Molybdenum （Mo） and Cobalt （Co） play an important role in nitrogen （N） metabolism of grain legumes. Their applications to alkaline soils have been scarcely studied. A field experiment was set up to evaluate the ...Molybdenum （Mo） and Cobalt （Co） play an important role in nitrogen （N） metabolism of grain legumes. Their applications to alkaline soils have been scarcely studied. A field experiment was set up to evaluate the Mo and Co application in common bean cv. Canario Centenario under two fertilization systems： inorganic fertilization and inoculation with Rhizobium etli. In each system, Mo and Mo ＋ Co were applied by seed impregnation at doses of 1.36 g/kg of seed for Mo and 0.26 g/kg of seed for Co; a control for each fertilization system and an absolute control were included. Yield components, nodules characteristics and N content by grains and foliage were evaluated. A completely randomized block design with seven treatments and five replications was used. Mo application increased the grain yield, grain size, nodulation and N accumulation in grains under both fertilization systems. Mo increased the total N uptake by the plant in 35.4% and 26%, for N fertilized and inoculated plants, respectively. Co application increased only nodules number and weight, and N content under inoculation. Mo application to beans cultivated in alkaline soils is recommended, but Co application is suitable only when beans are inoculated with rhizobia.展开更多
To make agricultural systems sustainable in terms of their greenness and efficiency,optimizing the tillage and fertilization practices is essential.To assess the effects of tilling and fertilization practices in wheat...To make agricultural systems sustainable in terms of their greenness and efficiency,optimizing the tillage and fertilization practices is essential.To assess the effects of tilling and fertilization practices in wheat-maize cropping systems,a three-year field experiment was designed to quantify the carbon footprint(CF)and energy efficiency of the cropping systems in the North China Plain.The study parameters included four tillage practices(no tillage(NT),conventional tillage(CT),rotary tillage(RT),and subsoiling rotary tillage(SRT))and two fertilizer regimes(inorganic fertilizer(IF)and hybrid fertilizer with organic and inorganic components(HF)).The results indicated that the most prominent energy inputs and greenhouse gas(GHG)emissions could be ascribed to the use of fertilizers and fuel consumption.Under the same fertilization regime,ranking the tillage patterns with respect to the value of the crop yield,profit,CF,energy use efficiency(EUE)or energy productivity(EP)for either wheat or maize always gave the same sequence of SRT>RT>CT>NT.For the same tillage,the energy consumption associated with HF was higher than IF,but its GHG emissions and CF were lower while the yield and profit were higher.In terms of overall performance,tilling is more beneficial than NT,and reduced tillage practices(RT and SRT)are more beneficial than CT.The fertilization regime with the best overall performance was HF.Combining SRT with HF has significant potential for reducing CF and increasing EUE,thereby improving sustainability.Adopting measures that promote these optimizations can help to overcome the challenges posed by a lack of food security,energy crises and ecological stress.展开更多
Controlled-release/stable nitrogen(N)fertilizers can improve vegetable yields and achieve lower greenhouse gas emissions,resulting in cost-effective and environmentally friendly vegetable production.However,there has ...Controlled-release/stable nitrogen(N)fertilizers can improve vegetable yields and achieve lower greenhouse gas emissions,resulting in cost-effective and environmentally friendly vegetable production.However,there has been limited research on the controlled-release/stable N fertilization in long-term fixed-position vegetable rotation fields.In this study,a five-year field experiment was conducted to examine the effects of long-term controlled-release/stable N fertilization in reducing greenhouse gas emissions and increasing lettuce yield.Six distinct treatments were employed for N fertilization:the control without N fertilizer(CK),normal local farming practices with application of urea fertilizer at 400 kg N ha^(-1)(T1),optimized application of urea at 320 kg N ha^(-1)(T2),optimized application of urea at 320 kg N ha^(-1)with supplementation of 1.0 kg ha^(-1)3,4-dimethylpyrazole phosphate(DMPP)as N inhibitor(T3),application of polyurethane-coated urea at 320 kg N ha^(-1)(T4),and application of polyurethane-coated urea at 320 kg N ha^(-1)with supplementation of 1.0 kg ha^(-1)DMPP(T5).The results showed that the T3,T4,and T5 treatments using controlled-release/stable N fertilization emitted about 12.2%-56.7%less average annual cumulative nitrous oxide(N_(2)O)and 1.31%-10.0%less carbon dioxide(CO_(2))than the T2 treatment.Nitrous oxide and CO_(2)emissions from the T4 and T5 treatments were considerably lower than those from the T3 treatment.No significant seasonal or interannual variability was observed in N_(2)O and CO_(2)emissions.The observed phenomena were attributed to the fluctuations in soil ammonium-and nitrate-N contents.The findings in this study revealed that long-term controlled-release/stable N fertilization resulted in reduced field N loss,benefitting vegetable yields without increasing CO_(2)emissions and highlighting the application potential of this technique for sustainable agricultural production.展开更多
