual cow milk and fat plus protein (Milk solids; MS) yield were lower for PRG-250N (5,018 and 452 kg, respectively), intermediate for PRGWC-125N (5,139 and 463 kg, respectively) and highest for MSS-125N (5,297 and 476 kg, respectively) while milk and MS production per hectare from grazing were similar during the study period (11,523 and 1,016 kg/ha, respectively). Breed also had a significant effect with the JFX having lower milk yield but higher fat and protein concentration compared with HF. This resulted in higher MS production per kg of BW for the JFX compared with HF (0.96 and 0.87 kg MS/kg BW, respectively). The results of this study highlight the possibility for more diverse pastures to reduce chemical N fertilizer input requirements and maintain pasture productivity while increasing animal performance within pasture-based spring calving systems.

Azolla as a Safe Food: Suppression of Cyanotoxin-Related Genes and Cyanotoxin Production in Its Symbiont, Nostoc azollae.

The floating freshwater fern Azolla is the only plant that retains an endocyanobiont, Nostoc azollae (aka Anabaena azollae), during its sexual and asexual reproduction. The increased interest in Azolla as a potential source of food and its unique evolutionary history have raised questions about its cyanotoxin content and genome. Cyanotoxins are potent toxins synthesized by cyanobacteria which have an anti-herbivore effect but have also been linked to neurodegenerative disorders including Alzheimer's and Parkinson's diseases, liver and kidney failure, muscle paralysis, and other severe health issues. In this study, we investigated 48 accessions of Azolla-Nostoc symbiosis for the presence of genes coding microcystin, nodularin, cylindrospermopsin and saxitoxin, and BLAST analysis for anatoxin-a. We also investigated the presence of the neurotoxin β-N-methylamino-L-alanine (BMAA) in Azolla and N. azollae through LC-MS/MS. The PCR amplification of saxitoxin, cylindrospermospin, microcystin, and nodularin genes showed that Azolla and its cyanobiont N. azollae do not have the genes to synthesize these cyanotoxins. Additionally, the matching of the anatoxin-a gene to the sequenced N. azollae genome does not indicate the presence of the anatoxin-a gene. The LC-MS/MS analysis showed that BMAA and its isomers AEG and DAB are absent from Azolla and Nostoc azollae. Azolla therefore has the potential to safely feed millions of people due to its rapid growth while free-floating on shallow fresh water without the need for nitrogen fertilizers.

Optimizing Nitrogen Fertilization to Maximize Yield and Bioactive Compounds in Ziziphora clinopodioides

Optimizing Nitrogen Fertilization to Maximize Yield and Bioactive Compounds in Ziziphora clinopodioides

Последействие органических удобрений на урожайность картофеля в условиях Чувашской Республики

In conditions of intensive load of agricultural production on the soil, in order to reproduce soil fertility, various non-traditional organic fertilizers are studied as an alternative to chemicals. The studies were conducted in the Chuvash Republic. The experimental plot is located in the agricultural production cooperative "Slava" of the Cheboksary district. The soil of the experimental plot is light gray forest, heavy loamy on loess-like loam. Climatic conditions are favorable for growing potatoes of the Gala variety, which in 2008 was included in the State Register of Breeding Plants in the Russian Federation and recommended for cultivation in the central and northern regions of the country. It is noted that it is rational to use both sapropel and lowland peat in doses of 15 t/ha, with the joint application of azophoska 200 kg / ha, which allows you to get a high potato yield. Keywords: ORGANIC FERTILIZERS, MINERAL FERTILIZERS, NITROGEN FERTILIZERS, SOIL, POTATOES, PRODUCTIVITY

Synergistic conservation approaches for nurturing soil, food security and human health towards sustainable development goals

Using chemical fertilizers extensively in small farms has helped increase crop yields, supporting food security and economic growth. However, recent studies show that these fertilizers are often used inefficiently and inconsistently. This leads to environmental harm, unbalanced soil nutrients, and lower-quality food production. These issues threaten food security, which is vital for human survival and may lead to the abandonment of arable land. This situation calls for a significant shift in soil conservation research to better connect scientific findings with practical conservation methods, ensuring that agricultural progress goes hand in hand with environmental sustainability. Effective use of nitrogen (N), phosphorus (P), and potassium (K) fertilizers is vital for both environmental sustainability and food security. Correcting nutritional imbalances, especially the disrupted N/P ratio caused by faulty fertilization practices, is key to ensuring a balanced nutrient supply. These imbalances have a substantial effect on aquatic and terrestrial ecosystems, altering their functionality, biodiversity and human nutrition Therefore, adopting balanced fertilization techniques is essential to combine environmental sustainability with global food security and achieve the Sustainable Development Goals (SDGs).To optimize nutrient consumption and production efficiency, regulations should be enacted to enforce the 4R principle, which involves applying the right nutrient source at the appropriate rate, time, method and location. This article emphasizes the connections between current agricultural practices, land use, fertilizer application, soil degradation, and future challenges. It promotes environmentally friendly farming methods that recognize the vital links between soil quality, food security, human health, and environmental sustainability.

