N2O emission factors for organic amendments in Japan from measurement campaign and systematic review.

Organic amendments are important sources of nitrous oxide (N2O) emissions from agricultural soils. In 2020, the total amount of N in organic amendments applied to Japanese agricultural soils (440 ktN) was larger than that of synthetic fertilizer (374 ktN). However, N2O emissions from organic amendments were estimated by using the country-specific N2O emission factor (EF) for synthetic fertilizer (0.31 % for rice paddy, 2.9 % for tea, and 0.62 % for other crops) in the National Greenhouse Gas Inventory Report of Japan. Thus, we conducted a N2O flux measurement campaign at 12 different experimental sites across Japan to estimate fertilizer-induced N2O EFs for major organic amendments in Japan, that is, poultry manure compost, swine manure compost, cattle manure compost, and organic fertilizer pellets. In addition, we conducted systematic review of N2O emissions and EFs for organic amendments, including data from our measurement campaign and published data from peer-reviewed papers in Japan. The final dataset, including the field measurement campaign and published data, resulted in 404 observations (including synthetic fertilizer and zero-N control) in 29 sites. Results showed that soil type affected EFs, that is, the mean EF of Andosols was lower than that of non-Andosols, which is similar to the case of EFs for synthetic fertilizer. Mean EFs for poultry manure compost, swine manure compost, cattle manure (compost and slurry), and non-animal manure organic fertilizers were 0.83 % (uncertainty range of 2.5th and 97.5th percentile: 0.09 % to 3.46 %), 0.70 % (0.02 % to 2.45 %), 0.39 % (0.00 % to 1.62 %), and 1.16 % (0.41 % to 3.03 %), respectively, when weighted by area of soil types. The mean EF of all organic amendments was 0.84 % (0.00 % to 2.91 %), when the area of soil type and amount of organic amendment used in Japan were considered. Our study provides country-specific EFs to estimate N2O emission from organic amendments in Japan.

Aging well: an update.

Population aging is a global phenomenon, and Japan is one of the front-runners of rapidly aging societies. In 2030, one-third of the Japanese population will be at least 65 years of age and 20% will be at least 75 years of age. The working age population is shrinking. Healthy aging is a crucial issue for both individual well-being and the sustainability of society. Along with biomedical research, the importance of the living environment and lifestyle has been long recognized and extensively studied. The issues have been identified and now it is time to establish solutions and actions - action-targeted research. The Institute of Gerontology at the University of Tokyo launched a social experiment, redesigning existing communities where people could live for 100 years and remain healthy, active, and connected, while still maintaining a sense of security. This requires co-creation by citizens, researchers, government, and industry. The ultimate goal is to make linkages among longevity, health, and wealth, and to build a sustainable society.

Effect of low C/N crop residue input on N2O, NO, and CH4 fluxes from Andosol and Fluvisol fields.

Crop residues are produced from agriculture in large amounts globally. Crop residues are known to be a source of nitrous oxide (N2O); however, contrasting results have been reported. Furthermore, the effect of crop residues on nitric oxide (NO) and methane (CH4) fluxes has not been well studied. We investigated N2O, NO, and CH4 fluxes after low C/N crop residue (cabbages and potatoes) inputs to lysimeter fields for two years using with automated flux monitoring system. Lysimeters were filled with two contrasting soil types, Andosol (total C: 33.1 g kg-1; clay: 18%) and Fluvisol (17.7 g kg-1; 36%). Nitrogen application rates were 250 kg N ha-1 of synthetic fertilizer and 272 kg N ha-1 of cow manure compost for cabbage, and 120 kg N ha-1 of synthetic fertilizer and 136 kg N ha-1 of cow manure compost for potato, respectively. Large N2O peaks were observed after crop residues were left on the surface of the soil for 1 to 2 weeks in summer, but not in winter. The annual N2O emission factors (EFs) for cabbage residues were 3.02% and 5.37% for Andosol and Fluvisol, respectively. Those for potatoes were 7.51% and 5.10% for Andosol and Fluvisol, respectively. The EFs were much higher than the mean EFs of synthetic fertilizers from Japan's agricultural fields (0.62%). Moreover, the EFs were much higher than the Intergovernmental Panel on Climate Change (IPCC) default N2O EFs for synthetic fertilizers and crop residues (1%). The annual NO EFs for potatoes were 1.35% and 2.44% for Andosol and Fluvisol, respectively, while no emission was observed after cabbage residue input. Crop residues did not affect CH4 uptake by soil. Our results suggest that low C/N crop residue input to soils can create a hotspot of N2O emission, when temperature and water conditions are not limiting factors for microbial activity.

