Soil nitrogen(N)is the main limiting nutrient for plant growth,which is sensitive to variations in the soil oxygen environment.To provide insights into plant N accumulation and yield under aerated and drip irrigation,...Soil nitrogen(N)is the main limiting nutrient for plant growth,which is sensitive to variations in the soil oxygen environment.To provide insights into plant N accumulation and yield under aerated and drip irrigation,a greenhouse tomato experiment was conducted with six treatments,including three fertilization types:inorganic fertilizer(NPK);organic fertilizer(OM);chemical(75%of applied N)+organic fertilizer(25%)(NPK+OM)under drip irrigation(DI)and aerated irrigation(AI)methods.Under Al,total soil carbon mineralization(C_(min))was significantly higher(by 5.7-7.0%)than under DI irrigation.C_(min)in the fertilizer treatments followed the order NPK+OM>OM>NPK under both AI and DI.Potentially mineralizable C(C_(0))and N(N_(0))was greater under AI than under DI.Gross N mineralization,gross nitrification,and NH_(4)^(+)immobilization rates were significantly higher under the AINPK treatment than the DINPK treatment by 2.58-3.27-,1.25-1.44-,and 1-1.26-fold,respectively.These findings demonstrated that AI and the addition of organic fertilizer accelerated the turnover of soil organic matter and N transformation processes,thereby enhancing N availability.Moreover,the combination of AI and organic fertilizer application was found to promote root growth(8.4-10.6%),increase the duration of the period of rapid N accumulation(ΔT),and increase the maximum N accumulation rate(V_(max)),subsequently encouraging aboveground dry matter accumulation.Consequently,the AI treatment yield was significantly greater(by 6.3-12.4%)than under the DI treatment.Further,N partial factor productivity(NPFP)and N harvest index(NHI)were greater under AI than under DI,by 6.3 to 12.4%,and 4.6 to 8.1%,respectively.The rankings of yield and NPFP remained consistent,with NPK+OM>OM>NPK under both AI and DI treatments.These results highlighted the positive impacts of AI and organic fertilizer application on soil N availability,N uptake,and overall crop yield in tomato.The optimal management measure was identified as the AINPK+OM treatment,which led to more efficient N management,better crop growth,higher yield,and more sustainable agricultural practices.展开更多
Good growth of tomato at the early growing stages is the key to final yield formation,for which water(W)and nitrogen(N)applications are two necessary factors.In this study,two irrigating systems(W1,W2)and three N appl...Good growth of tomato at the early growing stages is the key to final yield formation,for which water(W)and nitrogen(N)applications are two necessary factors.In this study,two irrigating systems(W1,W2)and three N applications(N1,N2,N3)were interacted(W×N)to plant the cherry tomato variety‘‘Jinling Meiyu’’in greenhouse.W1(reduced irrigation)and W2(normal irrigation)had a 7:9 irrigated ratio based on former research.N1,N2,and N3 were set at 100%,80%,and 60%normal N application,respectively.The tomato plant height(PH),stem circumference(SC),number of leaves(NL),number of first order fruits(NF),the single fruit weight(SFW),contents of fruit Vitamin C(VC)and soluble sugar(SS),fresh weights of root(RW),leaf(LW),and plant stem(PSW),as well as leaf chlorophyll fluorescence value(SPAD),temperature(T),humidity(RH),and nitrogen content(N)were investigated at the first flowering and fruiting stage.The results showed that W×N had significant impacts on early plant growth and fruit quality of tomato.W2N2 obviously received the largest values of tomato PH(152.5 cm),SC(4.1 cm),NF(11 fruits/plant),and LW(45.0 g/plant),but obtained the lowest VC(9.71 mg/kg)and SS(2.40%).However,W1N3 had the largest values of leaf RH(56.9%),N contents(14.23 mg/g),and VC(16.29 mg/kg),with NF also at 11.0 fruits/plant.W2N1 significantly had the highest RW(14.4 g/plant),PSW(71.8 g/plant),and SFW(21.3 g/fruit).W2N3,W1N1,and W1N2 obtained the most NL(103.7 pieces/plant),SS(4.06%),and leaf SPAD(36.85),respectively.Pearson correlation analysis results showed PH negatively significantly correlated with NF(p<0.05).The leaf SPAD positively significantly correlated with PH(p<0.05)and RH(p<0.01),but negatively significantly correlated with SC(p<0.05)and T(p<0.01).Moreover,leaf N content also had a positive significant correlation with PH(p<0.05),and an extremely positive significant correlation with RH and SPAD(p<0.01).However,it negatively significantly correlated with SC(p<0.01)and T(p<0.05).Significantly,VC had positive correlations with PSW,leaf SPAD,and N content(p<0.05).SS negatively correlated with PSW(p<0.05)and T(p<0.01),and extremely significantly positively correlated with SPAD(p<0.01).Additionally,RW had an extremely significant relationship with PSW(p<0.01).Two-factor analysis of variances showed W extremely significantly influenced leaf T,RH,SPAD,and N content(p<0.001),as well as SC(p<0.01)and SS(p<0.05).Meanwhile,N management extremely significantly influenced LW(p<0.001),RW(p<0.01),and leaf T(p<0.05).However,W×N obviously significantly influenced just PSW(p<0.01),RW(p<0.001),and VC(p<0.05).Taking all factors into account,the early reasonable W×N management could promote growth of tomato plants and fruit quality at the first fruiting and ripening stage.These results could provide a foundation for the subsequent growth of tomato fruits and could also be beneficial for the precise management of greenhouse tomatoes at the early growing stages.展开更多
The responses of drip-irrigated rice physiological traits to water and fertilizers have been widely studied.However,the responses of yield,root traits and their plasticity to the nitrogen environment in different nitr...The responses of drip-irrigated rice physiological traits to water and fertilizers have been widely studied.However,the responses of yield,root traits and their plasticity to the nitrogen environment in different nitrogen-efficient cultivars are not fully understood.An experiment was conducted from 2020-2022 with a high nitrogen use efficiency(high-NUE)cultivar(T-43)and a low-NUE cultivar(LX-3),and four nitrogen levels(0,150,300,and 450 kg ha^(-1))under drip irrigation in large fields.The aim was to study the relationships between root morphology,conformation,biomass,and endogenous hormone contents,yield and NUE.The results showed three main points:1)Under the same N application rate,compared with LX-3,the yield,N partial factor productivity(PFP),fine root length density(FRLD),shoot dry weight(SDW),root indole-3-acetic acid(IAA),and root zeatin and zeatin riboside(Z+ZR)of T-43 were significantly greater by11.4-18.9,11.3-13.5,11.6-15.7,9.9-31.1,6.1-48.1,and 22.8-73.6%,respectively,while the root-shoot ratio(RSR)and root abscisic acid(ABA)were significantly lower(P<0.05);2)nitrogen treatment significantly increased the rice root morphological indexes and endogenous hormone contents(P<0.05).Compared to N0,the yield,RLD,surface area density(SAD),root volume density(RVD),and root endogenous hormones(IAA,Z+ZR)were significantly increased in both cultivars under N2 by 61.6-71.6,64.2-74.0,69.9-105.6,6.67-9.91,54.0-67.8,and 51.4-58.9%,respectively.Compared with N3,the PFP and N agronomic efficiency(NAE)of nitrogen fertilizer under N2 increased by 52.3-62.4 and39.2-63.0%,respectively;3)the responses of root trait plasticity to the N environment significantly differed between the cultivars(P<0.05).Compared with LX-3,T-43 showed a longer root length and larger specific surface area,which is a strategy for adapting to changes in the nutrient environment.For the rice cultivar with high-NUE,the RSR was optimized by increasing the FRLD,root distribution in upper soil layers,and root endogenous hormones(IAA,Z+ZR)under suitable nitrogen conditions(N2).An efficient nutrient acquisition strategy can occur through root plasticity,leading to greater yield and NUE.展开更多
Climate change impacts soil nitrogen, influencing plant responses to elevated atmospheric [CO2]. Understanding the interaction between nitrogen supply and elevated [CO2] is crucial for predicting plant future performa...Climate change impacts soil nitrogen, influencing plant responses to elevated atmospheric [CO2]. Understanding the interaction between nitrogen supply and elevated [CO2] is crucial for predicting plant future performance. This study examined the interactive effects of elevated [CO2] and nitrogen supply on the eco-physiological performance of yellow birch. Seedlings were exposed to two [CO2] levels and five nitrogen supply levels for 4 months. Growth parameters such as seedling height and root collar diameter increased with higher nitrogen supply and elevated [CO2], while specific leaf area decreased. [CO2] elevation and increasing nitrogen supply also increased the total and stem, and leaf biomass. The elevated [CO2] increased the stem mass ratio but decreased the root-to-shoot ratio and root mass ratio. However, decreases in nitrogen supply increased root mass ratio and root-to-shoot ratio. The elevated [CO2] increased the maximum rate of Rubisco carboxylation (Vcmax) and photosynthetic electron transport (Jmax), but the effect on Jmax was statistically significant only at the two highest nitrogen supply levels. The results indicate that yellow birch may increase photosynthetic capacity, biomass, and growth in the future when [CO2] is higher.展开更多
