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MgO-Y 2 O 3 :Eu composite ceramics with high quantum yield and excellent thermal performance were successfully synthesized by vacuum sintering. All samples exhibited uniform composite microstructures and pure binary phase. Eu3+ ions were completely incorporated into Y 2 O 3 phase, and the optimal Eu concentration is 15 at%. Sintered at 1800 °C, the fluorescent properties of MgO- z vol% Y 2 O 3 : Eu (z = 30, 40, 50, 60, 70, 100) composites proved to be independent on component proportion, including the similar fluorescence lifetimes (953–983 μs), quantum yield (70%−80%), and activation energy (ΔE) of thermal quenching (0.163 eV). Significantly, thermal conductivity of composites with 30 vol%, 50 vol% and 70 vol% MgO attained 11.58, 17.45, and 29.65 W/(m∙K) at room temperature, which are nearly 2, 3, and 5 times as high as that of 15 at% Eu:Y 2 O 3 ceramic (5.90 W/(m∙K)), respectively, demonstrating their potential for application in high-power-density display and lighting technology. [ABSTRACT FROM AUTHOR]

Transparent calcium oxide (CaO) ceramic was successfully fabricated by pressureless vacuum sintering technique with 0.5 at% YF 3 as the sintering additive. In consideration of the hydrolysis of CaO, the precursor powders were calcined at 600 °C. Within the sintering temperature range of 1150–1450 °C, the effect of YF 3 additive on the phase structure, relative density, transmittance, and microstructure of CaO ceramics was studied. Benefiting from the assisted liquid-phase sintering mechanism and vacancy diffusion mechanism of YF 3 , full-dense (3.35 g/cm3) YF 3 -doped CaO transparent ceramic was fabricated at 1350 °C with high thermal conductivity of 15.42 W/(m·K). The in-line transmittance attained 47.10% at the wavelength of 1200 nm. Moreover, the hydrolysis resistance was extremely enhanced due to the pore-free structure. Compared to the CaO ceramic with low relative density of 78.66%, the weight gain of full-dense CaO ceramic greatly decreased from 22% to 1.2% within 35 days. [ABSTRACT FROM AUTHOR]

Abstract Biochar application is proposed having a potential of inhibiting greenhouse gases emissions from paddy fields, which is considered to be a main source of atmospheric greenhouse gases. However, the impacts of biochar on greenhouse gases from paddy field have not been investigated under controlled irrigation (CI). Field experiments were conducted during 2016–2017 to determine the effect of biochar application combined with controlled irrigation on rice yield and methane (CH 4) and nitrous oxide (N 2 O) emission from paddy fields in the Taihu Lake Region of China. Four treatments (0 t ha−1 biochar +CI, 20 t ha−1 biochar +CI, 40 t ha−1 biochar +CI, and 40 t ha−1 biochar + flooding irrigation (FI), named CA, CB, CC and FC, respectively) were designed in this study. The results showed that the effect of biochar application on greenhouse gases emissions from paddy fields under controlled irrigation had significant interannual differences. In the first season, CC decreased the global warming potential(GWP) of CH 4 and N 2 O emission, and the CB increased the GWP of CH 4 and N 2 O emission compared to CA, but these differences were not significant. For the second season, CB and CC decreased the GWP of CH 4 and N 2 O emission by 35.7% and 21.5% significantly compared to CA due to the significant mitigation of CH 4 and N 2 O emission. Biochar application significantly increased CH 4 emission and decreased N 2 O emission from paddy fields under flooding irrigation compared to controlled irrigation (CC), which led to the FC's GWP was 1.70 and 5.47 times higher than CC's in the first and second season. In addition, biochar application increased soil organic carbon, dissolved organic carbon and total nitrogen contents of paddy fields under controlled irrigation. And CB and CC increased rice yield by 16.7% and 24.3% and irrigation water productivity by 26.1% and 30.8% compared with CA (mean of two seasons). These results suggest that 20 and 40 t ha−1 biochar can be utilized under controlled irrigation not only for mitigation of CH 4 and N 2 O emission but also to increase rice yield, soil fertility and irrigation water productivity. Therefore, the combination of biochar amendment and controlled irrigation might be a good option for mitigating greenhouse gases emission and realizing the sustainable utilization of soil and water resources of paddy fields in the Taihu Lake Region of China. Highlights • 20 t ha−1 biochar application significantly increased soil DOC, TN, NH 4 +-N and decreased NO 3 −-N concentrations. • Biochar amendments increased rice yield and irrigation water productivity (mean of two rice seasons). • Biochar application combined with controlled irrigation reduced the mean GWP of two rice seasons. [ABSTRACT FROM AUTHOR]

Straw return (SR) and rice water-saving irrigation (WSI) affect the greenhouse gas emission of paddy fields. However, studies on CO2 exchange between paddy fields and the atmosphere with joint regulation of SR and WSI are few. We conducted a two-year field experiment to investigate the effects of SR on soil respiration and net ecosystem exchange of CO2 (NEE) in paddy fields under controlled irrigation (CI), which is a typical WSI technique. The rice yields, irrigation water use efficiency, seasonal variations in soil respiration, NEE, and soil organic carbon content were measured. Compared with the control (flooding irrigation and traditional chemical fertilizer), a significant increase in rice yield and irrigation water use efficiency in the paddy fields under CI and SR joint management (CS) was observed. CS increased the soil respiration rate during most of the rice growth stage and increased the net CO2 absorption rate before approximately 80 days after transplanting; afterward, the pattern reversed. Total CO2 emissions through soil respiration in CS paddy fields increased by 43.7% and 182% compared with the control in 2014 and 2015, respectively. However, CS also caused an increase in the total net CO2 absorption by 18.1% and 30.1% in these two years, respectively. The acceleration in the consumption and decomposition of soil organic carbon induced by frequent alternate wet–dry cycles of the CI paddy fields increased the soil respiration and decreased the net CO2 absorption. SR promoted soil respiration but also improved rice growth, increasing the net CO2 absorption. The soil organic carbon content of the CS paddy fields after harvesting increased by 23.2% compared with that before transplanting. The present study concluded that joint regulation of WSI and SR is an effective measure for maintaining yield, increasing irrigation water use efficiency, mitigating CO2 emission, and promoting paddy soil fertility. [ABSTRACT FROM AUTHOR]

The ecosystem services value of paddy fields has received increasing attention in agricultural policy decisions. This paper presents the first study to investigate the effects of rice water-saving irrigation on the economic value of gas exchange in a paddy field ecosystem based on a field experiment. The results showed that, compared to traditional flooding irrigation (FI), controlled irrigation (CI) decreased irrigation water input while maintaining high rice yield. Irrigation methods showed no significant influence on O2 production and its value in paddy fields. CI significantly reduced CH4 emissions and its negative economic value by 81.80%, but increased N2O by 136.86%. The economic value of CO2 uptake far outweighed the absolute value of negative economic values caused by CH4 and N2O emissions. Therefore, the irrigation methods showed no significant difference in economic value caused by greenhouse gas emissions (GHGs) from rice paddies. CI management significantly decreased ammonia volatilization (AV) and its economic value by 19.56%. Overall, CI increased economic value of gas exchange (O2 production, GHGs emission, and AV) by 8.96% compared to FI paddies. Our results suggest that CI significantly increased the economic value of gas exchange in a paddy field ecosystem while drastically reducing irrigation water input and ensuring rice yields. [ABSTRACT FROM AUTHOR]

Improper management practices lead to the reduction of phosphorus availability by rice and an increase in the risk of phosphorus release to the environment in paddy fields. This study aims at exploring the effects of biochar with the applicated rate of 0, 20, 40 t ha−1 under controlled or flooding irrigation on utilization efficiency of phosphorus fertilizer and phosphorus leaching loss from fields by observing the dynamics of phosphorus in paddy fields throughout the rice growing period. The results indicated that biochar application lessened the TP and DRP leaching loss by 6.77–17.62% and 6.22–10.28% respectively. It was also found that biochar improved the phosphorus efficiency of rice by 5.33–10.33%and reduced the soil phosphorus surplus by 3.45–6.66% for the increased soil Olsen-P concentration and soil solution dissolved reactive P concentration. In comparison with flooding irrigation, controlled irrigation apparently decreased P leaching loss by 34.64–55.15% by controlling the downward migration of phosphorus in soil solution. Although biochar addition in the field increased production cost, it was proved increasing net economic benefit by 2558–4655 yuan ha−1 y−1, which attributes to the increased rice yield in biochar applicated treatment. In order to improve phosphorus efficiency of rice and reduce the risk of phosphorus release to the environment, a combination of biochar and water-saving irrigation applied in rice fields can provide cleaner production of rice with a promising option, thus bringing both environmental and economic benefits. [Display omitted] • Dynamics of P in soil and soil solution were monitored in biochar applicated paddy field under water-saving irrigation. • Biochar application and water saving irrigation reduced P leaching loss from paddy field. • Biochar application increased P efficiency in water-saving paddy field. • Biochar drove the increase of available P content. [ABSTRACT FROM AUTHOR]