A review of indirect N2O emission factors from agricultural nitrogen leaching and runoff to update of the default IPCC values.

Indirect N2O emissions from agricultural nitrogen (N) leaching and runoff in water bodies contribute significantly to the global atmospheric N2O budget. However, considerable uncertainty regarding this source remains in the bottom-up N2O inventory. Indirect N2O emission factor associated with N leaching and runoff (EF5; kg N2ON per kg of NO3--N) incorporate three components for groundwater and surface drainage (EF5g), rivers (EF5r), and estuaries (EF5e). The 2006 IPCC default EF5 value was based on a small number of studies available at the time. Here we present the synthesis of 254 measurements of EF5, dissolved N2O, and nitrate from 106 studies. Our results do not support the further downward revision of EF5g by the IPCC and suggest an upward revision of EF5g of 0.0060. The emission factors for groundwater and springs (0.0079) was higher than that for surface drainage (0.0040). The emission factor for lakes, ponds, and reservoirs was 0.0012, whereas that for rivers was 0.0030, and a combined EF5r was 0.0026. Estimated EF5r and EF5e (0.0026) values from the study were close to the current IPCC default values (0.0025 each). We estimated an updated default EF5 value of 0.01 for the refinement of IPCC guidelines.

Indirect N2O emissions with seasonal variations from an agricultural drainage ditch mainly receiving interflow water.

Nitrogen (N)-enriched leaching water may act as a source of indirect N2O emission when it is discharged to agricultural drainage ditches. In this study, indirect N2O emissions from an agricultural drainage ditch mainly receiving interflow water were measured using the static chamber-gas chromatography technique during 2012-2015 in the central Sichuan Basin in southwestern China. We found the drainage ditch was a source of indirect N2O emissions contributing an inter-annual mean flux of 6.56 ±â€¯1.12 µg N m-2 h-1 and a mean indirect N2O emission factor (EF5g) value of 0.03 ±â€¯0.003%. The mean EF5g value from literature review was 0.51%, which was higher than the default EF5g value (0.25%) proposed by the Intergovernmental Panel on Climate Change (IPCC) in 2006. Our study demonstrated that, more in situ observations of N2O emissions as regards N leaching are required, to account for the large variation in EF5g values and to improve the accuracy and confidence of the default EF5g value. Indirect N2O emissions varied with season, higher emissions occurred in summer and autumn. These seasonal variations were related to drainage water NO3--N concentration, temperature, and precipitation. Our results showed that intensive precipitation increased NO3--N concentrations and N2O emissions, and when combined with warmer water temperatures, these may have increased the denitrification rate that led to the higher summer and autumn N2O emissions in the studied agricultural drainage ditch.

Effect of dolomite and biochar addition on N2O and CO2 emissions from acidic tea field soil.