Nitrogen(N)uptake is regulated by water availability,and a water deficit can limit crop N responses by reducing N uptake and utilization.The complex and multifaceted interplay between water availability and the crop N...Nitrogen(N)uptake is regulated by water availability,and a water deficit can limit crop N responses by reducing N uptake and utilization.The complex and multifaceted interplay between water availability and the crop N response makes it difficult to predict and quantify the effect of water deficit on crop N status.The nitrogen nutrition index(NNI)has been widely used to accurately diagnose crop N status and to evaluate the effectiveness of N application.The decline of NNI under water-limiting conditions has been documented,although the underlying mechanism governing this decline is not fully understood.This study aimed to elucidate the reason for the decline of NNI under waterlimiting conditions and to provide insights into the accurate utilization of NNI for assessing crop N status under different water-N interaction treatments.Rainout shelter experiments were conducted over three growing seasons from 2018 to 2021 under different N(75 and 225 kg N ha^(-1),low N and high N)and water(120 to 510 mm,W0 to W3)co-limitation treatments.Plant N accumulation,shoot biomass(SB),plant N concentration(%N),soil nitrate-N content,actual evapotranspiration(ET_a),and yield were recorded at the stem elongation,booting,anthesis and grain filling stages.Compared to W0,W1 to W3 treatments exhibited NNI values that were greater by 10.2 to 20.5%,12.6to 24.8%,14 to 24.8%,and 16.8 to 24.8%at stem elongation,booting,anthesis,and grain filling,respectively,across the 2018-2021 seasons.This decline in NNI under water-limiting conditions stemmed from two main factors.First,reduced ET_(a) and SB led to a greater critical N concentration(%N_(c))under water-limiting conditions,which contributed to the decline in NNI primarily under high N conditions.Second,changes in plant%N played a more significant role under low N conditions.Plant N accumulation exhibited a positive allometric relationship with SB and a negative relationship with soil nitrate-N content under water-limiting conditions,indicating co-regulation by SB and the soil nitrate-N content.However,this regulation was influenced by water availability.Plant N accumulation sourced from the soil nitrate-N content reflects soil N availability.Greater soil water availability facilitated greater absorption of soil nitrate-N into the plants,leading to a positive correlation between plant N accumulation and ET_(a)across the different water-N interaction treatments.Therefore,considering the impact of soil water availability is crucial when assessing soil N availability under water-limiting conditions.The findings of this study provide valuable insights into the factors contributing to the decline in NNI among different water-N interaction treatments and can contribute to the more accurate utilization of NNI for assessing winter wheat N status.展开更多
In order to protect the environment and economize energy,a nitrogen-fixing photocatalyst,VMCeact,is investigated in this work.This catalyst is prepared from a natural mineral,vermiculite,and modified by Ce-based metal...In order to protect the environment and economize energy,a nitrogen-fixing photocatalyst,VMCeact,is investigated in this work.This catalyst is prepared from a natural mineral,vermiculite,and modified by Ce-based metal-organic framework,Ce-UiO-66.Vermiculite was treated with formic acid;thus,Ce-UiO-66 particles grew in-situ on vermiculite;then,Ce-UiO-66 particles were activated by ultraviolet irradiation.The vermiculite absorbed visible light with a narrow band gap,and transferred photogenerated electrons to the active sites on Ce-UiO-66.Moreover,the lamella structure of vermiculite protected Ce-UiO-66 during photocatalytic process.Therefore,with only 45.92 wt%of Ce-UiO-66,the nitrogen fixation performance of VMCeact was 2.29 times that of pure activated Ce-UiO-66 particles under 455nm light irradiation(apparent quantum efficiency of 4.49%),and retained at least 96.05%performance after 7×24 h of photocatalytic reaction.This cost-reduced,efficient and stable photocatalyst has the opportunity to facilitate environmentally friendly ammonia production.展开更多
Ammonia is nowadays one of the most important commodities chemicals intensively produced at about 175 million tons per year,contributing to 1.8%of the global energy demand.The constantly increasing NH3 demand also par...Ammonia is nowadays one of the most important commodities chemicals intensively produced at about 175 million tons per year,contributing to 1.8%of the global energy demand.The constantly increasing NH3 demand also paralleleds by the high CO_(2) emissions associated with its production.Therefore,decarbonizing NH3 synthesis is one of the most urgent contemporary challenges.Taking inspiration from Nature,solar-driven nitrogen fixation under mild conditions is one of the most promising yet challenging alternatives to classic methods.In this review,we focused our attention on the photocatalytic methods for the synthesis of ammonia;in particular,we concentrated on stable and recyclable heterogeneous Fe-based photocatalysts for producing NH3.Indeed,recoverable and widely abundant and low-cost iron catalysts may represent a very promising tool for future sustainable access to this largely desired chemical target.After an overview of the pioneering works on Fe-driven nitrogen photofixation,the recent strategies on the use of Fe are herein reported.Compared with pristine photocatalysts,adding Fe as dopant or composite and heterojunction highly enhances the photocatalytic performances,opening the way to sustainable and low-cost nitrogen production.展开更多
The objectives of this study which included two experiments were to investigate the effects of dietary inclusion of sorghum grain rich in condensed tannins(CT)(18.9 g kg^(–1)dry matter(DM))on nitrogen(N)metabolism an...The objectives of this study which included two experiments were to investigate the effects of dietary inclusion of sorghum grain rich in condensed tannins(CT)(18.9 g kg^(–1)dry matter(DM))on nitrogen(N)metabolism and urine nitrous oxide(N_(2)O)emissions of beef steers.In experiment 1,six Limousin×Luxi crossbreed steers with an initial liveweight of(245.0±18.7)kg were used as experimental animals.Three levels of sorghum grain,i.e.,0,167 and 338 g kg^(–1)DM were included in diets as experimental treatments.The animals and the treatments were randomly assigned to a replicated 3×3 Latin square design.In experiment 2,static incubation technique was used to determine the N_(2)O emissions of the urine samples collected in experiment 1.The results of experiment 1 showed that dietary inclusion of sorghum grain linearly increased the faecal N excretion(P=0.001),the total N excretion(P=0.010)and the faecal N to N intake ratio(P=0.021),but it did not affect the N retention and the N utilization efficiency(P>0.10).The plasma metabolomic data showed that dietary inclusion of sorghum grain increased the relative concentrations of phenolic acid(N1,N5,N10-tris-trans-p-coumaroylspermine and prenyl cis-caffeate)and carnitine(3-hydroxyisovalerylcarnitine and linoelaidyl carnitine).The results also showed that dietary inclusion of sorghum grain linearly increased the urinary urea excretion(P=0.010)and decreased the urinary excretion of purine derivatives(P=0.041)as well as the estimated rumen microbial N supply(P=0.012)based on urinary purine derivatives.The results of experiment 2 showed that including sorghum grain in the diet linearly increased the average concentrations of NH_(4)^(+)-N(P=0.012),NO_(2)^(–)-N(P=0.009),NO_(3)^(-)-N(P=0.001)and the total inorganic N(P<0.001)in the soil enriched with urine samples.The urine sample N_(2)O-N flux(P=0.001),the estimated steer urine N_(2)O-N flux(P=0.021)and the N_(2)O-N to urinary N ratio(P=0.038)linearly increased with increasing inclusion of sorghum grain in the diet.In conclusion,dietary inclusion of sorghum grain containing high CT at 167 and 338 g kg^(–1)DM did not affect the N utilization efficiency of steers but increased the urine N_(2)O-N emissions by 5.7 and 31.4%,respectively.For reducing the N_(2)O emissions to the environment,high levels of sorghum grain should not be included in the diet of steers.展开更多
Electrochemical synthesis of ammonia represents a green and environmental-ly friendly method distinct from tradi-tional Harper-Bosch processes,which demand stringent conditions.However,identifying a catalyst with high...Electrochemical synthesis of ammonia represents a green and environmental-ly friendly method distinct from tradi-tional Harper-Bosch processes,which demand stringent conditions.However,identifying a catalyst with high selec-tivity and catalytic activity to cleave the robust triple bond of N_(2)remains a formidable challenge.Herein,we present a systematic study on the geo-metrical and electronic structure,intensity of N_(2)adsorption,reaction intermediates,change in Gibbs free energy,and desorption of by-product hydrazine for the nitrogen reduction reac-tion employing a MnNx-graphene(x=3,4)catalyst from a theoretical perspective.The com-putational results reveal that MnN3-graphene exhibits superior catalytic performance pre-dominantly via the distal mechanism,with a low potential of 0.49 V.Moreover,the detach-ment of the produced NH3 is facilitated with a free energy of only 0.27 eV,significantly lower than those of previous catalysts,ensuring the exceptional durability of MnN_(3)-graphene.This study offers theoretical insights guiding the exploration of single Mn atom catalysts in ammo-nia synthesis.展开更多
