Publications by authors named "Rongfeng Jiang"

27 Publications

  • Page 1 of 1

Liraglutide-induced structural modulation of the gut microbiota in patients with type 2 diabetes mellitus.

PeerJ 2021 1;9:e11128. Epub 2021 Apr 1.

Shanghai Biotecan Pharmaceuticals Co., Ltd., Shanghai, China.

Accumulating evidence has suggested the importance of gut microbiota in the development of type 2 diabetes mellitus (T2DM). In the present study, 40 patients with T2DM were treated with liraglutide for 4 months. Feces samples and clinical characteristics were collected from these 40 T2DM patients before and after the liraglutide treatment. The diversity and composition of gut microbiota in the two groups were determined by sequencing the V4 region of bacterial 16S rRNA genes. Meanwhile, blood glucose, insulin, hemoglobin A1c (HbA1c), and lipid metabolism were also measured in the pre- and post-liraglutide-treatment groups. We find that Baseline HbA1c was associated with liraglutide treatment response (  = 0.527,  =  - 0.726,  < 0.0001). After adjusted for baseline HbA1c, blood urea nitrogen was associated with liraglutide treatment response. Besides, our results showed reduced gut microbial alpha diversity, different community structure distribution and altered microbial interaction network in patients treated with liraglutide. The liner discriminant analysis (LDA) effect size (LEfSe) analysis showed that 21 species of bacteria were abundant in the pre-liraglutide-treatment group and 15 species were abundant in the post-liraglutide-treatment group. In addition, we also find that were significantly correlated with older age, diabetes duration and diabetic retinopathy, were significantly correlated with family history of diabetes and were significantly correlated with both diabetic retinopathy and diabetic peripheral neuropathy. Functional analysis based on Kyoto Encyclopedia of Genes and Genomes (KEGG) and cluster of orthologous groups (COG) annotations enriched three KEGG metabolic pathways and six functional COG categories in the post-liraglutide-treatment group. In conclusion, our research suggests that baseline HbA1c, blood urea nitrogen and gut microbiota are associated with the liraglutide treatment applied on patients with T2DM. These findings may contribute to the beneficial effects of liraglutide against diabetes.
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http://dx.doi.org/10.7717/peerj.11128DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8019531PMC
April 2021

Enhanced adsorption of Cu(II) and Zn(II) from aqueous solution by polyethyleneimine modified straw hydrochar.

Sci Total Environ 2021 Jul 2;778:146116. Epub 2021 Mar 2.

Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.

Heavy metals removal from aqueous phase by adsorption technique has recently attracted a considerable interest. Although various adsorbing materials have been developed, introducing more functional groups is considered as the most efficient way to promote the adsorption capacity of the selected adsorbent. However, this approach is usually limited in costly modification precursor and unguaranteed loading efficacy. In this study, waste corn straw was converted to adsorbent precursor by hydrothermal carbonization. The obtained hydrochar (HC) was chemically activated before being modified by polyethyleneimine (PEI). Multiple analysis methods including Scanning Electron Microscopy, Fourier Transform Infrared analysis, and X-ray Photoelectron Spectroscopy analysis verified the alkali activated hydrochar (alkali-HC) was more efficacy to enhance PEI grafting than acid activation. Based on this, the modified HC materials obtained a better adsorption performance. The sorption process of Cu(II) and Zn(II) on the acid-PEI-HC, alkali-PEI-HC, and pristine HC fitted the pseudo second order kinetic and Freundlich model well, and was dominated by chemisorption. Among these adsorbents, the adsorption capacity of alkali-PEI-HC to metal ions was the maximum, which was 207.6 mg/g to Zn(II) and 56.1 mg/g to Cu(II) at 298 K. Regeneration tests showed a result of no less than 60% of its removal capacity was achieved after five cycles. Therefore, alkali-PEI-HC performed as a promising composite sorbent for metal ions. In addition, the study described here has provided a new basis for the utilization of hydrochar (1.08 kWh kg) derived from agricultural resources as a promising adsorbent precursor.
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http://dx.doi.org/10.1016/j.scitotenv.2021.146116DOI Listing
July 2021

The quality of dissolved organic matter extracted at different times from pig compost and its copper binding capacity based on EEM-PARAFAC.

Ecotoxicol Environ Saf 2021 Jan 3;207:111545. Epub 2020 Nov 3.

College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094, China. Electronic address:

Dissolved organic matter extracted from compost tea, can be regarded as alternatives to inorganic fertilizers as well to be used as a washing agent for heavy metal polluted soil. However, the composition and quality of compost tea produced under different extraction time are still unknown. The objective of the current study was set to explore the influence of different extraction time (i.e., 6, 12, and 24 h) on the composition, quality, and copper binding capacity of compost tea originated from pig manure compost. The results indicated that the extraction time obviously influenced the phenolic, aromatic carboxylic, and polycyclic aromatic groups of compost tea. In addition, the compost tea undergo the shorter extraction time (i.e., 6 and 12 h) contained more protein and humic-like compositions. Among the all treatments tested herein, the compost tea produced from 12 h extraction time obviously exhibited higher aromaticity, molecular weight, and humification degree than other two treatments. The highest stability constant value (log K) was observed for the shortest extraction time, i.e., 6.08. According to the quality measures and copper binding capability, shorter extraction times (i.e., 6 and 12 h) would be suggested for compost tea production from pig manure compost.
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http://dx.doi.org/10.1016/j.ecoenv.2020.111545DOI Listing
January 2021

Ecological risk of copper and zinc and their different bioavailability change in soil-rice system as affected by biowaste application.