A laboratory study was conducted to study the effects of liming and different biochar amendments on N2O and CO2 emissions from acidic tea field soil. The first experiment was done with three different rates of N treatment; N 300 (300 kg N ha-1), N 600 (600 kg N ha-1) and N 900 (900 kg N ha-1) and four different rates of bamboo biochar amendment; 0%, 0.5%, 1% and 2% biochar. The second experiment was done with three different biochars at a rate of 2% (rice husk, sawdust, and bamboo) and a control and lime treatment (dolomite) and control at two moisture levels (50% and 90% water filled pore space (WFPS)). The results showed that dolomite and biochar amendment significantly increased soil pH. However, only biochar amendment showed a significant increase in total carbon (C), C/N (the ratio of total carbon and total nitrogen), and C/IN ratio (the ratio of total carbon and inorganic nitrogen) at the end of incubation. Reduction in soil NO3--N concentration was observed under different biochar amendments. Bamboo biochar with the rates of 0.5, 1 and 2% reduced cumulative N2O emission by 38%, 48% and 61%, respectively, compare to the control soil in experiment 1. Dolomite and biochar, either alone or combined significantly reduced cumulative N2O emission by 4.6% to 32.7% in experiment 2. Reduction in N2O production under biochar amendment was due to increases in soil pH and decreases in the magnitude of mineral-N in soil. Although, both dolomite and biochar increased cumulative CO2 emission, only biochar amendment had a significant effect. The present study suggests that application of dolomite and biochar to acidic tea field soil can mitigate N2O emissions.

Convoys of Social Relations in Cross-National Context.

Purpose of the Study: This study examines national variations in social networks among older adults across 4 countries in diverse regions of the world: Japan, Lebanon, Mexico, and the United States. The aim is to provide insights into universal as well as unique attributes of social networks in later life. Design and Methods: The analyses examine convoy characteristics among adults aged 50+ in metropolitan areas of Japan (N = 557), Lebanon (N = 284), Mexico (N = 556), and the United States (N = 583). Data were collected using the hierarchical mapping technique on representative samples in each locale. Multilevel models were conducted by nation to examine whether convoy characteristics vary by age and closeness. Results: Network size and geographic proximity were dimensions of social networks sensitive to national context. By contrast, how age and feelings of closeness varied with contact frequency and the presence of children in networks revealed universal patterns. Furthermore, feelings of closeness varied by age with regard to size and contact frequency in Lebanon, proximity in Japan, and composition in Mexico. Implications: Identifying universal and unique characteristics of social networks in later life provide a preliminary empirical basis upon which to advance a global perspective on convoys of social relations and how they inform policies that can facilitate health and well-being among middle-aged and older people around the world.

Responses of denitrifying bacterial communities to short-term waterlogging of soils.

Agricultural soil is often subjected to waterlogging after heavy rainfalls, resulting in sharp and explosive increases in the emission of nitrous oxide (N2O), an important greenhouse gas primarily released from agricultural soil ecosystems. Previous studies on waterlogged soil examined the abundance of denitrifiers but not the composition of denitrifier communities in soil. Also, the PCR primers used in those studies could only detect partial groups of denitrifiers. Here, we performed pyrosequencing analyses with the aid of recently developed PCR primers exhibiting high coverage for three denitrification genes, nirK, nirS, and nosZ to examine the effect of short-term waterlogging on denitrifier communities in soil. We found that microbial communities harboring denitrification genes in the top 5 cm of soil distributed according to soil depth, water-soluble carbon, and nitrate nitrogen. Short-term waterlogging scarcely affected abundance, richness, or the alpha-diversities of microbial communities harboring nirK, nirS, and nosZ genes, but significantly affected their composition, particularly in microbial communities at soil depths of 0 to 1 cm. Our results indicated that the composition of denitrifying microbial communities but not the abundance of denitrifiers in soil was responsive to short-term waterlogging of an agricultural soil ecosystem.

Cultural variation in communal versus exchange norms: Implications for social support.

