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    题名 作者 年代 出处 被引量
1Challenge and Opportunity in Improving Fertilizer-nitrogen Use Efficiency of Irrigated Rice in China显示文摘Today, about 30% of world nitrogen (N) fertilizer is consumed by China. Rice crops in China consume about 37% of the total N fertilizer used for rice production in the world. Average rate of N application for rice production in China is high and fertilizer-N use efficiency is low compared with other major rice growing countries. Research progresses have been made internationally and domestically on the application method, fertilizer-N sources, computer-based decision support systems, and real-time N management in order to reduce N losses and increase fertilizer-N use efficiency. In addition to continuous increase in N rate and lack of adoption of new knowledge and technology in N management by farmers, we hypothesize that high indigenous soil N supply, adoption of hybrid and super rice cultivars, improper timing of N application, and practice of mid-season drainage could be the causes for the low fertilizer-N use efficiency in China. Future research work on improving fertilizer-N use efficiency of rice crop in China should focus more on improving cultivar's N responsiveness, optimizing the timing and rate of N application based on crop N status, and achieving optimal soil N supply capacity.Roland Buresh Christian Witt 2002Agricultural Sciences in China2002,1,7:86
2Ideotype root architecture for efficient nitrogen acquisition by maize in intensive cropping systems显示文摘The use of nitrogen(N) fertilizers has contributed to the production of a food supply sufficient for both animals and humans despite some negative environmental impact.Sustaining food production by increasing N use efficiency in intensive cropping systems has become a major concern for scientists,environmental groups,and agricultural policymakers worldwide.In high-yielding maize systems the major method of N loss is nitrate leaching.In this review paper,the characteristic of nitrate movement in the soil,N uptake by maize as well as the regulation of root growth by soil N availability are discussed.We suggest that an ideotype root architecture for efficient N acquisition in maize should include(i) deeper roots with high activity that are able to uptake nitrate before it moves downward into deep soil;(ii) vigorous lateral root growth under high N input conditions so as to increase spatial N availability in the soil;and(iii) strong response of lateral root growth to localized nitrogen supply so as to utilize unevenly distributed nitrate especially under limited N conditions.MI GuoHua,CHEN FanJun,WU QiuPing,LAI NingWei,YUAN LiXing & ZHANG FuSuo* Key Laboratory of Plant Nutrition,MOA Key Laboratory of Plant-Soil Interaction,MOE College of Resources and Environmental Science,China Agricultural University,Beijing 100193,China 2010Science China(Life Sciences)2010,53,12:35
3Effect of low-nitrogen stress on photosynthesis and chlorophyll fluorescence characteristics of maize cultivars with different low-nitrogen tolerances显示文摘Nitrogen(N)is a critical element for plant growth and productivity that influences photosynthesis and chlorophyll fluorescence.We investigated the effect of low-N stress on leaf photosynthesis and chlorophyll fluorescence characteristics of maize cultivars with difference in tolerance to low N levels.The low-N tolerant cultivar ZH311 and low-N sensitive cultivar XY508 were used as the test materials.A field experiment(with three N levels:N0,0 kg ha–1;N1,150 kg ha–1;N2,300 kg ha–1)in Jiyanyang,Sichuan Province,China,and a hydroponic experiment(with two N levels:CK,4 mmol L–1;LN,0.04 mmol L–1)in Chengdu,Sichuan Province,China were conducted.Low-N stress significantly decreased chlorophyll content and rapid light response curves of the maximum fluorescence under light(Fm′),fluorescence instable state(Fs),non-photochemical quenching(qN),the maximum efficiency of PSII photochemistry under dark-adaption(Fv/Fm),potential activity of PSII(Fv/Fo),and actual photochemical efficiency of PSII(ΦPSII)of leaves.Further,it increased the chlorophyll(Chl)a/Chl b values and so on.The light compensation point of ZH311 decreased,while that of XY508 increased.The degree of variation of these indices in low-N tolerant cultivars was lower than that in low-N sensitive cultivars,especially at the seedling stage.Maize could increase Chl a/Chl b,apparent quantum yield and light saturation point to adapt to N stress.Compared to low-N sensitive cultivars,low-N tolerant cultivars maintained a higher net photosynthetic rate and electron transport rate to maintain stronger PSII activity,which further promoted the ability to harvest and transfer light.This might be a photosynthetic mechanism by which low-N tolerant cultivar adapt to low-N stress.WU Ya-wei LI Qiang JIN Rong CHEN Wei LIU Xiao-lin KONG Fan-lei KE Yong-pei SHI Haichun YUAN Ji-chao 2019Journal of Integrative Agriculture2019,18,6:25