Ecotoxicol Environ Saf 2020 Apr 12;192:110301. Epub 2020 Feb 12.

Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, Key Laboratory of Plant-Soil Interactions of the Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, People's Republic of China. Electronic address:

A large amount of organic fertilizer application could be accompanied by soil contamination caused by trace heavy metals. A field experiment was carried out in this study to examine the accumulation and availability of copper (Cu) and zinc (Zn) in soil, and their uptake by rice under continuous application of chicken manure, pig manure and sewage sludge. Results showed that after four years of chicken manure, pig manure and sewage sludge application, the soil Cu accumulation rates were 0.15-1.17 mg kg yr, 1.01-4.22 mg kg yr and 0.13-1.15 mg kg yr, respectively; Zn accumulation rates were 0.54-5.46 mg kg yr, 1.51-9.65 mg kg yr and 1.13-10.47 mg kg yr, respectively. Compared to the control, the chicken- and pig manure treatments significantly decreased the DTPA-extractable Cu, but increased the DTPA-extractable Zn in soils; thus decreased the Cu contents in rice grain by 2.2-40.6% and increased the grain Zn by 2.6-30.9%, respectively, with increasing application rates and number of years. The addition of sewage sludge significantly increased bioavailability of Zn in soil and its accumulation in rice, while had limited effect on Cu bioavailability. Results suggested that the continuous application of organic fertilizer with elevated Cu and Zn contents at high application rates can induce their accumulation in soil and affect their bioavailability differently.
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http://dx.doi.org/10.1016/j.ecoenv.2020.110301DOI Listing
April 2020

Energy and Nutrient Recovery from Sewage Sludge and Manure via Anaerobic Digestion with Hydrothermal Pretreatment.

Environ Sci Technol 2020 01 16;54(2):1147-1156. Epub 2019 Dec 16.

School of Earth and Atmospheric Sciences , Georgia Institute of Technology , 311 Ferst Dr. , Atlanta , Georgia 30332-0340 , United States.

Global expectation for sustainability has prompted the transition of practices in wastewater treatment plants toward not only waste management but also energy and nutrient recovery. It has been shown that low-temperature hydrotherm (HT) treatment can enhance downstream biogas production via anaerobic digestion (AD). Yet, because the application of combined HT and AD is still at an early stage, a systematic understanding of the dynamic speciation evolution of important elements is still lacking. This study investigates energy and nutrient recovery from sewage sludge and swine manure via combined HT-AD treatment. Bench-scale investigation was conducted to evaluate biogas production and understand the dynamic evolution of organic carbon (C) and phosphorus (P) speciation. C and P speciations were characterized using complementary chemical and spectroscopic techniques, including C nuclear magnetic resonance (NMR) spectroscopy, P X-ray absorption near edge structure (XANES) spectroscopy, and sequential chemical extraction. Results from this study suggest that low-temperature HT pretreatment can achieve enhanced biogas production for sludge compared to the minimal effect on the biogas production from manure. It also provides guidance for P recovery from liquid digestate and solid residue after the AD process.
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http://dx.doi.org/10.1021/acs.est.9b03269DOI Listing
January 2020

Phosphorus recovered from digestate by hydrothermal processes with struvite crystallization and its potential as a fertilizer.

Sci Total Environ 2020 Jan 2;698:134240. Epub 2019 Sep 2.

Institute for Agricultural Engineering, Conversion Technologies of Biobased Resources, University of Hohenheim, Garbenstrasse 9, 70599 Stuttgart, Germany.

Phosphorus (P) recovery from digestate has attracted considerable interest. In this study, hydrothermal processes in combination with struvite crystallization were performed to promote P solubilization and capture from digestate; its potential as a phosphate-based fertilizer was also investigated. Hydrothermal treatment with HCl and HO showed good results for the solubilization of organic and slightly soluble P, and achieved the lowest input energy need (768 kWhkg). Struvite crystallization reached 99.3% (Mg:PO1.84:1, pH 9.98). X-ray diffractometry and energy dispersive X-ray spectrometer mapping demonstrated the main precipitate component was struvite. For the fertilization of maize, P utilization from struvite was 19.0%. Light microscope analysis revealed that appropriate amounts of struvite may have an influence on the growth of the primary root. Overall, 16.6% of total P was recovered after P was solubilized, captured and made available.
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http://dx.doi.org/10.1016/j.scitotenv.2019.134240DOI Listing
January 2020

Exploring Future Food Provision Scenarios for China.

Environ Sci Technol 2019 02 22;53(3):1385-1393. Epub 2019 Jan 22.

Center for Resources, Environment and Food Security , China Agricultural University , Beijing 100193 , China.

Developing sustainable food systems is essential, especially for emerging economies, where food systems are changing rapidly and affect the environment and natural resources. We explored possible future pathways for a sustainable food system in China, using multiple environmental indicators linked to eight of the Sustainable Development Goals (SDGs). Forecasts for 2030 in a business as usual scenario (BAU) indicate increases in animal food consumption as well as increased shortages of the land available and the water needed to produce the required food in China. Associated greenhouse gas emissions and nitrogen and phosphorus losses could become 10-42% of global emissions in 2010. We developed three main pathways besides BAU [produce more and better food (PMB), consume and waste less food (CWL), and import more food (IMF)] and analyzed their impacts and contributions to achieving one or more of the eight SDGs. Under these scenarios, the demand for land and water and the emissions of GHG and nutrients may decrease by 7-55% compared to BAU, depending on the pathway followed. A combination of PMB and CWL was most effective, while IMF externalizes impacts to countries exporting to China. Modestly increasing feed or food imports in a selective manner could ease the pressure on natural resources. Our modeling framework allows us to analyze the effects of changes in food production-consumption systems in an integrated manner, and the results can be linked to the eight SDGs. Despite formidable technological, social, educational, and structural barriers that need to be overcome, our study indicates that the ambitious targets of China's new agricultural and environmental strategy appear to be achievable.
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http://dx.doi.org/10.1021/acs.est.8b04375DOI Listing
February 2019

Recovery of Phosphorus From Swine Manure by Ultrasound/HO Digestion, Struvite Crystallization, and Ferric Oxide Hydrate/Biochar Adsorption.

