The Identification of Management Strategies that Target Multiple Nitrogen Loss Pathways

2018 ◽  
Vol 102 (4) ◽  
pp. 16-19
Author(s):  
Tai McClellan Maaz ◽  
Cliff Snyder
Keyword(s):  
Ammonia Volatilization ◽  
Nitrogen Loss ◽  
Management Strategies ◽  
N2o Emissions ◽  
Nitrification Inhibitors ◽  
Urease Inhibitors ◽  
N Fertilizers ◽  
N Sources ◽  
Meta Analyses

Stabilized N sources are N fertilizers treated with urease inhibitors, nitrification inhibitors, or a combination of both. They can comprise “right source” in many situations in which 4R Nutrient Stewardship is implemented. Several meta-analyses demonstrate that nitrification inhibitors with and without urease inhibitors consistently reduce N2O emissions. Nitrification inhibitors are effective at decreasing NO3- leaching but can increase ammonia volatilization, while urease inhibitors are effective at preventing volatilization losses.

scholarly journals Modelling nitrification inhibitor effects on N<sub>2</sub>O emissions after fall- and spring-applied slurry by reducing nitrifier NH<sub>4</sub><sup>+</sup> oxidation rate

2020 ◽  
Vol 17 (7) ◽  
pp. 2021-2039 ◽  
Author(s):  
Robert F. Grant ◽  
Sisi Lin ◽  
Guillermo Hernandez-Ramirez
Keyword(s):  
Indirect Effects ◽  
Nitrification Inhibitor ◽  
Ecosystem Model ◽  
Time Dependent ◽  
N2o Emissions ◽  
Nitrification Inhibitors ◽  
Direct And Indirect Effects ◽  
Parameter Evaluation ◽  
Meta Analyses ◽  
Over Time

Abstract. Reductions in N2O emissions from nitrification inhibitors (NI) are substantial but remain uncertain because measurements of N2O emissions are highly variable and discontinuous. Mathematical modelling may offer an opportunity to estimate these reductions if the processes causing variability in N2O emissions can be accurately simulated. In this study, the effect of NI was simulated with a simple, time-dependent algorithm to slow NH4+ oxidation in the ecosystem model ecosys. Slower nitrification modelled with NI caused increases in soil NH4+ concentrations and reductions in soil NO3- concentrations and in N2O fluxes that were consistent with those measured following fall and spring applications of slurry over 2 years from 2014 to 2016. The model was then used to estimate direct and indirect effects of NI on seasonal and annual emissions. After spring slurry applications, NI reduced N2O emissions modelled and measured during the drier spring of 2015 (35 % and 45 %) less than during the wetter spring of 2016 (53 % and 72 %). After fall slurry applications, NI reduced modelled N2O emissions by 58 % and 56 % during late fall in 2014 and 2015 and by 8 % and 33 % during subsequent spring thaw in 2015 and 2016. Modelled reductions were consistent with those from meta-analyses of other NI studies. Simulated NI activity declined over time so that reductions in N2O emissions modelled with NI at an annual timescale were relatively smaller than those during emission events. These reductions were accompanied by increases in NH3 emissions and reductions in NO3- losses with NI that caused changes in indirect N2O emissions. With further parameter evaluation, the addition of this algorithm for NI to ecosys may allow emission factors for different NI products to be derived from annual N2O emissions modelled under diverse site, soil, land use and weather.

scholarly journals Effects of Enhanced-Efficiency Nitrogen Fertilizers on Soil Microbial Biomass and Respiration in Tropical Soil Under Upland Rice Cultivation

2021 ◽  
Vol 13 (6) ◽  
pp. 31
Author(s):  
Vinícius Almeida Oliveira ◽  
Eliana Paula Fernandes Brasil ◽  
Welldy Gonçalves Teixeira ◽  
Felipe Corrêa Veloso dos Santos ◽  
Atila Reis da Silva
Keyword(s):  
Microbial Biomass ◽  
Soil Respiration ◽  
Soil Microbial Biomass ◽  
Upland Rice ◽  
Microbial Biomass N ◽  
Urease Inhibitors ◽  
Soil Microbial ◽  
N Fertilizers ◽  
N Sources ◽  
N Rates

