Evaluating the effects of ground-level O3 on rice yield and economic losses in Southern China

A field experiment was carried out during the Boro season 2013 to find out the effects of water management practices on rice yield performance and water productivity index at Old Brahmaputra flood plain paddy land, Muktagacha, Mymensingh. The experiment was laid out in randomized complete block design (RCBD) with six (6) irrigation treatments. Two treatments, T1 and T3 were kept under continuous standing water levels (10 cm and 5 cm respectively) while in treatment T5 irrigation water was supplied for 1st 3 weeks then followed mid season drain out and re-flooded at flowering stage. Three alternate wetting and drying irrigation treatments, T2, T4 and T6 were selected in which irrigation water was applied when water level dropped 20cm, 10cm and 15cm below ground level, respectively. All the irrigation treatments significantly affected the rice yield and yield contributing parameters. The study revealed that the highest grain yield (5950 kg ha-1) was found in treatment T5 which was identical with AWDI treatment T4 (5820 kg ha-1) followed by AWDI treatment T6 (5460 kg ha-1). On the contrary, rice yield of 3350 kg ha-1, 4470 kg ha-1 and 4810 kg ha-1 were found in the treatment T1, T2 and T3, respectively. It was found that AWDI treatment T2 showed maximum water savings (15.1%) followed by T6 (11.3%), T4 (7.59%) and T5 (3.8%), however rice yield in the treatment T2 (4470 kg ha-1) was significantly lower compared to T6, T4 and T5 treatment. Therefore, it may be inferred that treatment T4 (AWDI; irrigation when water level fell 10 cm from ground level), T5 (Irrigation for 1st 3 weeks, then mid-season drain out and re-flooding at flowering) and T6 (AWDI; irrigation when water level fell 15cm from ground level) would be the feasible choice for the water savings, higher rice yield as well as maximum water productivity index (0.478, 0.472 and 0.467, respectively) for sustaining rice farming during the dry Boro season in Bangladesh.J. Environ. Sci. & Natural Resources, 9(2): 79-84 2016

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Changes in Rice Yield Stability in Southern China from 1949 to 2015

ael ◽

10.2134/ael2017.11.0038 ◽

2018 ◽

Vol 3 (1) ◽

pp. 170038 ◽

Cited By ~ 3

Author(s):

Xiaohong Yin ◽

Min Huang ◽

Yingbin Zou

Keyword(s):

Rice Yield ◽

Southern China ◽

Yield Stability

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Studies in Asian Nervilia (Nervilieae, Epidendroideae, Orchidaceae) VI: N. mekongensis, a new species from Thailand, Cambodia, Laos and Vietnam

Phytotaxa ◽

10.11646/phytotaxa.247.4.4 ◽

2016 ◽

Vol 247 (4) ◽

pp. 267 ◽

Cited By ~ 3

Author(s):

STEPHAN W. GALE ◽

ANDRÉ SCHUITEMAN ◽

SANTI WATTHANA ◽

TOMOKI SANDO ◽

KEOOUDONE SOUVANNAKHOUMMANE ◽

...

Keyword(s):

New Species ◽

Leaf Blade ◽

Southern China ◽

Ground Level ◽

Terrestrial Orchid ◽

Conservation Assessment ◽

Widespread Species ◽

Tropical Asia ◽

The Many ◽

A New Species

A new species of the terrestrial orchid genus Nervilia is described and illustrated from material collected at several localities in the Greater Mekong region of Southeast Asia. The multi-flowered inflorescence bearing relatively large flowers with a pubescent lip, and the many-veined, cordate-reniform leaf blade that is held well above ground level, place N. mekongensis in section Nervilia. Despite being superficially similar to N. aragoana, a widespread species of tropical Asia and Australasia, it is most closely affiliated to N. fordii, a species known from southern China and Thailand. It is distinguished by its stout inflorescence and lip that is broadest midway along the hypochile and which has acute, forward-projecting side-lobes and a short, ovate mid-lobe. A conservation assessment plus taxonomic notes are provided.

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Dust storms come to Central and Southwestern China, too: implications from a major dust event in Chongqing

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-2615-2010 ◽

2010 ◽

Vol 10 (6) ◽

pp. 2615-2630 ◽

Cited By ~ 40

Author(s):

Q. Zhao ◽

K. He ◽

K. A. Rahn ◽

Y. Ma ◽

Y. Jia ◽

...