Quantitative assessment of the effects of rising temperature on the grain protein of winter wheat in china and its adaptive strategies

With advancements in genetics and technology, wheat yields have continuously increased, but grain quality has remained stagnant or even decreased in recent decades. The effects of temperature on the future grain quality of winter wheat in China are unknown. This study used an improved WheatGrow model, along with two future temperature scenarios, to quantify the regional impacts of temperature increases on grain protein in China and aimed to find effective strategies to adapt to the impact of temperature increases on quality. Compared with those in the baseline period, the protein concentration of wheat grains in the main winter wheat production region of China increased by 0.27% and 0.41% under the 1.5 ℃ and 2.0 ℃ temperature increase scenarios, respectively. However, the grain protein concentrations in the Sichuan Basin of Medium and Weak Gluten Wheat Subregion (Ⅴ) decreased. The temperature rise was estimated to increase the proportion of strong gluten-type wheat but reduce the proportion of medium gluten-type wheat, with the proportion of weak gluten-type wheat changing slightly. Advanced planting date was projected to increase the grain protein concentration in the Northern Strong Gluten Wheat Subregion (Ⅰ), the Northern of Huang-Huai Strong and Medium Gluten Wheat Subregion (Ⅱ), the Southern of Huang-Huai Medium Gluten Wheat Subregion (Ⅲ) and the Yangzi River of Medium and Weak Gluten Wheat Subregion (Ⅳ), whereas a delayed planting date reduced the protein concentration in subregions Ⅰ, Ⅱ, and Ⅲ. In addition, the grain protein concentration was not significantly affected in the higher high-temperature threshold varieties in the southern winter wheat production region under the global warming scenarios. However, if more strong gluten-type wheat is required in the northern China in the future, varieties with lower high-temperature thresholds can be selected without considering wheat yields. Moreover, increasing the nitrogen fertilizer application rate could further increase the wheat protein concentration under future warming scenarios, and the protein concentration of wheat was more sensitive to the nitrogen fertilizer application rate in the northern winter wheat production region than in the southern region. These findings are crucial for improving grain quality across different wheat production regions of China in the future.

Yield performance of aromatic fine rice as influenced by nitrogen fertilization and weed control techniques

Nitrogen fertilization and weed management is the major concern to yield maximization of rice. The study was conducted to assess the influence of nitrogen and weed control to yield improvement of aromatic rice BRRI dhan34. The experiment included three nitrogen levels viz. 50, 100 and 150 kg N ha-1 as well as three weeding schedules viz. one hand weeding at 15 days after transplanting (DAT), two hand weeding at 15 and 30 DAT and three hand weeding at 15, 30 and 45 DAT. The experiment was conducted with randomized complete block design. The findings demonstrated important correlations between weeding techniques, nitrogen levels and yield components. When the crop was fertilized with 50 kg N ha-1 the highest numbers of total tillers hill-1 (8.53), effective tillers hill-1 (7.51), grains panicle-1 (128.0) and grain yield (3.97 t ha-1) were resulted. Regarding weeding practices, two manual weeding carried out at 15 and 30 DAT reported the highest numbers of effective tillers hill-1 (7.62), grains panicle-1 (128.1) and grain yield (4.10 t ha-1). The highest effective tillers hill-1 (8.33), the most grains panicle-1 (129.8), the grain yield (4.36 t ha-1) and straw yield (6.40 t ha-1) were found in two hand weeding at 15 and 30 DAT combined with 50 kg N ha-1 and the lowest grain yield (3.53 t ha-1) was obtained from one hand weeding given at 15 DAT along with 150 kg N ha-1. Therefore, the study demonstrated that BRRI dhan34 can be fertilized with 50 kg N ha-1 along with two hand weeding at 15 and 30 DAT to obtained higher yield.

Identification and characterization of QSFS.sau-MC-5A for sterile florets genetically independent of fertile ones per spike in wheat.