The trade-off between yield and environmental effects caused by nitrogen fertilizer application is an important issue in wheat production.A reduction in fertile florets is one of the main reasons for the lower yields ...The trade-off between yield and environmental effects caused by nitrogen fertilizer application is an important issue in wheat production.A reduction in fertile florets is one of the main reasons for the lower yields under low nitrogen application rates.Brassinosteroids(BRs)have been found to play a role in nitrogen-induced rice spikelet degeneration.However,whether BRs play a role in wheat floret development and the mechanisms involved are not clear.Therefore,a nitrogen gradient experiment and exogenous spraying experiment were conducted to investigate the role and mechanism of BRs in wheat floret development under low nitrogen stress.The results showed that as the nitrogen application decreased,the endogenous BRs content of the spikes decreased,photosynthesis weakened,and total carbon,soluble sugar and starch in the spikes decreased,leading to a reduction in the number of fertile florets.Under low nitrogen stress,exogenous spraying of 24-epibrassinolide promoted photosynthesis,and stimulated stem fructan hydrolysis and the utilization and storage of sucrose in spikes,which directed more carbohydrates to the spikes and increased the number of fertile florets.In conclusion,BRs mediate the effects of nitrogen fertilizer on wheat floret development,and under low nitrogen stress,foliar spraying of 24-epibrassinolide promotes the flow of carbohydrates from the stem to the spikes,alleviating wheat floret degeneration.展开更多
Ammonia and nitric acid,versatile industrial feedstocks,and burgeoning clean energy vectors hold immense promise for sustainable development.However,Haber–Bosch and Ostwald processes,which generates carbon dioxide as...Ammonia and nitric acid,versatile industrial feedstocks,and burgeoning clean energy vectors hold immense promise for sustainable development.However,Haber–Bosch and Ostwald processes,which generates carbon dioxide as massive by-product,contribute to greenhouse effects and pose environmental challenges.Thus,the pursuit of nitrogen fixation through carbon–neutral pathways under benign conditions is a frontier of scientific topics,with the harnessing of solar energy emerging as an enticing and viable option.This review delves into the refinement strategies for scale-up mild photocatalytic nitrogen fixation,fields ripe with potential for innovation.The narrative is centered on enhancing the intrinsic capabilities of catalysts to surmount current efficiency barriers.Key focus areas include the in-depth exploration of fundamental mechanisms underpinning photocatalytic procedures,rational element selection,and functional planning,state-of-the-art experimental protocols for understanding photo-fixation processes,valid photocatalytic activity evaluation,and the rational design of catalysts.Furthermore,the review offers a suite of forward-looking recommendations aimed at propelling the advancement of mild nitrogen photo-fixation.It scrutinizes the existing challenges and prospects within this burgeoning domain,aspiring to equip researchers with insightful perspectives that can catalyze the evolution of cutting-edge nitrogen fixation methodologies and steer the development of next-generation photocatalytic systems.展开更多
Macroalgae dominate nutrient dynamics and function as high-value foods for microbial,meio-and macrofaunal communities in coastal ecosystems.Because of this vital role,it is important to clarify the physiological infor...Macroalgae dominate nutrient dynamics and function as high-value foods for microbial,meio-and macrofaunal communities in coastal ecosystems.Because of this vital role,it is important to clarify the physiological information associated with environmental changes as it reflects their growth potential.To evaluate the effects of the changes in salinity and nutrients,the photosynthetic efficiency of a green macroalga Ulva fasciata from the Daya Bay was tested at a range of salinity(i.e.,31 to 10 psu)and nitrogen content(i.e.,5 to 60μmol L^(-1)).The results showed that cellular chlorophyll a(Chl a),carbohydrate and protein contents of U.fasciata were increased due to reduced salinity,and were decreased by interactive nitrogen enrichment.Within a short culture period(i.e.,18 h),the reduced salinity decreased the maximum photosynthetic efficiency(rETRmax and Pmax)derived from the rapid light response curve and photosynthetic oxygen evolution rate versus irradiance curve,respectively,as well as the saturation irradiance(E_(K)).This reducing effect diminished with enlonged cultivation time and reversed to a stimulating effect after 24 h of cultivation.The nitrogen enrichment stimulated the rETRmax and Pmax,as well as the E_(K),regardless of salinity,especially within short-term cultivation period(i.e.,<24 h).In addition,our results indicate that seawater freshening lowers the photosynthetic efficiency of U.fasciata in the short term,which is mitigated by nitrogen enrichment,but stimulates it in the long term,providing insight into how macroalgae thrive in coastal or estuarine waters where salinity and nutrients normally covary strongly.展开更多
Electrochemical nitrogen transformation techniques represent a burgeoning avenue for nitrogen pollutant remediation and synthesizing valuable nitrogenous products from atmospheric nitrogen.Intermetallic compounds(IMCs...Electrochemical nitrogen transformation techniques represent a burgeoning avenue for nitrogen pollutant remediation and synthesizing valuable nitrogenous products from atmospheric nitrogen.Intermetallic compounds(IMCs)nanocrystals,featured with unique geometric,electronic and functional properties,have emerged as promising candidates.The review discusses various synthesis approaches for IMCs,including thermal annealing,wet chemical synthesis,electrochemical synthesis,and other emerging methods,analyzing their advantages and limitations.Then we summarized the recent advances of IMCs in electrocatalytic nitrogen transformation reactions,such as nitrate reduction reaction,nitric oxide reduction reaction,nitrogen reduction reaction,and hydrazine oxidation reaction.Despite significant progress,challenges remain in the field,particularly in adopting more refined strategies to improve catalyst performance and stability.This review aims to comprehensively understand the structural properties of IMCs and their structure-performance relationship,guiding the development of more efficient and stable catalysts for future nitrogen electrochemistry.展开更多
Strip-till(ST),including straw mulching in the inter-row and localized fertilization in the intra-row,is a conservation tillage system for improving soil quality and crop growth.However,the yield advantage of maize un...Strip-till(ST),including straw mulching in the inter-row and localized fertilization in the intra-row,is a conservation tillage system for improving soil quality and crop growth.However,the yield advantage of maize under ST compared to conventional tillage(CT)remains unstable,and the strategies to increase maize yield under ST are unclear.This study aims to understand the physiological mechanism underlining maize yield formation under ST by comparing two maize cultivars,DKM753 and DK517,with contrasting yield performance in ST versus CT systems.Compared to CT,ST resulted in a 4.5%yield increase for DKM753 but a 5.6%decrease for DK517.These yield differences were primarily attributed to variations in grain number per ear(GN).During the rapid growth stage(V14-R3),i.e.,two weeks before and after silking,DKM753 showed a 6.7%increase in maximum growth rate(V_(max))and a 6.3%increase in average growth rate(V)under ST,whereas DK517 exhibited decline of 8.5%in V_(max) and 12.3%in V.Significant positive correlations are observed between V_(max) and V with GN under ST(R^(2)=0.79 and R^(2)=0.90,respectively).Enhanced dry matter accumulation in DKM753 under ST was attributed to increased leaf expansion rates,contributing to a larger photosynthate source.The straw mulching and localized nitrogen fertilization increased root-zone nitrogen availability at silking in ST compared to CT.DKM753 had a greater root system which made better use of the soil N and lead to an increased leaf nitrogen accumulation by 14.9%under ST.It is concluded that maize yield under the strip-till system is determined by grain number per ear,which can be increased by increasing nitrogen accumulation,plant growth,and ear development around silking stage.A sound root system can efficiently utilize soil nitrogen resources under the strip-till system,increasing plant nitrogen accumulation and thereby promoting plant growth.展开更多
In contrast to research on active sites in nanomaterials,lithium tantalate single crystals,known for their exceptional optical properties and long-range ordered lattice structure,present a promising avenue for in-dept...In contrast to research on active sites in nanomaterials,lithium tantalate single crystals,known for their exceptional optical properties and long-range ordered lattice structure,present a promising avenue for in-depth exploration of photocatalytic reaction systems with fewer constraints imposed by surface chemistry.Typically,the isotropy of a specific facet provides a perfect support for studying heteroatom doping.Herein,this work delves into the intrinsic catalytic sites for photocatalytic nitrogen fixation in iron-doped lithium tantalate single crystals.The presence of iron not only modifies the electronic structure of lithium tantalate,improving its light absorption capacity,but also functions as an active site for the nitrogen adsorption and activation.The photocatalytic ammonia production rate of the iron-doped lithium tantalate in pure water is maximum 26.95μg cm^(−2)h^(−1),which is three times higher than that of undoped lithium tantalate.The combination of first-principles simulations with in situ characterizations confirms that iron doping promotes the rate-determining step and changes the pathway of hydrogenation to associative alternating.This study provides a new perspective on in-depth investigation of intrinsic catalytic active sites in photocatalysis and other catalytic processes.展开更多