Keyword(s):

Southern China ◽

Ground Level ◽

Cold Season ◽

Asian Dust ◽

Dust Storms ◽

Southwestern China ◽

Gobi Desert ◽

Dust Event ◽

Back Trajectories ◽

Desert Dust

Abstract. Dust storms from major Asian sources are usually carried by northwesterly or westerly winds over Northern and Southeastern China to the Pacific Ocean. These pathways leave Central and Southwestern China nearly free of incursions. But a strong dust event on 5–6 May 2005 was captured in a 15-month series of weekly filter samples of PM2.5 at three sites in Chongqing. It illustrated that desert dust can be transported to this region, and sometimes strongly. Annual PM2.5 and dust were similar at the three sites, but higher than in simultaneous samples in Beijing. High correlations of dust concentrations were found between the cities during spring, indicating that Asian dust affects a broader swath of China than is often realized. During the event, the concentrations of mineral dust were high at all sites (20–30 μg m−3; 15%–20% of PM2.5 in Chongqing, and 15 μg m−3; 20%–30% of PM2.5 in Beijing), and were part of a broader spring maximum. The proportions of crustal elements and pollution-derived components such as Pb, SO42−, and organic carbon indicated that the sources for this dust differed from Beijing. The dust was considerably enriched in Ca and Mg, characteristic of western deserts, whereas Beijing's dust had the lower Ca and Mg of eastern deserts. This observation agrees with synoptic patterns and back-trajectories. Driven by a cold air outbreak from the northwest, dust from the western Gobi Desert was transported at lower altitudes (<2 km above ground level), while dust from the Takla Makan Desert was transported to Chongqing at higher altitudes. Desert dust can also be important to wide areas of China during the cold season, since almost all the weekly dust peaks in the two cities coincided with extensive dust emissions in source regions. These findings collectively suggest that the amount Asian-dust in China has been underestimated both spatially and temporally, and that transported alkaline dust can even be mitigating the effects of acidic deposition in Southern China.

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Rice yield, potassium uptake and apparent balance under long-term fertilization in rice-based cropping systems in southern China

Nutrient Cycling in Agroecosystems ◽

10.1007/s10705-010-9359-3 ◽

2010 ◽

Vol 88 (3) ◽

pp. 341-349 ◽

Cited By ~ 30

Author(s):

Huimin Zhang ◽

Minggang Xu ◽

Xiaojun Shi ◽

Zuzhang Li ◽

Qinghai Huang ◽

...

Keyword(s):

Rice Yield ◽

Southern China ◽

Cropping Systems ◽

Potassium Uptake

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Ozone production and hydrocarbon reactivity in Hong Kong, Southern China

Atmospheric Chemistry and Physics ◽

10.5194/acp-7-557-2007 ◽

2007 ◽

Vol 7 (2) ◽

pp. 557-573 ◽

Cited By ~ 111

Author(s):

J. Zhang ◽

T. Wang ◽

W. L. Chameides ◽

C. Cardelino ◽

J. Kwok ◽

...

Keyword(s):

Hong Kong ◽

Southern China ◽

Ground Level ◽

Ozone Production ◽

Back Trajectories ◽

Ground Level Ozone ◽

Abstract Data ◽

The Pearl River ◽

Ozone Episodes ◽

The Relationship

Abstract. Data obtained in Hong Kong during the Hong Kong and the Pearl River Delta (PRD) Pilot Air Monitoring Study in autumn 2002 are analyzed to unravel the relationship between ground-level ozone (O3), pollution precursors, and cross-border transport. Ten ozone episodes, during which the hourly O3 concentration exceeded 100 ppbv in 9 cases and 90 ppbv in one case, are subject to detailed analysis, including one case with hourly O3 of 203 ppbv, which is the highest concentration on record to date in Hong Kong. Combined with high-resolution back trajectories, dCO/dNOy (the ratio of enhancement of CO concentration above background to that of NOy) is used to define whether O3 is locally or regionally produced. Five out of the ten Hong Kong O3-episodes studied show a "pollution signature" that is indicative of impact from Guangdong Province. Examination of speciated volatile organic compounds (VOCs) shows that the reactivity of VOCs is dominated by anthropogenic VOCs, of which the reactive aromatics dominate, in particular xylenes and toluene. Calculations using a photochemical box model indicate that between 50–100% of the O3 increase observed in Hong Kong during the O3 episodes can be explained by photochemical generation within the Hong Kong area, provided that nitrous acid (HONO) is present at the concentrations derived from this study. An Observation-Based Model (OBM) is used to calculate the sensitivity of the O3 production to changes in the concentrations of the precursor compounds. Generally the production of O3 throughout much of the Hong Kong area is limited by VOCs, while high nitric oxide (NO) concentrations suppress O3 concentration.