[Display omitted] • DNDC-BC was established on the water balance principle and two-pool biochar model. • DNDC-BC can model GHG, SOC and rice yield of paddy under CI and biochar. • DNDC-BC performed better in simulating GHG and soil moisture than the original one. • Coupling CI and biochar decrease CH 4 and N 2 O emissions, boost SOC and rice yield. • CH 4 and N 2 O emissions from CI paddy are most sensitive to rainfall and irrigation. Simulating the impacts of biochar and controlled irrigation (CI, a water-saving irrigation technology without surface ponding of water) combination on greenhouse gas (GHG) emissions from paddy fields is crucial, however, the original DNDC model is not capable of capturing these management impacts on emissions. In this study, we have created a new modelling approach called DNDC-Biochar-Controlled Irrigation (DNDC-BC) by adding two modules to the original DNDC: the water balance principle, and the two-pool biochar model. The performance of the DNDC-BC was tested and validated using a two-year field experiment, designed with two irrigation treatments (flood irrigation (FI), and CI) and three biochar application rates (0, 20, and 40 t ha−1), carried in the Lake Taihu region, China. Results revealed that the DNDC-BC model performed satisfactorily in simulating impacts of biochar-CI combination on emissions of CH 4 , N 2 O, SOC, and grain yield. The corresponding R2 values of DNDC-BC increased by 22.63%-35.66%, 43.00%-71.26%, 1.06%-60.87% and 15.38%-34.78% compared with those of the original model. Sensitivity analysis for the DNDC-BC showed that CH 4 emissions were most sensitive to rainfall and irrigation; N 2 O emissions were sensitive to rainfall, irrigation and N fertilizer application rate, and SOC was sensitive to biochar application rates. Our results suggest that the combination of biochar- and CI can save water resources and mitigate GHG emissions without detrimental impacts on rice yield. The DNDC-BC can be used to estimate the long-term impacts of biochar-CI combination on GHG emission, crop productivity and climate change. [ABSTRACT FROM AUTHOR]

Quantifying greenhouse gas (GHG) emissions from irrigated paddy fields is of great significance for addressing climate change. Machine learning (ML) provides an alternative to empirical models and biogeochemical models, but it has not been used to simulate GHG emissions from paddy fields. In this study, a three-year field experiment dataset of paddy fields under controlled irrigation (CI, a kind of water-saving irrigation (WSI) technology) and flood irrigation (FI) in Kunshan, China, was collected, as well as a global dataset on WSI and FI. Then, the stacking ensemble model was developed based on three basic ML models, random forest (RF), K-Nearest Neighbor regression (KNN), gradient boosting regression (GBR), and a meta-learner, linear Regression (LR). Those models were used for the first time to simulate CH 4 and N 2 O emissions on different time scales from paddy fields under WSI and FI. The results showed that the cumulative CH 4 and N 2 O emissions from the WSI paddy fields decreased by 61.14% and increased by 19.52%, respectively, compared with FI. The ML algorithm can be applied to simulate daily, growth stages, and cumulative GHG emissions from paddy fields, but the performance of the linear regression model was worse than other ML models. Compared with the basic models, the stacking model improved the accuracy, improving the R 2 by 0.37∼13.36% and reducing the RMSE by 3.23∼42.78%. Soil redox, temperature, and moisture are necessary for accurate modeling. Meanwhile, training the model using data from WSI and FI separately is beneficial to improve the accuracy of the model. The availability of the stacking model in other stations was verified based on literature data, with R 2 varying between 0.7634 and 0.9985. Therefore, the stacking model is recommended to predict GHG emissions at different time scales from paddy fields, and this method can be extended to estimate GHG from paddy fields at various stations around the world. [Display omitted] • Machine learning (ML) was used to predict CH4 and N2O emissions from paddy fields. • The stacking model was the best in modeling greenhouse gas at various time scales. • Soil redox, temperature, and moisture are necessary for accurate modeling. • Separate training for different irrigated paddy fields is recommended. • The simulation method can be extended to paddy fields in different places. [ABSTRACT FROM AUTHOR]

Yield and rice quality indicators of crops are a direct reflection of the rational irrigation and fertilizer strategy. However, the effects of controlled irrigation (CI) combined with the split application of fertilization managements (straw returning, organic fertilizer, and conventional fertilizer) on rice quality are not clear in southeast China. This study aims at exploring the effects of three fertilization managements applied under CI or flooding irrigation on rice yield, quality, enzyme activity, and soluble sugar content including 43 indicators, to determine the optimal comprehensive evaluation model, management, and representative indexes. The results showed that compared with CF (CI + conventional fertilizer), CS (CI + straw returning) significantly increased yield (27.65%), irrigation water use efficiency (6.20%), chalky grain rate (9.67%), chalkiness (1.83%), protein content (4.29%), and amylose content (0.33%), indicating that CS improved yield and milling quality but decreased cooking and appearance quality. This was mainly because CS promoted the activities of alpha-amylase, ADPG (ADP-glucose pyrophosphorylase), and GBSS (granule-bound starch synthase) and reduced the soluble sugar content in rice. Grey relational degree analysis (GRD), the entropy method (ETM), and TOPSIS (the technique for order preference by similarity to an ideal solution) were used to comprehensively evaluate the rice quality and determined that CS treatments could synergistically improve yield and rice quality. The five indexes (adhesive strength, HPV, ADPG, soluble sugar (leaf), yield) and TOPSIS model can be used as the best indexes and model to evaluate the rice quality. These results could provide scientific management and evaluate practices for high-yield and high-quality rice cultivation, which may be promising for a cleaner production strategy. [ABSTRACT FROM AUTHOR]

Accurate water level prediction is the premise of farmland waterlogging prediction. A simple water level prediction model (FDPRE) based on four machine learning (ML) algorithms and weather forecasts were developed. The model can not only predict two key driving factors of waterlogging, rainfall and node water level but also estimate disaster losses. The results showed that the random forest and Multiple perception model (R2 ranged from 0.7180 to 0.9803 and 0.5717 to 0.9965) performed best. In the case of flooding lasting for one day, the economic loss of waterlogging under the 100 mm rainfall scenario (23.53 million dollars) was much higher than that under the 50 mm rainfall (12.69 million dollars). Under the two rainfall scenarios, the yield reduction rate in the lower reaches of the Sihu basin was higher than that in the upper reaches. The method of coupling ML and weather forecasts can well predict farmland waterlogging. • FDPRE, a simple water level prediction model, was developed. • Farmland flood disaster was predicted on machine learning and weather forecast. • Random forest performed best among the four machine learning models at most sites. • The economic loss of waterlogging under 100 mm rainfall was much higher than 50 mm. [ABSTRACT FROM AUTHOR]

Based on the results of continuous flux measurements in the Taihu Lake Region of China, the carbon dioxide (CO 2 ) exchange of paddy fields under water-saving irrigation and its influence factors were analyzed. The net ecosystem exchange of CO 2 ( NEE ) were negative during the daytime and positive at night, and the minimum value appeared around noon. The peak CO 2 uptake in the flourishing period was approximately 1.5 times the values observed in the tillering and ripening stages. Frequent alternation of wetting and drying in paddy fields with water-saving irrigation resulted in larger NEE for the typical day before soil rewatering than that for the day after soil rewatering in the early growth stage. These alterations had a minimal effect on diurnal variation of NEE in the late rice growth stage. The average NEE for the typical days after soil rewatering in July and August were 2.30 and 1.38 times that before soil rewatering, respectively. CO 2 exchange in paddy field ecosystem under water-saving irrigation displayed seasonal variation with the change of rice plant growth. The total ecosystem respiration ( R eco ), NEE and gross primary productivity ( GPP ) were 1996.88, −1284.15 and 3281.03 g m −2 , respectively, throughout the growth stage. These results showed that the paddy field ecosystem under water-saving irrigation was a sink for atmospheric CO 2 . Frequent alternation of wetting and drying processes increased the ecosystem reparation of paddy fields under water-saving irrigation and produced smaller net CO 2 absorption compared to that of flooding irrigation. The net CO 2 absorption because of plant photosynthesis during the daytime and the net CO 2 release at night measured by static transparent chamber method were larger than those measured by eddy covariance method ( P < 0.05). The nighttime respiration of paddy field ecosystem under water-saving irrigation increased exponentially with temperature. Additionally, a larger temperature sensitivity coefficient ( Q 10 ) was observed for paddy fields under water-saving irrigation compared to that under flooding irrigation. The photosynthetic photon flux density ( PPFD ) was the most important factor for regulating daytime GPP . And the light saturation point during the heading-flowering and milk stages of paddy field ecosystem with water-saving irrigation (1500 μmol m −2 s −1 ) was higher than that of fields with flooding irrigation in previous studies. A significant positive correlation was found between the leaf area index ( LAI ) and the daily GPP . [ABSTRACT FROM AUTHOR]