4Cereal area and nitrogen use efficiency are drivers of future nitrogen fertilizer consumption显示文摘At a global scale, cereal yields and fertilizer N consumption have increased in a near-linear fashion during the past 40 years and are highly correlated with one another. However,large differences exist in historical trends of N fertilizer usage and nitrogen use efficiency (NUE)among regions, countries, and crops. The reasons for these differences must be understood to estimate future N fertilizer requirements. Global nitrogen needs will depend on: (i) changes in cropped cereal area and the associated yield increases required to meet increasing cereal demand from population and income growth, and (ii) changes in NUE at the farm level. Our analysis indicates that the anticipated 38% increase in global cereal demand by 2025 can be met by a 30% increase in N use on cereals, provided that the steady decline in cereal harvest area is halted and the yield response to applied N can be increased by 20%. If losses of cereal cropping area continue at the rate of the past 20 years (-0.33% per year) and NUE cannot be increased substantially, a 60% increase in global N use on cereals would be required to meet cereal demand. Interventions to increase NUE and reduce N losses to the environment must be accomplished at the farm- or field-scale through a combination of improved technologies and carefully crafted local policies that contribute to the adoption of improved N management; uniform regional or national directives are unlikey to be effective at both sustaining yield increases and improving NUE. Examples from several countries show that increases in NUE at rates of 1% per year or more can be achieved if adequate investments are made in research and extension. Failure to arrest the decrease in cereal crop area and to improve NUE in the world's most important agricultural systems will likely cause severe damage to environmental services at local, regional, and global scales due to a large increase in reactive N load in the environment.Achim Dobermann Kenneth G.Cassman 2005Science China(Life Sciences)2005,48,z2:24
5Carbon and nitrogen storage in an age-sequence of Pinus densiflora stands in Korea显示文摘The carbon(C) and nitrogen(N) storage capabilities of Pinus densiflora in six different stand ages(10,27,30,32,44,and 71 years old) were investigated in Korea.Thirty sample trees were destructively harvested and 12 were excavated.Samples from the above and belowground tree components,coarse woody debris(CWD),forest floor,and mineral soil(0-30 cm) were collected.Tree biomass was highest in the 71-year-old stand(202.8 t ha-1) and lowest in the 10-year-old stand(18.4 t ha-1).C and N storage in the mineral soil was higher in the 71-year-old stand than in the other stands,mainly due to higher soil C and N concentrations.Consequently,the total ecosystem C and N storage(tree+forest floor+CWD+soil) was positively correlated with stand age:increasing from a minimum in the 10 year old stand(18.8 t C ha-1 and 1.3 t N ha-1) to a maximum in the 71-year-old stand(201.4 t C ha-1 and 8.5 t N ha-1).The total ecosystem C storage showed a similar sigmoidal pattern to that of tree C storage as a function of the age-sequence,while N storage in the CWD,forest floor and mineral soil showed no significant temporal trends.Our results provide important insights that will increase our understanding of C and N storage in P.densiflora stands and our ability to predict changes according to stand age in the region.NOH Nam-Jin SON Yowhan LEE Sue-Kyoung SEO Kyung-Won HEO Su-Jin1 YI Myong-Jong PARK Pil-Sun KIM Rae-Hyun SON Yeong-Mo LEE Kyeong-Hak 2010Science China(Life Sciences)2010,53,7:24
