Bioavailability and Methylation of Bulk Mercury Sulfide in Paddy Soils: New Insights into Mercury Risks in Rice Paddies

2021 ◽  
pp. 127394
Author(s):  
Hong Li ◽  
Yunyun Li ◽  
Wenli Tang ◽  
Yunpeng Liu ◽  
Lirong Zheng ◽  
...  
Keyword(s):  
Paddy Soils ◽  
Rice Paddies ◽  
Mercury Sulfide

scholarly journals Microbial community structure with trends in methylation gene diversity and abundance in mercury-contaminated rice paddy soils in Guizhou, China

2018 ◽  
Vol 20 (4) ◽  
pp. 673-685 ◽  
Author(s):  
Tatiana A. Vishnivetskaya ◽  
Haiyan Hu ◽  
Joy D. Van Nostrand ◽  
Ann M. Wymore ◽  
Xiaohang Xu ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
Gene Diversity ◽  
Rice Paddy ◽  
Paddy Soils ◽  
Rice Paddies ◽  
Sulfate Reducing ◽  
Rice Paddy Soils ◽  
Reducing Bacteria

Sulfate-reducing bacteria and methanogens are the primary Hg-methylators in Chinese rice paddies.

Spatial content and variability of mercury in agricultural soils in the province of Valencia (Spain), with an emphasis on those dedicated to rice crop

2021 ◽  
Author(s):  
Rafael Boluda ◽  
Luis Roca Pérez ◽  
Joaquín Ramos Miras ◽  
José A. Rodríguez Martín ◽  
Jaume Bech Borras
Keyword(s):  
Spatial Distribution ◽  
Rice Straw ◽  
Agricultural Soils ◽  
Simple Random Sampling ◽  
Rice Paddy ◽  
Paddy Soils ◽  
Systematic Sampling ◽  
Rice Paddies ◽  
Natural Park ◽  
Rice Paddy Soils

<p>Mercury (Hg) is a metal potentially dangerous that can accumulate in soils, move to plants and cause significant ecotoxicological risks. The province of Valencia is the third in Spain and has a great agricultural, industrial and tourist vocation; it has an area of 10,763 km<sup>2</sup>, of which it devotes 272,978 ha to cultivation, most of which are irrigated soils. To the south of the city of Valencia, is the Albufera Natural Park (ZEPA area and Ramsar wetland) with 14,806 ha dedicated to rice cultivation. Pollution and burning of rice straw in rice paddies are serious problems. Therefore, the concentration of Hg in agricultural soils in the province of Valencia according to use, with an emphasis on rice paddy soils, and spatial distribution were determined; and the effects of rice straw burning on Hg accumulation on rice paddy soils was assessed. Systematic sampling was carried out throughout the agricultural area at an intensity of a grid of 8 x 8 km, in which samples composed of soil between 0 and 20 cm were collected in a total of 98 plots; and a simple random sampling in the case of rice paddies in 35 sites, distinguishing between plots where the incineration of rice straw was carried out and where it was not. The concentration of Hg was determined with a direct DMA-80 Milestone analyzer in the previously pulverized sample. The detection limit was 1.0 g kg<sup>-1</sup>, the recovery was 95.1% to 101.0% ± 4.0%. The analyses were performed in triplicate. A basic descriptive statistic (means, medians, deviations, and ANOVA) was performed. Samples were grouped according to land use. For geostatistic analysis and in order to obtain the map of the spatial distribution of the concentration of Hg in soils, the classical geostatistic technique was used by ordinary kriging. The concentration of Hg in the soils of the province of Valencia showed great variability. The soils of the rice paddies together with those dedicated to the cultivation of citrus and horticultural of the coastal plain, showed the highest levels of Hg, in contrast to the soils of the interior areas dedicated to dry crops (vineyards, olive, almond and fodder). Spatial analysis reflected a concentration gradient from west to east, suggesting that the Hg in the soils of the interior has a geochemical origin, while in the coast soils it is of anthropic origin. On the other hand, it was observed that the burning of rice straw increased the Hg concentration in rice paddy soils. This research is the first information on the distribution of Hg in the soils of the province of Valencia and a contribution that can help weigh the effects of open burning of rice straw on Valencian rice paddies.</p>

scholarly journals Nitrogen Addition Decreases Dissimilatory Nitrate Reduction to Ammonium in Rice Paddies