Constructed wetlands(CWs)are a promising method to treat effluent from wastewater treatment plants(WWTPs).However,low carbon/nitrogen(C/N)ratios of the influent inhibit denitrification in CWs,resulting in poor nitroge...Constructed wetlands(CWs)are a promising method to treat effluent from wastewater treatment plants(WWTPs).However,low carbon/nitrogen(C/N)ratios of the influent inhibit denitrification in CWs,resulting in poor nitrogen removal efficiency.Herein,we compared traditional(control),biochar(BC),and b-cyclodextrin-functionalized biochar(BC@b-CD)CW systems to investigate nitrogen removal from influent with low C/N ratios,and the mechanisms that enhance this process.The highest nitrogen removal rates were observed in the BC@b-CD group,with rates 45.89%and 42.48%higher than those of the control,accompanied by a 70.57%and 85.45%decrease in nitrous oxide release,when the C/N ratio decreased from 4 to 2,respectively.Metagenomic and enzymatic analyses indicated that BC@b-CD enhances nitrogen removal by coordinately promoting carbon metabolism and increasing denitrification enzyme activities,without affecting microbial species diversity in CWs.Structural equation modeling confirmed that the foremost advantages of BC@b-CD were effective electron generation and transportation resulting from increased activities of nicotinamide adenine dinucleotide(NADH)dehydrogenase and the electron transfer system(ETS),thereby strategically reallocating more carbon metabolic flow to support denitrification.Our results show that the application of BC@b-CD in CWs to optimize the reallocation of electrons from carbon metabolism is a feasible strategy to enhance denitrification under low C/N conditions.展开更多
The role of brassinosteroids(BRs)in enabling plants to respond effectively to adverse conditions is well known,though the precise mechanism of action that helps plants cope with arsenic(As)toxicity is still difficult ...The role of brassinosteroids(BRs)in enabling plants to respond effectively to adverse conditions is well known,though the precise mechanism of action that helps plants cope with arsenic(As)toxicity is still difficult to interpret.Therefore we tested the effect of brassinolide(BL)spray(0,0.5,and 1 mg·L^(-1))on As(0,and 10 mg·L^(-1))stressed tomato defense responses As stress led to the induction of oxidative stress,impaired chlorophyll and nitrogen metabolism,and Fe uptake,in conjunction with a reduction in plant growth and biomass.BL spray,on the contrary,protected the photo synthetic system and helped plants grow better under As stress.This was achieved by controlling the metabolism of chlorophyll and proline and lowering the amounts of methylglyoxal and H_(2)O_(2) through glyoxalaseⅠandⅡand antioxidant enzyme s.BL decreased arsenic accumulation by directing As sequestration towards vacuoles and increased Fe amount in the leaves and roots by regulating the expression of As(Lsil and Lsi2)and Fe(IRT1,IRT2,NRAMP1,and NRAMP3)transporters in As-stressed tomatoes.Furthermore,BL boosted adaptability against As phytotoxicity,while reducing the damaging impacts on photosynthesis,nitrogen metabolism,sulfur asimilation,and Fe absorption.These results offer a solid framework for the development of exogenous BRs-based breeding strategies for safer agricultural development.展开更多
Understanding livestock performance in typical steppe ecosystems is essential for optimizing grassland-livestock interactions and minimizing environmental impact.To assess the effects of different stocking rates on th...Understanding livestock performance in typical steppe ecosystems is essential for optimizing grassland-livestock interactions and minimizing environmental impact.To assess the effects of different stocking rates on the growth performance,energy and nitrogen utilization,methane(CH_(4))emissions,and grazing behavior of Tan sheep,a 2-year grazing experiment in the typical steppe was conducted.The grazing area was divided into 9 paddocks,each 0.5 ha,with 3 spatial replicates for each stocking rate treatment(4,8,and 13 sheep per paddock),corresponding to 2.7,5.3,and 8.7 sheep ha^(–1).The results showed that the neutral detergent fiber(NDF)and acid detergent fiber(ADF)contents of herbage varied between grazing years(P<0.05),with a positive correlation between stocking rate and crude fiber content in the herbage(P<0.05).Dry matter intake(DMI)decreased with increasing stocking rate(P<0.05),and the average daily gain(ADG)was highest at 2.7 sheep ha^(–1)(P<0.05).Compared to 2.7 and 8.7 sheep ha^(–1),the5.3 sheep ha^(–1)treatment exhibited the lowest nutrient digestibility for dry matter,nitrogen,and ether extract(P<0.05).Fecal nitrogen was lowest at 8.7 sheep ha^(–1)(P<0.05),while retained nitrogen as a proportion of nitrogen intake was highest.Digestive energy(DE),metabolic energy(ME),and the ratios of DE to gross energy(GE)and ME to GE were highest at 8.7 sheep ha^(–1)(P<0.05).In contrast,CH_4 emissions,CH_4 per DMI,and CH_(4)E as a proportion of GE were highest at 2.7 sheep ha^(–1)(P<0.05).Stocking rate and grazing year did not significantly affect rumen fermentation parameters,including volatile fatty acids,acetate,propionate,and the acetate/propionate ratio.At 8.7sheep ha^(–1),daily grazing time and inter-individual distance increased,while time allocated to grazing,walking,and ruminating/resting decreased as stocking rates increased(P<0.05).This study highlights the importance of adjusting stocking rates based on the nutritional value of forage and grazing year to optimize grazing management.展开更多
The treatment of ammonia nitrogen wastewater(ANW)has garnered significant attention due to the ecology,and even biology is under increasing threat from over discharge ANW.Conventional ANW treatment methods often encou...The treatment of ammonia nitrogen wastewater(ANW)has garnered significant attention due to the ecology,and even biology is under increasing threat from over discharge ANW.Conventional ANW treatment methods often encounter challenges such as complex processes,high costs and secondary pollution.Considerable progress has been made in employing solar-induced evaporators for wastewater treatment.However,there remain notable barriers to transitioning from fundamental research to practical applications,including insufficient evaporation rates and inadequate resistance to biofouling.Herein,we propose a novel evaporator,which comprises a bio-enzyme-treated wood aerogel that serves as water pumping and storage layer,a cost-effective multi-walled carbon nanotubes coated hydrophobic/hydrophilic fibrous nonwoven mat functioning as photothermal evaporation layer,and aggregation-induced emission(AIE)molecules incorporated as anti-biofouling agent.The resultant bioinspired evaporator demonstrates a high evaporation rate of 12.83 kg m−2 h−1 when treating simulated ANW containing 30 wt%NH4Cl under 1.0 sun of illumination.AIE-doped evaporator exhibits remarkable photodynamic antibacterial activity against mildew and bacteria,ensuring outstanding resistance to biofouling over extended periods of wastewater treatment.When enhanced by natural wind under 1.0 sun irradiation,the evaporator achieves an impressive evaporation rate exceeding 20 kg m−2 h−1.This advancement represents a promising and viable approach for the effective removal of ammonia nitrogen wastewater.展开更多
Nitrogen(N)is an essential nutrient for both plants and soil microbes,but it often has limited availability.Currently,little is known about the effects of different vegetation patch types on the partitioning of N betw...Nitrogen(N)is an essential nutrient for both plants and soil microbes,but it often has limited availability.Currently,little is known about the effects of different vegetation patch types on the partitioning of N between plants and soil microorganisms in grassland ecosystems.In the present study,we performed a^(15)N-labelling experiment(using^(15)N-NO_(3)^(-)and^(15)N-NH_(4)^(+))to investigate N uptake by plant biomass and microbial biomass for five common vegetation patch types in a degraded alpine steppe on the Tibetan Plateau,China.The results showed that plants and soil microorganisms in all patches showed a clear preference for the uptake of NO_(3)^(-).Plants in patches dominated by palatable species absorbed more N than plants in unpalatable species patches,while N uptake in the microbial biomass in unpalatable species patches was higher than that in palatable species patches.For the two soil depths,plants in Poa litwinowiana patches had the highest N uptake(NO_(3)^(-):13.32-51.28 mg m^(-2);NH_(4)^(+):0.35-1.36 mg m^(-2)),whereas microbial biomass in Oxytropis glacialis patches had the highest N uptake(NO_(3)^(-):846.97-1,659.87 mg m^(-2);NH_(4)^(+):108.75-185.14 mg m^(-2))among the five vegetation patch types.For both forms of N,soil microorganisms acquired relatively more N than the plants in the five vegetation patch types(i.e.,the ratio of microbial biomass N uptake to plant biomass N uptake was greater than 1).The N-absorbing capacity of plants decreased,whereas the capacity of soil microorganisms to take up N increased with the degradation of vegetation patches.Microorganisms that compete more strongly for N might reduce the uptake of nutrients by plants in degraded patches,which would not be conducive to the restoration of vegetation in N-limited alpine grasslands.展开更多
基金supported by the National Natural Science Foundation of China for Young Scholars(52109066)the Postdoctoral Science Foundation of Shaanxi Province,China(2023BSHTBZZ29)the China Postdoctoral Science Foundation(2022M712604 and 2023T160534).
