Arsenic-enrichment enhanced root exudates and altered rhizosphere microbial communities and activities in hyperaccumulator <i>Pteris vittata</i>

Das, Suvendu,Chou, Mon-Lin,Jean, Jiin-Shuh,Yang, Huai-Jen,Kim, Pil Joo Elsevier 2017 Journal of hazardous materials Vol.325 No.-

<P><B>Abstract</B></P> <P>Phytoremediation of arsenic (As)-contaminated soil by hyperaccumulator <I>Pteris vittata</I> is promising. A better understanding of the rhizosphere microbial dynamics that regulate As availability and plant growth is important to optimize the phytoremediation process. In this study, Illumina sequencing of 16S rRNA genes was applied to assess the rhizosphere microbial community structure of <I>P. vittata</I>. Microbial functionality was monitored by soil enzyme activities and MPN-PCR targeting genes of interest. Arsenic (100mgkg<SUP>−1</SUP> AsV) addition to soil significantly increased DOC, root exudates, As and P uptake and the frond biomass of <I>P. vittata</I>. Moreover, As-enrichment significantly increased soil enzyme activities involved in N, P and S cycling and the gene abundance of As transforming bacteria, Fe- and S-reducing bacteria and N and C fixing bacteria in the rhizosphere of <I>P. vittata</I>. Together, the results revealed that the combined selective pressure of As and rhizosphere resulted in stimulation of microbial community, which most likely has a role in reductive dissolution of Fe and S, As and P mobilization, C degradation and fixation, and N fixation. These changes appeared to have a role in mitigation of As toxicity and to promote growth and the As uptake ability of <I>P. vittata</I> under As-enriched conditions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> As-enrichment enhanced root exudates and increased rhizosphere soil pH of <I>P. vittata</I>. </LI> <LI> As-enrichment enhanced As and P mobilization, uptake and growth of <I>P. vittata</I>. </LI> <LI> As-enrichment enhanced Fe- and S-reducing gene abundance of <I>P. vittata</I> rhizosphere. </LI> <LI> C and N fixation in <I>P. vittata</I> rhizosphere increased due to As-enrichment. </LI> <LI> As-enrichment reduced microbial community in the rhizosphere of <I>P. vittata</I>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Steel Slag Amendment Improved Soil Microbial Community and Activities in a Flooded Rice Cropping System

Suvendu Das,Pil Joo Kim 한국토양비료학회 2018 한국토양비료학회 학술발표회 초록집 Vol.2018 No.10

Arsenic enhanced root exudates and altered rhizosphere microbial communities and activities in hyperaccumulator Pteris vittata

Suvendu Das,Jiin-Shuh Jean,Pil Joo Kim 한국토양비료학회 2016 한국토양비료학회 학술발표회 초록집 Vol.2016 No.10

Nitrous oxide emissions from cover crops amended soils under different mulching systems

Gilwon Kim(김길원),Suvendu Das(수벤두다스),Hyun Young Hwang(황현영),Pil jooKim(김필주) 한국토양비료학회 2016 한국토양비료학회 학술발표회 초록집 Vol.2016 No.10

Fluxes of Methane and Nitrous Oxide in Water-Saving Rice Production from Eastern India

Tapan Kumar Adhya,Suvendu Das,Padmini Swain 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Nitrous oxide emissions from soils amended by cover-crops and under plastic film mulching: Fluxes, emission factors and yield-scaled emissions

Kim, Gil Won,Das, Suvendu,Hwang, Hyun Young,Kim, Pil Joo Elsevier 2017 Atmospheric environment Vol.152 No.-

<P>Assessment of nitrous oxide (N2O) emission factor (EF) for N2O emission inventory from arable crops fertilized with different nitrogen sources are under increased scrutiny because of discrepancies between the default IPCC EFs and low EFs reported by many researchers. Mixing ratio of leguminous and non leguminous cover crop residues incorporation and plastic film mulching (PFM) in upland soil has been recommended as a vital agronomic practice to enhance yield and soil quality. However, how these practices together affect N2O emissions, yield-scaled emissions and the EFs remain uncertain. Field experiments spanning two consecutive years were conducted to evaluate the effects of PFM on N2O emissions, yield-scaled emissions and the seasonal EFs in cover crop residues amended soil during maize cultivation. The mixture of barley (Hordeum vulgare) and hairy vetch (Vicia villosa) seeds with 75% recommended dose (RD 140 kg ha(-1)) and 25% recommended dose (RD 90 kg ha(-1)), respectively, were broadcasted during the fallow period and 0, 25, 50 and 100% of the total aboveground harvested biomass that correspond to 0, 76, 152 and 304 kg N ha(-1) were incorporated before maize transplanting. It was found that the mean seasonal EFs from cover crop residues amended soil under No-mulching (NM) and PFM were 1.13% (ranging from 0.81 to 1.23%) and 1.49% (ranging from 1.02 to 1.63%), respectively, which are comparable to the IPCC (2006) default EF (1%) for emission inventories of N2O from crop residues. The emission fluxes were greatly influenced by NH4+-N, NOT-N, DOC and DON contents of soil. The cumulative N2O emissions markedly increased with the increase in cover crop residues application rates and it was more prominent under PFM than under NM. However, the yield-scaled emissions markedly decreased under PFM compared to NM due to the improved yield. With relatively low yield-scaled N2O emissions, 25% biomass mixing ratio of barley and hairy vetch (76 kg N ha(-1)) under PFM could be recommended to enhance yield and to mitigate N2O emissions in an upland maize cropping system. (C) 2017 Elsevier Ltd. All rights reserved.</P>