Front Chem 2018 8;6:464. Epub 2018 Oct 8.

Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, Key Laboratory of Plant-Soil Interactions of Ministry of Education, Biomass Engineering Center, College of Resources and Environmental Sciences, China Agricultural University, Beijing, China.

Swine manure is potentially harmful to the environment but is also a readily accessible local source of phosphorus (P) for agricultural use. Decreasing the environmental impact of swine manure and recovering P from swine manure have been a challenge for a long time. In this study, an integrated process involving ultrasound/HO digestion, struvite crystallization, and ferric oxide hydrate (HFO)/biochar adsorption was used to recover P from swine manure. The ultrasound/HO treatment effectively solubilized the swine manure and converted organic P and other sparingly soluble P species into soluble phosphate. The struvite crystallization process allowed 85% of the available P to be recovered at pH 10.0 using a Mg:P molar ratio of 1.4 and a stirring rate of 150 rpm. HFO was loaded onto biochar synthesized by pyrolyzing ground corncob. The mechanism through which P was adsorbed was investigated by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The adsorption of P by the HFO/biochar followed pseudo-second-order kinetics and was primarily controlled by chemical processes. The maximum amounts of P adsorbed were 225.08-242.21 mg/g. Thermodynamic calculations indicated that the adsorption of P was endothermic and spontaneous and increased the degree of disorder in the overall system. P mass balance calculations indicated that 90.4% of the total P was recovered as struvite and P-saturated HFO/biochar.
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http://dx.doi.org/10.3389/fchem.2018.00464DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6187983PMC
October 2018

Pursuing sustainable productivity with millions of smallholder farmers.

Nature 2018 03 7;555(7696):363-366. Epub 2018 Mar 7.

Institute of Agricultural Resources and Environment, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, China.

Sustainably feeding a growing population is a grand challenge, and one that is particularly difficult in regions that are dominated by smallholder farming. Despite local successes, mobilizing vast smallholder communities with science- and evidence-based management practices to simultaneously address production and pollution problems has been infeasible. Here we report the outcome of concerted efforts in engaging millions of Chinese smallholder farmers to adopt enhanced management practices for greater yield and environmental performance. First, we conducted field trials across China's major agroecological zones to develop locally applicable recommendations using a comprehensive decision-support program. Engaging farmers to adopt those recommendations involved the collaboration of a core network of 1,152 researchers with numerous extension agents and agribusiness personnel. From 2005 to 2015, about 20.9 million farmers in 452 counties adopted enhanced management practices in fields with a total of 37.7 million cumulative hectares over the years. Average yields (maize, rice and wheat) increased by 10.8-11.5%, generating a net grain output of 33 million tonnes (Mt). At the same time, application of nitrogen decreased by 14.7-18.1%, saving 1.2 Mt of nitrogen fertilizers. The increased grain output and decreased nitrogen fertilizer use were equivalent to US$12.2 billion. Estimated reactive nitrogen losses averaged 4.5-4.7 kg nitrogen per Megagram (Mg) with the intervention compared to 6.0-6.4 kg nitrogen per Mg without. Greenhouse gas emissions were 328 kg, 812 kg and 434 kg CO equivalent per Mg of maize, rice and wheat produced, respectively, compared to 422 kg, 941 kg and 549 kg CO equivalent per Mg without the intervention. On the basis of a large-scale survey (8.6 million farmer participants) and scenario analyses, we further demonstrate the potential impacts of implementing the enhanced management practices on China's food security and sustainability outlook.
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http://dx.doi.org/10.1038/nature25785DOI Listing
March 2018

Transformation of Phosphorus during (Hydro)thermal Treatments of Solid Biowastes: Reaction Mechanisms and Implications for P Reclamation and Recycling.

Environ Sci Technol 2017 Sep 6;51(18):10284-10298. Epub 2017 Sep 6.

School of Earth and Atmospheric Sciences, Georgia Institute of Technology , 311 Ferst Drive, Atlanta, Georgia 30332-0340, United States.

Phosphorus (P) is an essential nutrient for all organisms, thus playing unique and critical roles at the food-energy-water nexus. Most P utilized by human activities eventually converges into various solid biowastes, such as crop biomass, animal manures, and sewage sludges. Therefore, integration of efficient P recovery practices into solid biowaste management will not only significantly reduce the dependence on limited geological P resources but also reduce P runoff and related water contamination issues associated with traditional waste management strategies. This study reviews the applications of (hydro)thermal techniques for the treatment of solid biowastes, which can greatly facilitate P recovery in addition to waste volume reduction, decontamination, and energy recovery. Research showed that P speciation (including molecular moiety, complexation state, and mineralogy) can experience significant changes during (hydro)thermal treatments, and are impacted by treatment techniques and conditions. Changes in P speciation and overall properties of the products can alter the mobility and bioavailability of P, and subsequent P reclamation and recycling efficiency of the treatment products. This review summarizes recent progresses in this direction, identifies the challenges and knowledge gaps, and provides a foundation for future research efforts targeting at sustainable management of nutrient-rich biowastes.
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http://dx.doi.org/10.1021/acs.est.7b02011DOI Listing
September 2017

Closing yield gaps in China by empowering smallholder farmers.

