Alternatives to Mineral Nitrogen Fertilizers in Agriculture: State of the Art, Challenges and Future Prospects

A special issue of Nitrogen (ISSN 2504-3129).

Deadline for manuscript submissions: 31 December 2024 | Viewed by 35416

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Guest Editor
Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ), Consejo Superior de Investigaciones Científicas (CSIC), 18008 Granada, Spain
Interests: composts; legumes; organic matter; organic and biological fertilizers; nitrous oxide; rhizobium; soil microorganisms; symbiotic nitrogen fixation
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Special Issue Information

Dear Colleagues,

Despite being one of the main components of the biosphere, nitrogen is still a limiting factor for agriculture. N-fertilizers produced by the Haber Bosch process have managed this situation, which has markedly increased crop yield and food production during the last century. Unfortunately, this process has unbalanced the soil nitrogen cycle due to the overapplication of mineral fertilisers in agricultural soils over several decades. Every year, thousands of tons of nitrogenous species are released, such as nitrogen oxides (NOx), ammonia (NH3), nitrous oxide (N2O) or the anion nitrate (NO3), in water, soil and also the atmosphere. Concomitantly, contamination events such as water eutrophication or greenhouse gas emissions, among others, are more frequent nowadays.

In order to develop an environmentally friendly agriculture, it seems mandatory to investigate alternatives that could results in a reduction in mineral N-fertilizers without compromising yield productivity. In this Special Issue, we invite the scientific community to share their investigations related to the minimization of environmental impacts of nitrogen application in agriculture and the optimization of fertilization. Research articles and reviews including agronomic, chemical, biological or multidisciplinary aspects covering these topics (but not limited to) are also welcome:

  • Biological and symbiotic nitrogen fixation;
  • Legume crops;
  • Vegetation cover;
  • Environmental contamination of nitrogen fertilizers;
  • Nitrogen emissions (NH3, N2O, NO or N2);
  • Manure and organic fertilisers;
  • Enhanced-efficiency nitrogen fertilisers;
  • Nitrogen transformation in organic waste treatments: composting, vermicomposting and anaerobic digestion;
  • Application of composts, vermicompost or digestate;
  • Plant-grow promoting microorganism;
  • Biostimulants;
  • Seaweed protein extraction and application;
  • New technologies for nitrogen recovering from organic waste;
  • N-cycle in soils: nitrification, denitrification, etc.

Dr. Germán Tortosa
Guest Editor

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Keywords

  • biological and symbiotic nitrogen fixation
  • legume crops
  • vegetation cover
  • NH3
  • N2O
  • NO
  • N2
  • manure and organic fertilisers
  • enhanced-efficiency nitrogen fertilisers
  • nitrogen transformation
  • organic waste treatments
  • composting
  • vermicomposting
  • anaerobic digestion
  • composts
  • vermicompost
  • digestate
  • plant-growth promoting microorganism
  • biostimulants
  • seaweed protein
  • soil N-cycle
  • nitrification
  • denitrification

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Published Papers (11 papers)

