Nitrous oxide and methane emissions from a Ferralsol as affected by loblolly pine cultivation time in subtropical Brazil.

We hypothesized that the age of loblolly pine stands influences soil methane (CH4) and nitrous oxide (N2O) emissions. This is a relevant topic to be studied in subtropical Brazil, where the pine plantation area is increasing considerably. We evaluated N2O and CH4 emissions for two years in a Ferralsol under loblolly pine (Pinus taeda L.) stands of 1, 9 and 18 year-olds and a native forest (NF). We calculated the net CO2eq emission by considering the N2O and CH4 emissions from soil and the carbon (C) accumulation as litter in the forest floor. The soil N2O emission reduced gradually over the loblolly pine cultivation years, whereas CH4 uptake rates showed no clear pattern. Soil N2O emission showed a positive relationship with soil temperature in NF, and with soil ammonium and nitrate intensities in the pine stands. Soil CH4 uptake was inversely related to water-filled pore space in the pine stands, but this relationship was not observed in NF. The soil CH4 uptake rate was 4.6 times higher (p < 0.10) in NF than the average uptake in loblolly pine stands. On the other hand, soil N2O emissions in 9 and 18-year-old stands were similar (p > 0.10) to those in NF (1.3 kg N ha-1 yr-1). Our results suggest that cultivation with loblolly pine for 18 years can reduce soil N2O emission, and the uptake of CH4 in this system offsets 17 % of N2O emissions. Furthermore, the C accumulation as litter in the forest floor of the mature pine stands (9- and 18-year-old) generated a net emission of -1.6 Mg CO2eq ha-1 yr-1, showing to be an expressive offsetting mechanism. Therefore, we conclude that aged loblolly forests can reach N2O emissions levels comparable to those of NF, and the C sequestration in these forests floor can significantly contribute to offset N2O emissions and act as sink for net atmospheric CO2eq.

DATAMAN: A global database of methane, nitrous oxide, and ammonia emission factors for livestock housing and outdoor storage of manure.

Livestock manure management systems can be significant sources of nitrous oxide (N2 O), methane (CH4 ), and ammonia (NH3 ) emissions. Many studies have been conducted to improve our understanding of the emission processes and to identify influential variables in order to develop mitigation techniques adapted to each manure management step (animal housing, outdoor storage, and manure spreading to land). The international project DATAMAN (http://www.dataman.co.nz) aims to develop a global database on greenhouse gases (N2 O, CH4 ) and NH3 emissions from the manure management chain to refine emission factors (EFs) for national greenhouse gas and NH3 inventories. This paper describes the housing and outdoor storage components of this database. Relevant information for different animal categories, manure types, livestock buildings, outdoor storage, and climatic conditions was collated from published peer reviewed research, conference papers, and existing databases published between 1995 and 2021. In the housing database, 2024 EFs were collated (63% for NH3 , 19.5% for CH4 , and 17.5% for N2 O). The storage database contains 654 NH3 EFs from 16 countries, 243 CH4 EFs from 13 countries, and 421 N2 O EFs from 17 countries. Across all gases, dairy cattle and swine production in temperate climate zones are the most represented animal and climate categories. As for the housing database, the number of EFs for the tropical climate zone is under-represented. The DATAMAN database can be used for the refinement of national inventories and better assessment of the cost-effectiveness of a range of mitigation strategies.

Management and implications of using nitrification inhibitors to reduce nitrous oxide emissions from urine patches on grazed pasture soils - A review.

Livestock urine patches are the main source of nitrous oxide (N2O) emissions in pastoral system, and nitrification inhibitors (NIs) have been widely investigated as a N2O mitigation strategy. This study reviews the current understanding of the effect of NIs use on N2O emissions from urine patches, including the factors that affect their efficacy, as well as the unintended consequences of NIs use. It brings together the fundamental aspects of targeted management of urine patches for reducing N2O emissions involving inhibitors. The available literature of 196 datasets indicates that dicyandiamide (DCD), 3,4-dimethylpyrazole phosphate (DMPP), and 2-chloro-6-(trichloromethyl) pyridine (nitrapyrin) reduced N2O emissions from urine patches by 44 ± 2%, 28 ± 38% and 28 ± 5%, (average ± s.e.), respectively. DCD also increased pasture dry matter and nitrogen (N) uptake by 13 ± 2% and 15 ± 3%, (average ± s.e.), respectively. The effect of DMPP and nitrapyrin on pasture dry matter and N uptake, assessed in only one study, was not significant. It also suggests that harmonizing the timing of inhibitor use with urine-N transformation increase the efficacy of NIs. No negative impacts on non-targeted soil and aquatic organisms have been reported with the recommended rate of DCD applied to urine and recommended applications of DMPP and nitrapyrin for treated mineral fertilisers and manures. However, there was evidence of the presence of small amounts of DCD residues in milk products as a result of its use on livestock grazed pasture. DMPP and nitrapyrin can also enter the food chain via grazing livestock. The study concludes that for the use of NIs in livestock grazed systems, research is needed to establish acceptable maximum residue level (MRL) of NIs in soil, plant, and animal products, and develop technologies that optimise physical mixing between NIs and urine patches.