A major and stable QTL for sterile florets per spike and sterile florets per spikelet was identified, it was mapped within a 2.22-Mb interval on chromosome 5AL, and the locus was validated using two segregating populations with different genetic backgrounds. Both the number of fertile florets per spike (FFS) and the number of sterile florets per spike (SFS) significantly influence the final yield of wheat (Triticum aestivum L.), and a trade-off theoretically exists between them. To enhance crop yield, wheat breeders have historically concentrated on easily measurable traits such as FFS, spikelets per spike, and spike length. Other traits of agronomic importance, including SFS and sterile florets per spikelet (SFPs), have been largely overlooked. In the study, reported here, genetic bases of SFS and SFPs were investigated based on the assessment of a population of recombinant inbred lines (RILs) population. The RIL population was developed by crossing a spontaneous mutant with higher SFS (msf) with the cultivar Chuannong 16. A total of 10 quantitative trait loci (QTL) were identified, with QSFS.sau-MC-5A for SFS and QSFPs.sau-MC-5A for SFPs being the major and stable ones, and they were co-located on the long arm of chromosome 5A. The locus was located within a 2.22-Mb interval, and it was further validated in two additional populations based on a tightly linked Kompetitive Allele-Specific PCR (KASP) marker, K_sau_5A_691403852. Expression differences and promoter sequence variations were observed between the parents for both TraesCS5A03G1247300 and TraesCS5A03G1250300. The locus of QSFS.sau-MC-5A/QSFPs.sau-MC-5A showed a significantly positive correlation with spike length, florets in the middle spikelet, and total florets per spike, but it showed no correlation with either kernel number per spike (KNS) or kernel weight per spike. Appropriate nitrogen fertilizer application led to reduced SFS and increased KNS, supporting results from previous reports on the positive effect of nitrogen fertilizer on wheat spike and floret development. Based on these results, we propose a promising approach for breeding wheat cultivars with multiple fertile florets per spike, which could increase the number of kernels per spike and potentially improve yield. Collectively, these findings will facilitate further fine mapping of QSFS.sau-MC-5A/QSFPs.sau-MC-5A and be instrumental in strategies to increase KNS, thereby enhancing wheat yield.

Optimising Nitrogen Fertilisation in a Potato–Oat Rotation and Implications for Nitrous Oxide Emissions in Volcanic Soils

High nitrogen (N) fertiliser rates are usually applied to increase agricultural yields, leading to high nitrous oxide (N2O) emissions. This is a greenhouse gas that contributes to climate change and depletes the ozone layer. This study aimed to optimise N use efficiency and quantify N2O emission factors (EF1) by measuring the effect of N rates on the yield of a potato-cover crop rotation, apparent N use efficiency (NUE) and N2O emissions. The two-year experiment was carried out on volcanic soils (1.6% carbon, 1.4% N) in southern Chile (40°52′ S, 73°03′ W). Three N application rates were evaluated (80, 150 and 300 kg N ha−1), 35% of which was applied at the planting stage (granular) and 65% at the tubering stage. A control treatment with no N addition was also included. Reducing N fertilisation to 80 kg N ha−1 increased NUE by three times, reduced N2O-N emissions by 33% and reduced emission intensity by 27% without a detrimental impact on crop yield and marketable tuber calibre. No significant difference (p < 0.05) was observed in the N2O emission factor (EF1) because of a low rainfall year. The results suggest that in rainfed agriculture systems, N fertiliser application can be significantly reduced without sacrificing potato yield, favouring the economic and environmental sustainability of potato production.

Reducing nitrogen fertilizer usage coupled with organic substitution improves soil quality and boosts tea yield and quality in tea plantations.

The utilization of chemical fertilizers is a key measure for maintaining tea yield and quality, but excessive use has negative environmental impacts. The substitution of chemical fertilizer with organic fertilizer has been promoted to sustain crop yield and soil quality. However, knowledge gaps regarding the effects of organic substitution on soil quality and tea yield in tea plantations still exist. A field experiment was conducted to investigate the influence of organic substitution treatments (i.e. 25% partial substitution: biogas slurry + green manure + formula fertilizer, BFG; sheep manure + formula fertilizer, OFF; 100% complete substitution: sheep manure + green manure, OG) on the soil quality, tea yield and quality, and nitrogen utilization efficiency in southwestern China. Results showed that all organic substitution treatments slightly increased soil pH, and significantly increased soil organic matter by 13.22-14.88% compared to conventional fertilization (CF). The BFG treatment was the most effective in enhancing the soil quality index, showing increases of 16.80%, 8.37% and 24.87% higher than the CF, OFF and OG treatments, respectively. Tea yield significantly increased under the BFG, OFF and OG treatments by 11.97%, 13.58% and 5.90% compared to CF, respectively. The BFG treatment increased the amino acid content by 7.78% and decreased the tea polyphenol/amino acid ratio by 6.87%. Additionally, the BFG, OFF and OG treatments greatly increased the nitrogen utilization efficiency of young sprouts by 70.71%, 82.54% and 34.28%, respectively. Overall, partial organic substitution could effectively improve soil quality while maintaining tea yield. © 2024 Society of Chemical Industry.