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Research

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17 pages, 4732 KiB  
Article
Nitrogen Assimilation, Biomass, and Yield in Response to Application of Algal Extracts, Rhizobium sp., and Trichoderma asperellum as Biofertilizers in Hybrid Maize
by Sandra Pérez-Álvarez, Erick H. Ochoa-Chaparro, Julio César Anchondo-Páez, César M. Escobedo-Bonilla, Joel Rascón-Solano, Marco A. Magallanes-Tapia, Luisa Patricia Uranga-Valencia, Reinier Hernández-Campos and Esteban Sánchez
Nitrogen 2024, 5(4), 1031-1047; https://doi.org/10.3390/nitrogen5040066 - 1 Nov 2024
Viewed by 565
Abstract
Nitrogen is essential for plants’ growth, yield, and crop quality, and its deficiency limits food production worldwide. In addition, excessive fertilization and inefficient use of N can increase production costs and cause environmental problems. A possible solution to this problem is the application [...] Read more.
Nitrogen is essential for plants’ growth, yield, and crop quality, and its deficiency limits food production worldwide. In addition, excessive fertilization and inefficient use of N can increase production costs and cause environmental problems. A possible solution to this problem is the application of biofertilizers, which improve N assimilation and increase biomass and yield. Therefore, the objective of this research was to evaluate the impact of the application of a combination of green and red algae (Ulva lactuca and Solieria spp.), Rhizobium sp., Trichoderma asperellum, and the combination of the above three biofertilizers on N assimilation. A completely randomized design was performed, with 10 plants per treatment and five treatments: T1 = control; T2 = algal extracts; T3 = Rhizobium sp.; T4 = T. asperellum; T5 = T2 + T3 + T4. Our analyses showed that the biofertilizers’ application was better than the control. The application of Rhizobium sp. had the best performance amongst all of the biofertilizers, with the highest nitrate reductase activity in maize leaves, which enhanced photosynthesis, increasing biomass and yield. The use of Rhizobium sp. showed increases in biomass (13.4%) and yield (11.82%) compared to the control. This research shows that biofertilizers can be a key component for sustainable agricultural practices. Full article
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12 pages, 4316 KiB  
Article
Iodine-Enriched Urea Reduces Volatilization and Improves Nitrogen Uptake in Maize Plants
by João Victor da Costa Cezar, Everton Geraldo de Morais, Jucelino de Sousa Lima, Pedro Antônio Namorato Benevenute and Luiz Roberto Guimarães Guilherme
Nitrogen 2024, 5(4), 891-902; https://doi.org/10.3390/nitrogen5040057 - 2 Oct 2024
Viewed by 674
Abstract
Urea is the primary source of nitrogen (N) used in agriculture. However, it has a high N loss potential through volatilization. Various mechanisms can be employed to reduce N volatilization losses by inhibiting urease. When added to urea, iodine (I) has high potential [...] Read more.
Urea is the primary source of nitrogen (N) used in agriculture. However, it has a high N loss potential through volatilization. Various mechanisms can be employed to reduce N volatilization losses by inhibiting urease. When added to urea, iodine (I) has high potential for this purpose. Thus, this study aimed to determine whether adding I to urea reduces volatilization losses and increases N uptake in maize plants. Maize plants were cultivated in greenhouse conditions for 36 days. Urea treatments were applied at 15 days of testing, including iodine-enriched urea, conventional urea, and no urea application. Additionally, a study concerning N volatilization from urea was conducted using the same treatments under the same environmental conditions. Iodine was incorporated and adhered to urea, at an I concentration of 0.2%, using potassium iodate (KIO3). Under controlled conditions and over a short period of time, it was observed that the application of iodine-enriched urea increased the chlorophyll b content, root N accumulation, and total N accumulation in maize plants compared with conventional urea. Moreover, iodine-enriched urea reduced N losses from volatilization by 11% compared with conventional urea. The reduction in N volatilization correlated positively with the increased chlorophyll b, total chlorophyll, root N accumulation, and total N accumulation favored by the iodine-enriched urea treatment. Our findings demonstrated that adding I to urea is an efficient and promising strategy to reduce N losses and increase N uptake in plants. Full article