2018 ◽  
Vol 84 (17) ◽  
Author(s):  
Arjun Pandey ◽  
Helen Suter ◽  
Ji-Zheng He ◽  
Hang-Wei Hu ◽  
Deli Chen
Keyword(s):  
Paddy Soil ◽  
Nitrate Reduction ◽  
Nitrogen Loss ◽  
Nitrogen Addition ◽  
N Fertilizer ◽  
Paddy Soils ◽  
N Addition ◽  
Rice Paddies ◽  
N Application ◽  
Dissimilatory Nitrate Reduction

ABSTRACTDissimilatory nitrate reduction to ammonium (DNRA), denitrification, anaerobic ammonium oxidation (anammox), and biological N2fixation (BNF) can influence the nitrogen (N) use efficiency of rice production. While the effect of N application on BNF is known, little is known about its effect on NO3−partitioning between DNRA, denitrification, and anammox. Here, we investigated the effect of N application on DNRA, denitrification, anammox, and BNF and on the abundance of relevant genes in three paddy soils in Australia. Rice was grown in a glasshouse with N fertilizer (150 kg N ha−1) and without N fertilizer for 75 days, and the rhizosphere and bulk soils were collected separately for laboratory incubation and quantitative PCR analysis. Nitrogen application reduced DNRA rates by >16% in all the soils regardless of the rhizospheric zone, but it did not affect thenrfAgene abundance. Without N, the amount and proportion of NO3−reduced by DNRA (0.42 to 0.52 μg g−1soil day−1and 45 to 55%, respectively) were similar to or higher than the amount and proportion reduced by denitrification. However, with N the amount of NO3−reduced by DNRA (0.32 to 0.40 μg g−1soil day−1) was 40 to 50% lower than the amount of NO3−reduced by denitrification. Denitrification loss increased by >20% with N addition and was affected by the rhizospheric zones. Nitrogen loss was minimal through anammox, while BNF added 0.02 to 0.25 μg N g−1soil day−1. We found that DNRA plays a significant positive role in paddy soil N retention, as it accounts for up to 55% of the total NO3−reduction, but this is reduced by N application.IMPORTANCEThis study provides evidence that nitrogen addition reduces nitrogen retention through DNRA and increases nitrogen loss via denitrification in a paddy soil ecosystem. DNRA is one of the major NO3−reduction processes, and it can outcompete denitrification in NO3−consumption when rice paddies are low in nitrogen. A significant level of DNRA activity in paddy soils indicates that DNRA plays an important role in retaining nitrogen by reducing NO3−availability for denitrification and leaching. Our study shows that by reducing N addition to rice paddies, there is a positive effect from reduced nitrogen loss but, more importantly, from the conversion of NO3−to NH4+, which is the favored form of mineral nitrogen for plant uptake.

scholarly journals Distribution of tetraether lipids in agricultural soils – differentiation between paddy and upland management

2016 ◽  
Vol 13 (5) ◽  
pp. 1647-1666 ◽  
Author(s):  
Cornelia Mueller-Niggemann ◽  
Sri Rahayu Utami ◽  
Anika Marxen ◽  
Kai Mangelsdorf ◽  
Thorsten Bauersachs ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Agricultural Soils ◽  
Methanogenic Archaea ◽  
Tropical Soils ◽  
Paddy Soils ◽  
Cultivated Plants ◽  
Alkaline Soils ◽  
Rice Paddies ◽  
Upland Soils