New Trial to Suppress Methane Emission using the Precursor of Ethylene as a Methanogenic Inhibitor Under Rice Cropping Systems

Song-rae Cho(조송래),Suvendu Das,Gil-Won Kim(김길원),Ji-Yeon Lim(임지연),Pil-Joo Kim(김필주) 한국토양비료학회 2021 한국토양비료학회 학술발표회 초록집 Vol.2021 No.11

Ethylene which is a regulator of plant growth and ripeness is known to have the strong inhibition effect on methanogenesis. However, since ethylene is gaseous form and has very low water solubility, it has not been developed as soil amendment to suppress methanogenesis in flooded rice paddies. To develop ethylene as a prospective soil amendment for reducing methane (CH₄) emission in flooded soil conditions, ethephon (2-Chloroethylphosphonic acid), a precursor of ethylene, was selected, and its application effect on CH₄ production was compared with specific inhibitors (2-Bromoethanesulfonate, 2-Chlomoethanesulfonate, 2-Mercaptoethanesulfonate) of methanogenesis under flooded soil condition. The application of ethephon at a rate of 1mg kg<SUP>-1</SUP> significant decreased total CH₄ emission by 43% compared to the un amended control, and its suppression effect was comparable with the specific methanogenic inhibitors. However, most of ethephon was hydrolyzed into ethylene within 10 days of incubation. To slow down the release of ethylene from ethephon and enhance its effect on suppressing methanogenesis, ethephon was mixed with cellulose based biodegradable polymers [sodium carboxymethyl cellulose (CMC), methyl cellulose (MC), hydroxyethyl cellulose (HEC), and cellulose acetate CA)] (10% of ethephon). Polymer mixtures significantly retarded the hydrolysis of ethephon and increased suppression of CH₄ production. In comparison, CA and CMC were most effective with approximately 25% higher reduction of CH₄ emission than no-polymer mixed ethephon.To determine the effect of ethephon amendment in rice cultivation and CH₄ emission, ethephon was mixed with the selected biodegradable polymer (CA) and gypsum. Ethephon amendment retarded the hydrolysis of ethephon to 90 days. And the CH₄ emission was decreased as maximum 89% than the control. The rice growth and yield did not show significant changes. The abundance of mcrA gene was decreased by 28-47% in ethephon amendment treatments compared to the control. In conclusion, ethephon, a precursor of ethylene, can be used as an effective additive to suppress CH₄ emission in rice paddy soil.

Investigation which Arable Land is the Main Contributor to Global Warming between Paddy and Upland Field under Nitrogen Fertilization?

Gil Won Kim(김길원),So Yeong Park(박소영),Suvendu Das(수벤두 다스),Pil Joo Kim(김필주) 한국토양비료학회 2021 한국토양비료학회 학술발표회 초록집 Vol.2021 No.11

Methane (CH₄) and nitrous oxide (N₂O) have been considered as two of the major greenhouse gases (GHGs) from agricultural land, out of which CH₄ is normally emitted from water-logged paddy fields while N₂O is emitted from aerobic upland soils. Both of these arable lands are thought to be the major GHGs emission sites, however, it has not been studied yet which land is responsible for higher contribution to GHGs emissions in the same region. A two year field study was conducted to calculate the contribution for global warming made by rice paddy fields and red pepper cultivation in upland soil under different nitrogen (N) fertilization levels. The urea as a source of nitrogen was applied at four different levels (0, 50, 100, and 200% of recommended doses for cultivation), and rice and red pepper were cultivated for paddy and upland fields, respectively during May to October. The CH₄ and N₂O were measured from both arable lands to quantify GHGs fluxes. The CH₄ emission was increased in a quadratic response with increasing nitrogen application level at rice paddy field and upland soil, but rice paddy has significantly higher CH₄ emission than red pepper upland soils. In contrast, N₂O emission showed a correlation of linear regression with N fertilization level increasing at both of the arable lands, however, upland soil showed significantly higher N₂O emission than rice paddy field. The rice paddy field has much higher global warming potential (GWP) than upland soil under lower levels of N fertilization (below 265 kg N ha<SUP>-1</SUP>) using carbon dioxide (CO₂) equivalent comparison. However, upland soil showed clearly higher GWP than rice paddy field under higher N fertilization. Therefore, we concluded that upland soil is a place which contribute much more to the GHGs emission caused by high N₂O fluxes under application of high N fertilizer.

Environmental risk assessment of steel-making slags and the potential use of LD slag in mitigating methane emissions and the grain arsenic level in rice (<i>Oryza sativa</i> L.)