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15 pages, 1756 KiB  
Article
Influence of Soil Type and Temperature on Nitrogen Mineralization from Organic Fertilizers
by Hanna Ibiapina de Jesus, Kate Cassity-Duffey, Bhabesh Dutta, Andre Luiz Biscaia Ribeiro da Silva and Timothy Coolong
Nitrogen 2024, 5(1), 47-61; https://doi.org/10.3390/nitrogen5010004 - 24 Jan 2024
Cited by 1 | Viewed by 1981
Abstract
Organic vegetable producers in Georgia, USA, utilize a range of amendments to supply nitrogen (N) for crop production. However, differences in soil type, fertilizers and environmental conditions can result in variability in N mineralization rates among commonly utilized organic fertilizers in the region. [...] Read more.
Organic vegetable producers in Georgia, USA, utilize a range of amendments to supply nitrogen (N) for crop production. However, differences in soil type, fertilizers and environmental conditions can result in variability in N mineralization rates among commonly utilized organic fertilizers in the region. In this study, the effects of temperature on N mineralization from three commercial organic fertilizers [feather meal (FM), pelleted poultry litter (PPL) and a mixed organic fertilizer (MIX)] in two soil types from Georgia, USA (Cecil sandy clay loam and Tifton loamy sand) were evaluated for 120 d. Net N mineralization (Net Nmin) varied with soil type, fertilizer and temperature. After 120 d, Net Nmin from the FM fertilizer ranged between 41% and 77% of total organic N applied, the MIX fertilizer ranged between 26% and 59% and the PPL fertilizer ranged between 0% and 22% across all soil types and temperatures. Incubation at higher temperatures (20 °C and 30 °C) impacted Net Nmin of FM fertilizer in the Tifton series soil. Temperature and soil type had a relatively minor impact on the potentially mineralizable N of the PPL and MIX fertilizers after 120 d of incubation; however, both factors impacted the rate of fertilizer release shortly after application, which could impact the synchronicity of N availability and plant uptake. Temperature-related differences in the mineralization of organic fertilizers may not be large enough to influence a grower’s decisions regarding N fertilizer inputs for vegetable crop production in the two soils. However, organic fertilizer source will likely play a significant role in N availability during the cropping season. Full article
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16 pages, 608 KiB  
Article
Effect of Methyl Jasmonate Plus Urea Foliar Application on the Polysaccharide and Monosaccharide Composition of Tempranillo Grapes and Wines and on the Wine’s Quality
by Miriam González-Lázaro, Leticia Martínez-Lapuente, Teresa Garde-Cerdán, Mikel Landín Ross-Magahy, Lesly L. Torres-Díaz, Eva P. Pérez-Álvarez, Zenaida Guadalupe and Belén Ayestarán
Nitrogen 2023, 4(3), 263-278; https://doi.org/10.3390/nitrogen4030019 - 8 Jul 2023
Cited by 1 | Viewed by 1374
Abstract
Polysaccharides are the main group of macromolecules in wines. Climate change is a major problem for viticulturists as it leads to the production of unbalanced grapes. This is attributed to a mismatch between the technological maturity and phenolic maturity of grapes, which can [...] Read more.
Polysaccharides are the main group of macromolecules in wines. Climate change is a major problem for viticulturists as it leads to the production of unbalanced grapes. This is attributed to a mismatch between the technological maturity and phenolic maturity of grapes, which can negatively impact the production of high quality wines. To mitigate this effect, biostimulants can be applied to grapevines. For the first time in the literature, this work studied the foliar application of methyl jasmonate plus urea (MeJ + Ur) on the vineyard and its effect on the monosaccharide and polysaccharide composition of Tempranillo grapes and wines over two consecutive seasons. To achieve this, the extraction and precipitation of polysaccharides was conducted, and the identification and quantitation of monosaccharides was performed via GC–MS. The effect of MeJ + Ur foliar treatment in both the grapes and wines was season-dependent. The MeJ + Ur treatment had a slight impact on the monosaccharide composition of the grapes and also demonstrated a small effect on the wines. Multifactor and discriminant analysis revealed that the season had a greater influence on the monosaccharide and polysaccharide composition of grapes and wines compared to the influence of MeJ + Ur treatment. Interestingly, the MeJ + Ur-treated wines exhibited a higher sensory evaluation than the control wines in the second vintage. To gain further insights into the effect of MeJ + Ur foliar application on the monosaccharide and polysaccharide composition of grapes and wines, further investigations should be conducted. Full article