Nature 2016 09 7;537(7622):671-674. Epub 2016 Sep 7.

Center for Animal Health and Productivity, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania 19348, USA.

Sustainably feeding the world's growing population is a challenge, and closing yield gaps (that is, differences between farmers' yields and what are attainable for a given region) is a vital strategy to address this challenge. The magnitude of yield gaps is particularly large in developing countries where smallholder farming dominates the agricultural landscape. Many factors and constraints interact to limit yields, and progress in problem-solving to bring about changes at the ground level is rare. Here we present an innovative approach for enabling smallholders to achieve yield and economic gains sustainably via the Science and Technology Backyard (STB) platform. STB involves agricultural scientists living in villages among farmers, advancing participatory innovation and technology transfer, and garnering public and private support. We identified multifaceted yield-limiting factors involving agronomic, infrastructural, and socioeconomic conditions. When these limitations and farmers' concerns were addressed, the farmers adopted recommended management practices, thereby improving production outcomes. In one region in China, the five-year average yield increased from 67.9% of the attainable level to 97.0% among 71 leading farmers, and from 62.8% to 79.6% countywide (93,074 households); this was accompanied by resource and economic benefits.
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http://dx.doi.org/10.1038/nature19368DOI Listing
September 2016

Phosphate enhance recovery from wastewater by mechanism analysis and optimization of struvite settleability in fluidized bed reactor.

Sci Rep 2016 08 30;6:32215. Epub 2016 Aug 30.

Research Institute for Phosphorus Atlas, Waseda University, Osaka 565-0871, Japan.

Since phosphorus, a non-renewable and non-substitutable resource, has become the principal contributor and limiting factor to water eutrophication, achieving phosphorus removal and recovery from wastewater is pretty essential. Even though struvite crystallization process has been widely used for phosphate (P) recovery in wastewater treatment, its application is hampered by difficulties controlling small particle size and crystal growth. This study was conducted to control the settleability of struvite by calculating and predicting the struvite-settling percentage (Ps), which is always affected by the initial concentration of P (CP), solution pH (pH), reaction time (t), reaction temperature (T), agitation rate (Ar), and inlet flow velocity (vf) of the fluidized bed reactor. The results showed that the settleability of struvite could be enhanced by increasing T and decreasing pH, Ar, or vf, and would perform worse with overlong t or excessive CP. The dynamic variation process of the solution supersaturated index (SI) combined with the phase equilibrium theory and Ostwald ripening mechanism explained the above results sufficiently. The logistic model was chosen to predict the Ps under multi-factors, but the accuracy needs to be improved.
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http://dx.doi.org/10.1038/srep32215DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5004189PMC
August 2016

Microwave-assisted digestion and NaOH treatment of waste-activated sludge to recover phosphorus by crystallizing struvite.

Environ Technol 2017 May 31;38(10):1211-1222. Epub 2016 Aug 31.

d State Key Laboratory of Plant Physiology and Biochemistry , College of Biological Sciences, China Agricultural University , Beijing , People's Republic of China.

A number of studies of waste-activated sludge (WAS) pretreatments, aimed at releasing phosphorus (P) from WAS and increasing the amount of P that can be recovered, have been performed. Here, a microwave-assisted digestion and NaOH treatment (MWs & NaOH) coupled crystallizing struvite, to promote the solubilization, transformation, and recovery of P from WAS, is proposed. Microwaves (MWs) can cause cavities to form in WAS, weakening the bonds between extracellular polymeric substances and the solid phase. Irradiating with MWs significantly increased the efficiency at which P was dissolved (i.e. transferred from the solid to the liquid phase) and the efficiency at which organic P was hydrolyzed and transformed into inorganic P when the NaOH treatment was performed. The P solubilization and transformation characteristic achieved in different treatments was examined by scanning electron microscopy and three-dimensional excitation emission matrix analysis. The MWs & NaOH method released 34.20-43.73% of total P from WAS, and 23.48-32.07% of the total P was recovered by crystallizing struvite at pH 9.5 and Mg:P ratio of 1.5:1. It would cost about USD 85-103 per ton of dry WAS to treat WAS using the MWs & NaOH method.
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http://dx.doi.org/10.1080/09593330.2016.1220630DOI Listing
May 2017

Grain production versus resource and environmental costs: towards increasing sustainability of nutrient use in China.

J Exp Bot 2016 09 3;67(17):4935-49. Epub 2016 Aug 3.

Centre for Resources, Environment and Food Security, Department of Plant Nutrition, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing 100193, China

Over the past five decades, Chinese grain production has increased 4-fold, from 110 Mt in 1961 to 557 Mt in 2014, with less than 9% of the world's arable land feeding 22% of the world's population, indicating a substantial contribution to global food security. However, compared with developed economies, such as the USA and the European Union, more than half of the increased crop production in China can be attributed to a rapid increase in the consumption of chemicals, particularly fertilizers. Excessive fertilization has caused low nutrient use efficiency and high environmental costs in grain production. We analysed the key requirements underpinning increased sustainability of crop production in China, as follows: (i) enhance nutrient use efficiency and reduce nutrient losses by fertilizing roots not soil to maximize root/rhizosphere efficiency with innovative root zone nutrient management; (ii) improve crop productivity and resource use efficiency by matching the best agronomic management practices with crop improvement; and (iii) promote technology transfer of the root zone nutrient management to achieve the target of high yields and high efficiency with low environmental risks on a broad scale. Coordinating grain production and environmental protection by increasing the sustainability of nutrient use will be a key step in achieving sustainable crop production in Chinese agriculture.
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http://dx.doi.org/10.1093/jxb/erw282DOI Listing
September 2016

In situ stable isotope probing of phosphate-solubilizing bacteria in the hyphosphere.