6Global leaf nitrogen and phosphorus stoichiometry and their scaling exponent显示文摘Leaf nitrogen(N) and phosphorus(P) concentrations constrain photosynthetic and metabolic processes,growth and the productivity of plants. Their stoichiometry and scaling relationships regulate the allocation of N and P from subcellular to organism, and even ecosystem levels, and are crucial to the modelling of plant growth and nutrient cycles in terrestrial ecosystems. Prior work has revealed a general biogeographic pattern of leaf N and P stoichiometric relationships and shown that leaf N scales roughly as two-thirds the power of P. However, determining whether and how leaf N and P stoichiometries, especially their scaling exponents, change with functional groups and environmental conditions requires further verification. In this study, we compiled a global data set and documented the global leaf N and P concentrations and the N:P ratios by functional group, climate zone and continent. The global overall mean leaf N and P concentrations were 18.9 mg g^(-1) and 1.2 mg g^(-1), respectively, with significantly higher concentrations in herbaceous than woody plants(21.72 mg g^(-1) vs. 18.22 mg g^(-1) for N; and 1.64 mg g^(-1) vs. 1.10 mg g^(-1) for P). Both leaf N and P showed higher concentrations at high latitudes than low latitudes. Among six continents, Europe had the highest N and P concentrations(20.79 and 1.54 mg g^(-1)) and Oceania had the smallest values(10.01 and 0.46 mg g^(-1)). These numerical values may be used as a basis for the comparison of other individual studies. Further, we found that the scaling exponent varied significantly across different functional groups,latitudinal zones, ecoregions and sites. The exponents of herbaceous and woody plants were 0.659 and0.705, respectively, with significant latitudinal patterns decreasing from tropical to temperate to boreal zones. At sites with a sample size ≥10, the values fluctuated from 0.366 to 1.928, with an average of 0.841.Several factors including the intrinsic attributes of different life forms, P-related growth rates and relative nutrient availability of soils likely account for the inconstant exponents of leaf N vs. P scaling relationships.Di Tian Zhengbing Yan Karl J.Niklas Wenxuan Han Jens Kattge Peter B.Reich Yongkai Luo Yahan Chen Zhiyao Tang Huifeng Hu Ian J.Wright Bernhard Schmid Jingyun Fang 2018National Science Review2018,5,5:24
7C:N:P stoichiometry and nutrient limitation of the soil microbial biomass in a grazed grassland site under experimental P limitation or exces显示文摘Introduction:The availability of essential nutrients,such as nitrogen(N)and phosphorus(P),can feedback on soil carbon(C)and the soil microbial biomass.Natural cycles can be supplemented by agricultural fertiliser addition,and we determined whether the stoichiometry and nutrient limitation of the microbial biomass could be affected by an unbalanced nutrient supply.Methods:Samples were taken from a long-term trial(in effect since 1968)with annual applications of 0,15 and 30 kg P ha^(−1) with constant N and potassium.Soil and microbial biomass CNP contents were measured and nutrient limitation assessed by substrate-induced respiration.Linear regression and discriminant analyses were used to identify the variables explaining nutrient limitation.Results:Soil and biomass CNP increased with increasing P fertiliser,and there was a significant,positive,correlation between microbial biomass P and biomass C,apart from at the highest level of P fertilisation when the microbial biomass was over-saturated with P.The molar ratios of C:N:P in the microbial biomass remained constant(homeostatic)despite large changes in the soil nutrient ratios.Microbial growth was generally limited by C and N,except in soil with no added P when C and P were the main limiting nutrients.C,N and P,however,did not explain all the growth limitation on the soils with no added P.Conclusions:Increased soil C and N were probably due to increased net primary production.Our results confirm that C:N:P ratios within the microbial biomass were constrained(i.e.homeostatic)under near optimum soil conditions.Soils with no added P were characterised by strong microbial P limitation and soils under high P by over-saturation of microorganisms with P.Relative changes in biomass C:P can be indicative of nutrient limitation within a site.Bryan S Griffiths Annette Spilles Michael Bonkowski 2012Ecological Processes2012,1,1:23