While over-use of N fertilizers can suppress microbial biomass, application of urease inhibitors is known to be a potential way to rebuilt microbial diversity and improve soil functions. However, the hypothesis of this study is that the application of N fertilizers regardless of the source would increase soil microbial biomass and reduce soil respiration. A two-year field experiment was conducted to assess the effects of enhanced-efficiency N sources on soil microbial biomass, and soil respiration. The experiment was set up in a randomized block design in a 3 &times; 4 + 1 factorial scheme, with four replicates. Treatments comprised three sources (conventional uncoated urea, NBPT (N-(n-butyl) thiophosphoric triamide)-treated urea, and polymer-coated urea) and four rates (30, 60, 90 and 120 kg ha-1) of N, in addition to a control treatment (no fertilizer application). Microbial biomass C (MBC) and microbial biomass N (MBN), and soil respiration (C-CO2 and qCO2) were determined in upland rice rhizosphere in each crop season. Responses of soil microbial properties to N fertilization were dependent on the N rates, but no significant effect of the N sources was observed. All measured parameters, except MBC in the first season and C-CO2 in the second season, were increased with increasing N rates. However, the application of N higher than 60 kg ha-1 suppressed soil microbial biomass, as well as soil respiration. &nbsp;Therefore, the lack of response by added urease inhibitors to the N sources indicate that optimizing N rates for upland rice production is a far more effective option for improving soil microbial community than using enhanced-efficiency N sources.

scholarly journals Nitrogen loss by volatilization of nitrogen fertilizers applied to coffee orchard

2016 ◽  
Vol 40 (2) ◽  
pp. 173-183 ◽  
Author(s):  
Anderson William Dominghetti ◽  
Douglas Ramos Guelfi ◽  
Rubens José Guimarães ◽  
André Luiz Carvalho Caputo ◽  
Carlos Roberto Spehar ◽  
...  
Keyword(s):  
Ammonium Nitrate ◽  
Ammonia Volatilization ◽  
Nitrogen Loss ◽  
Nitrogen Fertilizers ◽  
Elementary Sulfur ◽  
Coffee Plantations ◽  
Anionic Polymers ◽  
N Sources ◽  
Before And After ◽  
Plastic Resin

ABSTRACT Ammonia volatilization (N-NH3) is one of the main pathways of Nitrogen loss reducing nitrogen use efficiency in coffee orchard. This work aimed at quantifying ammonia volatilization (N-NH3) losses from N-sources to be used in coffee plantations fertilization in Brazil. The experiment was conducted in the field on a dystrophic red latosol (Ferralsol in FAO's classification) at the Coffee Research Sector, University of Lavras, MG, Brazil. The experimental design was of complete randomized blocks with three repetitions of the following treatments: conventional urea, ammonium nitrate and urea + 0.15% Cu and 0.4% B, urea + anionic polymers, urea + elementary sulfur (S0) + polymers, and urea + plastic resin. These N sources were split into three doses of 150 kg ha-1 and band applied. The N-NH3 losses by volatilization and variations of pH (H2O) were measured, before and after N application. The N-sources contributed to reduce the soil pH, measured after the third nitrogen fertilization. The N-NH3 losses by volatilization (average from three applications) was as follows: urea + anionic polymers (35.8%) > conventional urea (31.2%) = urea + S0 + polymers (31.0%) > urea + 0.15% Cu + 0.4 % B (25.6%) > urea + plastic resin (8.6%) = ammonium nitrate (1.0%).

scholarly journals Modelling Nitrification Inhibitor Effects on N<sub>2</sub>O Emissions after Fall and Spring-Applied Slurry by Reducing Nitrifier NH<sub>4</sub><sup>+</sup> Oxidation Rate

2019 ◽  
Author(s):  
Robert F. Grant ◽  
Sisi Lin ◽  
Guillermo Hernandez-Ramirez
Keyword(s):  
Indirect Effects ◽  
Nitrification Inhibitor ◽  
Ecosystem Model ◽  
N2o Emissions ◽  
Nitrification Inhibitors ◽  
Direct And Indirect Effects ◽  
Annual Time Scale ◽  
Parameter Evaluation ◽  
Meta Analyses ◽  
Annual Time