Global Research Alliance N2 O chamber methodology guidelines: Statistical considerations, emission factor calculation, and data reporting.

Static chambers are often used for measuring nitrous oxide (N2 O) fluxes from soils, but statistical analysis of chamber data is challenged by the inherently heterogeneous nature of N2 O fluxes. Because N2 O chamber measurements are commonly used to assess N2 O mitigation strategies or to determine country-specific emission factors (EFs) for calculating national greenhouse gas inventories, it is important that statistical analysis of the data is sound and that EFs are robustly estimated. This paper is one of a series of articles that provide guidance on different aspects of N2 O chamber methodologies. Here, we discuss the challenges associated with statistical analysis of heterogeneous data, by summarizing statistical approaches used in recent publications and providing guidance on assessing normality and options for transforming data that follow a non-normal distribution. We also recommend minimum requirements for reporting of experimental and metadata of N2 O studies to ensure that the robustness of the results can be reliably evaluated. This includes detailed information on the experimental site, methodology and measurement procedures, gas analysis, data and statistical analyses, and approaches to generate EFs, as well as results of ancillary measurements. The reliability, robustness, and comparability of soil N2 O emissions data will be improved through (a) application, and reporting, of more rigorous methodological standards by researchers and (b) greater vigilance by reviewers and scientific editors to ensure that all necessary information is reported in scientific publications.

Does Brachiaria humidicola and dicyandiamide reduce nitrous oxide and ammonia emissions from cattle urine patches in the subtropics?

Nitrous oxide (N2O) emissions from pasture-based livestock systems represent 34% of Brazil's agricultural greenhouse gas emissions. The forage species Brachiaria humidicola is known for its biological nitrification inhibition (BNI) capacity and N2O emissions reduction ability from urine patches under tropical conditions. However, there is little information about the effect of BNI on N2O emission and ammonia (NH3) volatilisation in the subtropics. This study aimed to: (i) evaluate the potential of Brachiaria humidicola, compared with Panicum maximum (Jacq. cv. Áries; guinea grass), a broadly used grass (with no BNI capacity), to reduce N2O emissions under subtropical conditions; (ii) determine the efficacy of nitrification inhibitor dicyandiamide (DCD) to decrease N2O emissions; and (iii) determine the effect of brachiaria and DCD application on NH3 volatilisation. A field experiment was carried out using a Cambisol, where cattle urine ± DCD was applied to brachiaria and guinea grass. Over the 67-day measurement period, cumulative N2O emissions were 20% lower from urine patches in the brachiaria treatment (1138 mg N m-2, Emission factor = 1.06%) compared to guinea grass (1436 mg N m-2, Emission factor = 1.33%) (P < .10). A greenhouse experiment, using pots with the same treatments as in the field experiment, suggested that this could have been due to lower soil nitrate levels under brachiaria forage compared to guinea grass, indicating that BNI could be a possible mechanism for lower N2O emissions from brachiaria. The DCD application was effective in both forage species, decreasing N2O emissions by 40-50% (P < .10) compared with the urine only treatment. Approximately 25% of the urine applied N was lost via NH3 volatilisation, however the NH3 loss was not affected by forage species or DCD application (P > .10). Overall, the results demonstrated that brachiaria and DCD use are strategies that can reduce N2O emissions from urine patches.

The efficacy of Plantago lanceolata for mitigating nitrous oxide emissions from cattle urine patches.

