In order to establish methods for indentification and screening of rice genotypes with high nitrogen （N） efficiency, N absorption efficiency （NAE）, N utilization efficiency （NUE） and N harvest index （NHI） in t...In order to establish methods for indentification and screening of rice genotypes with high nitrogen （N） efficiency, N absorption efficiency （NAE）, N utilization efficiency （NUE） and N harvest index （NHI） in ten rice genotypes were investgated at the elongation, booting, heading and maturity stages under six N levels in a pot experiment with soil-sand mixtures at various ratios. NAE in various rice genotypes firstly increased, peaked under a medium nitrogen rate of 0.177 g/kg and then decreased, but NUE and NHI always decreased with increasing nitrogen levels. NAE in various rice genotypes ever increased with growing process and NUE indicated a descending tendency of elongation stage〉heading stage〉maturity stage〉booting stage. N level influenced rice NAE, NUE and NHI most, followed by genotype, and the both effects were significant at 0.01 level. In addition, the interaction effects of genotype and nitrogen level on rice NAE and NUE were significant at 0.01 level, but not significant on rice NHI. Because the maximum differences of NAE and NUE were found at the elongation stage, it was thought to be the most suitable stage for identification and screening these two paremeters. Therefore, the optimum conditions for identification and screening of rice NAE, NUE and NHI in a pot experiment were the nitrogen rate of 0.157 g/kg at the elongation stage, low nitrogen at the elongation stage, and the nitrogen rate of 0.277 g/kg at the maturity stage, respectively.展开更多
Background:Protein releases amino acids faster than starch releases glucose in digestive tract of pigs fed lowprotein(LP)diets.Poor synchronization of dietary glucose and amino acids supply leads to compromised nitrog...Background:Protein releases amino acids faster than starch releases glucose in digestive tract of pigs fed lowprotein(LP)diets.Poor synchronization of dietary glucose and amino acids supply leads to compromised nitrogen efficiency.Dietary starch patterns modulation may improve this situation.Methods:Growing barrows(29.7±2.0 kg)were randomly allotted into 5 dietary treatments with LP diets consisting of different purified starches.Treatments included:waxy corn starch(W LP),corn starch+waxy corn starch(C+W LP),corn starch(C LP),pea starch+waxy corn starch(P+W LP)and pea starch(P LP).In the experiment,growth performance,protein deposition,nutrient metabolism,and fecal microbial community of pigs were investigated.In vitro starch digestion was used for predicting the in vivo glucose response.Results:Dietary starch in vitro glucose release profile was determined by starch source and the ratio of amylopectin and amylose.C+W LP treatment showed decreased total nitrogen excretion and plasma citrulline concentration and improved plasma leptin concentration among treatments(P<0.05).Besides,the highest nitrogen apparent biological value,whole-body protein deposition and growth performance and lowest urinary nitrogen excretion were also observed in C+W LP treatment.Compared with the other groups,C+W LP and C LP showed increased plasma pyruvate,IGF-1,and lipase concentrations(P<0.05).The W LP group presented dramatically increased plasma alanine and urea nitrogen concentration and decreased aldolase and leptin concentrations(P<0.05).Dietary starch patterns did not make an impact on bacterial richness and diversity,but changed the taxonomic and functional structures of the microbial communities.Microbial protein fermentation product(isobutyrate and isovalerate)presented increased in P LP treatments compared with the other treatments(P<0.05).Conclusions:Dietary starch patterns modulation can regulate dietary glucose release profile,nutrient metabolism,protein turnover,and fecal microbial fermentation in pigs.The optimal dietary glucose release profile effectively strengthened whole-body protein deposition and improve nitrogen efficiency and growth performance in growing pigs fed LP diets.展开更多
There are significant differences in nitrogen absorption and utilization effi- ciency among different maize varieties. So it is very essential to determine nitrogen efficiencies of different maize varieties. The effec...There are significant differences in nitrogen absorption and utilization effi- ciency among different maize varieties. So it is very essential to determine nitrogen efficiencies of different maize varieties. The effect of nitrogen application on maize growth can be reflected at the grain filling stage. Many scholars have researched the differences in grain filling characteristics among different maize varieties under the same nitrogen application conditions, but there are reare reports on the differ- ences under different nitrogen application conditions. In this study, the grain filling dynamics of maize were observed so as to determine the differences in nitrogen efficiency and to further compare the differences in grain filling characteristics a- mong different maize varieties. The test was carried out with Tunyu 99, Luyu 19 and Xianyu 335 as the materials during May 1st to October 7th, 2013. Under the nitrogen application levels of NO （0 kg/hm2 of pure nitrogen）, N1 （140 kg/hm2 of pure nitrogen） and N2 （210 kg/hm2 of pure nitrogen）, the filling dynamics of upper- and middle- lower-part grains of spring maize were studied. The results showed that among the three nitrogen application level, the grain fresh weight and dry weight of Tunyu 99 ranked as N2〉NI〉N0; the grain fresh weight and dry weight of Luyu 19 ranked as N1〉N2〉N0; the grain fresh weight and dry weight of Xianyu 335 ranked as （N1, N2）〉N0, and there was no significant difference between N1 and N2. Un- der the nitrogen application level of N1, Luyu 19 showed the best growth; under the nitrogen application level of N2, Tunyu 99 showed the best growth, The growth ad- vantage of Xianyu 335 was unobvious under neither N1 nor N2 nitrogen application levels. The development-promoting effect of nitrogen application was more obvious in upper-part grains than that in middle-lower-part grains.展开更多
The increase in soil temperature associated with climate change has introduced considerable challenges to crop production.Split nitrogen application(SN)represents a potential strategy for improving crop nitrogen use e...The increase in soil temperature associated with climate change has introduced considerable challenges to crop production.Split nitrogen application(SN)represents a potential strategy for improving crop nitrogen use efficiency and enhancing crop stress resistance.Nevertheless,the precise interaction between soil warming(SW)and SN remains unclear.In order to ascertain the impact of SW on maize growth and whether SN can improve the tolerance of maize to SW,a two-year field experiment was conducted(2022-2023).The aim was to examine the influence of two SW ranges(MT,warming 1.40℃;HT,warming 2.75℃)and two nitrogen application methods(N1,one-time basal application of nitrogen fertilizer;N2,one third of base nitrogen fertilizer+two thirds of jointing stage supplemental nitrogen fertilizer)on maize root growth,photosynthetic characteristics,nitrogen use efficiency,and yield.The results demonstrated that SW impeded root growth and precipitated the premature aging of maize leaves following anthesis,particularly in the HT,which led to a notable reduction in maize yield.In comparison to N1,SN has been shown to increase root length density by 8.54%,root bleeding rate by 8.57%,and enhance root distribution ratio in the middle soil layers(20-60 cm).The interaction between SW and SN had a notable impact on maize growth and yield.The SN improved the absorption and utilization efficiency of nitrogen by promoting root development and downward canopy growth,thus improving the tolerance of maize to SW at the later stage of growth.In particular,the N2HT resulted in a 14.51%increase in the photosynthetic rate,a 18.58%increase in nitrogen absorption efficiency,and a 18.32%increase in maize yield compared with N1HT.It can be posited that the SN represents a viable nitrogen management measure with the potential to enhance maize tolerance to soil high-temperature stress.展开更多