Whereas an interdependent cultural view of self has been linked to communal norms and to socially supportive behavior, its relationship to social support has been called into question in research suggesting that discomfort in social support is associated with an interdependent cultural view of self (e.g., Taylor et al., 2004). These contrasting claims were addressed in 2 studies conducted among Japanese, Indian, and American adults. Assessing everyday social support, Study 1 showed that Japanese and Americans rely on exchange norms more frequently than Indians among friends, whereas American rely on exchange norms more frequently than Indians and Japanese among siblings. Assessing responses to vignettes, Study 2 demonstrated that Japanese and Americans rely more frequently on exchange norms than Indians, with greatest relational concerns and most negative outlooks on social support observed among Japanese, less among Americans, and least among Indians. Results further indicated that relational concerns mediated the link between exchange norms and negative social support outlooks. Supporting past claims that relational concerns explain cultural variation in discomfort in social support (e.g., Kim, Sherman, & Taylor, 2008), the findings underscore the need to take into account as well the role of exchange norms in explaining such discomfort. The findings also highlight the existence of culturally variable approaches to exchange and call into question claims that discomfort in social support can be explained in terms of the global concept of an interdependent cultural view of self. (PsycINFO Database Record

An acid-tolerant ammonia-oxidizing γ-proteobacterium from soil.

Nitrification, the microbial oxidation of ammonia to nitrate via nitrite, occurs in a wide range of acidic soils. However, the ammonia-oxidizing bacteria (AOB) that have been isolated from soil to date are acid-sensitive. Here we report the isolation and characterization of an acid-adapted AOB from an acidic agricultural soil. The isolated AOB, strain TAO100, is classified within the Gammaproteobacteria based on phylogenetic characteristics. TAO100 can grow in the pH range of 5-7.5 and survive in highly acidic conditions until pH 2 by forming cell aggregates. Whereas all known gammaproteobacterial AOB (γ-AOB) species, which have been isolated from marine and saline aquatic environments, are halophiles, TAO100 is not phenotypically halophilic. Thus, TAO100 represents the first soil-originated and non-halophilic γ-AOB. The TAO100 genome is considerably smaller than those of other γ-AOB and lacks several genes associated with salt tolerance which are unnecessary for survival in soil. The ammonia monooxygenase subunit A gene of TAO100 and its transcript are higher in abundance than those of ammonia-oxidizing archaea and betaproteobacterial AOB in the strongly acidic soil. These results indicate that TAO100 plays an important role in the nitrification of acidic soils. Based on these results, we propose TAO100 as a novel species of a new genus, Candidatus Nitrosoglobus terrae.

Mitigation of soil N2O emission by inoculation with a mixed culture of indigenous Bradyrhizobium diazoefficiens.

Agricultural soil is the largest source of nitrous oxide (N2O), a greenhouse gas. Soybean is an important leguminous crop worldwide. Soybean hosts symbiotic nitrogen-fixing soil bacteria (rhizobia) in root nodules. In soybean ecosystems, N2O emissions often increase during decomposition of the root nodules. Our previous study showed that N2O reductase can be used to mitigate N2O emission from soybean fields during nodule decomposition by inoculation with nosZ++ strains [mutants with increased N2O reductase (N2OR) activity] of Bradyrhizobium diazoefficiens. Here, we show that N2O emission can be reduced at the field scale by inoculation with a mixed culture of indigenous nosZ+ strains of B. diazoefficiens USDA110 group isolated from Japanese agricultural fields. Our results also suggested that nodule nitrogen is the main source of N2O production during nodule decomposition. Isolating nosZ+ strains from local soybean fields would be more applicable and feasible for many soybean-producing countries than generating mutants.

Nitrogen loss factors of nitrogen trace gas emissions and leaching from excreta patches in grassland ecosystems: A summary of available data.