Canopy coverage of wheat measured with high accuracy using the HSV colour model and relative depth estimation model, MiDaS

ABSTRACT Canopy coverage calculated from 2D images effectively estimates several parameters, such as dry weight above the ground, stem number, and risk of lodging, without destroying the crops. This study aimed to clarify how to accurately calculate canopy coverage, regardless of environmental conditions, using various colour models and a relative depth estimation model, MiDaS. For wheat cultivated in 2022/23, the canopy coverage at the initiation of the stem elongation stage (CC30), calculated using only the HSV colour model, was overestimated because of the presence of weeds. However, when the heatmap generated using MiDaS was combined with the results extracted from the HSV colour model, it showed a CC30 similar to the accurate CC30 calculated by hand drawing, regardless of the wheat variety, sowing pattern, and location of the image taken, with an RMSE as low as 3.48. The CC30 calculated by combining the HSV colour model and MiDaS was significantly positively correlated with the number of stems, dry weight above ground, and nitrogen content above ground at the initiation of the stem elongation stage of ‘Sanukinoyume 2009’ grown in 2021/22 and 2022/23 (n = 72, r > 0.798). The combination of the HSV colour model and MiDaS effectively and accurately calculates canopy coverage regardless of environmental conditions and can be used for growth diagnosis and variable nitrogen fertiliser application after the initiation of the stem elongation stage.

Nitrogen Fertilization Using Conventional and Slow-Release Fertilizers at Multiple Levels in Lolium multiflorum Lam. Pastures

Pastures are essential for sustaining dairy production, particularly in temperate climates where year-round grazing is feasible. However, comprehensive analyses of their productivity, efficiency, and cost evaluation remain uncommon. This study evaluated the productivity, quality, nitrogen fertilization use efficiency, and production costs of Lolium multiflorum Lam pasture on a farm in São Miguel Island. The research compared conventional nitrogen fertilizer with slow-release nitrogen fertilizer at application rates of 320 and 160 kg N ha−1, alongside a control treatment. A Latin square design with five treatments was employed to assess both agronomic and economic performance. The results showed that the type of fertilizer did not significantly influence productivity or quality, while nitrogen levels had a notable impact. Higher nitrogen doses increased dry matter yield and crude protein content. Fiber characteristics remained relatively stable, though neutral detergent fiber and acid detergent fiber levels tended to rise with increased nitrogen application. Nitrogen fertilizer use efficiency consistently exceeded 70%, regardless of the fertilizer type or application rate. Regarding production costs, conventional fertilizer was significantly more cost-effective than slow-release fertilizer, underscoring the importance of selecting economically viable options without compromising agronomic performance in forage production.

Foliar Fertilization on BRRI dhan28 To Reduce Soil Application of Nitrogenous Fertilizer

The experiment was conducted at the research farm of Crop Physiology and Ecology Department, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur during November 2019 to June 2020 to find out the effect of foliar fertilization on the performance of rice var. BRRI dhan28 and to estimate how much nitrogenous fertilizer can be saved by foliar fertilization without yield reduction. The experiment was laid out following split plot design with three replications. Four levels of foliar fertilization (F0 – No foliar fertilization, F1 – Foliar fertilization with 2% KNO3, F2 - Foliar fertilization with 2% DAP and F3 - Foliar fertilization with 1% American NPKS) were placed in the main plot treatments whereas three nitrogen fertilizer levels (N50 -50% of the recommended nitrogen fertilizer, N75 – 75% of the recommended nitrogen fertilizer and N100 – 100% of the recommended nitrogen fertilizer) were placed randomly in the sub-plots. Foliar fertilization with KNO3, DAP (Di-ammonium phosphate) and American NPKS significantly increased the grain yield (t ha−1) compare to control (F0) but KNO3 and American NPKS performed better than DAP. Foliar fertilization with KNO3 and American NPKS could save 25% of recommended nitrogen fertilizer but foliar fertilization with DAP could not save nitrogen fertilizer applied in soil for getting comparable grain yield found in F0N100. Foliar fertilization of KNO3 and American NPKS with recommended nitrogen fertilizer applied in soil could increase 11.8 and 12.5% grain yield, respectively compare to F0N100. Bangladesh Agron. J. 2024, 26(2): 77-85

Tracking Carbon and Ammonia Emission Flows of China's Nitrogen Fertilizer System: Implications for Domestic and International Trade.