Gwon, Hyo Suk,Khan, Muhammad Israr,Alam, Muhammad Ashraful,Das, Suvendu,Kim, Pil Joo Elsevier 2018 Journal of hazardous materials Vol.353 No.-

<P><B>Abstract</B></P> <P>Over the past decades, with increasing steel manufacturing, the huge amount of by-products (slags) generated need to be reused in an efficient way not only to reduce landfill slag sites but also for sustainable and eco-friendly agriculture. Our preliminary laboratory study revealed that compared to blast furnace slag, electric arc furnace slag and ladle furnace slag, the Linz-Donawitz converter (LD) slag markedly decreased CH<SUB>4</SUB> production rate and increased microbial activity. In the greenhouse experiment, the LD slag amendment (2.0 Mg ha<SUP>−1</SUP>) significantly (<I>p</I> < 0.05) increased grain yield by 10.3–15.2%, reduced CH<SUB>4</SUB> emissions by 17.8–24.0%, and decreased inorganic As concentrations in grain by 18.3–19.6%, compared to the unamended control. The increase in yield is attributed to the increased photosynthetic rates and increased availability of nutrients to the rice plant. Whereas, the decrease in CH<SUB>4</SUB> emissions could be due to the higher Fe availability in the slag amended soil, which acted as an alternate electron acceptor, thereby, suppressed CH<SUB>4</SUB> emissions. The more Fe-plaque formation which could adsorb more As and the competitive inhibition of As uptake with higher availability of Si could be the reason for the decrease in As uptake by rice cultivated with LD slag amendment.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Compared to other steel slags, LD-slag suppressed CH<SUB>4</SUB> production in a paddy soil. </LI> <LI> LD-slag amendment mitigated CH<SUB>4</SUB> emissions by 17.8–24.0% in submerged paddies. </LI> <LI> LD-slag amendment decreased inorganic As concentrations in rice grain by 18.3–19.6%. </LI> <LI> LD-slag amendment increased grain yield by 10.3–15.2%. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Source partitioning and emission factor of nitrous oxide during warm and cold cropping seasons from an upland soil in South Korea

Alam, Muhammad Ashraful,Khan, Muhammad Israr,Cho, Song Rae,Lim, Ji Yeon,Song, Hyun Ji,Kim, Pil Joo,Das, Suvendu Elsevier 2019 Science of the Total Environment Vol.662 No.-

<P><B>Abstract</B></P> <P>Nitrous oxide (N<SUB>2</SUB>O) is a major greenhouse gas (GHG) with high global warming potential. A majority of the N<SUB>2</SUB>O flux comes from agricultural sources, mainly due to nitrogen (N) fertilization. The soil N<SUB>2</SUB>O flux, induced by N fertilization, mainly originated from two different sources, i.e., fertilizer and soil organic nitrogen (SON). It is essential to know the individual contribution of these two different sources in total N<SUB>2</SUB>O flux for planning necessary mitigation strategies. It is also indispensable to know the seasonal difference of emission factors (EF) for having more accurate N<SUB>2</SUB>O inventory. Therefore, an experiment was conducted in a South Korean upland soil during summer and winter seasons using <SUP>15</SUP>N labeled urea as an artificial N source and source specific N<SUB>2</SUB>O emissions were distinguished under different environmental conditions. To characterize the N<SUB>2</SUB>O emissions from urea, 0, 50, 100 and 200% of the Korean N recommendation rate was selected for specified crops. The Korean N recommendation rate for red pepper (<I>Capsicum annuum</I>) and garlic (<I>Allium sativum</I>) was 190 and 250 kg N ha<SUP>−1</SUP>, respectively. Direct emissions from urea were estimated from the difference of <SUP>15</SUP>N<SUB>2</SUB>O flux emitted from <SUP>15</SUP>N-urea treated soil and the natural abundance of <SUP>15</SUP>N<SUB>2</SUB>O. From total N<SUB>2</SUB>O fluxes, urea originated N<SUB>2</SUB>O flux was 0.87% and 0.13% of the applied N in warm and cold seasons, respectively and the rest comes from SON. Nitrous oxide EF in the warm season was 2.69% of applied N and in the cold season that was 0.25%. Nitrous oxide fluxes showed a significant exponential relationship with soil temperature. The results show the necessity of considering the different N<SUB>2</SUB>O EF for warm and cold cropping seasons to reduce uncertainty in N<SUB>2</SUB>O inventory. The findings of this research may help better understand N<SUB>2</SUB>O source partitioning and the emission budget from warm and cold cropping seasons.</P> <P><B>Highlights</B></P> <P> <UL> <LI> N<SUB>2</SUB>O flux originated from urea N was small compared with that of SON. </LI> <LI> N<SUB>2</SUB>O released from the urea application was 0.87 and 0.13% of applied urea in warm and cold seasons, respectively. </LI> <LI> N<SUB>2</SUB>O emission factors in the warm and cold season are 2.69 and 0.25, respectively. </LI> <LI> N<SUB>2</SUB>O emissions showed exponential relationship with soil temperature. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>