Urine deposited by grazing animals is the main source of nitrous oxide (N2O) emissions in New Zealand. Recent studies have suggested that certain pasture plants, for example plantain (Plantago lanceolata), can curb N2O emissions from livestock systems. This study aimed to i) evaluate the potential of plantain for reducing N2O emissions from cattle urine patches; ii) determine the effect of including plantain in animal diets on urine-N loading and its influence on N2O emissions; and, iii) evaluate whether any effects on N2O emissions reduction could be attributed to a 'urine' or a 'plant' effect. A static chamber method was used to measure N2O fluxes from urine collected from cows fed a 0, 15, 30 or 45% plantain mixed with "standard" ryegrass/clover (Lolium perenne/Trifolium repens) diet and applied to plots with the corresponding percentage of plantain in the sward. In addition, we measured N2O emissions from different proportions of plantain in the sward (0, 30, 60 and 100%) that received urine collected from cows fed on ryegrass/clover. The urine N loading rates of animals fed plantain, significantly reduced with increasing proportions of plantain in the diet (r2 = 0.987, P < 0.01). There was a trend of lower N2O emissions with an increasing proportion of plantain in the diet (r2 = 0.830, P < 0.08). However, there was no significantly difference in the N2O emission factors (P > 0.10). Following applications of standard urine, total N2O emissions and emission factor reduced linearly as the proportion of plantain in the sward increased (r2 = 0.969, P < 0.05 and 0.974, P < 0.05, respectively). The results suggest that the efficacy of plantain as a N2O mitigation option is due to both a reduction in urinary N excretion and a plant effect. The latter could be due to biological nitrification inhibition (BNI) caused by the release of root exudates and/or changes in the soil microclimate.

INITIAL CLINICAL PRESENTATION IN CASES OF INBORN ERRORS OF METABOLISM IN A REFERENCE CHILDREN'S HOSPITAL: STILL A DIAGNOSTIC CHALLENGE. / APRESENTAÇÃO CLÍNICA INICIAL DOS CASOS DE ERROS INATOS DO METABOLISMO DE UM HOSPITAL PEDIÁTRICO DE REFERÊNCIA: AINDA UM DESAFIO DIAGNÓSTICO.

OBJECTIVE: To assess the initial clinical presentation of confirmed cases of inborn errors of metabolism (IEM) at a reference facility for pediatric care. METHODS: Cross-sectional, observational and descriptive study with data collection of outpatients, from January 2009 to December 2013. Inclusion criterion: referral to IEM investigation. Exclusion criterion: prior diagnosis of IEM. Analyzed variables: identification data; status of diagnostic investigation; family history of IEM; initial clinical presentation, laboratory abnormalities related to the hypothesis of IEM. Descriptive statistical methods were used in the data analysis. RESULTS: We included 144 patients in the study, of which 62.5% were male. The mean and median ages were, respectively, 4.3 ± 4.7 years and 2.6 years. Twelve patients (8.3%) had a confirmed diagnosis of IEM (three with aminoacidopathies, three with organic acidemias, two with urea cycle disorders and four with lysosomal storage diseases). Cognitive impairment and seizures were the initial signs and symptoms, followed by growth retardation, neuropsychomotor developmental delay, seizures and hepatomegaly. The main laboratory abnormalities in the diagnosis were hyperammonemia and metabolic acidosis. CONCLUSIONS: The diagnosis of IEM still creates challenges to the pediatric practice. In this study, we identified the following factors: difficulty to access specific laboratory tests, reduced number of experts and poor dissemination of knowledge among healthcare schools. The early diagnosis of IEM majorly impacts the treatment and prevention of sequelae and should be considered in the initial diagnostic hypotheses.

OBJETIVO: Avaliar a apresentação clínica inicial dos casos com diagnóstico confirmado de erros inatos do metabolismo (EIM) em um serviço de referência em atendimento pediátrico. MÉTODOS: Estudo clínico, observacional, com delineamento transversal e de coleta retrospectiva em consulta ambulatorial de 2009 a 2013. Critério de inclusão: paciente encaminhado para investigação de EIM. Critério de exclusão: diagnóstico prévio de EIM. Variáveis analisadas: dados de identificação; situação atual da investigação diagnóstica; história familiar; apresentação clínica inicial; alterações laboratoriais. Os dados foram analisados por meio de estatística descritiva. RESULTADOS: Incluídos 144 pacientes, sendo 62,5% do sexo masculino. A mediana de idade foi de 2,6 anos e a média de 4,3 ± 4,7 anos. Doze pacientes (8,3%) tiveram o diagnóstico confirmado (três com aminoacidopatias, três com acidemias orgânicas, dois com distúrbios do ciclo da ureia e quatro com doenças de depósito lisossômico). Déficit cognitivo e convulsões foram os sinais e sintomas iniciais; seguidos de retardo de crescimento, atraso do desenvolvimento neuropsicomotor, convulsões e hepatomegalia. As principais alterações laboratoriais encontradas foram hiperamonemia e acidose metabólica. CONCLUSÕES: O diagnóstico dos EIM ainda traz desafios à prática pediátrica. Neste estudo foram identificados os seguintes fatores: dificuldade de acesso aos exames laboratoriais específicos, reduzido número de especialistas e pouca difusão do conhecimento nas faculdades da área da saúde. O diagnóstico precoce dos EIM tem impacto fundamental no tratamento e prevenção das sequelas, devendo ser considerado já nas hipóteses diagnósticas iniciais.