文摘Soil nitrogen(N)is the main limiting nutrient for plant growth,which is sensitive to variations in the soil oxygen environment.To provide insights into plant N accumulation and yield under aerated and drip irrigation,a greenhouse tomato experiment was conducted with six treatments,including three fertilization types:inorganic fertilizer(NPK);organic fertilizer(OM);chemical(75%of applied N)+organic fertilizer(25%)(NPK+OM)under drip irrigation(DI)and aerated irrigation(AI)methods.Under Al,total soil carbon mineralization(C_(min))was significantly higher(by 5.7-7.0%)than under DI irrigation.C_(min)in the fertilizer treatments followed the order NPK+OM>OM>NPK under both AI and DI.Potentially mineralizable C(C_(0))and N(N_(0))was greater under AI than under DI.Gross N mineralization,gross nitrification,and NH_(4)^(+)immobilization rates were significantly higher under the AINPK treatment than the DINPK treatment by 2.58-3.27-,1.25-1.44-,and 1-1.26-fold,respectively.These findings demonstrated that AI and the addition of organic fertilizer accelerated the turnover of soil organic matter and N transformation processes,thereby enhancing N availability.Moreover,the combination of AI and organic fertilizer application was found to promote root growth(8.4-10.6%),increase the duration of the period of rapid N accumulation(ΔT),and increase the maximum N accumulation rate(V_(max)),subsequently encouraging aboveground dry matter accumulation.Consequently,the AI treatment yield was significantly greater(by 6.3-12.4%)than under the DI treatment.Further,N partial factor productivity(NPFP)and N harvest index(NHI)were greater under AI than under DI,by 6.3 to 12.4%,and 4.6 to 8.1%,respectively.The rankings of yield and NPFP remained consistent,with NPK+OM>OM>NPK under both AI and DI treatments.These results highlighted the positive impacts of AI and organic fertilizer application on soil N availability,N uptake,and overall crop yield in tomato.The optimal management measure was identified as the AINPK+OM treatment,which led to more efficient N management,better crop growth,higher yield,and more sustainable agricultural practices.
基金funded by the Basic Research Program of Jiangsu(Grant No.BK20230112)supported by the Key Research and Development Project of Jiangsu Province(Grant No.BE2019378)the High-level Scientific Research Foundation for the Introduction of Talent of Jinling Institute of Technology(Grant No.jit-b-201914,jit-b-202005).
文摘Good growth of tomato at the early growing stages is the key to final yield formation,for which water(W)and nitrogen(N)applications are two necessary factors.In this study,two irrigating systems(W1,W2)and three N applications(N1,N2,N3)were interacted(W×N)to plant the cherry tomato variety‘‘Jinling Meiyu’’in greenhouse.W1(reduced irrigation)and W2(normal irrigation)had a 7:9 irrigated ratio based on former research.N1,N2,and N3 were set at 100%,80%,and 60%normal N application,respectively.The tomato plant height(PH),stem circumference(SC),number of leaves(NL),number of first order fruits(NF),the single fruit weight(SFW),contents of fruit Vitamin C(VC)and soluble sugar(SS),fresh weights of root(RW),leaf(LW),and plant stem(PSW),as well as leaf chlorophyll fluorescence value(SPAD),temperature(T),humidity(RH),and nitrogen content(N)were investigated at the first flowering and fruiting stage.The results showed that W×N had significant impacts on early plant growth and fruit quality of tomato.W2N2 obviously received the largest values of tomato PH(152.5 cm),SC(4.1 cm),NF(11 fruits/plant),and LW(45.0 g/plant),but obtained the lowest VC(9.71 mg/kg)and SS(2.40%).However,W1N3 had the largest values of leaf RH(56.9%),N contents(14.23 mg/g),and VC(16.29 mg/kg),with NF also at 11.0 fruits/plant.W2N1 significantly had the highest RW(14.4 g/plant),PSW(71.8 g/plant),and SFW(21.3 g/fruit).W2N3,W1N1,and W1N2 obtained the most NL(103.7 pieces/plant),SS(4.06%),and leaf SPAD(36.85),respectively.Pearson correlation analysis results showed PH negatively significantly correlated with NF(p<0.05).The leaf SPAD positively significantly correlated with PH(p<0.05)and RH(p<0.01),but negatively significantly correlated with SC(p<0.05)and T(p<0.01).Moreover,leaf N content also had a positive significant correlation with PH(p<0.05),and an extremely positive significant correlation with RH and SPAD(p<0.01).However,it negatively significantly correlated with SC(p<0.01)and T(p<0.05).Significantly,VC had positive correlations with PSW,leaf SPAD,and N content(p<0.05).SS negatively correlated with PSW(p<0.05)and T(p<0.01),and extremely significantly positively correlated with SPAD(p<0.01).Additionally,RW had an extremely significant relationship with PSW(p<0.01).Two-factor analysis of variances showed W extremely significantly influenced leaf T,RH,SPAD,and N content(p<0.001),as well as SC(p<0.01)and SS(p<0.05).Meanwhile,N management extremely significantly influenced LW(p<0.001),RW(p<0.01),and leaf T(p<0.05).However,W×N obviously significantly influenced just PSW(p<0.01),RW(p<0.001),and VC(p<0.05).Taking all factors into account,the early reasonable W×N management could promote growth of tomato plants and fruit quality at the first fruiting and ripening stage.These results could provide a foundation for the subsequent growth of tomato fruits and could also be beneficial for the precise management of greenhouse tomatoes at the early growing stages.
基金supported by the National Natural Science Foundation of China(31860345 and 31460541)the Youth Innovative Top Talents Project of Shihezi University,China(CXBJ202003)the Third Division of Xinjiang Production and Construction Corps Scientific and Technological Achievements Transfer and Transformation Project,China(KJ2023CG03)。
文摘The responses of drip-irrigated rice physiological traits to water and fertilizers have been widely studied.However,the responses of yield,root traits and their plasticity to the nitrogen environment in different nitrogen-efficient cultivars are not fully understood.An experiment was conducted from 2020-2022 with a high nitrogen use efficiency(high-NUE)cultivar(T-43)and a low-NUE cultivar(LX-3),and four nitrogen levels(0,150,300,and 450 kg ha^(-1))under drip irrigation in large fields.The aim was to study the relationships between root morphology,conformation,biomass,and endogenous hormone contents,yield and NUE.The results showed three main points:1)Under the same N application rate,compared with LX-3,the yield,N partial factor productivity(PFP),fine root length density(FRLD),shoot dry weight(SDW),root indole-3-acetic acid(IAA),and root zeatin and zeatin riboside(Z+ZR)of T-43 were significantly greater by11.4-18.9,11.3-13.5,11.6-15.7,9.9-31.1,6.1-48.1,and 22.8-73.6%,respectively,while the root-shoot ratio(RSR)and root abscisic acid(ABA)were significantly lower(P<0.05);2)nitrogen treatment significantly increased the rice root morphological indexes and endogenous hormone contents(P<0.05).Compared to N0,the yield,RLD,surface area density(SAD),root volume density(RVD),and root endogenous hormones(IAA,Z+ZR)were significantly increased in both cultivars under N2 by 61.6-71.6,64.2-74.0,69.9-105.6,6.67-9.91,54.0-67.8,and 51.4-58.9%,respectively.Compared with N3,the PFP and N agronomic efficiency(NAE)of nitrogen fertilizer under N2 increased by 52.3-62.4 and39.2-63.0%,respectively;3)the responses of root trait plasticity to the N environment significantly differed between the cultivars(P<0.05).Compared with LX-3,T-43 showed a longer root length and larger specific surface area,which is a strategy for adapting to changes in the nutrient environment.For the rice cultivar with high-NUE,the RSR was optimized by increasing the FRLD,root distribution in upper soil layers,and root endogenous hormones(IAA,Z+ZR)under suitable nitrogen conditions(N2).An efficient nutrient acquisition strategy can occur through root plasticity,leading to greater yield and NUE.
文摘Climate change impacts soil nitrogen, influencing plant responses to elevated atmospheric [CO2]. Understanding the interaction between nitrogen supply and elevated [CO2] is crucial for predicting plant future performance. This study examined the interactive effects of elevated [CO2] and nitrogen supply on the eco-physiological performance of yellow birch. Seedlings were exposed to two [CO2] levels and five nitrogen supply levels for 4 months. Growth parameters such as seedling height and root collar diameter increased with higher nitrogen supply and elevated [CO2], while specific leaf area decreased. [CO2] elevation and increasing nitrogen supply also increased the total and stem, and leaf biomass. The elevated [CO2] increased the stem mass ratio but decreased the root-to-shoot ratio and root mass ratio. However, decreases in nitrogen supply increased root mass ratio and root-to-shoot ratio. The elevated [CO2] increased the maximum rate of Rubisco carboxylation (Vcmax) and photosynthetic electron transport (Jmax), but the effect on Jmax was statistically significant only at the two highest nitrogen supply levels. The results indicate that yellow birch may increase photosynthetic capacity, biomass, and growth in the future when [CO2] is higher.