8Delayed sowing can increase lodging resistance while maintaining grain yield and nitrogen use efficiency in winter wheat显示文摘Lodging resistance of winter wheat(Trnticum aestivum L.) can be increased by late sowing.However, whether grain yield and nitrogen use efficiency(NUE) can be maintained with delayed sowing remains unknown. During the 2013-2014 and 2014-2015 growing seasons, two winter wheat cultivars were sown on three dates(early sowing on October 1, normal so,wing on October8, and late sowing on October 15) to investigate the responses of lodging resistance, grain yield,and NUE to sowing date. No significant differences in lodging resistance, grain yield, or NUE between early and normal sowing were observed. Averaging over the two cultivars and years,postponing the sowing date significantly increased lodging resistance by 53.6% and 49.6%compared with that following early and normal sowing, respectively. Lodging resistance was improved mainly through a reduction in the culm height at the center of gravity and an increase in the tensile strength of the base internode. Late sowing resulted in similar grain yield as well as kernel weight and number of kernels per square meter, compared to early and normal sowing.Averaging over the two cultivars and years, delayed sowing resulted in a reduction in nitrogen uptake efficiency(UPE) by 11.0% and 9.9% compared to early and normal sowing, respectively,owing to reduced root length density and dry matter accumulation before anthesis. An average increase in nitrogen utilization efficiency(UTE) of 12.9% and 11.2% compared to early and normal sowing, respectively, was observed with late sowing owing to a reduction in the grain nitrogen concentration. The increase in UTE offset the reduction in UPE, resulting in equal NUEs among all sowing dates. Thus, sowing later than normal could increase lodging resistance while maintaining grain yield and NUE.Xinglong Dai Yuechao Wang Xiuchun Dong Taifeng Qian Lijun Yin Shuxin Dong Jinpeng Chu Mingrong He 2017The Crop Journal2017,5,6:21
9Mitophagy links oxidative stress conditions and neurodegenerative diseases显示文摘Mitophagy is activated by a number of stimuli, including hypoxia, energy stress, and increased oxidative phosphorylation activity. Mitophagy is associated with oxidative stress conditions and central neurodegenerative diseases. Proper regulation of mitophagy is crucial for maintaining homeostasis; conversely, inadequate removal of mitochondria through mitophagy leads to the generation of oxidative species, including reactive oxygen species and reactive nitrogen species, resulting in various neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. These diseases are most prevalent in older adults whose bodies fail to maintain proper mitophagic functions to combat oxidative species. As mitophagy is essential for normal body function, by targeting mitophagic pathways we can improve these disease conditions. The search for effective remedies to treat these disease conditions is an ongoing process, which is why more studies are needed. Additionally, more relevant studies could help establish therapeutic conditions, which are currently in high demand. In this review, we discuss how mitophagy plays a significant role in homeostasis and how its dysregulation causes neurodegeneration. We also discuss how combating oxidative species and targeting mitophagy can help treat these neurodegenerative diseases.Ulfuara Shefa Na Young Jeong In Ok Song Hyung-Joo Chung Dokyoung Kim Junyang Jung Youngbuhm Huh 2019Neural Regeneration Research2019,14,5:21
10Review on photocatalytic and electrocatalytic artificial nitrogen fixation for ammonia synthesis at mild conditions: Advances,challenges and perspectives显示文摘The ammonia synthesis from nitrogen and water under ambient conditions is one of the most inviting but challenging reaction routes.Although nitrogen is abundant in the atmosphere and the ammonia synthesis reaction is exothermic on the thermodynamics,the conversion of N2 to ammonia is actually hard to proceed owing to the chemical inertness and stability of N2 molecules.In industry,ammonia synthesis is carried out by the Haber-Bosch process under harsh conditions (300-500 ℃,20-30 MPa) associated with the requirement of substantial energy input and the enormous emission of greenhouse gases (e.g.,CO2).Recently,a growing number of studies on photo(electro)catalytic and electrocatalytic nitrogen reduction reaction (NRR) in aqueous solution have attracted extensive attention,which holds great promise for nitrogen fixation under room temperature and atmospheric pressure.However,the very low efficiency and ambiguous mechanism still remain as the major hurdles for the development of photochemical and electrochemical NRR systems.Here we provide an overview of the latest progresses,remaining challenges and future prospects in photocatalytic and electrocatalytic nitrogen fixation.Moreover,this review offers a helpful guidance for the reasonable design of photocatalysts and electrocatalysts towards NRR by combining theory predictions and experiment results.We hope this review can stimulate more research interests in the relatively understudied but highly promising research field of NRR.Xiaolan Xue Renpeng Chen Changzeng Yan Peiyang Zhao Yi Hu Wenjun Zhang Songyuan Yang Zhong Jin 2019Nano Research2019,12,6:20