Patches of excreta voided by grazing animals are nitrogen (N) transformation hotspots in grassland ecosystems and an important source of N trace gas emissions and leaching. Previous studies have focused on individual N losses from excreta, but no quantitative analysis has been performed on all the N losses via N trace gas emissions and leaching. To better understand the fate of N in excreta patches, we summarized 418, 15, 65, 22, 54, 11, and 81 measurements of nitrous oxide (N2O), nitric oxide (NO), ammonia (NH3), and ammonium (NH4+) leaching, nitrate (NO3-) leaching, dissolved organic nitrogen (DON) leaching, and aboveground plant N uptake, respectively. The results based on field studies indicated that the average fractions of N lost via N2O were 0.28%, 0.76%, 0.08%, and 0.35% for cattle dung, cattle urine, sheep dung, and sheep urine, respectively. Only 0.01-0.12% of excreta N was lost via NO, whereas 1.69-12.7%, 0-4.58%, 16.4-24.6%, and 1.43-5.91% were lost by NH3 and NH4+, NO3-, and DON leaching, respectively. Aboveground plant parts assimilated 10.4-31.4% of the excreta N. The N lost via N2O from urine patches decreased as NH3 losses increased, and greater NO3- leaching occurred with lower plant N uptake. The combined N2O emission factors for dung and urine from cattle and sheep were 0.59% and 0.26%, respectively. Each N loss factor was much higher in urine patches than in dung patches, irrespective of animal type. This study provides general estimates of N losses and plant N uptake from excreta patches on grazed grassland based on currently available field data. More field studies are needed in the future with longer measurement periods from a wide range of climate zones to refine these N loss factors.

Associations between social networks and life satisfaction among older Japanese: Does birth cohort make a difference?

Japanese older people experienced drastic changes in family structure and values after World War II at different life stages by birth cohorts. We examined how linkages between different types of social ties and life satisfaction (LS) vary across cohorts, in conjunction with age and survey year differences. Data from face-to-face interviews conducted in 1987, 1999, and 2012 with a nationally representative sample of older Japanese (N = 4,917) were analyzed. The participants were members of 4 birth cohorts (C1: 1901-1912, C2: 1913-1924, C3: 1925-1936, C4: 1937-1949), categorized into 6 groups based on cohort and age at time of measurement (young-old [YO]: 63-74; old-old [OO]: 75-86): C1OO, C2YO, C2OO, C3YO, C3OO, and C4YO. Effects of social networks on LS among the 6 groups were compared simultaneously and separately by gender using the Amos software. There were significant cohort variations in the linkages between family network and LS. The positive association between being married and LS was stronger for later cohorts (C3, C4) among men, whereas that of co-residence with a child and LS was stronger for the earlier cohorts (C1, C2) among women. Moreover, the positive association between meeting with nonfamily members and LS increased from 1987 to 2012 among women, indicating a period effect over a cohort effect. The effects of being married and participation in community groups on LS also changed with age. Our results suggest that linkages between social relations and LS should be interpreted within the context of individual and social changes over time.

Continuous and unattended measurements of the site preference of nitrous oxide emitted from an agricultural soil using quantum cascade laser spectrometry with intercomparison with isotope ratio mass spectrometry.

RATIONALE: The difference between the (15)N natural abundance of (14)N-(15)N-O and (15)N-(14)N-O (site preference; SP) is used to understand the mechanisms underlying N2O emissions from soils. We investigated the use of quantum cascade laser (QCL) absorption spectrometry for continuous and precise analysis of the SP of N2O emitted from a field soil at atmospheric mixing ratios. METHODS: A QCL-based spectrometer was used to determine the SP of soil-emitted N2O accumulated in a closed chamber system without preconcentration. N2O standards (<2500 ppbv) were used to evaluate the precision of the QCL spectrometry (QCLS) system. CO2 and H2O were removed from the gas samples. Intercomparison measurements of QCLS and isotope ratio mass spectrometry (IRMS) were performed on N2O calibration gases at different mixing ratios. The observed dependency of the QCLS result on the N2O mixing ratio was corrected. RESULTS: Measurement of SP of N2O emitted from the field suggested that the SP of N2O varied from 0 to 40‰ over a period of 1 month. The precisions of the SP measurements (300-2500 ppbv) were <1.9‰ for δ(15)N(α) values, <2.6‰ for δ(15)N(ß) values, <2.1‰ for δ(15)N(bulk) values, and <2.1‰ for the SP (1 min averaging time) obtained on a once-an-hour calibrated QCLS system, with a cell temperature control precision of ±0.01 K. CONCLUSIONS: Continuous and unattended measurements of the SP of N2O emitted from soils were achieved at low N2O mixing ratios. The accuracy of the QCLS measurements for the SP of N2O was significantly improved by precisely controlling the temperature of the system and by correcting for the concentration dependency of the raw data through an intercomparison with IRMS measurements.