J Exp Bot 2016 Mar 21;67(6):1689-701. Epub 2016 Jan 21.

College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, PR China

This study used a [(13)C]DNA stable isotope probing (SIP) technique to elucidate a direct pathway for the translocation of (13)C-labeled photoassimilate from maize plants to extraradical mycelium-associated phosphate-solubilizing bacteria (PSB) that mediate the mineralization and turnover of soil organic phosphorus (P) in the hyphosphere. Inoculation with PSB alone did not provide any benefit to maize plants but utilized the added phytate-P to their own advantage, while inoculation with Rhizophagus irregularis alone significantly promoted shoot biomass and P content compared with the control. However, compared with both sole inoculation treatments, combined inoculation with PSB and R. irregularis in the hyphosphere enhanced organic P mineralization and increased microbial biomass P in the soil. There was no extra benefit to plant P uptake but the hyphal growth of R. irregularis was reduced, suggesting that PSB benefited from the arbuscular mycorrhizal (AM) fungal mycelium and competed for soil P with the fungus. The combination of T-RFLP (terminal restriction fragment length polymorphism) analysis with a clone library revealed that one of the bacteria that actively assimilated carbon derived from pulse-labeled maize plants was Pseudomonas alcaligenes (Pseudomonadaceae) that was initially inoculated into the hyphosphere soil. These results provide the first in situ demonstration of the pathway underlying the carbon flux from plants to the AM mycelium-associated PSB, and the PSB assimilated the photosynthates exuded by the fungus and promoted mineralization and turnover of organic P in the soil.
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http://dx.doi.org/10.1093/jxb/erv561DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4783358PMC
March 2016

Exploiting Co-Benefits of Increased Rice Production and Reduced Greenhouse Gas Emission through Optimized Crop and Soil Management.

PLoS One 2015 9;10(10):e0140023. Epub 2015 Oct 9.

Rothamsted Research, Harpenden, Herts, United Kingdom.

Meeting the future food security challenge without further sacrificing environmental integrity requires transformative changes in managing the key biophysical determinants of increasing agronomic productivity and reducing the environmental footprint. Here, we focus on Chinese rice production and quantitatively address this concern by conducting 403 on-farm trials across diverse rice farming systems. Inherent soil productivity, management practices and rice farming type resulted in confounded and interactive effects on yield, yield gaps and greenhouse gas (GHG) emissions (N2O, CH4 and CO2-equivalent) with both trade-offs and compensating effects. Advances in nitrogen, water and crop management (Best Management Practices-BMPs) helped closing existing yield gaps and resulted in a substantial reduction in CO2-equivalent emission of rice farming despite a tradeoff of increase N2O emission. However, inherent soil properties limited rice yields to a larger extent than previously known. Cultivating inherently better soil also led to lower GHG intensity (GHG emissions per unit yield). Neither adopting BMPs only nor improving soils with low or moderate productivity alone can adequately address the challenge of substantially increasing rice production while reducing the environmental footprint. A combination of both represents the most efficient strategy to harness the combined-benefits of enhanced production and mitigating climate change. Extrapolating from our farm data, this strategy could increase rice production in China by 18%, which would meet the demand for direct human consumption of rice by 2030. It would also reduce fertilizer nitrogen consumption by 22% and decrease CO2-equivalent emissions during the rice growing period by 7% compared with current farming practice continues. Benefits vary by rice-based cropping systems. Single rice systems have the largest food provision benefits due to its wider yield gap and total cultivated area, whereas double-rice system (especially late rice) contributes primarily to reducing GHG emissions. The study therefore provides farm-based evidence for feasible, practical approaches towards achieving realistic food security and environmental quality targets at a national scale.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0140023PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4599856PMC
July 2016

Market Survey and Risk Assessment for Trace Metals in Edible Fungi and the Substrate Role in Accumulation of Heavy Metals.

J Food Sci 2015 Jul 16;80(7):H1612-8. Epub 2015 Jun 16.

College of Resources and Environmental Sciences, China Agriculture Univ., Beijing, 100193, China.

Unlabelled: Levels of cadmium (Cd), arsenic (As), mercury (Hg), lead (Pb), iron (Fe), and zinc (Zn) were investigated in 285 samples of 9 species of edible fungi (Lentinus edodes, Auricularia auricula, Pleurotus ostreatus, Tremella fuciformis, Flammulina velutipes, Agrocybe chaxinggu, Armillaria mellea, Agaricus bisporus, and Pholiota nameko), which were collected from markets in Beijing, China. In addition, edible fungi and culture substrates were collected from 7 cultivation bases to examine the role of the substrate in trace metal accumulation. Trace metal concentrations were determined on a dry weight basis. Data showed that all the edible fungi contained trace metals, the levels of which varied among species, and there were significant positive correlations between trace metal (Cd, Pb, and As) concentrations in mushrooms and their substrates. The concentrations of Cd, As, Hg, Pb, Fe, and Zn in the tested fungi ranged from 0.005 to 13.8 mg/kg, nd to 1.62 mg/kg, nd to 0.506 mg/kg, 0.011 to 22.1 mg/kg, 46.3 to 2514 mg/kg, and 14.6 to 289 mg/kg, respectively. In general, concentrations of Cd, As, Hg, Pb, Fe, and Zn were relatively high in L. edodes, whereas Tremella fuciformis and P. nameko had relatively low levels of trace metals. Furthermore, the estimated weekly intake of trace metals was calculated and compared with the WHO/FAO provisional tolerable weekly intake. The estimated weekly intake of Cd, As, Hg, Pb, Fe, and Zn from consuming edible fungi was lower than the provisional tolerable weekly intake.