Irrigation mode is an important factor in regulating CH 4 and N 2 O emissions from croplands. However, there are no studies on the effects of irrigation mode practiced during the rice season on the annual integrative global warming potential (GWP) of CH 4 and N 2 O in the rice–winter wheat rotation systems. Thus, a field experiment was designed to study the effects of controlled irrigation (CI) during the rice season on the annual integrative GWP of CH 4 and N 2 O emissions from the rice–winter wheat rotation systems, with traditional irrigation (TI) as the control. A notable trade-off relationship between CH 4 and N 2 O emissions was observed in the rice–wheat rotation systems under both CI and TI of rice. CI during the rice season had obvious subsequent effects on CH 4 and N 2 O emissions from the following winter wheat season. Over the whole annual cycle, CI significantly reduced the cumulative CH 4 emission (13.27 kg ha −1 ) by 80.6% than that from the TI fields ( p < 0.001), but did not cause a significant difference on the cumulative N 2 O emission ( p > 0.05). The integrative GWP of CH 4 and N 2 O on a 100-year horizon for the CI rotation systems was 2720.35 kg CO 2 ha −1 , which was 41.1% lower than that for the TI fields ( p < 0.05). Moreover, the difference of rice and wheat yields between the CI and TI fields was not significant ( p > 0.05). This is the first study to investigate the effects of CI during the rice season on the annual integrative GWP of CH 4 and N 2 O in a rice–winter wheat rotation system. Our results suggest that CI can significantly mitigate the annual integrative greenhouse effect caused by CH 4 and N 2 O from the rice–winter wheat rotation systems, while ensuring the crop yields. [ABSTRACT FROM AUTHOR]

The effect of controlled drainage on methane (CH4) and nitrous oxide (N2O) emissions from a paddy field under controlled irrigation (CI) was investigated by controlling the sub-surface drainage percolation rate with a lysimeter. CI technology is one of the major water-saving irrigation methods for rice growing in China. Water percolation rates were adjusted to three values (2, 5, and 8 mm d−1) in the study. On the one hand, the CH4emission flux and total CH4emission from paddy fields under CI decreased with the increase of percolation rates. Total CH4emissions during the growth stage of rice were 1.83, 1.16, and 1.05 g m−2in the 2, 5, and 8 mm d−1plots, respectively. On the other hand, the N2O emission flux and total N2O emissions from paddy fields under CI increased with the increase of percolation rates. Total N2O emissions during the growth stage of rice were 0.304, 0.367, and 0.480 g m−2in the 2, 5, and 8 mm d−1plots, respectively. The seasonal carbon dioxide (CO2) equivalent of CH4and N2O emissions from paddy fields under CI was lowest in the 2 mm d−1plot (1364 kg CO2ha−1). This value was 1.4% and 19.4% lower compared with that in the 5 and 8 mm d−1plots, respectively. The joint application of CI and controlled drainage may be an effective mitigation strategy for reducing the carbon dioxide equivalents of CH4and N2O emissions from paddy fields. [ABSTRACT FROM AUTHOR]

High rates of nitrogen (N) fertilizer were applied to a paddy field in the Taihu Lake region of China to maximize crop production. Excessive N input has resulted in serious agricultural nonpoint pollution. Water and N management are two important approaches to regulating N loss from paddy fields. This study aimed to determine N losses through ammonia volatilization, runoff, and leaching from a paddy field during the rice-growing season in Taihu Lake region. Field experiments with two water and two N managements were conducted. The N exported to the environment through ammonia volatilization, runoff, and leaching from the paddy field was 37.2 kg N ha−1to 102 kg N ha−1, with ammonia volatilization accounting for 69.6% to 83.5% of N loss. Ammonium and dissolved organic N significantly contributed to N loss through runoff and leaching. Controlled irrigation and site-specific N management (CS) significantly decreased N losses through ammonia volatilization, runoff, and leaching. Compared with the N and irrigation water inputs in traditional water and N management, those generated by controlled irrigation and site-specific N management were reduced by 34.6% to 43.0% and 59.2% to 63.3%, respectively. Moreover, the reduction in N and water input in the CS paddy field enabled the maintenance of high rice yield; it significantly increased N use efficiency by 15.1% to 34.9% and decreased the N exported to the environment by ammonia volatilization, runoff, and leaching by 53.1% to 56.1%. Therefore, the joint application of controlled irrigation and site-specific N management efficiently reduces agricultural nonpoint pollution through N loss from paddy fields. [ABSTRACT FROM AUTHOR]

Abstract: Water-saving practices for rice production has become one of the major agricultural policies in China due to the severe water scarcity. However, greenhouse gases emissions from paddy field may be changed with water-saving practices. In the two-year field experiment at Thaihu Lake Basin of China, CH4 and N2O fluxes from paddy field under controlled irrigation and continuous flooding irrigation were monitored using closed chambers. Total CH4 emission from paddy field under controlled irrigation during the rice-growing period were 2.47 and 1.88gm−2 in 2006 and 2007, respectively, reduced by 79.1% on average compared with continuous flooding irrigation. The CH4 emission from paddy field was further concentrated in the initial and middle tillering stages of rice growth under controlled irrigation for 2years. The N2O emission from paddy field under controlled irrigation was mostly larger than those from flooding irrigation during the rice-growing period. Total N2O emission from paddy field under controlled irrigation during the rice-growing period was 106mgm−2, increased by 10.6% compared with those from flooding irrigation. Carbon dioxide equivalents of CH4 and N2O emissions from paddy field during the rice-growing period under controlled irrigation were 788kg CO2 ha−1, reduced by 61.4% compared with those from flooding irrigation. It can be concluded that controlled irrigation is an effective technique for mitigating the carbon dioxide equivalents of CH4 and N2O emissions from paddy field. [Copyright &y& Elsevier]

Biochar application (BA) and controlled irrigation (CI) can realize the resource utilization of biowaste and water respectively. Both BA and CI can affect soil carbon pool dynamics and greenhouse gas (GHG) emissions in paddy fields, but their synergistic effects and the microbial mechanism remain unclear. This study investigated the effects of BA on CO 2 exchange, GHG emissions, and soil microbial diversity of paddy fields under CI. BA increased soil respiration rate (R s) from CI paddy fields by 23.81%–41.45 %, possibly due to the increase of Curvibacter , while BA reduced global warming potential by 25.85%–37.84 %. The reduction of N 2 O emission under CI with BA may be attributed to the increase of Proteobacteria and the decrease of Nitrospira. CI decreased the net ecosystem exchange (NEE) and soil organic carbon but increased R s and dissolved organic carbon, compared with flood irrigation. Lactobacillus and Mortierella were dominant bacteria and fungi at milk stage. In addition, BA and CI mitigated CH 4 emissions and reduced the abundance of Russula. Both bacteria and fungi play important roles in soil carbon cycle, which is mainly affected by soil temperature, humidity, and ammonium. These results indicate that BA combined with CI is a promising cleaner production strategy to simultaneously improve soil health, mitigate GHG emission, and mediate soil microbial community structure. [Display omitted] • Biochar decreased the global warming potential by 25.85%–37.84 %. • Biochar reduced N 2 O emission via enriching Proteobacteria and reducing Nitrospira. • Biochar increased soil respiration by 23.81%–41.45 % via enriching Curvibacter. • Both biochar and controlled irrigation reduced Russula and mitigated CH 4 emissions. • Biochar decreased the abundance of Mortierella , thereby increased soil carbon pool. [ABSTRACT FROM AUTHOR]

Zero valent iron (ZVI) coupled with bioreactors is arising as a promising technology for antibiotic resistance genes (ARGs) mitigation, whereas the succession and behaviors of microbes caused by ZVI in relieving ARGs propagation remain unclear. Herein, the effects of ZVI on microbial quorum sensing (QS), quorum quenching (QQ) system and community dynamics were examined in anaerobic bioreactor fed with oxytetracycline (tet), to illustrate the roles of evolutive microbial communication and community composition in ARGs attenuation. With the addition of 5 g/L ZVI, the total absolute abundance of tet ARGs was retarded by approximate 95% and 72% in sludge and effluent after 25 days operation. The abundance of mobile genetic elements and the heredity of antibiotic resistant bacteria revealed the declined horizontal and vertical transfer of ARGs, which directly led to the reduced ARGs propagation. Potential mechanisms are that the positive effects of ZVI on QQ activity via the functional bacteria enrichment inhibited QS system and thus ARGs transfer. Partial least--squares path modeling further demonstrated that ARGs abundance was strongly limited by the dynamics of bacterial composition and thereby less frequent microbial communication. These results provide new insights into the mechanisms of antibiotic resistome remission in anaerobic bioreactor modified by ZVI. [Display omitted] • Zero valent iron could mitigate ARGs propagation in anaerobic bioreactor. • Horizontal transfer of ARGs and proliferation of resistant strains were suppressed. • The weakened bacterial communication led to decreased ARGs transfer. • The reduced potential host bacteria contributed to relieving ARGs dissemination. [ABSTRACT FROM AUTHOR]