Long-term excessive nitrogen(N)application neither increases nor enhances grain yield and N use efficiency(NUE)of maize,yet the mechanisms involving root morphological and physiological characteristics remain unclear....Long-term excessive nitrogen(N)application neither increases nor enhances grain yield and N use efficiency(NUE)of maize,yet the mechanisms involving root morphological and physiological characteristics remain unclear.This study aimed to elucidate the mechanisms underlying stagnant grain yield under excessive N application by examining root morphological and physiological characteristics.A 10-year N fertilizer trial was conducted in Jilin Province,Northeast China,cultivating maize at three N fertilizer levels(zero N,N0;recommended N,N2;and high N level,N4)from 2019 to 2021.Two widely cultivated maize genotypes,‘Xianyu 335’(XY335)and‘Zhengdan 958’(ZD958),were evaluated.Grain yield,N content,root morphology,and physiological characteristics were analyzed to assess the relationships between N uptake,N utilization,plant growth,and root systems under different N treatments.Compared to N0,root biomass,post-silking N uptake,and grain yield improved significantly with increased N input,while no significant differences emerged between recommended N and high N.High N application enhanced root length and root surface area but decreased root activity(measured by TTC(2,3,5-triphenyltetrazolium chloride)method),nitrate reductase activity,and root activity absorbing area across genotypes.Root length and root to shoot ratio negatively affected N uptake(by-1.2 and-24.6%),while root surface area,root activity,nitrate reductase activity,and root activity absorbing area contributed positively.The interaction between cultivar and N application significantly influenced NUE.XY335 achieved the highest NUE(11.6%)and N recovery efficiency(18.4%)through superior root surface area(23.6%),root activity(12.5%),nitrate reductase activity(8.3%),and root activity absorbing area(6.9%)compared to other treatments.Recommended N application enhanced Post N uptake,NUE,and grain yield through improved root characteristics,while high N application failed to increase or decreased NUE by reducing these parameters.This study demonstrates that root surface area,root activity,nitrate reductase activity,and root activity absorbing area limit NUE increase under high N application.展开更多
Elucidating crops'physiological and molecular mechanisms to adapt to low nitrogen environment and promoting nitrogen transfer from senescent leaves to new leaves is crucial in improving Brassica's nitrogen use...Elucidating crops'physiological and molecular mechanisms to adapt to low nitrogen environment and promoting nitrogen transfer from senescent leaves to new leaves is crucial in improving Brassica's nitrogen use efficiency(NUE).Glutamine synthetase gene(GS)plays a vital role in helping plants reassimilate ammonium released from protein degradation in leaves,and it was the focus of our research on this topic.In this study,we identified high(H141)and low(L65)NUE genotypes of Brassica juncea with different responses to low-nitrogen stress.We found that H141 has a lower nitrate content but higher ammonium and free amino acid contents as well as higher nitrate reductase and GS activities in the shoots.These physiological indicators are responsible for the high NUE of H141.Wholegenome resequencing data revealed that 5,880 genes associated with NUE are polymorphic between H141 and L65.These genes participate in various amino acid,carbohydrate,and energy metabolic pathways.Haplotype analysis revealed two haplotypes for BjuB05.GS1.4,Hap1 and Hap2,which have multiple single nucleotide polymorphisms or insertions/deletions in the regulatory regions of the 5′and 3′untranslated regions and introns.Furthermore,the shoot NUE of Hap1 is significantly lower than that of Hap2.These two haplotypes of BjuB05.GS1.4 lead to differences in the shoot NUEs of different genetic populations of mustard and are associated with the local soil nitrogen content,suggesting that they might help mustard to adapt to different geographic localities.In conclusion,the results of our study shed light on the physiological and molecular mechanisms underlying different mustard NUE genotypes and demonstrate the enormous potential of NUE breeding in B.juncea.展开更多
The well-facilitated farmland projects(WFFPs)involve the typical sustainable intensification of farmland use and play a key role in raising food production in China.However,whether such WFFPs can enhance the nitrogen(...The well-facilitated farmland projects(WFFPs)involve the typical sustainable intensification of farmland use and play a key role in raising food production in China.However,whether such WFFPs can enhance the nitrogen(N)use efficiency and reduce environmental impacts is still unclear.Here,we examined the data from 502 valid questionnaires collected from WFFPs in the major grain-producing area,the Huang-Huai-Hai Region(HHHR)in China,with 429 samples for wheat,328 for maize,and 122 for rice.We identified gaps in N use efficiency(NUE)and N losses from the production of the three crops between the sampled WFFPs and counties based on the statistical data.The results showed that compared to the county-level(wheat,39.1%;maize,33.8%;rice,35.1%),the NUEs for wheat(55.2%),maize(52.1%),and rice(50.2%)in the WFFPs were significantly improved(P<0.05).In addition,the intensities of ammonia(NH3)volatilization(9.9-12.2 kg N ha–1),N leaching(6.5-16.9 kg N ha–1),and nitrous oxide(N2O)emissions(1.2-1.6 kg N ha–1)from crop production in the sampled WFFPs were significantly lower than the county averages(P<0.05).Simulations showed that if the N rates are reduced by 10.0,15.0,and 20.0%for the counties,the NUEs of wheat,maize,and rice in the HHHR will increase by 2.9-6.3,2.4-5.2,and 2.6-5.7%,respectively.If the N rate is reduced to the WFFP level in each county,the NUEs of the three crops will increase by 12.9-19.5%,and the N leaching,NH3,and N2O emissions will be reduced by 48.9-56.2,37.4-42.9,and 46.0-66.5%,respectively.Our findings highlight that efficient N management practices in sustainable intensive farmland have considerable potential for reducing environmental impacts.展开更多
[Objective]The aim was to study heterosis of N use efficiency for grain production （NUEg） of Brassica napus L. and provide theoretical basis for breeding N-efficient cultivars. [Method]Dry matter production and N co...[Objective]The aim was to study heterosis of N use efficiency for grain production （NUEg） of Brassica napus L. and provide theoretical basis for breeding N-efficient cultivars. [Method]Dry matter production and N content of six B.napus parents （Zheshuang 3,Yangyou 7,ZJ1,Shilijia,Ningyou 14 and Huyou 16） and their F1 combinations from 6 × 6 complete diallel cross in maturity stage under two N levels were measured; heterosis of NUEg,combining ability and heritability size were analyzed and calculated. [Result]The results showed that NUEg has obvious heterosis; combining ability variance analysis indicated that NUEg was mainly controlled by additive,dominant and cytoplasmic effects; genetic variance analysis showed that additive effects and dominance effects were all significant in low nitrogen fertilizer and dominance effects were significant in high nitrogen fertilizer. [Conclusion]NUEg of B.napus has obvious heterosis.展开更多
[Objective] The study aimed at investigating the effects of different geographic sites,soil chemical characteristics and nitrogen application levels on nitrogen accumulation and distribution in different organs and ut...[Objective] The study aimed at investigating the effects of different geographic sites,soil chemical characteristics and nitrogen application levels on nitrogen accumulation and distribution in different organs and utilization efficiency for mid-season hybrid rice.[Method] By using mid-season rice varieties II-you 7 and Yuxiangyou203 as the experimental materials,field experiment was conducted at seven ecological sites in four provinces or cities in Southwestern China in 2009.A total of four nitrogen application levels were set as follows：by using 75 kg/hm2 of P2O5 and 75 kg/hm2 of K2O as the base fertilizer,extra 0,90,150 and 210 kg/hm2 of nitrogen fertilizer（in which,base fertilizer,base-tillering fertilizer and base-earing fertilizer respectively accounted for 60%,20% and 20%.） was applied,respectively.In the split-plot design,fertilizer was considered as the main factor while rice variety was taken as the secondary factor.A total of eight treatments were set with three replications.[Result] Highly significant differences of grain yield were found among seven locations,two varieties,four nitrogen application levels,interactions of site × variety and site × nitrogen application level,but the interaction of variety ×nitrogen application level had no significant influence on rice yield.There were highly significant effects of site,varieties and nitrogen application level on dry matter production,nitrogen content,nitrogen utilization efficiency.Highly significant negative correlations between uptake efficiency and utilization efficiency for nitrogen were found;and multiple stepwise regression analysis showed that nitrogen uptake-utilization efficiency were significantly influenced by different ecological sites,chemical quality of soil and the levels of nitrogen application.[Conclusion] The research will provide theoretical and practical basis for the highly efficient application of nitrogen in mid-season hybrid rice cultivation.展开更多
The field experiments were conducted in Anhui during 2016 to investigate the effects of controlled-release nitrogen （CRN） rates and mixture of controlled-re- lease nitrogen and conventional nitrogen （CN） on the yi...The field experiments were conducted in Anhui during 2016 to investigate the effects of controlled-release nitrogen （CRN） rates and mixture of controlled-re- lease nitrogen and conventional nitrogen （CN） on the yield and nitrogen efficiency of summer maize. Six treatments included CK （with no application of N）, CNIO0% splits （CN）, CRFIO0% （CRN1）, CRN60%＋CN40% （CRN2）, CRN85% （CRN3） and CRN70% （CRN4）. The results showed proper CRN increased yields and output val- ue. Compared with CN, CRN2 significantly increased by 13.74%, CRN1 increased by 4.84%, and CRN3 was equal to CN. CRN increased yield by grain number per spike of yield components. CRN2 had the highest apparent nitrogen fertilizer recov- ery efficiency and CRN1 was the second, which were significantly higher than CN. Nitrogen agronomic efficiency of CRN2 was significantly higher than CN. Nitrogen physiological efficiency of CRN2 was higher than CN. The partial productivity of CRN1 was higher than that with CN. And the effect of nitrogen fertilizer of CRN2 was the highest, which was increased 758 yuan/hm2. Considering yield, nitrogen use efficiency and economic benefit, applying the mixture of CRN and CN was the most beneficial treatment. CRN1 was the second treatment, and CRN3 didn＇t reduce yield.展开更多