基金supported by the National Natural Science Foundation of China(51609247)the Henan Provincial Natural Science Foundation,China(222300420589,202300410553)+4 种基金the Central Public-interest Scientific Institution Basal Research Fund,China(FIRI2022-22)the Science&Technology Fundamental Resources Investigation Program,China(2022FY101601)the Science and Technology Project of Xinxiang City,Henan Province,China(GG2021024)the Major Special Science and Technology Project of Henan Province,China(221100110700)the Joint Fund of Science and Technology Research and Development Plan of Henan Province,China(Superior Discipline Cultivation)(222301420104)。
文摘Nitrogen(N)uptake is regulated by water availability,and a water deficit can limit crop N responses by reducing N uptake and utilization.The complex and multifaceted interplay between water availability and the crop N response makes it difficult to predict and quantify the effect of water deficit on crop N status.The nitrogen nutrition index(NNI)has been widely used to accurately diagnose crop N status and to evaluate the effectiveness of N application.The decline of NNI under water-limiting conditions has been documented,although the underlying mechanism governing this decline is not fully understood.This study aimed to elucidate the reason for the decline of NNI under waterlimiting conditions and to provide insights into the accurate utilization of NNI for assessing crop N status under different water-N interaction treatments.Rainout shelter experiments were conducted over three growing seasons from 2018 to 2021 under different N(75 and 225 kg N ha^(-1),low N and high N)and water(120 to 510 mm,W0 to W3)co-limitation treatments.Plant N accumulation,shoot biomass(SB),plant N concentration(%N),soil nitrate-N content,actual evapotranspiration(ET_a),and yield were recorded at the stem elongation,booting,anthesis and grain filling stages.Compared to W0,W1 to W3 treatments exhibited NNI values that were greater by 10.2 to 20.5%,12.6to 24.8%,14 to 24.8%,and 16.8 to 24.8%at stem elongation,booting,anthesis,and grain filling,respectively,across the 2018-2021 seasons.This decline in NNI under water-limiting conditions stemmed from two main factors.First,reduced ET_(a) and SB led to a greater critical N concentration(%N_(c))under water-limiting conditions,which contributed to the decline in NNI primarily under high N conditions.Second,changes in plant%N played a more significant role under low N conditions.Plant N accumulation exhibited a positive allometric relationship with SB and a negative relationship with soil nitrate-N content under water-limiting conditions,indicating co-regulation by SB and the soil nitrate-N content.However,this regulation was influenced by water availability.Plant N accumulation sourced from the soil nitrate-N content reflects soil N availability.Greater soil water availability facilitated greater absorption of soil nitrate-N into the plants,leading to a positive correlation between plant N accumulation and ET_(a)across the different water-N interaction treatments.Therefore,considering the impact of soil water availability is crucial when assessing soil N availability under water-limiting conditions.The findings of this study provide valuable insights into the factors contributing to the decline in NNI among different water-N interaction treatments and can contribute to the more accurate utilization of NNI for assessing winter wheat N status.
基金supported by the National Natural Science Foundation of China(Nos.21978251,22102141 and U1904215)Natural Science Foundation of Jiangsu Province(No.BK20200044).
文摘In order to protect the environment and economize energy,a nitrogen-fixing photocatalyst,VMCeact,is investigated in this work.This catalyst is prepared from a natural mineral,vermiculite,and modified by Ce-based metal-organic framework,Ce-UiO-66.Vermiculite was treated with formic acid;thus,Ce-UiO-66 particles grew in-situ on vermiculite;then,Ce-UiO-66 particles were activated by ultraviolet irradiation.The vermiculite absorbed visible light with a narrow band gap,and transferred photogenerated electrons to the active sites on Ce-UiO-66.Moreover,the lamella structure of vermiculite protected Ce-UiO-66 during photocatalytic process.Therefore,with only 45.92 wt%of Ce-UiO-66,the nitrogen fixation performance of VMCeact was 2.29 times that of pure activated Ce-UiO-66 particles under 455nm light irradiation(apparent quantum efficiency of 4.49%),and retained at least 96.05%performance after 7×24 h of photocatalytic reaction.This cost-reduced,efficient and stable photocatalyst has the opportunity to facilitate environmentally friendly ammonia production.
基金funded by the European Union-NextGenerationEU under the Italian Ministry of University and Research(MUR)National Innovation Ecosystem grant ECS00000041-VITALITYThe University of Perugia is acknowledged for financial support to the university project“Fondo Ricerca di Ateneo,edizione 2021”and“Fondo Ricerca di Ateneo,edizione 2022”CSGI(Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase)for the support.
文摘Ammonia is nowadays one of the most important commodities chemicals intensively produced at about 175 million tons per year,contributing to 1.8%of the global energy demand.The constantly increasing NH3 demand also paralleleds by the high CO_(2) emissions associated with its production.Therefore,decarbonizing NH3 synthesis is one of the most urgent contemporary challenges.Taking inspiration from Nature,solar-driven nitrogen fixation under mild conditions is one of the most promising yet challenging alternatives to classic methods.In this review,we focused our attention on the photocatalytic methods for the synthesis of ammonia;in particular,we concentrated on stable and recyclable heterogeneous Fe-based photocatalysts for producing NH3.Indeed,recoverable and widely abundant and low-cost iron catalysts may represent a very promising tool for future sustainable access to this largely desired chemical target.After an overview of the pioneering works on Fe-driven nitrogen photofixation,the recent strategies on the use of Fe are herein reported.Compared with pristine photocatalysts,adding Fe as dopant or composite and heterojunction highly enhances the photocatalytic performances,opening the way to sustainable and low-cost nitrogen production.
基金supported by the National Natural Science Foundation of China(31572428)。
文摘The objectives of this study which included two experiments were to investigate the effects of dietary inclusion of sorghum grain rich in condensed tannins(CT)(18.9 g kg^(–1)dry matter(DM))on nitrogen(N)metabolism and urine nitrous oxide(N_(2)O)emissions of beef steers.In experiment 1,six Limousin×Luxi crossbreed steers with an initial liveweight of(245.0±18.7)kg were used as experimental animals.Three levels of sorghum grain,i.e.,0,167 and 338 g kg^(–1)DM were included in diets as experimental treatments.The animals and the treatments were randomly assigned to a replicated 3×3 Latin square design.In experiment 2,static incubation technique was used to determine the N_(2)O emissions of the urine samples collected in experiment 1.The results of experiment 1 showed that dietary inclusion of sorghum grain linearly increased the faecal N excretion(P=0.001),the total N excretion(P=0.010)and the faecal N to N intake ratio(P=0.021),but it did not affect the N retention and the N utilization efficiency(P>0.10).The plasma metabolomic data showed that dietary inclusion of sorghum grain increased the relative concentrations of phenolic acid(N1,N5,N10-tris-trans-p-coumaroylspermine and prenyl cis-caffeate)and carnitine(3-hydroxyisovalerylcarnitine and linoelaidyl carnitine).The results also showed that dietary inclusion of sorghum grain linearly increased the urinary urea excretion(P=0.010)and decreased the urinary excretion of purine derivatives(P=0.041)as well as the estimated rumen microbial N supply(P=0.012)based on urinary purine derivatives.The results of experiment 2 showed that including sorghum grain in the diet linearly increased the average concentrations of NH_(4)^(+)-N(P=0.012),NO_(2)^(–)-N(P=0.009),NO_(3)^(-)-N(P=0.001)and the total inorganic N(P<0.001)in the soil enriched with urine samples.The urine sample N_(2)O-N flux(P=0.001),the estimated steer urine N_(2)O-N flux(P=0.021)and the N_(2)O-N to urinary N ratio(P=0.038)linearly increased with increasing inclusion of sorghum grain in the diet.In conclusion,dietary inclusion of sorghum grain containing high CT at 167 and 338 g kg^(–1)DM did not affect the N utilization efficiency of steers but increased the urine N_(2)O-N emissions by 5.7 and 31.4%,respectively.For reducing the N_(2)O emissions to the environment,high levels of sorghum grain should not be included in the diet of steers.
基金supported by the Excellent Research and Innovation Team Project of Anhui Province(2022AH010001)。
文摘Electrochemical synthesis of ammonia represents a green and environmental-ly friendly method distinct from tradi-tional Harper-Bosch processes,which demand stringent conditions.However,identifying a catalyst with high selec-tivity and catalytic activity to cleave the robust triple bond of N_(2)remains a formidable challenge.Herein,we present a systematic study on the geo-metrical and electronic structure,intensity of N_(2)adsorption,reaction intermediates,change in Gibbs free energy,and desorption of by-product hydrazine for the nitrogen reduction reac-tion employing a MnNx-graphene(x=3,4)catalyst from a theoretical perspective.The com-putational results reveal that MnN3-graphene exhibits superior catalytic performance pre-dominantly via the distal mechanism,with a low potential of 0.49 V.Moreover,the detach-ment of the produced NH3 is facilitated with a free energy of only 0.27 eV,significantly lower than those of previous catalysts,ensuring the exceptional durability of MnN_(3)-graphene.This study offers theoretical insights guiding the exploration of single Mn atom catalysts in ammo-nia synthesis.