Guangzhou city in South China has experienced an accelerated urban development since the 1980s. This paper examines the impact of the urban development on urban heat islands through a historical analysis of urban–rural air temperature differences. Remote sensing techniques were applied to derive information on land use/cover and land surface temperatures and to assess the thermal response patterns of land cover types. The results revealed an overriding importance of urban land cover expansion in the changes in heat island intensity and surface temperature patterns. Urban development was also related to a continual air temperature increase in the 1980s and 1990s. The combined use of satellite-derived vegetation and land cover distributions with land surface temperature maps provides a potential useful tool for many planning applications. The city''s greening campaigns and landscaping designs should consider the different cooling effects of forest, shrubs and grassy lawns for temperature control and should plant more tall trees. [Copyright &y& Elsevier]

• Zero valent iron (ZVI) less than 10 g/L improved ARGs reduction in anaerobes. • Horizontal transfer of ARGs and proliferation of resistant strains were inhibited. • Iron-dependent homeostasis and its roles as regulators led to ARGs reduction. • The improved antioxidant capacity of bacteria mitigated ARGs proliferation. • 20 g/L ZVI made no effects on ARGs attenuation in anaerobic bioreactor. Zero valent iron (ZVI) has been previously documented to attenuate the propagation of antibiotic resistance genes (ARGs) in microbes, while how ZVI affects the evolution of ARGs remains unclear. Herein, we investigated the influences of ZVI on ARGs dissemination in anaerobic bioreactor treating oxytetracycline (tet) containing wastewater, by deciphering the roles of iron homeostasis and regulatory effects. A net reduction of tet gene targets ranging from 0.75 to 1.88 and 0.67 to 2.08 log unit in intracellular and extracellular DNA was achieved at the optimal dosage of 5 g/L ZVI, whereas 20 g/L ZVI made no effects on ARGs reduction. The reduced ARGs abundance by ZVI was directly related to the inhibited horizontal transfer of ARGs and decreased proliferation of resistant strains (mainly Paludibacter and WCHB1–32). The potential mechanisms included the increased antioxidant capacity, the depressed efflux pump system and the weakened energy driving force by Fur regulon in microbes (especially for Cloacibacterium and Dechloromonas). The negligible influence of 20 g/L ZVI on ARGs reduction was ascribed to the iron-catalyzed oxidative damage and reduced physiological activity. This study firstly illustrated the potential relationships among activation of iron uptake regulator leading to protection against oxidative stress, alternation of physiological metabolisms and reduction of ARGs dissemination. This work extents our understanding about the priority of ZVI in mitigating ARGs proliferation and sheds light on its potential application in wastewater treatment plants. [Display omitted] [ABSTRACT FROM AUTHOR]

• WHCNS model performed well in simulating water and N fates in rice systems. • Controlled irrigation greatly reduced irrigation water use and water consumption. • Site-specific N reduced N gas emission, N leaching, and runoff N loss. • Combining controlled irrigation and site-specific N practice enhanced WUE and NUE. Quantifying water consumption, nitrogen (N) fates, and crop yield is crucial in developing the best management practices for rice production systems. A 2-year field experiment was conducted in Taihu Lake region, China. The experiment consisted of water-saving controlled and conventional flooding irrigation regimes that are factorially combined with two N management practices (farmers' N fertilization and site-specific N management). A simple surface ponding water layer component was incorporated into the original WHCNS (soil water heat carbon nitrogen simulator) model to simulate and comprehensively evaluate water consumption, N fates, and rice yield for water-saving and conventional rice production systems. Field experiment data, including surface water ponding depth, soil water content, runoff, runoff N loss, crop N uptake, and yield, was measured to test the improved model. Results showed agreement between the measured and simulated values of surface ponding water depth, soil water content, runoff, N runoff loss, ammonia volatilization, crop N uptake, and yield and simulated values agreed well, with average relative root mean squared error values of 24.0%, 9.3%, 26.1%, 20.9%, 21.3%, 7.9%, and 4.6%, respectively. Crop yield showed no significant difference under different water and N management practices. Compared with conventional flooding system, controlled irrigation saved 34.1% of irrigation water and greatly reduced nonproductive water consumption (evaporation + runoff + deep percolation) by 16.9%–20.0%, thus increasing the water use efficiency (WUE). Site-specific N management substantially reduced N losses from ammonia volatilization, leaching, denitrification, and runoff by 50.1%, 33.8%, 13.3%, and 42.7%, respectively, compared with those of the farmers' N fertilization practice. These results indicated that the combination of controlled irrigation regime and site-specific N management regime reduced the water consumption, N losses, and N 2 O emission and increased WUE and N use efficiency. [ABSTRACT FROM AUTHOR]

Biochar has been widely applied to paddy fields to improve soil fertility, crop productivity and carbon sequestration, thereby leading to variations in the CO 2 exchange between the paddy fields under flooding irrigation and the atmosphere, as indicated by many previous reports. However, few relevant reports have focused on paddy fields under water-saving irrigation. This study conducted a field experiment to investigate the effects of three biochar addition rates (0, 20 and 40 t ha−1) on the CO 2 exchange between paddy fields under controlled irrigation (CI, a water-saving irrigation technique) and the atmosphere in the Taihu Lake region of Southeast China. Our results showed that biochar addition increased the paddy field ecosystem respiration (R eco) and the soil respiration rate (R s) in the CI paddy fields. And biochar application increased the total CO 2 emissions and the total soil CO 2 emissions, especially at a rate of 40 t ha−1. In contrast, gross primary productivity (GPP) was decreased and the net ecosystem exchange of CO 2 (NEE) was increased with biochar addition. However, biochar addition at a rate of 20 t ha−1 significantly increased the total CO 2 absorption and the net CO 2 absorption of the CI paddy fields (p < 0.05), whereas biochar addition at a rate of 40 t ha−1 had no effect on the total CO 2 absorption and decreased the total net CO 2 absorption. At the same time, biochar addition significantly increased soil catalase, invertase and urease activities and contributed substantially to the increase in soil invertase activity. In addition, the soil bacterial, fungal and actinomycetal abundances were evidently increased with biochar addition, of which the soil fungal abundance showed the greatest increase. A high correlation was observed between soil catalase and invertase activities and soil microbial abundance. R eco was highly correlated with air and soil temperatures and soil enzyme activity. A significant quadratic polynomial correlation was observed between GPP and leaf area index (p < 0.01). The combination of biochar addition at a rate of 20 t ha−1 and water-saving irrigation has the potential to increase the size of the carbon sink and promote soil enzyme and microbial activities in paddy field ecosystems. • Biochar addition increased R eco, R s and NEE and decreased GPP of CI paddy fields. • Total CO 2 emissions and soil CO 2 emissions increased with biochar addition rates. • Biochar addition increased soil enzyme and microbial activities of CI paddy fields. • Soil catalase and invertase activities were highly correlated to microbial abundance. • Air and soil temperatures, soil enzyme activity and LAI affected CO 2 exchange. [ABSTRACT FROM AUTHOR]

Coordination of yield, quality and economic benefits increase remains an attractive problem in agricultural production. This study investigated how irrigation regimes could synergistically interact with different fertilization to increase irrigation water use efficiency (IWUE), yield, quality and output/input ratio in rice. A field experiment was conducted during 2020–2021 with three fertilization management (straw returning, organic fertilizer, conventional fertilizer) and two irrigation regimes (controlled irrigation (CI) and flood irrigation (FI)). This study reveals that CI reduced rice plant height (5.24% ∼ 11.99%), tiller number (9.52% ∼ 26.31%), SPAD (7.98% ∼ 15.83%), yield (9.12% ∼ 9.23%), and protein (4.85% ∼ 5.02%) compared to FI. Conversely, CI improved chalky grain rate (5.83% ∼ 8.52%), chalkiness (11.35% ∼ 14.68%), IWUE (51.01% ∼ 59.91%). CS (controlled irrigation + straw returning) and CM (controlled irrigation + organic fertilizer) significantly boosted rice quality and yield compared to CF (controlled irrigation + conventional fertilizer): setting rate increased by 20.23% (CS) and 18.20% (CM), yield rose by 19.43% (CS) and 19.83% (CM), and positive impacts were observed in polished rice rate, head milled rice rate, and protein content. However, both CS and CM led to reduced amylose content (0.35% and 1.06%) and taste value (0.82% and 3.25%). The study observed consistent interannual changes in straw returning, while variations were noted in organic fertilizer application. This difference was primarily attributed to the significant influence of temperature (with a 5.34 ℃ difference during the two years at the milky ripening stage). The analysis of economic benefits showed that the output/input ratio of CS was the highest, ranging from 2.69% to 2.88%. By employing the TOPSIS method, an integrated multi-index decision analysis approach, CS was identified as the optimal mode for rice in southern China. The study provides an optimal irrigation and fertilization model for the synergistic realization of water saving, high yield, high quality, economic benefits, and further achieves the goal of sustainable agricultural development. • Under controlled irrigation (CI), rice growth, yield, appearance and nutritional quality got worse. • CS (controlled irrigation + straw returning) could increase yield, milling, appearance and nutritional quality. • CM (controlled irrigation + organic fertilizer) can promote rice yield and quality, but unstable under climate influence. • The analysis of economic benefits shows that the output/input ratio of CS was the highest. • Using the TOPSIS method, the optimal management mode was determined as CS. [ABSTRACT FROM AUTHOR]