Expression of denitrification genes in response to a waterlogging event in a Fluvisol and its relationship with large nitrous oxide pulses.

The contributions of large N2 O pulses following waterlogging to the annual cumulative N2 O productions were significant in a Fluvisol. To uncover the mechanisms underlying these large N2 O pulses, a Fluvisol sampled from an agricultural field in Japan was subjected to waterlogging during incubation. Larger N2 O emissions were observed in intact soil cores when compared to emissions from sieved soils, indicating the importance of soil properties. The most important factor controlling the magnitude of the N2 O pulses after waterlogging was the soil moisture prior to waterlogging. The major pathway for N2 O production was denitrification. Quantitative PCR and quantitative RT-PCR analyses showed that the denitrification genes (nirS, nirK, and nosZ) correlated with N2 O emissions at the mRNA level but not at the DNA level. The change in denitrification gene mRNA levels was more prominent in the 0- to 1-cm soil compared with the 1- to 3-cm soil. Water-soluble and hot-water-soluble carbon contents also showed the highest amount in the 0- to 1-cm soil. These indicate that there was a strong variation in soil microbial properties over very small changes in soil depth, and this variation is important in determining the magnitude of N2 O emissions.

Cognitive aging explains age-related differences in face-based recognition of basic emotions except for anger and disgust.

This study aimed at a detailed understanding of the possible dissociable influences of cognitive aging on the recognition of facial expressions of basic emotions (happiness, surprise, fear, anger, disgust, and sadness). The participants were 36 older and 36 young adults. They viewed 96 pictures of facial expressions and were asked to choose one emotion that best described each. Four cognitive tasks measuring the speed of processing and fluid intelligence were also administered, the scores of which were used to compute a composite measure of general cognitive ability. A series of hierarchical regression analyses revealed that age-related deficits in identifying happiness, surprise, fear, and sadness were statistically explained by general cognitive ability, while the differences in anger and disgust were not. This provides clear evidence that age-related cognitive impairment remarkably and differentially affects the recognition of basic emotions, contrary to the common view that cognitive aging has a uniformly minor effect.

Interactions of household composition and required care level with functional and cognitive status among disabled Japanese elderly living in a suburban apartment complex.

AIM: In the forthcoming super-aging society, the appropriate assessment of functional and cognitive conditions of disabled elderly people will become increasingly significant in providing care services. Care level and household composition would be key factors to assess function. There might also be an interaction between the two factors with the function. The present study examined the associations of household composition and care level with functional and cognitive status among the disabled elderly living in a suburban apartment complex with a high rate of aged residents (39% in 2009). METHODS: Participants were 190 disabled elderly persons aged 65 years and over who lived in the apartment complex. Cross-sectional data were collected between May 2009 and August 2010, including care level, household composition, basic activities of daily living (BADL), instrumental activities of daily living (IADL) and the independence level in relation to cognitive status. Lower scores meant less independence in BADL and IADL, and as determined by the cognitive/independence scale. RESULTS: Approximately half of the participants lived alone. Generalized linear model procedure showed significant interactions with the BADL score and cognitive/independence scale between household composition and care level. Scores for BADL and the cognitive/independence scale in groups receiving a higher care level were lower; however, the slope of the trend for the elderly living alone was more gradual than for the elderly living with others. CONCLUSION: It is important for health-care providers to assess in detail the status of the disabled elderly considering both their household composition and care level in planning and providing assistance for them.