Abstract. Reductions in N2O emissions from nitrification inhibitors (NI) are substantial, but remain uncertain because measurements of N2O emissions are highly variable and discontinuous. Mathematical modelling may offer an opportunity to estimate these reductions if the processes causing variability in N2O emissions can be accurately simulated. In this study, the effect of NI was simulated with a simple, time-dependent algorithm to slow NH4&amp;plus; oxidation in the ecosystem model ecosys. Slower nitrification modelled with NI caused increases in soil NH4&amp;plus; concentrations and reductions in soil NO3− concentrations and in N2O fluxes that were consistent with those measured following fall and spring applications of slurry over two years from 2014 to 2016. The model was then used to estimate direct and indirect effects of NI on seasonal and annual emissions. After spring slurry applications, NI reduced N2O emissions modelled and measured during the drier spring of 2015 (35 % and 45%) less than during the wetter spring of 2016 (53 % and 72 %). After fall slurry applications, NI reduced modelled N2O emissions by 58 % and 56 % during late fall in 2014 and 2015, and by 8 % and 33 % during subsequent spring thaw in 2015 and 2016. Modelled reductions were consistent with those from meta-analyses of other NI studies. Simulated NI activity declined over time, so that reductions in N2O emissions modelled with NI at an annual time scale were relatively smaller than those during emission events. These reductions were accompanied by increases in NH3 emissions and reductions in NO3− losses with NI that caused changes in indirect N2O emissions. With further parameter evaluation, the addition of this algorithm for NI to ecosys may allow emission factors for different NI products to be derived from annual N2O emissions modelled under diverse site, soil, land use and weather.

scholarly journals More than 50 long-term effects of COVID-19: a systematic review and meta-analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sandra Lopez-Leon ◽  
Talia Wegman-Ostrosky ◽  
Carol Perelman ◽  
Rosalinda Sepulveda ◽  
Paulina A. Rebolledo ◽  
...  
Keyword(s):  
Systematic Review ◽  
Meta Analysis ◽  
Management Strategies ◽  
Original Data ◽  
Long Term Effects ◽  
Pooled Prevalence ◽  
Attention Disorder ◽  
Initial Recovery ◽  
Meta Analyses

AbstractCOVID-19 can involve persistence, sequelae, and other medical complications that last weeks to months after initial recovery. This systematic review and meta-analysis aims to identify studies assessing the long-term effects of COVID-19. LitCOVID and Embase were searched to identify articles with original data published before the 1st of January 2021, with a minimum of 100 patients. For effects reported in two or more studies, meta-analyses using a random-effects model were performed using the MetaXL software to estimate the pooled prevalence with 95% CI. PRISMA guidelines were followed. A total of 18,251 publications were identified, of which 15 met the inclusion criteria. The prevalence of 55 long-term effects was estimated, 21 meta-analyses were performed, and 47,910 patients were included (age 17–87 years). The included studies defined long-COVID as ranging from 14 to 110 days post-viral infection. It was estimated that 80% of the infected patients with SARS-CoV-2 developed one or more long-term symptoms. The five most common symptoms were fatigue (58%), headache (44%), attention disorder (27%), hair loss (25%), and dyspnea (24%). Multi-disciplinary teams are crucial to developing preventive measures, rehabilitation techniques, and clinical management strategies with whole-patient perspectives designed to address long COVID-19 care.

Combining nitrification inhibitors with a reduced N rate maintains yield and reduces N2O emissions in sweet corn

2022 ◽  
Author(s):  
Jesse Muller ◽  
Daniele De Rosa ◽  
Johannes Friedl ◽  
Massimiliano De Antoni Migliorati ◽  
David Rowlings ◽  
...  
Keyword(s):  
Sweet Corn ◽  
N2o Emissions ◽  
Nitrification Inhibitors

scholarly journals Ammonia volatilization in no-till system in the south-central region of the State of Paraná, Brazil

2010 ◽  
Vol 34 (5) ◽  
pp. 1677-1684 ◽  
Author(s):  
Sandra Mara Vieira Fontoura ◽  
Cimélio Bayer
Keyword(s):  
Controlled Release ◽  
Central Region ◽  
Ammonia Volatilization ◽  
Nh3 Volatilization ◽  
The South ◽  
N Application ◽  
N Sources ◽  
South Central ◽  
N Source ◽  
No Till