Practical Application: This paper reports information about trace metal concentrations in edible fungi collected from Beijing, China. This paper provides useful information for consumers and regulators about levels of trace metals in edible fungi.
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http://dx.doi.org/10.1111/1750-3841.12923DOI Listing
July 2015

Phosphorus recovery from biogas fermentation liquid by Ca-Mg loaded biochar.

J Environ Sci (China) 2015 Mar 7;29:106-14. Epub 2015 Jan 7.

Key Laboratory of Plant-Soil Interactions of Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.

Shortage in phosphorus (P) resources and P wastewater pollution is considered as a serious problem worldwide. The application of modified biochar for P recovery from wastewater and reuse of recovered P as agricultural fertilizer is a preferred process. This work aims to develop a calcium and magnesium loaded biochar (Ca-Mg/biochar) application for P recovery from biogas fermentation liquid. The physico-chemical characterization, adsorption efficiency, adsorption selectivity, and postsorption availability of Ca-Mg/biochar were investigated. The synthesized Ca-Mg/biochar was rich in organic functional groups and in CaO and MgO nanoparticles. With the increase in synthesis temperature, the yield decreased, C content increased, H content decreased, N content remained the same basically, and BET surface area increased. The P adsorption of Ca-Mg/biochar could be accelerated by nano-CaO and nano-MgO particles and reached equilibrium after 360min. The process was endothermic, spontaneous, and showed an increase in the disorder of the solid-liquid interface. Moreover, it could be fitted by the Freundlich model. The maximum P adsorption amounts were 294.22, 315.33, and 326.63mg/g. The P adsorption selectivity of Ca-Mg/biochar could not be significantly influenced by the typical pH level of biogas fermentation liquid. The nano-CaO and nano-MgO particles of Ca-Mg/biochar could reduce the negative interaction effects of coexisting ions. The P releasing amounts of postsorption Ca-Mg/biochar were in the order of Ca-Mg/B600>Ca-Mg/B450>Ca-Mg/B300. Results revealed that postsorption Ca-Mg/biochar can continually release P and is more suitable for an acid environment.
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http://dx.doi.org/10.1016/j.jes.2014.08.019DOI Listing
March 2015

Uptake kinetics and translocation of selenite and selenate as affected by iron plaque on root surfaces of rice seedlings.

Planta 2015 Apr 20;241(4):907-16. Epub 2014 Dec 20.

Key Laboratory of Plant-Soil Interactions of the Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, People's Republic of China,

Main Conclusion: Iron plaque on root surfaces greatly influenced selenium uptake and played different roles in selenite and selenate uptake. Iron plaque commonly forms on rice root surfaces under flooded conditions, but little is known about the relationship between iron plaque and selenium (Se) accumulation. Here, we investigate the effects of iron plaque on Se uptake by and translocation within rice (Oryza sativa) seedlings, and the kinetics of selenite and selenate influx into rice roots (with or without iron plaque) were determined in short-term (30 min) experiments. Rice seedlings were planted in nutrient solutions containing different levels of ferrous ion for 3 days and then transplanted into nutrient solutions with selenite or selenate. Se concentrations in iron plaque were positively associated with the amounts of iron plaque in both selenite and selenate treatments and iron plaque had a higher affinity for selenite than selenate. Results showed that iron plaque on root surfaces greatly influenced Se uptake and played different roles in selenite and selenate uptake. The selenite and selenate uptake kinetics results demonstrated that the presence of iron plaque enhanced selenite uptake, but decreased selenate uptake. In addition, root-Se concentrations increased with the increasing amounts of iron plaque, but Se translocation from roots to shoots was reduced with the increasing amounts of iron plaque in the +selenite treatment. Iron plaque significantly influenced selenite uptake and might act as a pool to selenite accumulation in rice plants. However, iron plaque had no significant effect on selenate uptake or even as a barrier to selenate uptake.
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http://dx.doi.org/10.1007/s00425-014-2227-7DOI Listing
April 2015

Application of a rotation system to oilseed rape and rice fields in Cd-contaminated agricultural land to ensure food safety.

Ecotoxicol Environ Saf 2014 Oct 7;108:287-93. Epub 2014 Aug 7.

Key Laboratory of Plant-Soil Interactions of the Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, People׳s Republic of China. Electronic address:

This field experiment analyzed the phytoremediation effects of oilseed rape in moderately cadmium (Cd)-contaminated farmland and the food safety of successive rice in an oilseed rape-rice rotation system. Two oilseed rape cultivars accumulated Cd at different rates. The rapeseed cultivar Zhucang Huazi exhibited high Cd accumulation rates, higher than the legal limit for human consumption (0.2mgkg(-1)); Cd concentrations in the cultivar Chuanyou II-93 were all below the maximum allowed level. Planting oilseed rape increased the uptake of Cd by the successive rice crop compared with a previous fallow treatment. Most Cd concentrations of brown rice were below the maximum allowed level. The phytoextraction efficiency was lower in the moderately Cd-contaminated soil in field experiments. The results suggest screening rice cultivars with lower Cd accumulation can assure the food safety; the mobilization of heavy metals by roots of different plant species should be considered during crop rotation to assure food safety.
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http://dx.doi.org/10.1016/j.ecoenv.2014.07.019DOI Listing
October 2014

Integrated analysis of DNA methylation and RNA transcriptome during in vitro differentiation of human pluripotent stem cells into retinal pigment epithelial cells.