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8 pages, 1589 KiB  
Communication
“Alperujo” Compost Improves Nodulation and Symbiotic Nitrogen Fixation of Soybean Inoculated with Bradyrhizobium diazoefficiens
by Germán Tortosa, Socorro Mesa, María J. Delgado and Carol V. Amaya-Gómez
Nitrogen 2023, 4(2), 223-230; https://doi.org/10.3390/nitrogen4020015 - 16 May 2023
Cited by 3 | Viewed by 2439
Abstract
The utilization of compost to enhance plant productivity and symbiotic nitrogen fixation (SNF) has been recognized as an effective alternative to synthetic nitrogen fertilizers. This environmentally sustainable method is readily accessible to farmers. This study investigated the effect of olive pomace (“alperujo”, AL) [...] Read more.
The utilization of compost to enhance plant productivity and symbiotic nitrogen fixation (SNF) has been recognized as an effective alternative to synthetic nitrogen fertilizers. This environmentally sustainable method is readily accessible to farmers. This study investigated the effect of olive pomace (“alperujo”, AL) compost on the nodulation and SNF of soybeans (Glycine max L.) and their natural symbiont (Bradyrhizobium diazoefficiens). For that, soybean plants were subjected to several doses of AL compost under controlled greenhouse conditions. At the end of the experiment, the dry weight of plant biomass (aerial part and roots), the number and fresh weight of nodules, and nitrogen and leghaemoglobin contents were analyzed. The application of AL compost significantly improved soybean growth, as demonstrated by an increase in both plant biomass and height. Furthermore, nodular leghaemoglobin content and nitrogen content were found to be enhanced by the addition of AL compost (7 and 40%, respectively), indicating an increase in nodule effectiveness and symbiotic efficiency. Our results provide clear evidence of the synergetic effect of AL compost on the soybean-B. diazoefficiens association, probably due to AL-compost improved soybean roots development, and rhizospheric organic matter and nutrients assimilation by rhizobia. Full article
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10 pages, 1450 KiB  
Article
Environmental Impact Assessment for Animal Waste, Organic and Synthetic Fertilizers
by Vassilis D. Litskas
Nitrogen 2023, 4(1), 16-25; https://doi.org/10.3390/nitrogen4010002 - 6 Jan 2023
Cited by 17 | Viewed by 4648
Abstract
The use of fertilizers is of the utmost importance for food security on a global scale. However, fertilizer production and overuse may yield environmental issues. In this research, Life Cycle Assessment (LCA) was used to estimate eighteen environmental impact categories for six different [...] Read more.
The use of fertilizers is of the utmost importance for food security on a global scale. However, fertilizer production and overuse may yield environmental issues. In this research, Life Cycle Assessment (LCA) was used to estimate eighteen environmental impact categories for six different fertilizer products: three synthetic (ammonium nitrate; calcium ammonium nitrate; and urea ammonium nitrate) and three organic (cattle manure; compost; and a mixture of compost and synthetic fertilizer). The processes for fertilizer production were obtained from the Agribalyse database. The system boundaries were from cradle to factory gate (or farm gate in the case of animal waste), and the impact indicators were calculated per kg of nitrogen (N). The data showed that the organo-mineral fertilizer (a mix of compost and synthetic fertilizer) had the highest environmental impact according to the results for most of the impact categories. The median values for this product regarding water consumption, fossil resource use and global warming potential were 322.5 L, 3.82 kg oil equivalent and 13.70 kg CO2 equivalent, respectively, per kg of N. The respective values for cattle manure, for which the lowest environmental impact was observed, were 0.23 L of water, 0.002 kg oil-eq and 3.29 kg of CO2-eq, respectively, per kg of N. Further research should focus on the determination of the impact from other stages of the life cycle (e.g., transportation and application to the field) which were not included in this work. This research could support the selection of N fertilizer in sustainable food production. Full article