[Display omitted] • nZVI exposure increased the antibiotic resistome in anaerobic digestion. • Efflux pump and rRNA methyltransferase shaped the antibiotic resistome variation. • Improved adaptability of efflux pump benefited the anaerobes withstanding nZVI. • Increased acquisition of rRNA methyltransferase preserved the structure of protein. • Polyspecificity of multidrug resistance drove the ARGs evolution in anaerobes. Nano zero-valent iron (nZVI) assisted anaerobic digestion (AD) is considered an effective approach for mediating antibiotic resistance genes (ARGs) dissemination in activated sludge. However, little is known about the mechanisms that drive antibiotic resistomes evolution in relation with their physiological roles distinct from protection of bacteria against antimicrobials. Metagenomic sequencing showed that efflux pumps and rRNA methyltransferase genes were the most prevalent ARGs in anaerobes, being responsible for the variations of antibiotic resistome upon nZVI addition. Particularly, to withstand the oxidative stimuli derived from initially 9 days nZVI exposure, genes involved in the two component systems (PhoRB , BaeSR , EvgSA) and global regulator networks (MarA , SoxS) were increased, activating the chromosomally encoded intrinsic efflux pumps expression. Furthermore, to benefit for survival, the polyspecific efflux pumps were involved in the microbial physiological adaptations of enhanced siderophores, lipid moieties, and quorum sensing molecules exportation, which induced the adaptative efflux pumps expression. On the other hand, to maintain the protein synthesis under oxidative condition, genes encoding Rsm, Erm, and Rlu family methyltransferases were notably up-regulated via horizontal transfer, inducing the acquired rRNA methylation resistance. Importantly, after prolonged exposure to nZVI for 18 and 27 days, the antibiotic resistomes were measurably decreased, due to the recovered oxidative state and increased membrane rigidity. Overall, these findings provide a deep understanding on the necessity of antibiotic resistome evolution for anaerobes to adapt to nZVI exposure for survival, which can be introduced to improve the ARGs risks analysis. [ABSTRACT FROM AUTHOR]

While vapor condensation in arid and semiarid areas has garnered much attention, such information is scarce for humid crop production areas such as rice fields. In a water-saving irrigation (WSI) rice field, high-precision weighed microlysimeters allowed the direct and independent quantification of condensation over plants (Cc) and soil (Cs) through mass balance calculations. The occurrence frequency and rate of Cc generally exceeded that of Cs. Predominantly occurring between sunset and sunrise, particularly between 0400 and 0500 local time, Cc showed an overall maximum rate of 0.096 mm h−1. In contrast, Cs was highest between 0100 and 1100 local time and showed an overall maximum rate of 0.044 mm h−1. The occurrence of Cc, unlike that of Cs, required a surface temperature lower than the ambient temperature or dewpoint. Of 65 rain-free days, Cc and Cs occurred on 60 and 33 days, respectively. Seasonal Cc, Cs, and Cc + Cs were estimated as 32.3, 3.1, and 35.4 mm, respectively, and their contributions to seasonal rice transpiration T, evaporation E, and evapotranspiration (ET) were 9.5%, 1.6%, and 6.7%, respectively. The seasonal Cc + Cs was similar in magnitude to a routine irrigation quota and accounted for 10.8% of rainfall and 14.4% of irrigation in the WSI rice field. Therefore, vapor condensation in rice fields in a subtropical monsoon climate is an important component of the hydrological cycle and cannot be ignored when tabulating the field water balance, calculating field water consumption, or in irrigation scheduling. [ABSTRACT FROM AUTHOR]

A two-year experiment was conducted to investigate the inter-seasonal and cross-treatment variability in measured rice evapotranspiration ( ET cMea ), measured single-crop coefficients ( K cMea ), and treatment-specific calibrated coefficients ( K cCal ), under different drying-wetting cycles in a subtropical monsoon climate in East China. For each drying-wetting treatment, ET cMea was determined based on data collected in lysimeters, and K cMea was calculated from ET cMea , reference evapotranspiration, and soil moisture deficit coefficient. Following the single-crop coefficient method, K cCal was determined by matching K cMea . In 2012 and 2013, ET cMea varied from 459.5 to 486.7 mm, and 544.5–605.1 mm, respectively. Its inter-seasonal variability was larger than the cross-treatment variability. Stage-wise average K cMea were 1.07–1.17, 1.30–1.51, 1.49–1.54, and 1.17-1.29 in 2012, and 1.06–1.12, 1.31–1.49, 1.43–1.57, and 1.26–1.27 in 2013 during the initial, crop development, mid-season, and late season stages, respectively. Treatment-specific K cCal were calibrated as 1.09–1.20, 1.51–1.60, and 0.74–0.78 in 2012, and 1.05–1.14, 1.47–1.64, and 0.96–1.01 in 2013 for the initial, mid-season, and end-season stages, respectively. The inter-seasonal and cross-treatment variability in K cMea and K cCal was low. Each treatment-specific K cCal set performed similarly when rice ET c was calculated under different drying-wetting treatments. Cross validation indicated that large daily uncertainty in ET c estimation occurred when daily ET cMea was high, and uncertainty in seasonal ET c calculated using different treatment-specific K cCal sets ranged from 45.7 to 60.1 mm (approximate to one irrigation). Calibrating K cCal using more data (season-specific K cCal or mixed treatment K cCal ) would improve the accuracy of K cCal in ET c estimation. [ABSTRACT FROM AUTHOR]

Water management is an important practice with significant effect on greenhouse gases (GHG) emission from soils. Nitrous oxide (N 2 O) and carbon dioxide (CO 2 ) emissions and their global warming potentials (GWPs) from subsurface watering soil (SUW) were investigated, with surface watering (SW) as a control. Results indicated that the N 2 O and CO 2 emissions from SUW soils were somewhat different to those from SW soil, with the peak N 2 O and CO 2 fluxes from SUW soil reduced by 28.9% and 19.4%, and appeared 72 h and 168 h later compared with SW. The fluxes of N 2 O and CO 2 from SUW soils were lower than those from SW soil in both pulse and post-pulse periods, and the reduction was significantly ( p < 0.05 ) in pulse period. Compare to SW, the cumulative N 2 O and CO 2 emissions and its integrative GWPs from SUW soil decreased by 21.0% ( p < 0.05 ), 15.9% and 18.0%, respectively. The contributions of N 2 O to GWPs were lower than those of CO 2 during most of time, except in pulse emission periods, and the proportion of N 2 O from SUW soil was 1.4% ( p > 0.1 ) lower that from SW soil. Moreover, N 2 O and CO 2 fluxes from both watering treatments increased exponentially with increase of soil water-filled pore space (WFPS) and temperature. Our results suggest that watering soil from subsurface could significantly reduce the integrative greenhouse effect caused by N 2 O and CO 2 and is a promising strategy for soil greenhouse gases (GHGs) mitigation. And the pulse period, contributed most to the reduction in emissions of N 2 O and CO 2 from soils between SW and SUW, should be a key period for mitigating GHGs emissions. Response of N 2 O and CO 2 emissions to soil WFPS and temperature illustrated that moisture was the dominant parameters that triggering GHG pulse emissions (especially for N 2 O), and temperature had a greater effect on the soil microorganism activity than moisture in drier soil. Avoiding moisture and temperature are appropriate for GHG emission at the same time is essential for GHGs mitigation, because peak N 2 O and CO 2 emission were observed only when moisture and temperature are both appropriate. [ABSTRACT FROM AUTHOR]