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Meteorological Factors and Swine Erysipelas Transmission in Southern China

Acta veterinaria ◽

10.2478/acve-2020-0002 ◽

2020 ◽

Vol 70 (1) ◽

pp. 37-50

Author(s):

Qin Hong-Yu ◽

Xin Xiu ◽

Sha Wanli ◽

Wang Ben ◽

Hu Xiansheng ◽

...

Keyword(s):

Negative Binomial ◽

Meteorological Factors ◽

Southern Oscillation ◽

Southern China ◽

Meteorological Variables ◽

Maximum Temperature ◽

Economic Losses ◽

Lag Effects ◽

Cross Correlation Analysis ◽

Swine Erysipelas

AbstractSwine erysipelas (SE) is one of the best-known and most serious diseases that affect domestic pigs, which is caused by Erysipelothrix rhusiopathiae. It is endemic in Nanning and has been circulating for decades, causing considerable economic losses. The aim of this study was to investigate the effect of meteorological-related variations on the epidemiology of swine erysipelas in Nanning City, a subtropical city of China. Data on monthly counts of reported swine erysipelas and climate data in Nanning are provided by the authorities over the period from 2006 to 2015. Cross-correlation analysis was applied to identify the lag effects of meteorological variables. A zero-inflated negative binomial (ZINB) regression model was used to evaluate the independent contribution of meteorological factors to SE transmission. After controlling seasonality, autocorrelation and lag effects, the results of the model indicated that Southern Oscillation Index (SOI) has a positive effect on SE transmission. Moreover, there is a positive correlation between monthly mean maximum temperature and relative humidity at 0-1 month lag and the number of cases. Furthermore, there is a positive association between the number of SE incidences and precipitation, with a lagged effect of 2 months. In contrast, monthly mean wind velocity negatively correlated with SE of the current month. These findings indicate that meteorological variables may play a significant role in SE transmission in southern China. Finally, more public health actions should be taken to prevent and control the increase of SE disease with consideration of local weather variations.

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Population Genomics Reveals Gene Flow and Adaptive Signature in Invasive Weed Mikania micrantha

Genes ◽

10.3390/genes12081279 ◽

2021 ◽

Vol 12 (8) ◽

pp. 1279

Author(s):

Xiaoxian Ruan ◽

Zhen Wang ◽

Yingjuan Su ◽

Ting Wang

Keyword(s):

Gene Flow ◽

Environmental Variables ◽

Mixed Model ◽

Population Genomics ◽

Southern China ◽

Defense Responses ◽

Economic Losses ◽

Functional Genes ◽

Invasive Weed ◽

Mikania Micrantha

A long-standing and unresolved issue in invasion biology concerns the rapid adaptation of invaders to nonindigenous environments. Mikania micrantha is a notorious invasive weed that causes substantial economic losses and negative ecological consequences in southern China. However, the contributions of gene flow, environmental variables, and functional genes, all generally recognized as important factors driving invasive success, to its successful invasion of southern China are not fully understood. Here, we utilized a genotyping-by-sequencing approach to sequence 306 M. micrantha individuals from 21 invasive populations. Based on the obtained genome-wide single nucleotide polymorphism (SNP) data, we observed that all the populations possessed similar high levels of genetic diversity that were not constrained by longitude and latitude. Mikania micrantha was introduced multiple times and subsequently experienced rapid-range expansion with recurrent high gene flow. Using FST outliers, a latent factor mixed model, and the Bayesian method, we identified 38 outlier SNPs associated with environmental variables. The analysis of these outlier SNPs revealed that soil composition, temperature, precipitation, and ecological variables were important determinants affecting the invasive adaptation of M. micrantha. Candidate genes with outlier signatures were related to abiotic stress response. Gene family clustering analysis revealed 683 gene families unique to M. micrantha which may have significant implications for the growth, metabolism, and defense responses of M. micrantha. Forty-one genes showing significant positive selection signatures were identified. These genes mainly function in binding, DNA replication and repair, signature transduction, transcription, and cellular components. Collectively, these findings highlight the contribution of gene flow to the invasion and spread of M. micrantha and indicate the roles of adaptive loci and functional genes in invasive adaptation.

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