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11 pages, 4358 KiB  
Article
Using the Haney Soil Test to Predict Nitrogen Requirements in Winter Wheat (Triticum aestivum L.)
by Debankur Sanyal and Christopher Graham
Nitrogen 2022, 3(2), 376-386; https://doi.org/10.3390/nitrogen3020024 - 9 Jun 2022
Viewed by 2150
Abstract
Managing nitrogen (N) is one of the of the biggest challenges in achieving environmental and economic sustainability in the agroecosystem. As N fertilizer prices have increased significantly, farmers are considering a revised N recommendation to optimize crop production, while addressing negative environmental impacts [...] Read more.
Managing nitrogen (N) is one of the of the biggest challenges in achieving environmental and economic sustainability in the agroecosystem. As N fertilizer prices have increased significantly, farmers are considering a revised N recommendation to optimize crop production, while addressing negative environmental impacts of excess N in water bodies. This study analyzes the accuracy of using the Haney Soil Test (HST) to predict the N requirement (HSTNR) of winter wheat (Triticum aestivum L.) in a semi-arid climate. The accuracy of the HST to predict the economically optimum N rate (EONR) was dependent on in-season precipitation. In drought conditions, the HSTNR was 33 kg N ha−1 lower on average than the EONR. Conversely, in wetter years, the HSTNR was 35 kg N ha−1 higher than the EONR. Net return was approximately USD 19 ha−1 lower than that with the EONR under both precipitation scenarios. Similar differences were found for protein content. There was a strong correlation between soil respiration and the soil health calculation, within the HST, and the difference between the net return on yield from the HSTNR and the EONR yield. These indicators may serve as useful metrics for formulating soil health-based N recommendations in winter wheat. However, in drought-prone areas, the HSTNR may significantly underpredict the EONR in many years due to an overestimation of N mineralization. Full article
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21 pages, 4006 KiB  
Article
Effects of Drainage Water Management in a Corn–Soy Rotation on Soil N2O and CH4 Fluxes
by Jacob G. Hagedorn, Eric A. Davidson, Thomas R. Fisher, Rebecca J. Fox, Qiurui Zhu, Anne B. Gustafson, Erika Koontz, Mark S. Castro and James Lewis
Nitrogen 2022, 3(1), 128-148; https://doi.org/10.3390/nitrogen3010010 - 17 Mar 2022
Cited by 6 | Viewed by 3686
Abstract
Drainage water management (DWM), also known as controlled drainage, is a best management practice (BMP) deployed on drainage ditches with demonstrated success at reducing dissolved nitrogen export from agricultural fields. By slowing discharge from agricultural ditches, subsequent anaerobic soil conditions provide an environment [...] Read more.
Drainage water management (DWM), also known as controlled drainage, is a best management practice (BMP) deployed on drainage ditches with demonstrated success at reducing dissolved nitrogen export from agricultural fields. By slowing discharge from agricultural ditches, subsequent anaerobic soil conditions provide an environment for nitrate to be reduced via denitrification. Despite this success, incomplete denitrification might increase nitrous oxide (N2O) emissions and more reducing conditions might increase methanogenesis, resulting in increased methane (CH4) emissions. These two gases, N2O and CH4, are potent greenhouse gases (GHG) and N2O also depletes stratospheric ozone. This potential pollution swapping of nitrate reduction for GHG production could negatively impact the desirability of this BMP. We conducted three years of static chamber measurements of GHG emissions from the soil surface in farm plots with and without DWM in a corn–soybean rotation on the Delmarva Peninsula. We found that DWM raised the water table at the drainage ditch edge, but had no statistically significant effect on water-filled pore space in the field soil surface. Nor did we find a significant effect of DWM on GHG emissions. These findings are encouraging and suggest that, at least for this farm site, DWM can be used to remove nitrate without a significant tradeoff of increased GHG emissions. Full article
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Review