Partial wetting irrigation influences soil moisture distribution, which potentially changes soil nitrous oxide (N 2 O) emission. Incubation experiments were conducted to reveal the impact of non-uniform moisture distribution on soil N 2 O emissions under subsurface-drip-irrigation (SDI), with surface-irrigation (SI) as a control. Results indicated that soil N 2 O emission from different subregions of SDI soil varied synchronized to soil moisture. The wetting-drying process in different soil subregions under SDI incurred pulse N 2 O emissions unexceptionally, but the pulse magnitudes and timing of the occurrence varied among subregions. The pulse N 2 O emission magnitudes positively correlated to the match degree of soil moisture to the optimal soil moisture level for peak N 2 O emissions. The soil water-filled-porosity WFPS ranges for peak N 2 O fluxes, the determine coefficient of the exponential functions between N 2 O flux and soil WFPS and its average slopes, decreased gradually from the central to periphery SDI soil subregions. Both peak and cumulative N 2 O fluxes were much lower from the periphery subregions than from central subregions. On the whole, SDI reduced the cumulative N 2 O emissions by 77.3–86.7% compared to SI, with periphery suberegions of R3 and R4 contributing for more than 76%. The partial wetting SDI irrigation can significantly reduce soil N 2 O emissions and is a promising strategy for soil N 2 O emission mitigation. Further research should be conducted on how to design SDI properly to balance the soil moisture uniformity/efficiency and soil N 2 O emission reduction. [ABSTRACT FROM AUTHOR]

A canopy-resistance-based Penman-Monteith (PM) model’s performance in estimating rice evapotranspiration (ET) under water-saving irrigation (WSI) condition at hourly and daily intervals was evaluated. To improve the performance of Jarvis-type canopy-resistance model in calculating rice ET under water-saving irrigation condition with Penman-Monteith (PM) model, a term of effective leaf area index was used to reflect the influence of canopy coverage condition, and field capacity was replace by saturated soil moisture (θ s ) in soil water response functions due to the specific field moisture condition in WSI rice fields. Two years of hourly rice ET measured using eddy covariance ( ET h EC ) with energy balance closure adjustment served to calibrate (2014 data) and validate (2015 data) a canopy-resistance-based PM model. Results indicate that the PM model’s output ( ET h sim ) with calibrated canopy resistance model parameters closely matched measured ET h EC , with a regression slope, intercept, coefficient of determination (R 2 ), root mean squared error (RMSE) and index of agreement (IOA) of 1.001, 0.010 mm h −1 , 0.942, 0.057 mm h −1 and 0.985, respectively for validation data set in 2015, better than the results calculated by model with parameters calibrated for general paddy field. The improved PM model performed well not only in a dense canopy condition ( LAI > 3) but also for a sparse canopy ( LAI < 3). The model also performed well both in sunny and cloudy days of each rice growth stages. A more detailed analysis indicated that ET h sim tended to overestimate or underestimate ET h EC in varied degrees at noon time or during the transition period from day to night. These differences between ET h sim and ET h EC associated with the variation of net radiation ( Rn ), soil heat flux ( G 0 ), and soil moisture ( θ ). Additionally, the PM model calibrated on hourly dataset, performed well in calculating the daily ET directly under WSI for 2014 ( R 2 = 0.973, RMSE = 0.237 mm d −1 , IOA = 0.993) and 2015 ( R 2 = 0.961, RMSE = 0.302 mm d −1 , IOA = 0.990). Therefore, the PM model calibrated using the hourly data was capable of accurately estimating both hourly and daily ET for rice under WSI condition. [ABSTRACT FROM AUTHOR]

To reveal the impact of soil disturbance and surface watering (SW) following soil disturbance on the pulse nitrous oxide (N2O) emissions, incubated experiments were conducted on disturbed soil with two watering regimes [surface watering only (SWO) and subsurface watering followed by surface watering (SUW+SW)]. Intensive soil disturbance led to pulses N2O emissions from SUW + SW soil (>8,693 μg N2O m−2h−1with a peak of 30,938 μg N2O m−2h−1), although the water-filled pore space (WFPS) was substantially lower than the previously reported optimal soil moisture range (45–75% WFPS) for peak N2O emissions. N2O emissions from the disturbed soil after SW were much lower than those from SUW + SW soil, increased as the soil dried, and peaked when the WFPS fell within the optimal soil moisture range. These peaks were considerably less than those resulting from the intensive disturbance in SUW + SW soil. Thus, SW after intensive soil disturbance may be effective for mitigating of pulse N2O emissions caused by soil disturbance. [ABSTRACT FROM AUTHOR]

Fields experiment was done to investigate the effect of a typical water saving irrigation technique, namely non-flooding controlled irrigation (NFI), on the extractability, solubility, and bioavailability of zinc (Zn) in a non-polluted paddy soil. The Zn contents in the soil solutions, soil extractions by modified BCR (European Community Bureau of Reference) sequential extraction procedure, and the plant digestions were measured. Compared with the Zn in flooding irrigation (FI) soil, Zn contents in extractable (EXT) form and Zn contents in soil solutions was increased in 0-20 cm NFI soil, accompanied with a little reduction of soil Zn in oxidizable (OXD) form. That confirmed the Zn in OXD form was released into soil solution under the wetting-drying cycle condition in NFI fields, and hence resulted in high extractability and solubility of Zn in top surface soil. As a result, Zn contents in the rice plant parts in NFI fields were higher than in FI fields. It can be concluded that NFI irrigation is help to enhance soil Zn bioavailability and food Zn nutrients status in the soil without Zn-pollution and Zn deficiency, but might led to soil Zn depletion in Zn deficient soil or rice foodstuffs pollution in Zn-polluted soil. © 2015 Friends Science Publishers [ABSTRACT FROM AUTHOR]

Abstract: Ammonia volatilization (AV) is one of the main pathways of nitrogen (N) loss from a rice paddy, which results in low N use efficiency and many other environmental problems. To reveal AV losses from rice paddies with different combined irrigation and N managements, field experiments were conducted using site-specific nutrient management (SSNM), controlled released nitrogen management (CRN), and non-flooding controlled irrigation (NFI). The interactive effect of N management and irrigation management on AV losses is significant. N management is the dominant management factor of AV losses from a rice paddy. Weekly AV losses followed by fertilization comprise the majority of seasonal AV losses. Ammonium contents in surface water or top soil solutions determine the AV loss rate for both flooding irrigation (FI) and NFI paddies. Moreover, AV losses are less sensitive to surface ammonium nitrogen contents for the NFI paddy than that for the FI paddy. Shallower water condition in the NFI paddy immediately after fertilization may result in higher AV losses than that in the FI paddy in a short term during the first wet–dry cycle after fertilization. However, the following wet–dry cycles result in lower AV losses in most of the rice growth stages. Seasonal AV losses from the NFI paddy using farmers’ fertilization practice (FFP), SSNM, and CRN treatments were 125.27, 37.63, and 23.73kgNha−1, which account for 31.1%, 23.2%, and 13.2% of the seasonal N inputs, respectively. These results were reduced by 14.0%, −17.1%, and 28.7% compared with those from the FI paddy with the same N management. A combination of NFI and CRN is the optimal treatment, with the lowest AV losses and high potential in reducing nutrient leaching risks. Increasing the water depth and the duration of flooding for the first wet–dry cycle after fertilization is a promising measure to reduce AV losses and improve N use efficiency in an NFI paddy. [Copyright &y& Elsevier]

To the Editors, VEXAS syndrome is a recently described entity in which an X-linked somatic mutation in I UBA1 i causes widespread inflammatory manifestations in older men, typically accompanied by a hematological disorder, particularly myelodysplastic syndromes [[2]]. Finally, a condition similar to adult-onset Still's disease, which shares both clinical and pathophysiological features with HLH, has been reported in several patients with VEXAS syndrome [[3], [11]]. Diagnosis of HLH in patients with VEXAS syndrome may be challenging due to pre-existing cytopenia and inflammatory manifestations. [Extracted from the article]

Idiotypic determinants are potential patient-specific tumor antigens in multiple myeloma (MM). In this study, we have determined the DNA sequence of the variable region of the tumor immunoglobulin (Ig) in 6 patients with MM. We then selected high affinity class I-restricted T-cell peptide epitopes in tumor Ig using two different internet-based epitope prediction programs. High affinity binding peptides were identified by at least one program in 4 out of 6 patients. Of these 35 peptides, only 3 scored high by both analyses. Given that all 6 patients had expanded T-cell clones with a cytotoxic (CD57[SUP+] CD8[SUP+] CD28[SUP-] perforin[SUP+]) phenotype, known to be associated with a longer survival and postulated to recognise tumor epitopes, this analysis indicates that such clones are unlikely to be exclusively directed towards tumor immuoglobulin, and suggests the need to expand the scope of the search for tumor epitopes with the ability to stimulate cytotoxic T cells in vivo. [ABSTRACT FROM AUTHOR]