[Objective] This study and nitrogen use efficiency in aimed to investigate the nitrogen dynamic changes maize under different nitrogen application patterns. [Method] Maize cultivar Xianyu 335 was selected as the expe...[Objective] This study and nitrogen use efficiency in aimed to investigate the nitrogen dynamic changes maize under different nitrogen application patterns. [Method] Maize cultivar Xianyu 335 was selected as the experimental material and was planted at two densities 85 000 and 95 000 plants/hm2. The total amount of fertilizers applied kept constant. The nitrogen content in leaves, stems, sheathes, husks, grains, cobs, tassels and filaments of maize plants in jointing stage, silking stage, 15, 30, 45 and 60 d after silking stage was measured. [Result] Total nitrogen content in maize plant reached the peak around 45 d after silking stage and a higher population was helpful to nitrogen accumulation. Total nitrogen content of maize plant was positively correlated with yield and it got closer in higher popula- tion. Grain nitrogen content and nitrogen harvest index were significantly positively correlated with yield in higher population. High ratio of nitrogen fertilizer in silking stage was beneficial to nitrogen accumulation in leaf and ear, as well as nitrogen translocation in stem and sheath, but high ratio of nitrogen fertilizer in earlier stage delayed nitrogen metabolism. Nitrogen uptake peak was from silking stage to 15 d after silking stage, and nitrogen uptake rate increased high ratio of nitrogen fertilizer was applied in later growth stages and moved forward in higher plant population. [Conclusion] It was advantaged for nitrogen fertilizer efficiency on condition that ni- trogen application was moved backward. Accumulating too much nitrogen in earlier stages inhibited nitrogen uptake in later periods展开更多
ln order to explore the effect of broadcast application of urea （BR-U） and surface concentrated-fertilization on grain yield and nitrogen agronomy efficiency of two-line super hybrid rice, this experiment was conduc...ln order to explore the effect of broadcast application of urea （BR-U） and surface concentrated-fertilization on grain yield and nitrogen agronomy efficiency of two-line super hybrid rice, this experiment was conducted with super hybrid rice Y-Liangyou 1 and Liangyou 0293 to determine til ering dynamics, SPAD, LAl and dry matter accumulation. lts total N application was 180 kg/hm2 and different application rate and topdressing methods were set respectively. The results showed that grain yield and nitrogen agronomy efficiency were significantly improved with the T3 and T4 nitrogenous fertilizer application model. The improving of grain yield and nitrogen agronomy efficiency was benefited from rational postponing N application. However, neither single application of base fertilizer （T2） nor single application of topdressing fertilizer （T5 and T6） can coordinate the relationship between source and sink. Both grain yield and nitrogen agronomy efficiency were insignificantly under the broadcast application of urea and surface concentrated fertilization.展开更多
In 1996, a mega project that aimed to develop rice varieties with super-high yield potential （super rice） was launched by the Ministry of Agriculture （MOA） in China using a combination of the ideotype approach and...In 1996, a mega project that aimed to develop rice varieties with super-high yield potential （super rice） was launched by the Ministry of Agriculture （MOA） in China using a combination of the ideotype approach and intersubspecific heterosis. Significant progress has been made in the last two decades, with a large number of super rice varieties being approved by the MOA and the national average grain yield being increased from 6.21 t ha^-1 in 1996 to 6.89 t ha^-1 in 2015. The increase in yield potential of super rice was mainly due to the larger sink size which resulted from larger panicles. Moreover, higher photosynthetic capacity and improved root physiological traits before heading contributed to the increase in sink size. However, the poor grain filling of the later-flowering inferior spikelets and the quickly decreased root activity of super rice during grain filling period restrict the achievement of high yield potential of super rice. Furthermore, it is widely accepted that the high yield potential of super rice requires a large amount of N fertilizer input, which has resulted in an increase in N consumption and a decrease in nitrogen use efficiency （NUE）, although it remains unclear whether super rice per se is responsible for the latter. In the present paper, we review the history and success of China＇s Super Rice Breeding Pro- gram, summarize the advances in agronomic and physiological mechanisms underlying the high yield potential of super rice, and examine NUE differences between super rice and ordinary rice varieties. We also provide a brief introduction to the Green Super Rice Project, which aims to diversify breeding targets beyond yield improvement alone to address global concerns around resource use and environmental change. It is hoped that this review will facilitate further improvement of rice production into the future.展开更多
In China, the abuse of chemical nitrogen （N） fertilizer results in decreasing N use efficiency （NUE）, wasting resources and causing serious environmental problems. Cereal-legume intercropping is widely used to enh...In China, the abuse of chemical nitrogen （N） fertilizer results in decreasing N use efficiency （NUE）, wasting resources and causing serious environmental problems. Cereal-legume intercropping is widely used to enhance crop yield and improve resource use efficiency, especially in Southwest China. To optimize N utilization and increase grain yield, we conducted a two-year field experiment with single-factor randomized block designs of a maize-soybean intercropping system （IMS）. Three N rates, NN （no nitrogen application）, LN （lower N application： 270 kg N ha-1）, and CN （conventional N application： 330 kg N ha-1）, and three topdressing distances of LN （LND）, e.g., 15 cm （LND1）, 30 cm （LND2） and 45 cm （LND3） from maize rows were evaluated. At the beginning seed stage （R5）, the leghemoglobin content and nitrogenase activity of LND3 were 1.86 mg plant-1 and 0.14 mL h-1 plant-1, and those of LND1 and LND2 were increased by 31.4 and 24.5%, 6.4 and 32.9% compared with LND3, respectively. The ureide content and N accumulation of soybean organs in LND1 and LND2 were higher than those of LND3. The N uptake, NUE and N agronomy efficiency （NAE） of IMS under CN were 308.3 kg ha-1, 28.5%, and 5.7 kg grain kg-1 N, respectively; however, those of LN were significantly increased by 12.4, 72.5, and 51.6% compared with CN, respectively. The total yield in LND1 and LND2 was increased by 12.3 and 8.3% compared with CN, respectively. Those results suggested that LN with distances of 15-30 cm from the topdressing strip to the maize row was optimal in maize-soybean intercropping. Lower N input with an optimized fertilization location for IMS increased N fixation and N use efficiency without decreasing grain yield.展开更多
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 ...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.展开更多
Excessive or insufficient application of fertilizer has raised broader concerns regarding soil and environmental degradation.One-time application of slow release fertilizer (SF) has been widely used to reduce yield ga...Excessive or insufficient application of fertilizer has raised broader concerns regarding soil and environmental degradation.One-time application of slow release fertilizer (SF) has been widely used to reduce yield gap with potential maize yield and improve nitrogen use efficiency (NUE).A 2-year field experiment (2018–2019) was conducted to evaluate the effects of SF rates from 0 to 405 kg N ha^(–1) (named F0,SF225,SF270,SF315,SF360,and SF405) and 405 kg N ha^(–1) of common fertilizer(CF405) on the grain yield,biomass and N accumulation,enzymatic activities related with carbon–nitrogen metabolism,NUE and economic analysis.Results indicated that the highest grain yields,NUEs and economic returns were achieved at SF360in both varieties.The enzymatic activities related with carbon–nitrogen metabolism,pre-and post-silking accumulation of biomass and N increased with increasing SF rate,and they were the highest at SF360 and SF405.The grain yield at SF360had no significant difference with that at SF405.However,the N partial factor productivity,N agronomic efficiency and N recovery efficiency at SF360 were 9.8,6.6 and 8.9% higher than that at SF405.The results also indicated that the average grain yields,NUE and economic benefit at SF405 were 5.2,12.3 and 18.1% higher than that at CF405.In conclusion,decreasing N rate from 405 kg ha^(–1)(CF) to 360 kg ha^(–1)(SF) could effectively reduce the yield gap between realized and potential maize yields.The N decreased by 11.1%,but the yield,NUE and economic benefit increased by 3.2,22.2 and 17.5%,which created a simple,efficient and business-friendly system for spring maize production in Jiangsu Province,China.展开更多