Abstract. Rice paddies constitute almost a fifth of global cropland and provide more than half of the world's population with staple food. At the same time, they are a major source of methane and therewith significantly contribute to the current warming of Earth's atmosphere. Despite their apparent importance in the cycling of carbon and other elements, however, the microorganisms thriving in rice paddies are insufficiently characterized with respect to their biomolecules. Hardly any information exists on human-induced alteration of biomolecules from natural microbial communities in paddy soils through varying management types (affecting, e.g., soil or water redox conditions, cultivated plants). Here, we determined the influence of different land use types on the distribution of glycerol dialkyl glycerol tetraethers (GDGTs), which serve as molecular indicators for microbial community structures, in rice paddy (periodically flooded) and adjacent upland (non-flooded) soils and, for further comparison, forest, bushland and marsh soils. To differentiate local effects on GDGT distribution patterns, we collected soil samples in locations from tropical (Indonesia, Vietnam and Philippines) and subtropical (China and Italy) sites. We found that differences in the distribution of isoprenoid GDGTs (iGDGTs) as well as of branched GDGTs (brGDGTs) are predominantly controlled by management type and only secondarily by climatic exposition. In general, upland soil had higher crenarchaeol contents than paddy soil, which by contrast was more enriched in GDGT-0. The GDGT-0 ∕ crenarchaeol ratio, indicating the enhanced presence of methanogenic archaea, was 3–27 times higher in paddy soils compared to other soils and increased with the number of rice cultivation cycles per year. The index of tetraethers consisting of 86 carbons (TEX86) values were 1.3 times higher in upland, bushland and forest soils than in paddy soils, potentially due to differences in soil temperature. In all soils brGDGT predominated over iGDGTs with the relative abundance of brGDGTs increasing from subtropical to tropical soils. Higher branched vs. isoprenoid tetraether (BIT) values in paddy soils compared to upland soils together with higher BIT values in soils from subtropical climates indicated effects on the amounts of brGDGT induced by differences in management as well as climate. In acidic soils cyclization ratio of branched tetraethers (CBT) values correlated well with soil pH. In neutral to alkaline soils, however, no correlation but an offset in CBT between paddy and upland managed soils was detected. This is interpreted as indicating soil moisture exerting an additional control on the CBT in these soils. Lower modified methylation index of branched tetraether (MBT′) values and temperatures calculated from this (TMC) in paddy soils compared to upland soils are attributed to a management-induced (e.g. enhanced soil moisture via flooding) effect on mean annual soil temperature (MST).

Effects and mechanisms of amendments on remediation of cadmium contaminated acid paddy soils

2010 ◽  
Vol 18 (4) ◽  
pp. 847-851 ◽  
Author(s):  
Qi-Hong ZHU ◽  
Dao-You HUANG ◽  
Guo-Sheng LIU ◽  
Guang-Xu ZHU ◽  
Han-Hua ZHU ◽  
...  
Keyword(s):  
Paddy Soils

Early responses of vegetation and soil organic carbon to waterlogging and winter wildfire on abandoned red paddy soils

2014 ◽  
Vol 38 (6) ◽  
pp. 626-634
Author(s):  
TIAN Wen-Wen ◽  
◽  
WANG Wei ◽  
CHEN An-Lei ◽  
LI Yu-Yuan ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Paddy Soils

Abiotic and biotic regulation on carbon mineralization and stabilization in paddy soils along iron oxide gradients

2021 ◽  
pp. 108312
Author(s):  
Peduruhewa H. Jeewani ◽  
Lukas Van Zwieten ◽  
Zhenke Zhu ◽  
Tida Ge ◽  
Georg Guggenberger ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Carbon Mineralization ◽  
Paddy Soils

scholarly journals Evaluation of Seasonal Groundwater Quality Changes Associated with Groundwater Pumping and Level Fluctuations in an Agricultural Area, Korea

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 51
Author(s):  
Kyoochul Ha ◽  
Eunhee Lee ◽  
Hyowon An ◽  
Sunghyun Kim ◽  
Changhui Park ◽  
...  
Keyword(s):  
Water Quality ◽  
Groundwater Quality ◽  
Groundwater Level ◽  
Irrigation Water ◽  
Agricultural Area ◽  
Water Type ◽  
Quality Changes ◽  
Groundwater Pumping ◽  
Rice Paddies ◽  
Groundwater Levels

This study was conducted to evaluate seasonal groundwater quality due to groundwater pumping and hydrochemical characteristics with groundwater level fluctuations in an agricultural area in Korea. Groundwater levels were observed for about one year using automatic monitoring sensors, and groundwater uses were estimated based on the monitoring data. Groundwater use in the area is closely related to irrigation for rice farming, and rising groundwater levels occur during the pumping, which may be caused by the irrigation water of rice paddies. Hydrochemical analysis results for two separate times (17 July and 1 October 2019) show that the dissolved components in groundwater decreased overall due to dilution, especially at wells in the alluvial aquifer and shallow depth. More than 50% of the samples were classified as CaHCO3 water type, and changes in water type occurred depending on the well location. Water quality changes were small at most wells, but changes at some wells were evident. In addition, the groundwater quality was confirmed to have the effect of saltwater supplied during the 2018 drought by comparison with seawater. According to principal component analysis (PCA), the water quality from July to October was confirmed to have changed due to dilution, and the effect was strong at shallow wells. In the study areas where rice paddy farming is active in summer, irrigation water may be one of the important factors changing the groundwater quality. These results provide a qualitative and quantitative basis for groundwater quality change in agricultural areas, particularly rice paddies areas, along with groundwater level and usage.

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