11Comprehensive analysis of nitrogen distributions and ammonia nitrogen release fluxes in the sediments of Baiyangdian Lake, China显示文摘The condition of Baiyangdian Lake(BYDL) will improve as the Xiongan New Area evolves and fulfills its role of easing overcrowding and supporting economic growth. Water and sediment samples from BYDL were analyzed to provide information on nitrogen(N) contamination in BYDL. The mean ammonium N(NH_4^+-N), nitrate N, and total N concentrations in the water samples were 0.36, 0.12, and 2.22 mg/L, respectively, and the ranges were 0.003–8.38, 0.06–0.30,and 1.25–10.34 mg/L, respectively. The N concentrations in water gradually increased from the north to the south of BYDL. Sediment at 90% of the sampling sites was in or above the moderately contaminated class(1000–2000 mg/kg) defined in US Environmental Protection Agency total N pollution standards. Positive NH_4^+-N fluxes were found for 28 of the 34 sediment core samples, so the potential for NH_4^+-N being released from sediment was relatively high. The NH_4^+-N fluxes were 5.35–48.76 mg/m^2/day, and the mean and maximum fluxes were 8.71 and 48.76 mg/m^2/day, respectively. Benthic organisms will be affected more by NH_4^+-N and NH_3·H_2O in the surface sediment pore water(mean concentrations 4.93 and 0.13 mg/L, respectively) than by the other forms of N.Yaoyao Zhu Xin Jin Wenzhong Tang Xin Meng Baoqing Shan 2019Journal of Environmental Sciences2019,31,2:20
12Nitrogen doped porous carbon as excellent dual anodes for Li-and Na-ion batteries显示文摘Biomass-derived carbon materials have obtained great attention due to their sustainability,easy availability,low cost and environmentally benign.In this work,bamboo leaves derived nitrogen doped hierarchically porous carbon have been efficiently synthesized via an annealing approach,followed by an etching process in HF solution.Electrochemical measurements demonstrate that the unique porous structure,together with the inherent high nitrogen content,endow the as-derived carbon with excellent lithium/sodium storage performance.The porous carbon annealed at 700℃presents outstanding rate capability and remarkable long-term stability as anodes for both lithium-ion batteries and sodium-ion batteries.The optimized carbon delivers a high discharge capacity of 450 mAh/g after 500 cycles at the current density of 0.2 A/g for LIBs,and a discharge capacity of 180 mAh/g after 300 cycles at the current density of 0.1 A/g for SIBs.Zhanheng Yan Qin-Wen Yang Qinghong Wang Jianmin Ma 2020Chinese Chemical Letters2020,31,2:20
13Nitrogen in global animal production and management options for improving nitrogen use efficiency显示文摘Animal production systems convert plant protein into animal protein. Depending on animal species, ration and management, between 5% and 45 % of the nitrogen (N) in plant protein is converted to and deposited in animal protein. The other 55%-95% is excreted via urine and feces, and can be used as nutrient source for plant (= often animal feed) production. The estimated global amount of N voided by animals ranges between 80 and 130 Tg N per year, and is as large as or larger than the global annual N fertilizer consumption. Cattle (60%), sheep (12%) and pigs (6%) have the largest share in animal manure N production.The conversion of plant N into animal N is on average more efficient in poultry and pork production than in dairy production, which is higher than in beef and sheep production. However, differences within a type of animal production system can be as large as differences between types of animal production systems, due to large effects of the genetic potential of animals, animal feed and management. The management of animals and animal feed, together with the genetic potential of the animals, are key factors to a high efficiency of conversion of plant protein into animal protein.The efficiency of the conversion of N from animal