基金supported by the Key Research and Development Program of Shaanxi,China(2021NY-083)the National Natural Science Foundation of China(31871567)。
文摘The trade-off between yield and environmental effects caused by nitrogen fertilizer application is an important issue in wheat production.A reduction in fertile florets is one of the main reasons for the lower yields under low nitrogen application rates.Brassinosteroids(BRs)have been found to play a role in nitrogen-induced rice spikelet degeneration.However,whether BRs play a role in wheat floret development and the mechanisms involved are not clear.Therefore,a nitrogen gradient experiment and exogenous spraying experiment were conducted to investigate the role and mechanism of BRs in wheat floret development under low nitrogen stress.The results showed that as the nitrogen application decreased,the endogenous BRs content of the spikes decreased,photosynthesis weakened,and total carbon,soluble sugar and starch in the spikes decreased,leading to a reduction in the number of fertile florets.Under low nitrogen stress,exogenous spraying of 24-epibrassinolide promoted photosynthesis,and stimulated stem fructan hydrolysis and the utilization and storage of sucrose in spikes,which directed more carbohydrates to the spikes and increased the number of fertile florets.In conclusion,BRs mediate the effects of nitrogen fertilizer on wheat floret development,and under low nitrogen stress,foliar spraying of 24-epibrassinolide promotes the flow of carbohydrates from the stem to the spikes,alleviating wheat floret degeneration.
基金financially supported by the National Natural Science Foundation of China(No.21675131)the Volkswagen Foundation(Freigeist Fellowship No.89592)+1 种基金the Natural Science Foundation of Chongqing(No.2020jcyj-zdxmX0003,CSTB2023NSCQ-MSX0924)the National Research Foundation,Singapore,and A*STAR(Agency for Science Technology and Research)under its LCER Phase 2 Programme Hydrogen&Emerging Technologies FI,Directed Hydrogen Programme(Award No.U2305D4003).
文摘Ammonia and nitric acid,versatile industrial feedstocks,and burgeoning clean energy vectors hold immense promise for sustainable development.However,Haber–Bosch and Ostwald processes,which generates carbon dioxide as massive by-product,contribute to greenhouse effects and pose environmental challenges.Thus,the pursuit of nitrogen fixation through carbon–neutral pathways under benign conditions is a frontier of scientific topics,with the harnessing of solar energy emerging as an enticing and viable option.This review delves into the refinement strategies for scale-up mild photocatalytic nitrogen fixation,fields ripe with potential for innovation.The narrative is centered on enhancing the intrinsic capabilities of catalysts to surmount current efficiency barriers.Key focus areas include the in-depth exploration of fundamental mechanisms underpinning photocatalytic procedures,rational element selection,and functional planning,state-of-the-art experimental protocols for understanding photo-fixation processes,valid photocatalytic activity evaluation,and the rational design of catalysts.Furthermore,the review offers a suite of forward-looking recommendations aimed at propelling the advancement of mild nitrogen photo-fixation.It scrutinizes the existing challenges and prospects within this burgeoning domain,aspiring to equip researchers with insightful perspectives that can catalyze the evolution of cutting-edge nitrogen fixation methodologies and steer the development of next-generation photocatalytic systems.
基金funded by the National Key Research and Development Program of China(No.20022YFC3102405)the National Natural Science Foundation of China(Nos.42425004,32371665)the Natural Science Foundation of Guangdong Province(Nos.2022A1515011461,2022A1515011831)。
文摘Macroalgae dominate nutrient dynamics and function as high-value foods for microbial,meio-and macrofaunal communities in coastal ecosystems.Because of this vital role,it is important to clarify the physiological information associated with environmental changes as it reflects their growth potential.To evaluate the effects of the changes in salinity and nutrients,the photosynthetic efficiency of a green macroalga Ulva fasciata from the Daya Bay was tested at a range of salinity(i.e.,31 to 10 psu)and nitrogen content(i.e.,5 to 60μmol L^(-1)).The results showed that cellular chlorophyll a(Chl a),carbohydrate and protein contents of U.fasciata were increased due to reduced salinity,and were decreased by interactive nitrogen enrichment.Within a short culture period(i.e.,18 h),the reduced salinity decreased the maximum photosynthetic efficiency(rETRmax and Pmax)derived from the rapid light response curve and photosynthetic oxygen evolution rate versus irradiance curve,respectively,as well as the saturation irradiance(E_(K)).This reducing effect diminished with enlonged cultivation time and reversed to a stimulating effect after 24 h of cultivation.The nitrogen enrichment stimulated the rETRmax and Pmax,as well as the E_(K),regardless of salinity,especially within short-term cultivation period(i.e.,<24 h).In addition,our results indicate that seawater freshening lowers the photosynthetic efficiency of U.fasciata in the short term,which is mitigated by nitrogen enrichment,but stimulates it in the long term,providing insight into how macroalgae thrive in coastal or estuarine waters where salinity and nutrients normally covary strongly.
基金funded by the National Natural Science Foundation of China(No.22405173)the Shanghai Pujiang Program(No.23PJ1409100)the Project of Overseas Leading Talent of Shanghai.
文摘Electrochemical nitrogen transformation techniques represent a burgeoning avenue for nitrogen pollutant remediation and synthesizing valuable nitrogenous products from atmospheric nitrogen.Intermetallic compounds(IMCs)nanocrystals,featured with unique geometric,electronic and functional properties,have emerged as promising candidates.The review discusses various synthesis approaches for IMCs,including thermal annealing,wet chemical synthesis,electrochemical synthesis,and other emerging methods,analyzing their advantages and limitations.Then we summarized the recent advances of IMCs in electrocatalytic nitrogen transformation reactions,such as nitrate reduction reaction,nitric oxide reduction reaction,nitrogen reduction reaction,and hydrazine oxidation reaction.Despite significant progress,challenges remain in the field,particularly in adopting more refined strategies to improve catalyst performance and stability.This review aims to comprehensively understand the structural properties of IMCs and their structure-performance relationship,guiding the development of more efficient and stable catalysts for future nitrogen electrochemistry.
基金the National Key Research and Development Program of China(2022YFD1500705)National Natural Science Foundation of China(U19A2035)for financial support。
文摘Strip-till(ST),including straw mulching in the inter-row and localized fertilization in the intra-row,is a conservation tillage system for improving soil quality and crop growth.However,the yield advantage of maize under ST compared to conventional tillage(CT)remains unstable,and the strategies to increase maize yield under ST are unclear.This study aims to understand the physiological mechanism underlining maize yield formation under ST by comparing two maize cultivars,DKM753 and DK517,with contrasting yield performance in ST versus CT systems.Compared to CT,ST resulted in a 4.5%yield increase for DKM753 but a 5.6%decrease for DK517.These yield differences were primarily attributed to variations in grain number per ear(GN).During the rapid growth stage(V14-R3),i.e.,two weeks before and after silking,DKM753 showed a 6.7%increase in maximum growth rate(V_(max))and a 6.3%increase in average growth rate(V)under ST,whereas DK517 exhibited decline of 8.5%in V_(max) and 12.3%in V.Significant positive correlations are observed between V_(max) and V with GN under ST(R^(2)=0.79 and R^(2)=0.90,respectively).Enhanced dry matter accumulation in DKM753 under ST was attributed to increased leaf expansion rates,contributing to a larger photosynthate source.The straw mulching and localized nitrogen fertilization increased root-zone nitrogen availability at silking in ST compared to CT.DKM753 had a greater root system which made better use of the soil N and lead to an increased leaf nitrogen accumulation by 14.9%under ST.It is concluded that maize yield under the strip-till system is determined by grain number per ear,which can be increased by increasing nitrogen accumulation,plant growth,and ear development around silking stage.A sound root system can efficiently utilize soil nitrogen resources under the strip-till system,increasing plant nitrogen accumulation and thereby promoting plant growth.
基金supported by Natural Science Foundation of Shandong Province(Nos.ZR2022YQ42,ZR2021JQ15,ZR2021QE011,ZR2021ZD20,2022GJJLJRC-01)Innovative Team Project of Jinan(No.2021GXRC019)the National Natural Science Foundation of China(Nos.52022037,52202366).
文摘In contrast to research on active sites in nanomaterials,lithium tantalate single crystals,known for their exceptional optical properties and long-range ordered lattice structure,present a promising avenue for in-depth exploration of photocatalytic reaction systems with fewer constraints imposed by surface chemistry.Typically,the isotropy of a specific facet provides a perfect support for studying heteroatom doping.Herein,this work delves into the intrinsic catalytic sites for photocatalytic nitrogen fixation in iron-doped lithium tantalate single crystals.The presence of iron not only modifies the electronic structure of lithium tantalate,improving its light absorption capacity,but also functions as an active site for the nitrogen adsorption and activation.The photocatalytic ammonia production rate of the iron-doped lithium tantalate in pure water is maximum 26.95μg cm^(−2)h^(−1),which is three times higher than that of undoped lithium tantalate.The combination of first-principles simulations with in situ characterizations confirms that iron doping promotes the rate-determining step and changes the pathway of hydrogenation to associative alternating.This study provides a new perspective on in-depth investigation of intrinsic catalytic active sites in photocatalysis and other catalytic processes.