Current rice production is usually guaranteed by applying large amount of chemical nitrogen fertilizers to paddy soils. The improvement of nitrogen use efficiency is of great importance not only in rice production its...Current rice production is usually guaranteed by applying large amount of chemical nitrogen fertilizers to paddy soils. The improvement of nitrogen use efficiency is of great importance not only in rice production itself but in environmental protection as well. In this study we performed a molecular marker-based genetic analysis of nitrogen use efficiency for biomass production （NUEp） and several other related traits in a recombinant inbred line （RIL） population, derived from a cross of the parents of Shanyou 63, the most widely cultivated indica hybrid in China. A total of 12 QTLs were detected using interval mapping with a LOD threshold of 2.0, among which one QTL controlling NUEp was located at the marker interval of Waxy-C1496 on chromosome 6, and the rest 11 QTLs associated nitrogen concentration and accumulation in rice plant were positioned on chromosomes 1, 2, 4 and 6, respectively. Correlation between NUEp and other traits was analyzed and the implications of the results with respect to the improvement of the hybrid rice were discussed.展开更多
Optimized nitrogen(N)management can increase N-use efficiency in intercropping systems.Legume-nonlegume intercropping systems can reduce N input by exploiting biological N fixation by legumes.Measurement of N utilizat...Optimized nitrogen(N)management can increase N-use efficiency in intercropping systems.Legume-nonlegume intercropping systems can reduce N input by exploiting biological N fixation by legumes.Measurement of N utilization can help in dissecting the mechanisms underlying N uptake and utilization in legume-nonlegume intercropping systems.An experiment was performed with three planting patterns:monoculture maize(MM),monoculture soybean(SS),and maize-soybean relay intercropping(IMS),and three N application levels:zero N(NN),reduced N(RN),and conventional N(CN)to investigate crop N uptake and utilization characteristics.N recovery efficiency and 15N recovery rate of crops were higher under RN than under CN,and those under RN were higher under intercropping than under the corresponding monocultures.Compared with MM,IMS showed a lower soil N-dependent rate(SNDR)in 2012.However,the SNDR of MM rapidly declined from 86.8%in 2012 to 49.4%in 2014,whereas that of IMS declined slowly from 75.4%in 2012 to 69.4%in 2014.The interspecific N competition rate(NCRms)was higher under RN than under CN,and increased yearly.Soybean nodule dry weight and nitrogenase activities were respectively 34.2%and 12.5%higher under intercropping than in monoculture at the beginning seed stage.The amount(Ndfa)and ratio(%Ndfa)of soybean N2 fixation were significantly greater under IS than under SS.In conclusion,N fertilizer was more efficiently used under RN than under CN;in particular,the relay intercropping system promoted N fertilizer utilization in comparison with the corresponding monocultures.An intercropping system helps to maintain soil fertility because interspecific N competition promotes biological N fixation by soybean by reducing N input.Thus,a maize-soybean relay intercropping system with reduced N application is sustainable and environmentally friendly.展开更多
Improving nitrogen use efficiency （NUE） and decreasing N loss are critical to sustainable agriculture. The objective of this research was to investigate the effect of various fertilization regimes on yield, NUE, N a...Improving nitrogen use efficiency （NUE） and decreasing N loss are critical to sustainable agriculture. The objective of this research was to investigate the effect of various fertilization regimes on yield, NUE, N agronomic efficiency （NAE） and N loss in long-term （16- or 24-yr） experiments carried out at three rice-wheat rotation sites （Chongqing, Suining and Wuchang） in subtropical China. Three treatments were examined： sole chemical N, N＋phosphorus （NP）, and NP＋potassium （NPK） fertilizations. Grain yields at three sites were significantly increased by 9.3-81.6% （rice） and 54.5-93.8% （wheat） under NP compared with N alone, 1.7-9.8% （rice） and 0-17.6% （wheat） with NPK compared with NP. Compared to NP, NUE significantly increased for wheat at Chongqing （9.3%） and Wuchang （11.8%）, but not at Suining, China. No changes in NUE were observed in rice between NP and NPK at all three sites. The rice-wheat rotation＇s NAE was 3.3 kg kg1 higher under NPK than under NP at Chongqing, while NAE was similar for NP and NPK at Suining and Wuchang. We estimated that an uptake increase of 1.0 kg N hal would increase 40 kg rice and 30 kg wheat ha-1. Nitrogen loss/input ratios were -60, -40 or -30% under N, NP or NPK at three sites, indicating significant decrease of N loss by P or PK additions. We attribute part of the increase in NUE soil N accumulation which significantly increased by 25-55 kg ha-1 yr1 under NPK at three sites, whereas by 35 kg ha-1 yr-1 under NP at Chongqing only. This paper illustrates that apply P and K to wheat, and reduce K application to rice is an effective nutrient management strategy for both the NUE improvement and N losses reduction in China.展开更多
Side deep placement of nitrogen plays an important role in improving rice yield and nitrogen use efficiency.Few studies have examined the effects of reducing the times of nitrogen(RTN)application and reducing the nitr...Side deep placement of nitrogen plays an important role in improving rice yield and nitrogen use efficiency.Few studies have examined the effects of reducing the times of nitrogen(RTN)application and reducing the nitrogen rate(RNR)of application on rice yield and nitrogen use efficiency under side deep placement of nitrogen in paddy fields.Therefore,a field experiment of RNT and RNR treatments was conducted with nine fertilization modes during the 2018–2019 rice growing seasons in a rice–wheat cropping system of the lower reaches of the Yangtze River,China.Rice yield and nitrogen use efficiency were investigated under side deep placement of nitrogen.We found that under the same nitrogen application rate,the yield of RTN3 increased by 9.64 and 10.18%in rice varieties NJ9108 and NJ5718,respectively,compared with the farmers’fertilizer practices(FFP).The nitrogen accumulation of RTN3 was the highest at heading stage,at 11.30 t ha^(–1)across 2018 and 2019.Under the same nitrogen application rate,the N agronomic use efficiency(NAE),N physiological efficiency(NPE)and N recovery efficiency(NRE)of RTN3 were 8.1–21.28%,8.51–41.76%and 0.28–14.52%higher than those of the other fertilization modes,respectively.RNR led to decreases in SPAD value,leaf area index(LAI),dry matter accumulation,nitrogen accumulation,and nitrogen use efficiency.These results suggest that RTN3 increased rice yield and nitrogen use efficiency under the side deep placement of nitrogen,and RNR1 could achieve the goals of saving cost and increasing resource use efficiency.Two fertilization modes RTN3 and RNR1 both could achieve the dual goals of increasing grain yield and resource use efficiency and thus are worth further application and investigation.展开更多
基金supported by the National High-Tech Research&Development program(Grant No.2003AA206030)the National Natural Science Foundation of China(Grant No.30030090)
文摘In order to establish methods for indentification and screening of rice genotypes with high nitrogen （N） efficiency, N absorption efficiency （NAE）, N utilization efficiency （NUE） and N harvest index （NHI） in ten rice genotypes were investgated at the elongation, booting, heading and maturity stages under six N levels in a pot experiment with soil-sand mixtures at various ratios. NAE in various rice genotypes firstly increased, peaked under a medium nitrogen rate of 0.177 g/kg and then decreased, but NUE and NHI always decreased with increasing nitrogen levels. NAE in various rice genotypes ever increased with growing process and NUE indicated a descending tendency of elongation stage〉heading stage〉maturity stage〉booting stage. N level influenced rice NAE, NUE and NHI most, followed by genotype, and the both effects were significant at 0.01 level. In addition, the interaction effects of genotype and nitrogen level on rice NAE and NUE were significant at 0.01 level, but not significant on rice NHI. Because the maximum differences of NAE and NUE were found at the elongation stage, it was thought to be the most suitable stage for identification and screening these two paremeters. Therefore, the optimum conditions for identification and screening of rice NAE, NUE and NHI in a pot experiment were the nitrogen rate of 0.157 g/kg at the elongation stage, low nitrogen at the elongation stage, and the nitrogen rate of 0.277 g/kg at the maturity stage, respectively.