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10 pages, 785 KiB  
Review
Beyond Soil Inoculation: Cyanobacteria as a Fertilizer Replacement
by Michael S. Massey and Jessica G. Davis
Nitrogen 2023, 4(3), 253-262; https://doi.org/10.3390/nitrogen4030018 - 4 Jul 2023
Cited by 9 | Viewed by 3745
Abstract
Nitrogen-fixing bacteria such as cyanobacteria have the capability to fix atmospheric nitrogen at ambient temperature and pressure, and intensive cultivation of cyanobacteria for fertilizer could lead to its use as an “environmentally friendly” replacement or supplement for nitrogen (N) fertilizer derived from the [...] Read more.
Nitrogen-fixing bacteria such as cyanobacteria have the capability to fix atmospheric nitrogen at ambient temperature and pressure, and intensive cultivation of cyanobacteria for fertilizer could lead to its use as an “environmentally friendly” replacement or supplement for nitrogen (N) fertilizer derived from the Haber–Bosch process. Prior research has focused on the use of N-fixing bacteria as a soil inoculum, and while this can improve crop yields, yield improvements are generally attributed to plant-growth-promoting substances produced by the bacteria, rather than to biological N fixation. The intensive cultivation of cyanobacteria in raceways or bioreactors can result in a fertilizer that provides N and organic carbon, as well as potentially similar growth-promoting substances observed in prior research work. On-farm or local production of cyanobacterial fertilizer could also circumvent infrastructure limitations, economic and geopolitical issues, and challenges in distribution and transport related to Haber–Bosch-derived N fertilizers. The use of cyanobacterial N fertilizer could have many agronomic and environmental advantages over N fertilizer derived from the Haber–Bosch process, but study of cyanobacteria as a replacement for other N fertilizers remains very limited. Scientific and practical challenges remain for this promising but as-yet unproven approach to maintaining or improving soil N fertility. Full article
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16 pages, 1026 KiB  
Review
Efficiency and Management of Nitrogen Fertilization in Sugar Beet as Spring Crop: A Review
by Ivana Varga, Jurica Jović, Mirta Rastija, Antonela Markulj Kulundžić, Vladimir Zebec, Zdenko Lončarić, Dario Iljkić and Manda Antunović
Nitrogen 2022, 3(2), 170-185; https://doi.org/10.3390/nitrogen3020013 - 12 Apr 2022
Cited by 19 | Viewed by 6169
Abstract
Sugar beet fertilization is a very complex agrotechnical measure for farmers. The main reason is that technological quality is equally important as sugar beet yield, but the increment of the root yield does not follow the root quality. Technological quality implies the concentration [...] Read more.
Sugar beet fertilization is a very complex agrotechnical measure for farmers. The main reason is that technological quality is equally important as sugar beet yield, but the increment of the root yield does not follow the root quality. Technological quality implies the concentration of sucrose in the root and the possibility of its extraction in the production of white table sugar. The great variability of agroecological factors that directly affect root yield and quality are possible good agrotechnics, primarily by minimizing fertilization. It should be considered that for sugar beet, the status of a single plant available nutrient in the soil is more important than the total amounts of nutrients in the soil. Soil analysis will show us the amount of free nutrients, the degree of soil acidity and the status of individual elements in the soil so that farmers can make a compensation plan. An estimate of the mineralizing ability of the soil, the N min, is very important in determining the amount of mineral nitrogen that the plant can absorb for high root yield and good technological quality. The amount of N needed by the sugar beet crop to be grown is an important factor, and it will always will be in the focus for the producers, especially from the aspect of trying to reduce the N input in agricultural production to preserve soils and their biodiversity but also to establish high yields and quality. Full article
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15 pages, 3454 KiB  
Review
Identifying Sustainable Nitrogen Management Practices for Tea Plantations
by Rhys Rebello, Paul J. Burgess and Nicholas T. Girkin
Nitrogen 2022, 3(1), 43-57; https://doi.org/10.3390/nitrogen3010003 - 14 Jan 2022
Cited by 9 | Viewed by 5474
Abstract
Tea (Camellia sinensis L.) is the most widely consumed beverage in the world. It is mostly grown in the tropics with a heavy dependence on mineral nitrogen (N) fertilisers to maintain high yields while minimising the areas under cultivation. However, N is [...] Read more.
Tea (Camellia sinensis L.) is the most widely consumed beverage in the world. It is mostly grown in the tropics with a heavy dependence on mineral nitrogen (N) fertilisers to maintain high yields while minimising the areas under cultivation. However, N is often applied in excess of crop requirements, resulting in substantial adverse environmental impacts. We conducted a systematic literature review, synthesising the findings from 48 studies to assess the impacts of excessive N application on soil health, and identify sustainable, alternative forms of N management. High N applications lead to soil acidification, N leaching to surface and groundwater, and the emission of greenhouse gases including nitrous oxide (N2O). We identified a range of alternative N management practices, the use of organic fertilisers, a mixture of organic and inorganic fertilisers, controlled release fertilisers, nitrification inhibitors and soil amendments including biochar. While many practices result in reduced N loading or mitigate some adverse impacts, major trade-offs include lower yields, and in some instances increased N2O emissions. Practices are also frequently trialled in isolation, meaning there may be a missed opportunity from assessing synergistic effects. Moreover, adoption rates of alternatives are low due to a lack of knowledge amongst farmers, and/or financial barriers. The use of site-specific management practices which incorporate local factors (for example climate, tea variety, irrigation requirements, site slope, and fertiliser type) are therefore recommended to improve sustainable N management practices in the long term. Full article
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