manure, following application to land, into plant protein ranges between 0 and 60%, while the estimated global mean is about 15%. The other 40%- 100% is lost to the wider environment via NH3 volatilization, denitrification, leaching and run-off in pastures or during storage and/or following application of the animal manure to land. On a global scale, only 40%-50% of the amount of N voided is collected in barns, stables and paddocks, and only half of this amount is recycled to crop land. The N losses from animal manure collected in barns, stables and paddocks depend on the animal manure management system. Relative large losses occur in confined animal feeding operations, as these often lack the land base to utilize the N from animal manure effectively.Losses will be relatively low when all manure are collected rapidly in water-tight and covered basins, and when they are subsequently applied to the land in proper amounts and at the proper time, and using the proper method (low-emission techniques).There is opportunity for improving the N conversion in animal production systems by improving the genetic production potential of the herd, the composition of the animal feed, and the management of the animal manure. Coupling of crop and animal production systems, at least at a regional scale, is one way to high N use efficiency in the whole system. Clustering of confined animal production systems with other intensive agricultural production systems on the basis of concepts from industrial ecology with manure processing is another possible way to improve Nuse efficiency.Oene Oenema Seerp Tamminga 2005Science China(Life Sciences)2005,48,z2:18
14Integration of Growing Milk Vetch in Winter and Reducing Nitrogen Fertilizer Application Can Improve Rice Yield in Double-Rice Cropping System显示文摘To study whether integrative fertilization [growing milk vetch in winter and reducing the dose of chemical nitrogen(N) fertilizer] can improve rice yield, and to reveal the underlying regulatory mechanisms for integrative fertilization, a three-year field trial including two treatments, milk vetch-rice-rice(MRR) and winter fallow-rice-rice(FRR), was conducted in 2010, 2011 and 2012.Our results demonstrated that the MRR treatment could significantly improve rice yield compared with the FRR treatment, especially when the application ratio of milk vetch and chemical fertilizer was 1:2.MRR treatment increased the effective panicle number and the spikelet number per panicle.In addition, a higher tillering number, leaf area index, photosynthetic-potential and photosynthetic-potential to grain ratio were observed in MRR treatment, which could provide enough dry matter for yield formation.Moreover, in MRR treatment, we discovered a higher transportation ratio and transformation ratio of dry matter in culm and leaves, and a stronger total sink capacity and spikelet-root bleeding intensity at the heading stage and 15 d after heading.Furthermore, the MRR treatment showed higher total N, phosphorus and potassium uptakes than FRR treatment, which was associated with the higher root dry weight in each soil layers.These results suggest that growing milk vetch in winter can improve rice yield under less chemical N fertilizer application, which is due to the improvement of soil nutrient status and the increased of rice root growth and development.ZHOU Chun-huo ZHAO Zun-kang PAN Xiao-hua HUANG Shan TAN Xue-ming WU Jian-fu SHI Qing-hua 2016Rice science2016,23,3:18
15Effects of the accumulation of the rare earth elements on soil macrofauna community显示文摘The accumulation of rare earth elements (REEs) in soil has occurred due to the pollution caused by the exploitation of rare earth resources and the wide rare earth fertilizers in agriculture. The accumulation of REEs has a toxic effect on the soil macrofauna community. 