基金financially supported by the Beijing Swine Innovation Team of Modern Agriculture Industry Technological System.
文摘Background:Protein releases amino acids faster than starch releases glucose in digestive tract of pigs fed lowprotein(LP)diets.Poor synchronization of dietary glucose and amino acids supply leads to compromised nitrogen efficiency.Dietary starch patterns modulation may improve this situation.Methods:Growing barrows(29.7±2.0 kg)were randomly allotted into 5 dietary treatments with LP diets consisting of different purified starches.Treatments included:waxy corn starch(W LP),corn starch+waxy corn starch(C+W LP),corn starch(C LP),pea starch+waxy corn starch(P+W LP)and pea starch(P LP).In the experiment,growth performance,protein deposition,nutrient metabolism,and fecal microbial community of pigs were investigated.In vitro starch digestion was used for predicting the in vivo glucose response.Results:Dietary starch in vitro glucose release profile was determined by starch source and the ratio of amylopectin and amylose.C+W LP treatment showed decreased total nitrogen excretion and plasma citrulline concentration and improved plasma leptin concentration among treatments(P<0.05).Besides,the highest nitrogen apparent biological value,whole-body protein deposition and growth performance and lowest urinary nitrogen excretion were also observed in C+W LP treatment.Compared with the other groups,C+W LP and C LP showed increased plasma pyruvate,IGF-1,and lipase concentrations(P<0.05).The W LP group presented dramatically increased plasma alanine and urea nitrogen concentration and decreased aldolase and leptin concentrations(P<0.05).Dietary starch patterns did not make an impact on bacterial richness and diversity,but changed the taxonomic and functional structures of the microbial communities.Microbial protein fermentation product(isobutyrate and isovalerate)presented increased in P LP treatments compared with the other treatments(P<0.05).Conclusions:Dietary starch patterns modulation can regulate dietary glucose release profile,nutrient metabolism,protein turnover,and fecal microbial fermentation in pigs.The optimal dietary glucose release profile effectively strengthened whole-body protein deposition and improve nitrogen efficiency and growth performance in growing pigs fed LP diets.
基金Supported by National Natural Science Foundation of China(31271645)Agricultural Science and Technology Project of Shanxi Province(20140311007-4)~~
文摘There are significant differences in nitrogen absorption and utilization effi- ciency among different maize varieties. So it is very essential to determine nitrogen efficiencies of different maize varieties. The effect of nitrogen application on maize growth can be reflected at the grain filling stage. Many scholars have researched the differences in grain filling characteristics among different maize varieties under the same nitrogen application conditions, but there are reare reports on the differ- ences under different nitrogen application conditions. In this study, the grain filling dynamics of maize were observed so as to determine the differences in nitrogen efficiency and to further compare the differences in grain filling characteristics a- mong different maize varieties. The test was carried out with Tunyu 99, Luyu 19 and Xianyu 335 as the materials during May 1st to October 7th, 2013. Under the nitrogen application levels of NO （0 kg/hm2 of pure nitrogen）, N1 （140 kg/hm2 of pure nitrogen） and N2 （210 kg/hm2 of pure nitrogen）, the filling dynamics of upper- and middle- lower-part grains of spring maize were studied. The results showed that among the three nitrogen application level, the grain fresh weight and dry weight of Tunyu 99 ranked as N2〉NI〉N0; the grain fresh weight and dry weight of Luyu 19 ranked as N1〉N2〉N0; the grain fresh weight and dry weight of Xianyu 335 ranked as （N1, N2）〉N0, and there was no significant difference between N1 and N2. Un- der the nitrogen application level of N1, Luyu 19 showed the best growth; under the nitrogen application level of N2, Tunyu 99 showed the best growth, The growth ad- vantage of Xianyu 335 was unobvious under neither N1 nor N2 nitrogen application levels. The development-promoting effect of nitrogen application was more obvious in upper-part grains than that in middle-lower-part grains.
基金supported by the Natural Science Fund of China(31771724)the Key Research and Development Project of Shaanxi Province(2024NC-ZDCYL-01-10).
文摘The increase in soil temperature associated with climate change has introduced considerable challenges to crop production.Split nitrogen application(SN)represents a potential strategy for improving crop nitrogen use efficiency and enhancing crop stress resistance.Nevertheless,the precise interaction between soil warming(SW)and SN remains unclear.In order to ascertain the impact of SW on maize growth and whether SN can improve the tolerance of maize to SW,a two-year field experiment was conducted(2022-2023).The aim was to examine the influence of two SW ranges(MT,warming 1.40℃;HT,warming 2.75℃)and two nitrogen application methods(N1,one-time basal application of nitrogen fertilizer;N2,one third of base nitrogen fertilizer+two thirds of jointing stage supplemental nitrogen fertilizer)on maize root growth,photosynthetic characteristics,nitrogen use efficiency,and yield.The results demonstrated that SW impeded root growth and precipitated the premature aging of maize leaves following anthesis,particularly in the HT,which led to a notable reduction in maize yield.In comparison to N1,SN has been shown to increase root length density by 8.54%,root bleeding rate by 8.57%,and enhance root distribution ratio in the middle soil layers(20-60 cm).The interaction between SW and SN had a notable impact on maize growth and yield.The SN improved the absorption and utilization efficiency of nitrogen by promoting root development and downward canopy growth,thus improving the tolerance of maize to SW at the later stage of growth.In particular,the N2HT resulted in a 14.51%increase in the photosynthetic rate,a 18.58%increase in nitrogen absorption efficiency,and a 18.32%increase in maize yield compared with N1HT.It can be posited that the SN represents a viable nitrogen management measure with the potential to enhance maize tolerance to soil high-temperature stress.
基金supported by the National Key Research and Development Program of China(2023YFD2301702)the earmarked Fund for China Agriculture Research System(CARS-02)the National Natural Science Foundation of China(31971852).
文摘Long-term excessive nitrogen(N)application neither increases nor enhances grain yield and N use efficiency(NUE)of maize,yet the mechanisms involving root morphological and physiological characteristics remain unclear.This study aimed to elucidate the mechanisms underlying stagnant grain yield under excessive N application by examining root morphological and physiological characteristics.A 10-year N fertilizer trial was conducted in Jilin Province,Northeast China,cultivating maize at three N fertilizer levels(zero N,N0;recommended N,N2;and high N level,N4)from 2019 to 2021.Two widely cultivated maize genotypes,‘Xianyu 335’(XY335)and‘Zhengdan 958’(ZD958),were evaluated.Grain yield,N content,root morphology,and physiological characteristics were analyzed to assess the relationships between N uptake,N utilization,plant growth,and root systems under different N treatments.Compared to N0,root biomass,post-silking N uptake,and grain yield improved significantly with increased N input,while no significant differences emerged between recommended N and high N.High N application enhanced root length and root surface area but decreased root activity(measured by TTC(2,3,5-triphenyltetrazolium chloride)method),nitrate reductase activity,and root activity absorbing area across genotypes.Root length and root to shoot ratio negatively affected N uptake(by-1.2 and-24.6%),while root surface area,root activity,nitrate reductase activity,and root activity absorbing area contributed positively.The interaction between cultivar and N application significantly influenced NUE.XY335 achieved the highest NUE(11.6%)and N recovery efficiency(18.4%)through superior root surface area(23.6%),root activity(12.5%),nitrate reductase activity(8.3%),and root activity absorbing area(6.9%)compared to other treatments.Recommended N application enhanced Post N uptake,NUE,and grain yield through improved root characteristics,while high N application failed to increase or decreased NUE by reducing these parameters.This study demonstrates that root surface area,root activity,nitrate reductase activity,and root activity absorbing area limit NUE increase under high N application.