Ammonia (NH3) volatilization can reduce the efficiency of urea applied to the surface of no-till (NT) soils. Thus, the objectives of this study were to evaluate the magnitude of NH3 losses from surface-applied urea and to determine if this loss justifies the urea incorporation in soil or its substitution for other N sources under the subtropical climatic conditions of South-Central region of Paraná State, Brazil. The experiment, performed over four harvesting seasons in a clayey Hapludox followed a randomized block design with four replicates. A single dose of N (150 kg ha-1) to V5 growth stage of corn cultivated under NT system was applied and seven treatments were evaluated, including surface-applied urea, ammonium sulfate, ammonium nitrate, urea with urease inhibitor, controlled-release N source, a liquid N source, incorporated urea, and a control treatment with no N application. Ammonia volatilization was evaluated for 20 days after N application using a semi-open static system. The average cumulative NH3 loss due to the superficial application of urea was low (12.5 % of the applied N) compared to the losses observed in warmer regions of Southeastern Brazil (greater than 50 %). The greatest NH3 losses were observed in dry years (up to 25.4 % of the applied N), and losses decreased exponentially as the amount of rainfall after N application increased. Incorporated urea and alternative N sources, with the exception of controlled-release N source, decreased NH3 volatilization in comparison with surface-applied urea. Urea incorporation is advantageous for the reduction of NH3 volatilization; however, other aspects as its low operating efficiency should be considered before this practice is adopted. In the South-Central region of Paraná, the low NH3 losses from the surface-applied urea in NT system due to wet springs and mild temperatures do not justify its replacement for other N sources.

scholarly journals Identifying Sustainable Nitrogen Management Practices for Tea Plantations

Nitrogen ◽  
2022 ◽  
Vol 3 (1) ◽  
pp. 43-57
Author(s):  
Rhys Rebello ◽  
Paul J. Burgess ◽  
Nicholas T. Girkin
Keyword(s):  
Management Practices ◽  
Synergistic Effects ◽  
Soil Health ◽  
N Leaching ◽  
N2o Emissions ◽  
Nitrification Inhibitors ◽  
Financial Barriers ◽  
Trade Offs ◽  
High Yields ◽  
N Management

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.

scholarly journals Efficacy of Non-Halofuginone-Based Strategies to Prevent or Treat Cryptosporidiosis in Bovine Calves: A Systematic Review

2020 ◽  
Author(s):  
Julii Brainard ◽  
Charlotte C. Hammer ◽  
Kevin Tyler ◽  
Paul R. Hunter
Keyword(s):  
Systematic Review ◽  
Weight Gain ◽  
Kinase Inhibitors ◽  
Management Strategies ◽  
Evidence Base ◽  
High Morbidity ◽  
Case Control Studies ◽  
Nutritional Strategy ◽  
Before And After ◽  
Meta Analyses

Cryptosporidiosis is a common illness in young cattle that causes high morbidity and some mortality. A common prophylactic treatment are halofuginone products but it seems likely disease could be reduced by other other pharmacological products or some management strategies. We undertook a systematic review and meta-analyses on key outcomes for treatment of calves before and after 5 days of age with any management strategy, any nutritional strategy or any non-halofuginone product. A systematic literature search was undertaken with data extracted for outcomes = oocyst shedding, diarrhea, mortality and weight gain. Experiments had to describe results for same age animals in contemporary arms. Control animals had to be observed concurrently in planned experiments (pre-post and case-control studies were not eligible). Both randomized and other clinically controlled trials were eligible. Results were subgrouped by study design and outcomes were described in detail where at least two articles described the same treatment strategy. 55 articles were found. Significantly lower incidence of oocyst shedding, diarrhea burden and mortality was reported in many experimental arms, especially when animals started treatment before 5 days old. Weight gain was not mostly affected by treatment, however, by three weeks of age. The evidence base is at least encouraging but insufficient about paromomycin, bumped kinase inhibitors and azithromycin treatment, especially for diarrhea and oocyst shedding, given late or early. Azithromycin is the most promising of these.

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