PLoS One 2014 17;9(3):e91416. Epub 2014 Mar 17.

Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America; Advanced Institute of Translational Medicine, School of Life Sciences and Technology, Tongji University, Shanghai, China.

Using the paradigm of in vitro differentiation of hESCs/iPSCs into retinal pigment epithelial (RPE) cells, we have recently profiled mRNA and miRNA transcriptomes to define a set of RPE mRNA and miRNA signature genes implicated in directed RPE differentiation. In this study, in order to understand the role of DNA methylation in RPE differentiation, we profiled genome-scale DNA methylation patterns using the method of reduced representation bisulfite sequencing (RRBS). We found dynamic waves of de novo methylation and demethylation in four stages of RPE differentiation. Integrated analysis of DNA methylation and RPE transcriptomes revealed a reverse-correlation between levels of DNA methylation and expression of a subset of miRNA and mRNA genes that are important for RPE differentiation and function. Gene Ontology (GO) analysis suggested that genes undergoing dynamic methylation changes were related to RPE differentiation and maturation. We further compared methylation patterns among human ESC- and iPSC-derived RPE as well as primary fetal RPE (fRPE) cells, and discovered that specific DNA methylation pattern is useful to classify each of the three types of RPE cells. Our results demonstrate that DNA methylation may serve as biomarkers to characterize the cell differentiation process during the conversion of human pluripotent stem cells into functional RPE cells.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0091416PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3956675PMC
January 2015

Plant-based assessment of inherent soil productivity and contributions to China's cereal crop yield increase since 1980.

PLoS One 2013 18;8(9):e74617. Epub 2013 Sep 18.

Center for Resources, Environment and Food Security, China Agricultural University, Beijing, P. R. China.

Objective: China's food production has increased 6-fold during the past half-century, thanks to increased yields resulting from the management intensification, accomplished through greater inputs of fertilizer, water, new crop strains, and other Green Revolution's technologies. Yet, changes in underlying quality of soils and their effects on yield increase remain to be determined. Here, we provide a first attempt to quantify historical changes in inherent soil productivity and their contributions to the increase in yield.

Methods: The assessment was conducted based on data-set derived from 7410 on-farm trials, 8 long-term experiments and an inventory of soil organic matter concentrations of arable land.

Results: Results show that even without organic and inorganic fertilizer addition crop yield from on-farm trials conducted in the 2000s was significantly higher compared with those in the 1980s - the increase ranged from 0.73 to 1.76 Mg/ha for China's major irrigated cereal-based cropping systems. The increase in on-farm yield in control plot since 1980s was due primarily to the enhancement of soil-related factors, and reflected inherent soil productivity improvement. The latter led to higher and stable yield with adoption of improved management practices, and contributed 43% to the increase in yield for wheat and 22% for maize in the north China, and, 31%, 35% and 22% for early and late rice in south China and for single rice crop in the Yangtze River Basin since 1980.

Conclusions: Thus, without an improvement in inherent soil productivity, the 'Agricultural Miracle in China' would not have happened. A comprehensive strategy of inherent soil productivity improvement in China, accomplished through combining engineering-based measures with biological-approaches, may be an important lesson for the developing world. We propose that advancing food security in 21st century for both China and other parts of world will depend on continuously improving inherent soil productivity.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0074617PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3776784PMC
June 2014

Maximizing root/rhizosphere efficiency to improve crop productivity and nutrient use efficiency in intensive agriculture of China.

J Exp Bot 2013 Mar 18;64(5):1181-92. Epub 2012 Dec 18.

Centre of Resources, Environment and Food Security, Department of Plant Nutrition, China Agricultural University, Beijing 100193, China.

Root and rhizosphere research has been conducted for many decades, but the underlying strategy of root/rhizosphere processes and management in intensive cropping systems remain largely to be determined. Improved grain production to meet the food demand of an increasing population has been highly dependent on chemical fertilizer input based on the traditionally assumed notion of 'high input, high output', which results in overuse of fertilizers but ignores the biological potential of roots or rhizosphere for efficient mobilization and acquisition of soil nutrients. Root exploration in soil nutrient resources and root-induced rhizosphere processes plays an important role in controlling nutrient transformation, efficient nutrient acquisition and use, and thus crop productivity. The efficiency of root/rhizosphere in terms of improved nutrient mobilization, acquisition, and use can be fully exploited by: (1) manipulating root growth (i.e. root development and size, root system architecture, and distribution); (2) regulating rhizosphere processes (i.e. rhizosphere acidification, organic anion and acid phosphatase exudation, localized application of nutrients, rhizosphere interactions, and use of efficient crop genotypes); and (3) optimizing root zone management to synchronize root growth and soil nutrient supply with demand of nutrients in cropping systems. Experiments have shown that root/rhizosphere management is an effective approach to increase both nutrient use efficiency and crop productivity for sustainable crop production. The objectives of this paper are to summarize the principles of root/rhizosphere management and provide an overview of some successful case studies on how to exploit the biological potential of root system and rhizosphere processes to improve crop productivity and nutrient use efficiency.
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http://dx.doi.org/10.1093/jxb/ers342DOI Listing
March 2013

Improving crop productivity and resource use efficiency to ensure food security and environmental quality in China.