基金supported by the National Natural Science Foundation of China(U21A20236,32072664)the Natural Science Foundation of Hunan Province,China(2022RC3053,2021JC0001,2021RC3086,2022NK2009)+1 种基金the China Agriculture Research System(CARS-01-30)the Innovation Foundation for Graduate of Hunan Agricultural University,China(2023XC116)。
文摘Elucidating crops'physiological and molecular mechanisms to adapt to low nitrogen environment and promoting nitrogen transfer from senescent leaves to new leaves is crucial in improving Brassica's nitrogen use efficiency(NUE).Glutamine synthetase gene(GS)plays a vital role in helping plants reassimilate ammonium released from protein degradation in leaves,and it was the focus of our research on this topic.In this study,we identified high(H141)and low(L65)NUE genotypes of Brassica juncea with different responses to low-nitrogen stress.We found that H141 has a lower nitrate content but higher ammonium and free amino acid contents as well as higher nitrate reductase and GS activities in the shoots.These physiological indicators are responsible for the high NUE of H141.Wholegenome resequencing data revealed that 5,880 genes associated with NUE are polymorphic between H141 and L65.These genes participate in various amino acid,carbohydrate,and energy metabolic pathways.Haplotype analysis revealed two haplotypes for BjuB05.GS1.4,Hap1 and Hap2,which have multiple single nucleotide polymorphisms or insertions/deletions in the regulatory regions of the 5′and 3′untranslated regions and introns.Furthermore,the shoot NUE of Hap1 is significantly lower than that of Hap2.These two haplotypes of BjuB05.GS1.4 lead to differences in the shoot NUEs of different genetic populations of mustard and are associated with the local soil nitrogen content,suggesting that they might help mustard to adapt to different geographic localities.In conclusion,the results of our study shed light on the physiological and molecular mechanisms underlying different mustard NUE genotypes and demonstrate the enormous potential of NUE breeding in B.juncea.
基金supported by the National Key Research and Development Program of China(2022YFB3903505)the National Natural Science Foundation of China(72221002)。
文摘The well-facilitated farmland projects(WFFPs)involve the typical sustainable intensification of farmland use and play a key role in raising food production in China.However,whether such WFFPs can enhance the nitrogen(N)use efficiency and reduce environmental impacts is still unclear.Here,we examined the data from 502 valid questionnaires collected from WFFPs in the major grain-producing area,the Huang-Huai-Hai Region(HHHR)in China,with 429 samples for wheat,328 for maize,and 122 for rice.We identified gaps in N use efficiency(NUE)and N losses from the production of the three crops between the sampled WFFPs and counties based on the statistical data.The results showed that compared to the county-level(wheat,39.1%;maize,33.8%;rice,35.1%),the NUEs for wheat(55.2%),maize(52.1%),and rice(50.2%)in the WFFPs were significantly improved(P<0.05).In addition,the intensities of ammonia(NH3)volatilization(9.9-12.2 kg N ha–1),N leaching(6.5-16.9 kg N ha–1),and nitrous oxide(N2O)emissions(1.2-1.6 kg N ha–1)from crop production in the sampled WFFPs were significantly lower than the county averages(P<0.05).Simulations showed that if the N rates are reduced by 10.0,15.0,and 20.0%for the counties,the NUEs of wheat,maize,and rice in the HHHR will increase by 2.9-6.3,2.4-5.2,and 2.6-5.7%,respectively.If the N rate is reduced to the WFFP level in each county,the NUEs of the three crops will increase by 12.9-19.5%,and the N leaching,NH3,and N2O emissions will be reduced by 48.9-56.2,37.4-42.9,and 46.0-66.5%,respectively.Our findings highlight that efficient N management practices in sustainable intensive farmland have considerable potential for reducing environmental impacts.
基金Supported by Agricultural Science &Technology Project of Jiangsu Province(BE2008369)~~
文摘[Objective]The aim was to study heterosis of N use efficiency for grain production （NUEg） of Brassica napus L. and provide theoretical basis for breeding N-efficient cultivars. [Method]Dry matter production and N content of six B.napus parents （Zheshuang 3,Yangyou 7,ZJ1,Shilijia,Ningyou 14 and Huyou 16） and their F1 combinations from 6 × 6 complete diallel cross in maturity stage under two N levels were measured; heterosis of NUEg,combining ability and heritability size were analyzed and calculated. [Result]The results showed that NUEg has obvious heterosis; combining ability variance analysis indicated that NUEg was mainly controlled by additive,dominant and cytoplasmic effects; genetic variance analysis showed that additive effects and dominance effects were all significant in low nitrogen fertilizer and dominance effects were significant in high nitrogen fertilizer. [Conclusion]NUEg of B.napus has obvious heterosis.
基金Supported by Construction of Southwestern Rice Innovation System,Science and Technology Project on Food Production (2006BAD02-A05)Agriculture Science Technology Achievement TransformationFund (2006GB2F000256)+2 种基金Sichuan Provincial Foundation for Lead-ers of Disciplines in ScienceProject of Rice Breeding Technology ofSichuanProgram Promoted by Sichuan Financial Administration~~
文摘[Objective] The study aimed at investigating the effects of different geographic sites,soil chemical characteristics and nitrogen application levels on nitrogen accumulation and distribution in different organs and utilization efficiency for mid-season hybrid rice.[Method] By using mid-season rice varieties II-you 7 and Yuxiangyou203 as the experimental materials,field experiment was conducted at seven ecological sites in four provinces or cities in Southwestern China in 2009.A total of four nitrogen application levels were set as follows：by using 75 kg/hm2 of P2O5 and 75 kg/hm2 of K2O as the base fertilizer,extra 0,90,150 and 210 kg/hm2 of nitrogen fertilizer（in which,base fertilizer,base-tillering fertilizer and base-earing fertilizer respectively accounted for 60%,20% and 20%.） was applied,respectively.In the split-plot design,fertilizer was considered as the main factor while rice variety was taken as the secondary factor.A total of eight treatments were set with three replications.[Result] Highly significant differences of grain yield were found among seven locations,two varieties,four nitrogen application levels,interactions of site × variety and site × nitrogen application level,but the interaction of variety ×nitrogen application level had no significant influence on rice yield.There were highly significant effects of site,varieties and nitrogen application level on dry matter production,nitrogen content,nitrogen utilization efficiency.Highly significant negative correlations between uptake efficiency and utilization efficiency for nitrogen were found;and multiple stepwise regression analysis showed that nitrogen uptake-utilization efficiency were significantly influenced by different ecological sites,chemical quality of soil and the levels of nitrogen application.[Conclusion] The research will provide theoretical and practical basis for the highly efficient application of nitrogen in mid-season hybrid rice cultivation.