Apresentação clínica inicial dos casos de erros inatos do metabolismo de um hospital pediátrico de referência: ainda um desafio diagnóstico / Initial clinical presentation in cases of inborn errors of metabolism in a reference children's hospital: still a diagnostic challenge

RESUMO Objetivo: Avaliar a apresentação clínica inicial dos casos com diagnóstico confirmado de erros inatos do metabolismo (EIM) em um serviço de referência em atendimento pediátrico. Métodos: Estudo clínico, observacional, com delineamento transversal e de coleta retrospectiva em consulta ambulatorial de 2009 a 2013. Critério de inclusão: paciente encaminhado para investigação de EIM. Critério de exclusão: diagnóstico prévio de EIM. Variáveis analisadas: dados de identificação; situação atual da investigação diagnóstica; história familiar; apresentação clínica inicial; alterações laboratoriais. Os dados foram analisados por meio de estatística descritiva Resultados: Incluídos 144 pacientes, sendo 62,5% do sexo masculino. A mediana de idade foi de 2,6 anos e a média de 4,3 ± 4,7 anos. Doze pacientes (8,3%) tiveram o diagnóstico confirmado (três com aminoacidopatias, três com acidemias orgânicas, dois com distúrbios do ciclo da ureia e quatro com doenças de depósito lisossômico). Déficit cognitivo e convulsões foram os sinais e sintomas iniciais; seguidos de retardo de crescimento, atraso do desenvolvimento neuropsicomotor, convulsões e hepatomegalia. As principais alterações laboratoriais encontradas foram hiperamonemia e acidose metabólica. Conclusões: O diagnóstico dos EIM ainda traz desafios à prática pediátrica. Neste estudo foram identificados os seguintes fatores: dificuldade de acesso aos exames laboratoriais específicos, reduzido número de especialistas e pouca difusão do conhecimento nas faculdades da área da saúde. O diagnóstico precoce dos EIM tem impacto fundamental no tratamento e prevenção das sequelas, devendo ser considerado já nas hipóteses diagnósticas iniciais.

ABSTRACT Objective: To assess the initial clinical presentation of confirmed cases of inborn errors of metabolism (IEM) at a reference facility for pediatric care. Methods: Cross-sectional, observational and descriptive study with data collection of outpatients, from January 2009 to December 2013. Inclusion criterion: referral to IEM investigation. Exclusion criterion: prior diagnosis of IEM. Analyzed variables: identification data; status of diagnostic investigation; family history of IEM; initial clinical presentation, laboratory abnormalities related to the hypothesis of IEM. Descriptive statistical methods were used in the data analysis. Results: We included 144 patients in the study, of which 62.5% were male. The mean and median ages were, respectively, 4.3 ± 4.7 years and 2.6 years. Twelve patients (8.3%) had a confirmed diagnosis of IEM (three with aminoacidopathies, three with organic acidemias, two with urea cycle disorders and four with lysosomal storage diseases). Cognitive impairment and seizures were the initial signs and symptoms, followed by growth retardation, neuropsychomotor developmental delay, seizures and hepatomegaly. The main laboratory abnormalities in the diagnosis were hyperammonemia and metabolic acidosis. Conclusions: The diagnosis of IEM still creates challenges to the pediatric practice. In this study, we identified the following factors: difficulty to access specific laboratory tests, reduced number of experts and poor dissemination of knowledge among healthcare schools. The early diagnosis of IEM majorly impacts the treatment and prevention of sequelae and should be considered in the initial diagnostic hypotheses.