基金supported by the National Natural Science Foundation of China(52321005)the Guangdong Basic and Applied Basic Research Foundation(2023A1515012383 and 2024A1515030138)+1 种基金the State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology,2021TS30)the Shenzhen Science and Technology Program(KQTD20190929172630447 and KCXFZ20211020163404007).
文摘Constructed wetlands(CWs)are a promising method to treat effluent from wastewater treatment plants(WWTPs).However,low carbon/nitrogen(C/N)ratios of the influent inhibit denitrification in CWs,resulting in poor nitrogen removal efficiency.Herein,we compared traditional(control),biochar(BC),and b-cyclodextrin-functionalized biochar(BC@b-CD)CW systems to investigate nitrogen removal from influent with low C/N ratios,and the mechanisms that enhance this process.The highest nitrogen removal rates were observed in the BC@b-CD group,with rates 45.89%and 42.48%higher than those of the control,accompanied by a 70.57%and 85.45%decrease in nitrous oxide release,when the C/N ratio decreased from 4 to 2,respectively.Metagenomic and enzymatic analyses indicated that BC@b-CD enhances nitrogen removal by coordinately promoting carbon metabolism and increasing denitrification enzyme activities,without affecting microbial species diversity in CWs.Structural equation modeling confirmed that the foremost advantages of BC@b-CD were effective electron generation and transportation resulting from increased activities of nicotinamide adenine dinucleotide(NADH)dehydrogenase and the electron transfer system(ETS),thereby strategically reallocating more carbon metabolic flow to support denitrification.Our results show that the application of BC@b-CD in CWs to optimize the reallocation of electrons from carbon metabolism is a feasible strategy to enhance denitrification under low C/N conditions.
基金financial support from the National Key Research and Development Program of China(Grant No.2023YFD220120302)supported by RUDN University Strategic Academic Leadership Program。
文摘The role of brassinosteroids(BRs)in enabling plants to respond effectively to adverse conditions is well known,though the precise mechanism of action that helps plants cope with arsenic(As)toxicity is still difficult to interpret.Therefore we tested the effect of brassinolide(BL)spray(0,0.5,and 1 mg·L^(-1))on As(0,and 10 mg·L^(-1))stressed tomato defense responses As stress led to the induction of oxidative stress,impaired chlorophyll and nitrogen metabolism,and Fe uptake,in conjunction with a reduction in plant growth and biomass.BL spray,on the contrary,protected the photo synthetic system and helped plants grow better under As stress.This was achieved by controlling the metabolism of chlorophyll and proline and lowering the amounts of methylglyoxal and H_(2)O_(2) through glyoxalaseⅠandⅡand antioxidant enzyme s.BL decreased arsenic accumulation by directing As sequestration towards vacuoles and increased Fe amount in the leaves and roots by regulating the expression of As(Lsil and Lsi2)and Fe(IRT1,IRT2,NRAMP1,and NRAMP3)transporters in As-stressed tomatoes.Furthermore,BL boosted adaptability against As phytotoxicity,while reducing the damaging impacts on photosynthesis,nitrogen metabolism,sulfur asimilation,and Fe absorption.These results offer a solid framework for the development of exogenous BRs-based breeding strategies for safer agricultural development.
基金supported by the National Natural Science Foundation of China(32161143028)the Key Technology of Grassland Ecological Civilization Demonstration Area in Ningxia Hui Autonomous Region,China(20210239)the Northwest Shelterbelt Construction Bureau of the National Forestry and Grassland Administration,China。
文摘Understanding livestock performance in typical steppe ecosystems is essential for optimizing grassland-livestock interactions and minimizing environmental impact.To assess the effects of different stocking rates on the growth performance,energy and nitrogen utilization,methane(CH_(4))emissions,and grazing behavior of Tan sheep,a 2-year grazing experiment in the typical steppe was conducted.The grazing area was divided into 9 paddocks,each 0.5 ha,with 3 spatial replicates for each stocking rate treatment(4,8,and 13 sheep per paddock),corresponding to 2.7,5.3,and 8.7 sheep ha^(–1).The results showed that the neutral detergent fiber(NDF)and acid detergent fiber(ADF)contents of herbage varied between grazing years(P<0.05),with a positive correlation between stocking rate and crude fiber content in the herbage(P<0.05).Dry matter intake(DMI)decreased with increasing stocking rate(P<0.05),and the average daily gain(ADG)was highest at 2.7 sheep ha^(–1)(P<0.05).Compared to 2.7 and 8.7 sheep ha^(–1),the5.3 sheep ha^(–1)treatment exhibited the lowest nutrient digestibility for dry matter,nitrogen,and ether extract(P<0.05).Fecal nitrogen was lowest at 8.7 sheep ha^(–1)(P<0.05),while retained nitrogen as a proportion of nitrogen intake was highest.Digestive energy(DE),metabolic energy(ME),and the ratios of DE to gross energy(GE)and ME to GE were highest at 8.7 sheep ha^(–1)(P<0.05).In contrast,CH_4 emissions,CH_4 per DMI,and CH_(4)E as a proportion of GE were highest at 2.7 sheep ha^(–1)(P<0.05).Stocking rate and grazing year did not significantly affect rumen fermentation parameters,including volatile fatty acids,acetate,propionate,and the acetate/propionate ratio.At 8.7sheep ha^(–1),daily grazing time and inter-individual distance increased,while time allocated to grazing,walking,and ruminating/resting decreased as stocking rates increased(P<0.05).This study highlights the importance of adjusting stocking rates based on the nutritional value of forage and grazing year to optimize grazing management.
基金supported by the National Natural Science Foundation of China(52203226)the Fundamental Research Funds for the Central Universities(2232023G-06).
文摘The treatment of ammonia nitrogen wastewater(ANW)has garnered significant attention due to the ecology,and even biology is under increasing threat from over discharge ANW.Conventional ANW treatment methods often encounter challenges such as complex processes,high costs and secondary pollution.Considerable progress has been made in employing solar-induced evaporators for wastewater treatment.However,there remain notable barriers to transitioning from fundamental research to practical applications,including insufficient evaporation rates and inadequate resistance to biofouling.Herein,we propose a novel evaporator,which comprises a bio-enzyme-treated wood aerogel that serves as water pumping and storage layer,a cost-effective multi-walled carbon nanotubes coated hydrophobic/hydrophilic fibrous nonwoven mat functioning as photothermal evaporation layer,and aggregation-induced emission(AIE)molecules incorporated as anti-biofouling agent.The resultant bioinspired evaporator demonstrates a high evaporation rate of 12.83 kg m−2 h−1 when treating simulated ANW containing 30 wt%NH4Cl under 1.0 sun of illumination.AIE-doped evaporator exhibits remarkable photodynamic antibacterial activity against mildew and bacteria,ensuring outstanding resistance to biofouling over extended periods of wastewater treatment.When enhanced by natural wind under 1.0 sun irradiation,the evaporator achieves an impressive evaporation rate exceeding 20 kg m−2 h−1.This advancement represents a promising and viable approach for the effective removal of ammonia nitrogen wastewater.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program,China(2019QZKK0404)the National Natural Science Foundation of China(42271070)+1 种基金the West Light Scholar of Chinese Academy of Sciences(xbzg-zdsys-202202)the Technology Major Project of Tibetan Autonomous Region of China(XZ202201ZD0005G01)。
文摘Nitrogen(N)is an essential nutrient for both plants and soil microbes,but it often has limited availability.Currently,little is known about the effects of different vegetation patch types on the partitioning of N between plants and soil microorganisms in grassland ecosystems.In the present study,we performed a^(15)N-labelling experiment(using^(15)N-NO_(3)^(-)and^(15)N-NH_(4)^(+))to investigate N uptake by plant biomass and microbial biomass for five common vegetation patch types in a degraded alpine steppe on the Tibetan Plateau,China.The results showed that plants and soil microorganisms in all patches showed a clear preference for the uptake of NO_(3)^(-).Plants in patches dominated by palatable species absorbed more N than plants in unpalatable species patches,while N uptake in the microbial biomass in unpalatable species patches was higher than that in palatable species patches.For the two soil depths,plants in Poa litwinowiana patches had the highest N uptake(NO_(3)^(-):13.32-51.28 mg m^(-2);NH_(4)^(+):0.35-1.36 mg m^(-2)),whereas microbial biomass in Oxytropis glacialis patches had the highest N uptake(NO_(3)^(-):846.97-1,659.87 mg m^(-2);NH_(4)^(+):108.75-185.14 mg m^(-2))among the five vegetation patch types.For both forms of N,soil microorganisms acquired relatively more N than the plants in the five vegetation patch types(i.e.,the ratio of microbial biomass N uptake to plant biomass N uptake was greater than 1).The N-absorbing capacity of plants decreased,whereas the capacity of soil microorganisms to take up N increased with the degradation of vegetation patches.Microorganisms that compete more strongly for N might reduce the uptake of nutrients by plants in degraded patches,which would not be conducive to the restoration of vegetation in N-limited alpine grasslands.