基金Supported by National Science and Technology Major Project(2015ZX07204-007)Key Laboratory of Nutrient Cycling and Resources Environment of Anhui Province(1606c08231)Special Fund for Agro-scientific Research in the Public Interest(201503122)~~
文摘The field experiments were conducted in Anhui during 2016 to investigate the effects of controlled-release nitrogen （CRN） rates and mixture of controlled-re- lease nitrogen and conventional nitrogen （CN） on the yield and nitrogen efficiency of summer maize. Six treatments included CK （with no application of N）, CNIO0% splits （CN）, CRFIO0% （CRN1）, CRN60%＋CN40% （CRN2）, CRN85% （CRN3） and CRN70% （CRN4）. The results showed proper CRN increased yields and output val- ue. Compared with CN, CRN2 significantly increased by 13.74%, CRN1 increased by 4.84%, and CRN3 was equal to CN. CRN increased yield by grain number per spike of yield components. CRN2 had the highest apparent nitrogen fertilizer recov- ery efficiency and CRN1 was the second, which were significantly higher than CN. Nitrogen agronomic efficiency of CRN2 was significantly higher than CN. Nitrogen physiological efficiency of CRN2 was higher than CN. The partial productivity of CRN1 was higher than that with CN. And the effect of nitrogen fertilizer of CRN2 was the highest, which was increased 758 yuan/hm2. Considering yield, nitrogen use efficiency and economic benefit, applying the mixture of CRN and CN was the most beneficial treatment. CRN1 was the second treatment, and CRN3 didn＇t reduce yield.
基金Supported by National High Technology Research and Development Program of China(863 Program,2011AA100504)National Science and Technology Plan Project(2012BAD04B02)+1 种基金a Grant from the Department of Science and Technology of Jilin Province(20116031)Special Fund for Agro-scientific Research in the Public Interest(201303125)~~
文摘[Objective] This study and nitrogen use efficiency in aimed to investigate the nitrogen dynamic changes maize under different nitrogen application patterns. [Method] Maize cultivar Xianyu 335 was selected as the experimental material and was planted at two densities 85 000 and 95 000 plants/hm2. The total amount of fertilizers applied kept constant. The nitrogen content in leaves, stems, sheathes, husks, grains, cobs, tassels and filaments of maize plants in jointing stage, silking stage, 15, 30, 45 and 60 d after silking stage was measured. [Result] Total nitrogen content in maize plant reached the peak around 45 d after silking stage and a higher population was helpful to nitrogen accumulation. Total nitrogen content of maize plant was positively correlated with yield and it got closer in higher popula- tion. Grain nitrogen content and nitrogen harvest index were significantly positively correlated with yield in higher population. High ratio of nitrogen fertilizer in silking stage was beneficial to nitrogen accumulation in leaf and ear, as well as nitrogen translocation in stem and sheath, but high ratio of nitrogen fertilizer in earlier stage delayed nitrogen metabolism. Nitrogen uptake peak was from silking stage to 15 d after silking stage, and nitrogen uptake rate increased high ratio of nitrogen fertilizer was applied in later growth stages and moved forward in higher plant population. [Conclusion] It was advantaged for nitrogen fertilizer efficiency on condition that ni- trogen application was moved backward. Accumulating too much nitrogen in earlier stages inhibited nitrogen uptake in later periods
基金Supported by Nation Key technology R&D Program(2012BAD07B02)National Innovation Experiment Program for University Students(104892013032)Hubei Provincial Key Discipline of Crop Science in Yangtze University~~
文摘ln order to explore the effect of broadcast application of urea （BR-U） and surface concentrated-fertilization on grain yield and nitrogen agronomy efficiency of two-line super hybrid rice, this experiment was conducted with super hybrid rice Y-Liangyou 1 and Liangyou 0293 to determine til ering dynamics, SPAD, LAl and dry matter accumulation. lts total N application was 180 kg/hm2 and different application rate and topdressing methods were set respectively. The results showed that grain yield and nitrogen agronomy efficiency were significantly improved with the T3 and T4 nitrogenous fertilizer application model. The improving of grain yield and nitrogen agronomy efficiency was benefited from rational postponing N application. However, neither single application of base fertilizer （T2） nor single application of topdressing fertilizer （T5 and T6） can coordinate the relationship between source and sink. Both grain yield and nitrogen agronomy efficiency were insignificantly under the broadcast application of urea and surface concentrated fertilization.
基金financially supported by the grants from the National High-Tech R&D Program of China(863 Program,2014AA10A605)the Fundamental Research Funds for the Central Universities,China(2015BQ002)
文摘In 1996, a mega project that aimed to develop rice varieties with super-high yield potential （super rice） was launched by the Ministry of Agriculture （MOA） in China using a combination of the ideotype approach and intersubspecific heterosis. Significant progress has been made in the last two decades, with a large number of super rice varieties being approved by the MOA and the national average grain yield being increased from 6.21 t ha^-1 in 1996 to 6.89 t ha^-1 in 2015. The increase in yield potential of super rice was mainly due to the larger sink size which resulted from larger panicles. Moreover, higher photosynthetic capacity and improved root physiological traits before heading contributed to the increase in sink size. However, the poor grain filling of the later-flowering inferior spikelets and the quickly decreased root activity of super rice during grain filling period restrict the achievement of high yield potential of super rice. Furthermore, it is widely accepted that the high yield potential of super rice requires a large amount of N fertilizer input, which has resulted in an increase in N consumption and a decrease in nitrogen use efficiency （NUE）, although it remains unclear whether super rice per se is responsible for the latter. In the present paper, we review the history and success of China＇s Super Rice Breeding Pro- gram, summarize the advances in agronomic and physiological mechanisms underlying the high yield potential of super rice, and examine NUE differences between super rice and ordinary rice varieties. We also provide a brief introduction to the Green Super Rice Project, which aims to diversify breeding targets beyond yield improvement alone to address global concerns around resource use and environmental change. It is hoped that this review will facilitate further improvement of rice production into the future.
基金supported by the National Key Research and Development Program of China (2016YFD0300202)the National Natural Science Foundation of China (31671625, 31271669)
文摘In China, the abuse of chemical nitrogen （N） fertilizer results in decreasing N use efficiency （NUE）, wasting resources and causing serious environmental problems. Cereal-legume intercropping is widely used to enhance crop yield and improve resource use efficiency, especially in Southwest China. To optimize N utilization and increase grain yield, we conducted a two-year field experiment with single-factor randomized block designs of a maize-soybean intercropping system （IMS）. Three N rates, NN （no nitrogen application）, LN （lower N application： 270 kg N ha-1）, and CN （conventional N application： 330 kg N ha-1）, and three topdressing distances of LN （LND）, e.g., 15 cm （LND1）, 30 cm （LND2） and 45 cm （LND3） from maize rows were evaluated. At the beginning seed stage （R5）, the leghemoglobin content and nitrogenase activity of LND3 were 1.86 mg plant-1 and 0.14 mL h-1 plant-1, and those of LND1 and LND2 were increased by 31.4 and 24.5%, 6.4 and 32.9% compared with LND3, respectively. The ureide content and N accumulation of soybean organs in LND1 and LND2 were higher than those of LND3. The N uptake, NUE and N agronomy efficiency （NAE） of IMS under CN were 308.3 kg ha-1, 28.5%, and 5.7 kg grain kg-1 N, respectively; however, those of LN were significantly increased by 12.4, 72.5, and 51.6% compared with CN, respectively. The total yield in LND1 and LND2 was increased by 12.3 and 8.3% compared with CN, respectively. Those results suggested that LN with distances of 15-30 cm from the topdressing strip to the maize row was optimal in maize-soybean intercropping. Lower N input with an optimized fertilization location for IMS increased N fixation and N use efficiency without decreasing grain yield.
基金financial support from theNational Natural Science Foundation of China (31471443, 31501262)the Fundamental Research Funds for the Central Universities, China (KJQN201632)the Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University
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.