12 study samples were collected near a mine tailings dam with a large amount of REEs by distance gradient sample method. The total concentration of REEs was analyzed and the results were compared with that of the sample from a control site. The effects of the amount of REEs in the soil on the soil macrofauna community were also analyzed. The results showed that the accumulation of REEs in soil was significant in the study area and its concentration was strongly correlated with the distance from the pollution source. One-way ANOVA analysis indicated the significant differences in soil macrofauna communities among the different sites. The ordination obtained through the redundancy analysis demonstrated that the concentration of REEs and the total nitrogen, total potassium and pH, had affected the soil macrofauna community. A small amount of REEs in the soil can promote the diversity of soil macrofauna, but a large amount of REEs can reduce its diversity. The insect groups of Carabidae and Dermaptera were comparatively sensitive to the concentration of REEs in soil, and could be used as an indicator of soil pollution of REEs. However, the Formicidae and Stibaropus formosanus exhibited a high tolerance to REEs in soil. We believe that it is very important for the soil environment protection to strictly control the application of the rare earth fertilizers in agriculture in China.李金霞 红梅 殷秀琴 刘继亮 2010Journal of Rare Earths2010,28,6:18
16Postponed and reduced basal nitrogen application improves nitrogen use efficiency and plant growth of winter wheat显示文摘Excessive nitrogen(N) fertilization with a high basal N ratio in wheat can result in lower N use efficiency(NUE) and has led to environmental problems in the Yangtze River Basin, China. However, wheat requires less N fertilizer at seedling growth stage, and its basal N fertilizer utilization efficiency is relatively low; therefore, reducing the N application rate at the seedling stage and postponing the N fertilization period may be effective for reducing N application and increasing wheat yield and NUE. A 4-year field experiment was conducted with two cultivars under four N rates(240 kg N ha–1(N240), 180 kg N ha–1(N180), 150 kg N ha–1(N150), and 0 kg N ha–1(N0)) and three basal N application stages(seeding(L0), fourleaf stage(L4), and six-leaf stage(L6)) to investigate the effects of reducing the basal N application rate and postponing the basal N fertilization period on grain yield, NUE, and N balance in a soil-wheat system. There was no significant difference in grain yield between the N180 L4 and N240 L0(control) treatments, and the maximum N recovery efficiency and N agronomy efficiency were observed in the N180 L4 treatment. Grain yield and NUE were the highest in the L4 treatment. The leaf area index, flag leaf photosynthesis rate, flag leaf nitrate reductase and glutamine synthase activities, dry matter accumulation, and N uptake post-jointing under N180 L4 did not differ significantly from those under N240 L0. Reduced N application decreased the inorganic N content in the 0–60-cm soil layer, and the inorganic N content of the L6 treatment was higher than those of the L0 and L4 treatments at the same N level. Surplus N was low under the reduced N rates and delayed basal N application treatments. Therefore, postponing and reducing basal N fertilization could maintain a high yield and improve NUE by improving the photosynthetic production capacity, promoting N uptake and assimilation, and reducing surplus N in soil-wheat systems.TIAN Zhong-wei LIU Xiao-xue GU Shi-lu YU Jin-hong ZHANG Lei ZHANG Wei-wei JIANG Dong CAO Wei-xing DAI Ting-bo 2018Journal of Integrative Agriculture2018,17,12:18
17A Chromosome-Scale Genome Assembly of Paper Mulberry(Bmussonetia papyrifera)Provides New Insights into Its Forage and Papermaking Usage显示文摘Paper mulberry(Broussonetia papyrifera)is a well-known woody tree historically used for Cai Lun papermaking,one of the four great inventions of ancient China.More recently,Paper mulberry has also been used as forage to address the shortage of feedstuff because of its digestible crude fiber and high protein contents.In this study,we obtained a chromosome-scale genome assembly for Paper mulberry using integrated approaches,including Illumina and PacBio sequencing platform as well as Hi-C,optical,and genetic maps.The assembled Paper mulberry genome consists of 386.83 Mb,which is close to the estimated size,and 99.25%(383.93 Mb)of the assembly was assigned to 13 pseudochromosomes.Comparative genomic analysis revealed the expansion and contraction in the flavonoid and lignin biosynthetic gene families,respectively,accounting for the enhanced flavonoid and decreased lignin biosynthesis in Paper mulberry.Moreover,the increased ratio of syringyl-lignin to guaiacyl-lignin in Paper mulberry underscores its suitability for use in medicine,forage,papermaking,and barkcloth making.We also identified the rootassociated microbiota of Paper mulberry and found that Pseudomonas and Rhizobia were enriched in its roots and may provide the source of nitrogen for its stems and leaves via symbiotic