Surface energy distribution in paddy fields and the ratio of latent heat flux (LE) to available energy, termed as the evaporative fraction (EF), are essential for an understanding of water and energy processes. They are expected to vary in different ways in response to changes in the soil moisture condition under water-saving irrigation practice. In this study, the diurnal and seasonal variations in energy distribution were examined based on the data measured by the eddy covariance system and corrected with enforcing energy balance closure by the EF method in water-saving irrigated rice paddies in 2015 and 2016. Soil heat flux (G) values were similar in magnitude to sensible heat flux (Hs) values, with both accounting for approximately 5% of the energy input. Both magnitudes of G and Hs were significantly lower than that of LE. Generally, EF in water-saving irrigated rice paddies was larger than that of other ecosystems, and varied within a narrow range from 0.7 to 1.0. Diurnally, EF decreased till noon and then increased slowly in the afternoon till sunset. It was found be less varied between 10:00 and 14:00. Seasonally, the alternative drying-wetting soil water conditions in water-saving irrigated rice paddies resulted in a change in the variation of the EF. The LE flux is the largest component of available energy, with EF being mostly higher than 0.9. EF, increasing consistently till the tillering stage, remaining high from the late tillering to milk stage, and then following a declining trend. The maximum EF (approaching 1.0) was found in the milk stage. The results of EF in water-saving irrigated rice paddies will be helpful for estimating daily or long temporal scale evapotranspiration (ET) by the EF method based on satellite-derived ET. [ABSTRACT FROM AUTHOR]

Highlights • AquaCrop performed well in simulating rice crop development and yield under drying-wetting cycle condition. • Crop coefficients modelled by AquaCrop were less varied along with rice growth than observed. • Water deficit coefficient for rice was overestimated under drying-wetting cycle condition. • The method in AquaCrop to estimate crop coefficient should be improved for rice under drying-wetting cycle condition. • The method in AquaCrop to estimate water deficit coefficient should be improved for rice under drying-wetting cycle condition. Abstract Various crop growth models have been developed to simulate the crop development and were used to assess the effects of climate, cultivation and irrigation methods. To evaluate the feasibility of water driven model-AquaCrop in simulating crop development, production and field water balance in paddy soil under drying – wetting cycle condition, the model was calibrated and validated based on data during 2012–2013 rice season in Eastern China. Results showed that the accuracy of this model in simulating canopy cover (CC), evapotranspiration (ET), biomass, yield were generally acceptable, with the root mean square of error (RMSE) less than 10% for CC, 1.0 mm for ET, 0.61t ha−1 for biomass and with relative deviation of 3.6% for yield. Meanwhile, AquaCrop tended to overestimate CC, biomass and yield slightly during the midseason. Yet, its performance in simulating soil moisture content was not as good as expected. It tended to underestimate soil moisture with a RMSE of 14.81%, but overestimated the water deficit coefficient (Ks). The method for Ks calculation incorporated in AquaCrop should be revised for rice under drying-wetting cycle condition. [ABSTRACT FROM AUTHOR]

Noncontinuous flooding irrigation is an important means of reducing water use, mitigating greenhouse gas emission, and maintaining crop yield in rice production systems. Quantifying the CH 4 and N 2 O emissions in continuous and noncontinuous flooding irrigation systems is crucial to the exploration of sustainable water management practices in rice systems. In this study, a simple "anaerobic ball" method was incorporated into the WHCNS (soil Water Heat Carbon Nitrogen Simulator) model to simulate and evaluate the CH 4 and N 2 O emissions under continuous and noncontinuous flooding irrigation conditions. This model considers the processes of dissolved organic carbon (DOC) release and transport in the soil profile, CH 4 production, oxidation, and transport, and N 2 O production, reduction, and transport. Three years of field experiment data, including soil and environment variables (e.g., ponding water depth, soil water content, and soil temperature) and daily CH 4 and N 2 O emission fluxes under different irrigation practices were collected to test the improved WHCNS model. Results show that the model performs well in simulating soil and environment variables, with performance indices IA , NSE , and Pearson's r varying from 0.772 to 0.966, 0.530–0.853, and 0.780–0.934, respectively. Furthermore, the daily dynamics of CH 4 and N 2 O emissions were captured under different rice irrigation systems, with average IA , NSE , and Pearson's r values of 0.857, 0.476, and 0.763, respectively. The observed and simulated results indicate that noncontinuous irrigation reduces CH 4 emission but increases N 2 O emission. Compared with continuous flooding irrigation, noncontinuous flooding irrigation significantly decreased the accumulated CH 4 emission by 82.1%, but significantly increased the N 2 O emission by 129.4%, resulting in the global warming potential reduction of 23.5%. The improved model reflects the effects of continuous and noncontinuous flooding practices on CH 4 and N 2 O emissions, and exhibits great potential for the development of sustainable water management for rice production systems. [Display omitted] • A process-based model was developed to simulate GHG emission for continuous and noncontinuous flooding rice systems. • A simple "anaerobic ball" method was incorporated into WHCNS_Rice model for simulating CH 4 and N 2 O emission. • The model performed well in CH 4 and N 2 O emission for continuous and noncontinuous flooding rice systems. • Controlled irrigation significantly decreased the CH 4 emission by 82.1%, but increased N 2 O emission by 129.4%. • WHCNS_Rice model showed a great potential for developing sustainable water management to achieve a low GHG emission. [ABSTRACT FROM AUTHOR]

Proper methods for estimating reference evapotranspiration (ET0) using limited climatic data are critical, if complete weather data are unavailable. Based on the weather data of 19 stations in Guizhou Province, China, several simple methods for ET0estimation, including the Hargreaves, Priestley–Taylor, Irmak–Allen, McCloud, Turk, and Valiantzas methods, were involved in comparison with the standard FAO-56 Penman–Monteith (PM) method. The Turk equation performs well for estimating ET0in humid locations. Both the Turk method and the Valiantzas method initially performed acceptably with mean root-mean-square difference (RMSD) of 0.1472 and 0.1282 mm d−1, respectively, with only requiring parameters of temperature (T), relative humidity (RH), and sunshine duration (n). The corresponding calibration formulas to Turk and Valiantzas method were suggested as the most appropriate method for ET0estimation with the RMSD of 0.0098 and 0.0250 mm d−1, respectively. The local calibrated Hargreaves–Samani method performed well and can be applied as the substitute of FAO-56 PM method under the condition that only the daily mean, maximum, and minimum temperatures were available, and local calibrated McCloud method was acceptable if only the mean temperature was available. [ABSTRACT FROM AUTHOR]

Myeloid derived suppressor cells (MDSCs) are a heterogeneous population of cells that have been implicated as inhibitors of lymphopoiesis in patients with malignancies. They have a consensus phenotype of CD33+/CD11b+/HLA-DRlo/− and can be further divided into CD15 + granulocytic (G-MDSC) and CD14 + monocytic (M-MDSC) subsets. We characterized MDSCs in patients with multiple myeloma (MM) and found a significant increase in G-MDSCs in the blood of patients with progressive MM. Flow-sorted MDSCs from patients with MM induced the generation of regulatory T cells (Treg). MDSCs from both patients with MM and aged-matched controls demonstrated a dose-dependent inhibition of lymphocyte proliferation in carboxyfluorescein succinimidyl ester (CFSE)-tracking experiments. Granulocyte colony stimulating factor (G-CSF) administered to induce stem cell mobilization caused an increase in the number of MDSCs in the peripheral blood of patients with MM and a concentration of these immune-suppressive cells in peripheral blood stem cell collections. MDSCs are likely to cause immune dysfunction in patients with MM. [ABSTRACT FROM AUTHOR]

Discrepancies in the literature between regulatory T cell (Treg) and pro-inflammatory T helper 17 (Th17) numbers in multiple myeloma (MM) can be largely explained by technical differences in methodology and patient selection. In this study, Treg cells were defined as CD3+CD4+CD25++CD127lo cells. Patients with MM ( n = 20) had a significant imbalance in Treg/Th17 ratio when compared with either aged-matched controls ( n = 28) or other monoclonal gammopathies, and this was associated with a significantly worse survival. The percent Treg in bone marrow of patients with MM was higher than that in matched peripheral blood samples ( p = 0.02), although FOXP3 expression within bone marrow T cells was lower ( p = 0.02). We observed increased Treg function, both in vivo and in vitro, due at least partially to an increase in CTLA-4 expression by concurrent treatment with dexamethasone and immune modulatory compounds (iMiDs). We suggest that immunoregulatory balance is important during active chemotherapy and that conclusions related to the immunostimulatory effect of iMiDs based on in vitro testing must be considered with caution. [ABSTRACT FROM AUTHOR]

Prediction of daily reference evapotranspiration (ET0) is the basis of real-time irrigation scheduling. A multiple regression method forET0prediction based on its seasonal variation pattern and public weather forecast data was presented for application in East China. The forecasted maximum temperature (Tmax), minimum temperature (Tmin) and weather condition index (WCI) were adopted to calculate the correction coefficient by multilinear regression under five time-division regimes (10 days, monthly, seasonal, semi-annual and annual). The multiple regression method was tested for its feasibility forET0prediction using forecasted weather data as the input, and the monthly regime was selected as the most suitable. Average absolute error (AAE) and root mean square error (RMSE) were 0.395 and 0.522 mm d−1, respectively.ET0prediction errors increased linearly with the increase in temperature prediction error. A temperature error within 3 K is likely to result in acceptableET0predictions, with AAE and average absolute relative error (AARE) <0.142 mm d−1and 5.8%, respectively. However, one rank error inWCIresults in a much larger error inET0prediction due to the high sensitivity of the correction coefficient toWCIand the large relative error inWCIcaused by one rank deviation. Improving the accuracy of weather forecasts, especially forWCIprediction, is helpful in obtaining better estimations ofET0based on public weather data. [ABSTRACT FROM AUTHOR]