China is the world's largest producer, consumer, and exporter of synthetic nitrogen (N) fertilizer. To assess the impact of domestic demand and international exports, we quantified the life-cycle CO2eq and ammonia (NH3) emissions by tracking carbon (C) and nitrogen (N) flows from coal/gas mining through ammonia production to N fertilizer production, application, and export. In 2020, China's N fertilizer system emitted 496.04 Tg of CO2eq and 3.74 Tg of NH3, with ammonia production and N fertilizer application processes contributing 36 and 85% of the life-cycle CO2eq and NH3 emissions, respectively. As the largest importers of N fertilizer, India, Myanmar, South Korea, Malaysia, and the Philippines collectively shifted 112.41 Tg of CO2eq. For every ton of N fertilizer produced and used in China, 16 t of CO2eq and 0.18 t of NH3 were emitted, compared to 9.7 t of CO2eq and 0.13 t of NH3 in Europe. By adopting currently available technologies, improving N fertilizer utilization efficiency and employing nitrification inhibitors could synergistically reduce CO2eq emissions by 20% and NH3 emissions by 75%, while energy transformation efforts would primarily reduce CO2eq emissions by 59%. The production of ammonia using green electricity or green hydrogen could significantly enhance the decarbonization of China's N fertilizer system.

Unexpected sustained soil carbon flux in response to simultaneous warming and nitrogen enrichment compared with single factors alone.

Recent observations document that long-term soil warming in a temperate deciduous forest leads to significant soil carbon loss, whereas chronic soil nitrogen enrichment leads to significant soil carbon gain. Most global change experiments like these are single factor, investigating the impacts of one stressor in isolation of others. Because warming and ecosystem nitrogen enrichment are happening concurrently in many parts of the world, we designed a field experiment to test how these two factors, alone and in combination, impact soil carbon cycling. Here, we show that long-term continuous soil warming or nitrogen enrichment when applied alone followed the predicted response, with warming resulting in significant soil carbon loss and nitrogen fertilization tending towards soil carbon gain. The combination treatment showed an unanticipated response, whereby soil respiratory carbon loss was significantly higher than either single factor alone, but without a concomitant decline in soil carbon storage. Observations suggest that when soils are exposed to both factors simultaneously, plant carbon inputs to the soil are enhanced, counterbalancing soil carbon loss and helping maintain soil carbon stocks near control levels. This has implications for both atmospheric CO2 emissions and soil fertility and shows that coupling two important global change drivers results in a distinctive response that was not predicted by the behaviour of the single factors in isolation.

Growth, Photosynthesis and Yield Responses of Common Wheat to Foliar Application of Methylobacterium symbioticum under Decreasing Chemical Nitrogen Fertilization

Current agriculture intensifies crop cultivation to meet food demand, leading to unsustainable use of chemical fertilizers. This study investigates a few physiological and agronomic responses of common wheat following the inoculation with plant growth-promoting bacteria to reduce nitrogen inputs. A field trial was conducted in 2022–2023, in Legnago (Verona, Italy) on Triticum aestivum var. LG-Auriga comparing full (180 kg ha−1) and reduced (130 kg ha−1) N doses, both with and without foliar application at end tillering of the N-fixing bacterium Methylobacterium symbioticum. Biofertilization did not improve shoot growth, while it seldom increased the root length density in the arable layer. It delayed leaf senescence, prolonged photosynthetic activity, and amplified stomatal conductance and PSII efficiency under the reduced N dose. Appreciable ACC-deaminase activity of such bacterium disclosed augmented nitrogen retrieval and reduced ethylene production, explaining the ameliorated stay-green. Yield and test weight were unaffected by biofertilization, while both glutenin-to-gliadin and HMW-to-LMW ratios increased together with dough tenacity. It is concluded that Methylobacterium symbioticum can amplify nitrogen metabolism at a reduced nitrogen dose, offering a viable approach to reduce chemical fertilization under suboptimal growing conditions for achieving a more sustainable agriculture. Further research over multiple growing seasons and soil types is necessary to corroborate these preliminary observations.