J Exp Bot 2012 Jan 30;63(1):13-24. Epub 2011 Sep 30.

Department of Plant Nutrition, China Agricultural University, Key Laboratory of Plant Nutrition and Nutrient Cycling, Ministry of Agriculture, and Key Laboratory of Plant-Soil Interactions, Ministry of Education, Beijing 100193, China.

In recent years, agricultural growth in China has accelerated remarkably, but most of this growth has been driven by increased yield per unit area rather than by expansion of the cultivated area. Looking towards 2030, to meet the demand for grain and to feed a growing population on the available arable land, it is suggested that annual crop production should be increased to around 580 Mt and that yield should increase by at least 2% annually. Crop production will become more difficult with climate change, resource scarcity (e.g. land, water, energy, and nutrients) and environmental degradation (e.g. declining soil quality, increased greenhouse gas emissions, and surface water eutrophication). To pursue the fastest and most practical route to improved yield, the near-term strategy is application and extension of existing agricultural technologies. This would lead to substantial improvement in crop and soil management practices, which are currently suboptimal. Two pivotal components are required if we are to follow new trajectories. First, the disciplines of soil management and agronomy need to be given increased emphasis in research and teaching, as part of a grand food security challenge. Second, continued genetic improvement in crop varieties will be vital. However, our view is that the biggest gains from improved technology will come most immediately from combinations of improved crops and improved agronomical practices. The objectives of this paper are to summarize the historical trend of crop production in China and to examine the main constraints to the further increase of crop productivity. The paper provides a perspective on the challenge faced by science and technology in agriculture which must be met both in terms of increased crop productivity but also in increased resource use efficiency and the protection of environmental quality.
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http://dx.doi.org/10.1093/jxb/err248DOI Listing
January 2012

Integrated soil-crop system management: reducing environmental risk while increasing crop productivity and improving nutrient use efficiency in China.

J Environ Qual 2011 Jul-Aug;40(4):1051-7

Department of Plant Nutrition, China Agricultural University, Beijing, China.

During the past 47 yr (1961-2007), Chinese cereal production has increased by 3.2-fold, successfully feeding 22% of the global human population with only 9% of the world's arable land, but at high environmental cost and resource consumption. Worse, crop production has been stagnant since 1996 while the population and demand for food continue to rise. New advances for sustainability of agriculture and ecosystem services will be needed during the coming 50 yr to reduce environmental risk while increasing crop productivity and improving nutrient use efficiency. Here, we advocate and develop integrated soil-crop system management (ISSM). In this approach, the key points are (i) to take all possible soil quality improvement measures into consideration, (ii) to integrate the utilization of various nutrient resources and match nutrient supply to crop requirements, and (iii) to integrate soil and nutrient management with high-yielding cultivation systems. Recent field experiments have shed light on how ISSM can lead to significant increases in crop yields while increasing nutrient use efficiency and reducing environmental risk.
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http://dx.doi.org/10.2134/jeq2010.0292DOI Listing
August 2011

The role of root hairs in cadmium acquisition by barley.

Environ Pollut 2011 Feb 18;159(2):408-15. Epub 2010 Nov 18.

Key Laboratory of Plant-Soil Interactions of the Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094, People's Republic of China.

The role of root hairs in Cd acquisition from soil was investigated in three pot experiments using a root hairless mutant (bald root barley, brb) and its wild-type (WT) cultivar of barley (Hordeum vulgare). brb had significantly lower concentrations and lower total amounts of Cd in shoots than WT. The Cd uptake efficiency based on total root length was 8-45% lower in brb than in WT. The difference between brb and WT increased with increasing extractable Cd in soil under the experimental conditions used. Additions of phosphate to soil decreased Cd extractability. Both soil and foliar additions of phosphate decreased root length, and root hair formation in WT. These effects resulted in decreased Cd uptake with increasing P supply. Cd uptake in WT correlated significantly with root length, root hair length and density, and soil extractable Cd. Root hairs contribute significantly to Cd uptake by barley.
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http://dx.doi.org/10.1016/j.envpol.2010.10.034DOI Listing
February 2011

Nitrous oxide emissions from an intensively managed greenhouse vegetable cropping system in Northern China.

Environ Pollut 2009 May 23;157(5):1666-72. Epub 2009 Jan 23.

Key Laboratory of Plant-soil Interactions of Ministry of Education, Key Laboratory of Plant Nutrition of Minstry of Agriculture, College of Resources and Environmental Sciences, China Agricultural University, Haidian District, Beijing 100193, China.

Nitrous oxide (N(2)O) emissions from a typical greenhouse vegetable system in Northern China were measured from February 2004 to January 2006 using a close chamber method. Four nitrogen management levels (NN, MN, CN, and SN) were used. N(2)O emissions occurred intermittently in the growing season, strongly correlating with N fertilization and irrigation. No peak emissions were observed after fertilization in the late Autumn season due to low soil temperature. 57-94% of the seasonal N(2)O emissions came from the initial growth stage, corresponding to the rewetting process in the soil. The annual N(2)O emissions ranged from 2.6 to 8.8 kg N ha(-1) yr(-1), accounting for 0.27-0.30% of the annual nitrogen input. Compared with conventional N management, site-specific N management reduced N fertilization rate by 69% in 2004 and by 76% in 2005, and consequently reduced N(2)O emissions by 51% in 2004 and 27% in 2005, respectively.
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http://dx.doi.org/10.1016/j.envpol.2008.12.017DOI Listing
May 2009
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