Abstract: Water management is one of the most important practices that affect methane (CH4) and nitrous oxide (N2O) emissions from paddy fields. A field experiment was designed to study the effects of controlled irrigation (CI) on CH4 and N2O emissions from paddy fields, with traditional irrigation (TI) as the control. The effects of CI on CH4 and N2O emissions from paddy fields were very clear. The peaks of CH4 emissions from the CI paddies were observed 1–2d after the water layer disappeared. Afterward, the emissions reduced rapidly and remained low until the soil was re-flooded. A slight increase of CH4 emission was observed in a short period after re-flooding. N2O emissions peaks from CI paddies were all observed 8–10d after the fertilization at the WFPS ranging from 78.1% to 85.3%. Soil drying caused substantial N2O emissions, whereas no substantial N2O emissions were observed when the soil was re-wetted after the dry phase. Compared with TI, the cumulative CH4 emissions from the CI fields were reduced by 81.8% on the average, whereas the cumulative N2O emissions were increased by 135.4% on the average. The integrative global warming potential of CH4 and N2O on a 100-year horizon decreased by 27.3% in the CI paddy fields, whereas no significant difference in the rice yield was observed between the CI and TI fields. These results suggest that CI can effectively mitigate the integrative greenhouse effect caused by CH4 and N2O emissions from paddy fields while ensuring the rice yield. [Copyright &y& Elsevier]

The expanded T cell clones are associated with a prolonged survival in patients with multiple myeloma. We sought to confirm this prognostic significance in a multicenter patient cohort and investigate the effect of thalidomide on clones and T regulatory cells (Tregs). Blood was collected from 120 patients enrolled in a Phase III trial of maintenance therapy ± thalidomide after autologous stem cell transplantation. TCR Vβ repertoire analysis identified T cell expansions in 48% of patients pre-transplant and 68% after 8-month maintenance. T cell expansions, previously shown to be clonal, were predominantly CD8 + (93%) and all 24 TCR Vβ families tested were represented. Thalidomide therapy was associated with a significant increase in the incidence of patients with multiple expansions (49% vs. 23%; χ2=6.8; p=0.01). The presence of expansions regardless of therapy was associated with a significantly longer median progression free survival (PFS) (32.1 vs. 17.6 months; χ2=5.6; p=0.02) and overall survival (OS) (χ2=3.9; p<0.05). Median PFS in the thalidomide arm was 50.9 months for patients with expansions and 28.3 months for patients without expansions (χ2=19.4; p=0.0002). Thalidomide did not appear to modulate Treg numbers. Expanded T cell clones are prognostically significant and have an impact on progression after thalidomide therapy in a proportion of patients. [ABSTRACT FROM AUTHOR]

The article presents a study on the use of an evidence of up-regulated fibroblast growth factor receptor 3 (FGFR3) to detect measurable residual disease (MRD) in both bone marrow (BM) and peripheral blood (PB) samples from patients with multiple myeloma (MM). The gene expression data showed that most patients with MM would have either unregulated FGFR3, cyclin D3 or c-maf expression. The study shows that dPCR possesses sufficient sensitivity for the detection of MRD in MM patients.

A letter to the editor is presented in response to the article about the presence of side population (SP) cells in multuple myeloma.

BACKGROUND: Immunoglobulin A antibodies (anti-IgA) are rare but can cause transfusion-associated anaphylaxis. The detection of anti-IgA has traditionally been performed using a labor-intensive hemagglutination assay in a limited number of reference laboratories. STUDY DESIGN AND METHODS: Two simple gel card assays are now available that can be used to screen for anti-IgA and IgA deficiency. A total of 24 serum samples that had been previously assayed for anti-IgA over a 3-year period were used to assess the DiaMed anti-IgA and IgA deficiency assays. RESULTS: The DiaMed assays correctly identified patients (n = 6) who had significant IgA deficiency and anti-IgA. All patients with an abnormal anti-IgA titer by hemagglutination assay and who were also IgA-deficient had anti-IgA detected using the DiaMed screening test. One patient, previously shown to have an IgA level of less than 0.067 g per L, failed to be detected as IgA-deficient in the DiaMed IgA deficiency test; however, anti-IgA were not present. Samples with slightly increased anti-IgA titers tended to have normal IgA levels. CONCLUSION: The DiaMed gel card screening assays are appropriate screening tools for the investigation of transfusion-related anaphylactic reactions and can be used in any routine blood bank laboratory. [ABSTRACT FROM AUTHOR]

• The temperature rise inside bulk HTS in the fluctuating magnetic field is collected and analyzed. • A complete set of magnetic levitation device is developed, which can simulate the internal temperature rise characteristics of HTS bulk under different magnetic fields. • The results show the relationship between the internal temperature rise and the cooling height, the working height and the frequency of the fluctuating magnetic field. In high-temperature superconductor (HTS) Maglev system, the permanent magnet guideway (PMG) can't be formed by the whole permanent magnet (PM), which results in the existence of multiple PM splicing slots in the PMG. Moreover, this kind of splicing gap will become bigger with the longer service time of PMG. In addition, due to material inhomogeneity and magnetization difference inside a single PM and there will be fluctuation in magnetic field (MF) above PMG. The fluctuation may have a great impact on the efficient and stable operation of the Maglev system. This paper focuses on the influence of fluctuant MF on the temperature rise inside bulk HTS, including the internal loss caused by cooling height (CH), working height (WH) and frequency of MF change. Finally, the HTS Maglev system is analyzed from temperature rise inside the bulk HTS. The results and analyses of this article are useful for the application of bulk HTSs in the Maglev system. [ABSTRACT FROM AUTHOR]

• Variation of energy budget components was used to explain the pattern observed in EF. • The patterns of hourly, daytime and daily EF for WSI rice paddies were examined. • The time-of-day representativeness of EF in estimating daily ET was investigated. • A considerable gap serves in forming a relationship between ET EF,d and ET true,d. • An improved EF up-scaling method is proposed for estimating effective daily ET. Evaporative fraction (EF), which is known to exhibit variation in response to changes in crop species, soil and meteorologic conditions, plays an important role in interpreting the components of energy budget and estimating evapotranspiration (ET), while such information is scarce for humid rice fields. The present study discussed the variation of energy balance components and then examined the pattern of hourly, daytime and daily EF after monitoring energy components by eddy covariance for water-saving irrigated (WSI) rice paddies of 2015 and 2016. Then the daily ET was estimated by an improved EF up-scaling method in the subtropical monsoon climate region of East China. Diurnally, hourly EF is deemed as an approximately concave-up shape in different growth stages of rice season. The seasonal average EF varies gently, with a minimum around 10:00–11:00 AM. Seasonally, the mean daytime EF for the whole growth stage is 0.86, 7% lower than the daily value. Daily EF exhibits mostly higher than 0.8 except later yellow ripening period, approaching 1.0 in the milk stage. EF over WSI rice exhibits obviously greater than the reports that from upland crops. In addition, differences are noted in the results with respect to the daily ET estimation by EF up-scaling method. The estimated daily ET (ET EF,d) from hourly EF during 10:00–11:00 h is highly correlated to the measured ET (ET true) by the weighed micro-lysimeters though the ET EF,d value is underestimated. Such a considerable gap serves in forming a relationship between ET EF,d and ET true,d , that is, by simply multiplying the representativeness ET value based on the EF up-scaling method by a correction procedure calibrated for this region. In conclusion, an improved EF up-scaling method is proposed for extrapolating remote sensing based ET estimates to daily values. [ABSTRACT FROM AUTHOR]

Photosynthetic light response (PLR) curves of leaves are usually fitted by non-rectangular hyperbola (NRH) equation, and those fitted NRH parameters may change with leaf aging. The objectives of this study were 1) to reveal the response of NRH parameters of rice leaves, light-saturated net photosynthetic rate (Pnmax), quantum yield of assimilation (φ), dark respiration rate (Rd) and convexity of the curve (k), to leaf age; and 2) to improve the performance of NRH equation in simulating the PLR curves for leaves at various ages. The PLR for rice leaves at ages of 3–53 days were measured, and the general NRH equation was developed by incorporating the relationship between NRH parameters and leaf age into the NRH equation. The results showed that the NRH parameters of Pnmax, φ and Rd increased rapidly to maximum at approximately 10 days and then declined linearly toward the age of 53 days. However, the value of k was not sensitive to leaf age. The general NRH equation can be used to simulate leaf PLR continuously along with leaf aging. [ABSTRACT FROM AUTHOR]