nitrogen fixation.Collectively,these results suggest that Paper mulberry might have undergone adaptive evolution and recruited nitrogen-fixing microbes to promote growth by enhancing flavonoid production and altering lignin monomer composition.Our study provides significant insights into genetic basis of the usefulness of Paper mulberry in papermaking and barkcloth making,and as forage.These insights will facilitate further domestication and selection as well as industrial utilization of Paper mulberry worldwide.Xianjun Peng Hui Liu Peilin Chen Feng Tang Yanmin Hu Fenfen Wang Zhi Pi Meiling Zhao Naizhi Chen Hui Chen Xiaokang Zhang Xueqing Yan Min Liu Xiaojun Fu Guofeng Zhao Pu Yao Lili Wang He Dai Xuming Li Wei Xiong Wencai Xu Hongkun Zheng Haiyan Yu Shihua Shen 2019Molecular Plant2019,12,5:18
18Hydropower reservoirs on the upper Mekong River modify nutrient bioavailability downstream显示文摘Hydropower development is the key strategy in many developing countries for energy supply,climate-change mitigation and economic development.However,it is commonly assumed that river dams retain nutrients and therefore reduce downstream primary productivity and fishery catches,compromising food security and causing trans-boundary disputes.Contrary to expectation,here we found that a cascade of reservoirs along the upper Mekong River increased downstream bioavailability of nitrogen andphosphorus.The dams caused phytoplankton density to increase with hydraulic residence time and stratification of the stagnant reservoirs caused hypoxia at depth.This allowed the release of bioavailable phosphorus from the sediment and an increase in dissolved inorganic nitrogen as well as a shift in nitrogen species from nitrate to ammonium,which were transported downstream by the discharge of water from the base of the dam.Our findings provide a new perspective on the environmental impacts of river dams on nutrient cycling and ecosystem functioning,with potential implications for sustainable development of hydropower worldwide.Qiuwen Chen Wenqing Shi Jef Huisman Stephen C.Maberly Jianyun Zhang Juhua Yu Yuchen Chen Daniele Tonina Qitao Yi 2020National Science Review2020,7,9:15
19Nitrogen deposition as an important nutrient from the environment and its impact on ecosystems in China显示文摘As an example of atmospheric nitrogen(N) deposition,the paper summarizes the definition,form and amount of nutrient from the environment(NFE) and the relationship between NFE and anthro-pogenic reactive N emission.Based on our own study and published articles,we find that N wet and dry deposition has been an important nutrient resource in agricultural and natural ecosystems in China.The total amount of N deposition and other environment-derived N in China was up to 18 Tg N/a,equal to ap-proximately 60% of the national N fertilizer consumption.Nitrogen deposition is expected to contribute substantially to nutrient cycling and net primary productivity in various ecosystems.Therefore,it is crucial to utilize this environment-derived nutrient resource by integrated nutrient resource management in order to realize the sustainable development of both agricultural and non-agricultural ecosystems.Liu, XueJun Song, Ling He, ChunE Zhang, FuSuo 2010Journal of Arid Land2010,2,2:15
20不同施氮水平下枸杞主要次生代谢产物与多糖的关系研究(英文)显示文摘[Objective] The aim of this study is to investigate the optimum application amount of nitrogen in Lycium barbarum based on considering the relationship between main secondary metabolites and polysaccharide.[Method]Under field conditions,the effects of different application amounts of nitrogen on main secondary metabolites of betaine,carotenoid and flavone of Lycium barbarum and the relationship between main secondary metabolites and polysaccharide.[Result] The main secondary metabolites of betaine,carotenoid and flavone of Lycium barbarum varied under different application amounts of nitrogen.The proper application amount of nitrogen(600-900 kg/hm2)was beneficial to the formation and accumulation of secondary metabolites such as carotenoids.Correlation analysis results showed that polysaccharide were negatively correlated with betaine,carotenoid and flavone at significant probability level.[Conclusion]Considering the relationship between the output and quality of the fruits of Lycium barbarum,the optimum nitrogen application amount should be 600-900 kg/hm2.康建宏 吴宏亮 杨涓 杨剑涛 2008Agricultural Science & Technology2008,9,5:15
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