基金financial support from the National Key Research and Development Program of China(2016YFD0300109)the National Natural Science Foundation of China(31771709)+2 种基金the Jiangsu Agricultural Industry Technology System of China(JATS[2019]458)the High-end Talent Support Program of Yangzhou University,Chinathe Priority Academic Program Development of Jiangsu Higher Education Institutions,China。
文摘Excessive or insufficient application of fertilizer has raised broader concerns regarding soil and environmental degradation.One-time application of slow release fertilizer (SF) has been widely used to reduce yield gap with potential maize yield and improve nitrogen use efficiency (NUE).A 2-year field experiment (2018–2019) was conducted to evaluate the effects of SF rates from 0 to 405 kg N ha^(–1) (named F0,SF225,SF270,SF315,SF360,and SF405) and 405 kg N ha^(–1) of common fertilizer(CF405) on the grain yield,biomass and N accumulation,enzymatic activities related with carbon–nitrogen metabolism,NUE and economic analysis.Results indicated that the highest grain yields,NUEs and economic returns were achieved at SF360in both varieties.The enzymatic activities related with carbon–nitrogen metabolism,pre-and post-silking accumulation of biomass and N increased with increasing SF rate,and they were the highest at SF360 and SF405.The grain yield at SF360had no significant difference with that at SF405.However,the N partial factor productivity,N agronomic efficiency and N recovery efficiency at SF360 were 9.8,6.6 and 8.9% higher than that at SF405.The results also indicated that the average grain yields,NUE and economic benefit at SF405 were 5.2,12.3 and 18.1% higher than that at CF405.In conclusion,decreasing N rate from 405 kg ha^(–1)(CF) to 360 kg ha^(–1)(SF) could effectively reduce the yield gap between realized and potential maize yields.The N decreased by 11.1%,but the yield,NUE and economic benefit increased by 3.2,22.2 and 17.5%,which created a simple,efficient and business-friendly system for spring maize production in Jiangsu Province,China.
基金This research was financially supported by the National Natural Science Foundation of China(NSFC)fund from the Education Committee of Jiangsu Province,China.The recombinant inbred line(RIL)population,derived from a cross of the parents of Shanyou 63,and relevant genetic information were provided by the National Key Lab for Crop Genetic Improvement of China.
文摘Current rice production is usually guaranteed by applying large amount of chemical nitrogen fertilizers to paddy soils. The improvement of nitrogen use efficiency is of great importance not only in rice production itself but in environmental protection as well. In this study we performed a molecular marker-based genetic analysis of nitrogen use efficiency for biomass production （NUEp） and several other related traits in a recombinant inbred line （RIL） population, derived from a cross of the parents of Shanyou 63, the most widely cultivated indica hybrid in China. A total of 12 QTLs were detected using interval mapping with a LOD threshold of 2.0, among which one QTL controlling NUEp was located at the marker interval of Waxy-C1496 on chromosome 6, and the rest 11 QTLs associated nitrogen concentration and accumulation in rice plant were positioned on chromosomes 1, 2, 4 and 6, respectively. Correlation between NUEp and other traits was analyzed and the implications of the results with respect to the improvement of the hybrid rice were discussed.
基金supported by the National Natural Science Foundation of China(31671625,31271669)the National Key Research and Development Program of China(2016YFD0300202)
文摘Optimized nitrogen(N)management can increase N-use efficiency in intercropping systems.Legume-nonlegume intercropping systems can reduce N input by exploiting biological N fixation by legumes.Measurement of N utilization can help in dissecting the mechanisms underlying N uptake and utilization in legume-nonlegume intercropping systems.An experiment was performed with three planting patterns:monoculture maize(MM),monoculture soybean(SS),and maize-soybean relay intercropping(IMS),and three N application levels:zero N(NN),reduced N(RN),and conventional N(CN)to investigate crop N uptake and utilization characteristics.N recovery efficiency and 15N recovery rate of crops were higher under RN than under CN,and those under RN were higher under intercropping than under the corresponding monocultures.Compared with MM,IMS showed a lower soil N-dependent rate(SNDR)in 2012.However,the SNDR of MM rapidly declined from 86.8%in 2012 to 49.4%in 2014,whereas that of IMS declined slowly from 75.4%in 2012 to 69.4%in 2014.The interspecific N competition rate(NCRms)was higher under RN than under CN,and increased yearly.Soybean nodule dry weight and nitrogenase activities were respectively 34.2%and 12.5%higher under intercropping than in monoculture at the beginning seed stage.The amount(Ndfa)and ratio(%Ndfa)of soybean N2 fixation were significantly greater under IS than under SS.In conclusion,N fertilizer was more efficiently used under RN than under CN;in particular,the relay intercropping system promoted N fertilizer utilization in comparison with the corresponding monocultures.An intercropping system helps to maintain soil fertility because interspecific N competition promotes biological N fixation by soybean by reducing N input.Thus,a maize-soybean relay intercropping system with reduced N application is sustainable and environmentally friendly.
基金Financial supports are from the National Natural Science Foundation of China (41001175)the National Basic Research Program of China (2011CB100501)the Special Basic Research Fund for Public Institutes in China (202-2)
文摘Improving nitrogen use efficiency （NUE） and decreasing N loss are critical to sustainable agriculture. The objective of this research was to investigate the effect of various fertilization regimes on yield, NUE, N agronomic efficiency （NAE） and N loss in long-term （16- or 24-yr） experiments carried out at three rice-wheat rotation sites （Chongqing, Suining and Wuchang） in subtropical China. Three treatments were examined： sole chemical N, N＋phosphorus （NP）, and NP＋potassium （NPK） fertilizations. Grain yields at three sites were significantly increased by 9.3-81.6% （rice） and 54.5-93.8% （wheat） under NP compared with N alone, 1.7-9.8% （rice） and 0-17.6% （wheat） with NPK compared with NP. Compared to NP, NUE significantly increased for wheat at Chongqing （9.3%） and Wuchang （11.8%）, but not at Suining, China. No changes in NUE were observed in rice between NP and NPK at all three sites. The rice-wheat rotation＇s NAE was 3.3 kg kg1 higher under NPK than under NP at Chongqing, while NAE was similar for NP and NPK at Suining and Wuchang. We estimated that an uptake increase of 1.0 kg N hal would increase 40 kg rice and 30 kg wheat ha-1. Nitrogen loss/input ratios were -60, -40 or -30% under N, NP or NPK at three sites, indicating significant decrease of N loss by P or PK additions. We attribute part of the increase in NUE soil N accumulation which significantly increased by 25-55 kg ha-1 yr1 under NPK at three sites, whereas by 35 kg ha-1 yr-1 under NP at Chongqing only. This paper illustrates that apply P and K to wheat, and reduce K application to rice is an effective nutrient management strategy for both the NUE improvement and N losses reduction in China.
基金the National Key Research and Development Program of China(2018YFD0300802 and 2016YFD0200805)the Key Research Program of Jiangsu Province,China(BE2017343 and BE2018362)。
文摘Side deep placement of nitrogen plays an important role in improving rice yield and nitrogen use efficiency.Few studies have examined the effects of reducing the times of nitrogen(RTN)application and reducing the nitrogen rate(RNR)of application on rice yield and nitrogen use efficiency under side deep placement of nitrogen in paddy fields.Therefore,a field experiment of RNT and RNR treatments was conducted with nine fertilization modes during the 2018–2019 rice growing seasons in a rice–wheat cropping system of the lower reaches of the Yangtze River,China.Rice yield and nitrogen use efficiency were investigated under side deep placement of nitrogen.We found that under the same nitrogen application rate,the yield of RTN3 increased by 9.64 and 10.18%in rice varieties NJ9108 and NJ5718,respectively,compared with the farmers’fertilizer practices(FFP).The nitrogen accumulation of RTN3 was the highest at heading stage,at 11.30 t ha^(–1)across 2018 and 2019.Under the same nitrogen application rate,the N agronomic use efficiency(NAE),N physiological efficiency(NPE)and N recovery efficiency(NRE)of RTN3 were 8.1–21.28%,8.51–41.76%and 0.28–14.52%higher than those of the other fertilization modes,respectively.RNR led to decreases in SPAD value,leaf area index(LAI),dry matter accumulation,nitrogen accumulation,and nitrogen use efficiency.These results suggest that RTN3 increased rice yield and nitrogen use efficiency under the side deep placement of nitrogen,and RNR1 could achieve the goals of saving cost and increasing resource use efficiency.Two fertilization modes RTN3 and RNR1 both could achieve the dual goals of increasing grain yield and resource use efficiency and thus are worth further application and investigation.