Long-term straw return with appropriate nitrogen(N)fertilization increases seedcotton yield and fiber quality,and the root system plays an important role in cotton production.However,under straw return and N fertiliza...Long-term straw return with appropriate nitrogen(N)fertilization increases seedcotton yield and fiber quality,and the root system plays an important role in cotton production.However,under straw return and N fertilization,the relationship between the cotton boll-loading capacity of the root system and seedcotton yield remains unclear.In this study,a ten years of long-term field experiment was conducted in a wheat-cotton rotation system.The effects of straw treatments(straw return and straw removal)and N rates(N0,N75,N150 and N300 representing 0,75,150 and 300 kg N ha^(-1),respectively)on cotton root activity,boll-loading capacity of the root system and their relationship to seedcotton yield from 2019 to 2022 were quantified.The results showed that straw return with an appropriate N fertilization of N150 increased root biomass,the rate and components of root-bleeding sap,as well as boll-loading capacity of the root system and seedcotton yield,but decreased the ratio of root to shoot biomass.Furthermore,the root-bleeding sap rate reached the maximum at 30 d post anthesis(DPA)during the peak boll setting stage.However,the contents of nitrate-N,free amino acids and soluble sugar in root-bleeding sap decreased from 10 DPA.Notably,in 2021 and at 30 DPA,the highest contents of nitrate-N(4.8μg mL^(-1))and free amino acids(8.3μg mL^(-1)),as well as soluble sugar(3.4μg mL^(-1))were observed at N150 under straw return.The increase in seedcotton yield is positively correlated to the soluble sugar content.Straw return significantly increased the boll-loading capacity of the root system,which first increased but then decreased with the increase in N fertilization.Under straw return with N150,the maximum seecotton yield(3455-4544 kg ha^(-1))was recorded,and the largest boll loading(49-54 boll 100 g^(-1))and boll capacity(242-292 g 100 g^(-1))of root system at the boll opening stage were observed.Therefore,straw return with appropriate N fertilization improved root activity and the boll-loading capacity of the root system,thereby increasing seedcotton yield.This study provides new insights into improving seedcotton yield from the perspective of coordinating cotton growth.展开更多
Rationale:This case report describes a couple with recurrent fertilization failure despite undergoing multiple cycles of intracytoplasmic sperm injection(ICSI).The principal clinical concern was suspected oocyte activ...Rationale:This case report describes a couple with recurrent fertilization failure despite undergoing multiple cycles of intracytoplasmic sperm injection(ICSI).The principal clinical concern was suspected oocyte activation deficiency(OAD),in which fertilization is impeded due to the oocyte’s inability to initiate embryogenesis,commonly attributed to inadequate intracellular calcium(Ca^(2+))release following sperm injection.Patient concerns:The couple repeatedly experienced complete or near-complete fertilization failure in previous ICSI cycles,raising suspicion of an underlying oocyte activation defect.Diagnosis:Based on the repeated absence of fertilization post-ICSI and clinical history,a diagnosis of suspected OAD leading to recurrent ICSI fertilization failure was considered.Interventions:Artificial oocyte activation(AOA)using the calcium ionophore A23187 was performed.After ICSI,unfertilized oocytes were exposed to the ionophore to induce Ca^(2+)influx,simulating physiological calcium oscillations essential for oocyte activation.The efficacy of intervention was evaluated through subsequent embryonic development,morphological grading,and chromosomal integrity.Outcomes:Following AOA treatment,successful oocyte activation occurred,resulting in the formation of high-grade embryos with normal developmental progression.Chromosomal analysis revealed no detectable abnormalities,indicating genomic stability.Lessons:Calcium ionophore–mediated AOA may serve as an effective adjunct in cases of recurrent ICSI failure attributed to OAD.This case highlights the importance of individualized therapeutic strategies in assisted reproduction;however,further research is needed to refine protocols,validate broader clinical efficacy,and assess long-term safety,including potential epigenetic risks.展开更多
This paper presented a novel variable rate fertilization system based on the method of adjusting the active feed-roll length of a fluted roller.The feasibility of this method was discussed using analysis of the fluted...This paper presented a novel variable rate fertilization system based on the method of adjusting the active feed-roll length of a fluted roller.The feasibility of this method was discussed using analysis of the fluted roller model.One seed drill produced by Kuhn Company(France),which could sow and fertilize simultaneously,was used as a test platform to implement the mechanical structure of variable rate fertilization.The design methods for the variable rate fertilization mechanical structure and actuator were introduced in detail.A low-cost and stable embedded support decision subsystem and corresponding software were developed.The support decision subsystem is based on grid management.Each grid field cell contains information about corresponding spatial position and fertilizer application rate.A SpatiaLite database was employed to solve the spatial location search and spatial data query.Experiments were conducted to evaluate the fertilization uniformity and dynamic response time.The average value of coefficient of variation is 8.4%in five different active feed-roll lengths which reflects good uniformity.The dynamic response times for the adjustment of variable rate fertilization system from 204 kg/hm^(2) to 319 kg/hm^(2) and 319 kg/hm^(2) to 204 kg/hm^(2) are about 4.2 s.The results suggest that the variable rate fertilization system performs well in dynamic adjustment and stability.展开更多
Rational application of nitrogen （N） fertilizers is an important measure to raise N fertilizer recovery rate and reduce N loss.A two-year field experiment of rice-wheat rotation was employed to study the effects of ...Rational application of nitrogen （N） fertilizers is an important measure to raise N fertilizer recovery rate and reduce N loss.A two-year field experiment of rice-wheat rotation was employed to study the effects of N fertilization modes including a N fertilizer reduction and an organic manure replacement on crop yield,nutrient uptake,soil enzyme activity,and number of microbes as well as diversity of microbes.The result showed that 20% reduction of traditional N fertilizer dose of local farmers did not significantly change crop yield,N uptake,soil enzyme activity,and the number of microbes （bacteria,actinomycetes,and fungi）.On the basis of 20% reduction of N fertilizer,50% replacement of N fertilizer by organic manure increased the activity of sucrose,protease,urease,and phosphatase by 46-62,27-89,33-46,and 35-74%,respectively,and the number of microbes,i.e.,bacteria,actinomycetes,and fungi by 36-150,11-153,and 43-56%,respectively.Further,organic fertilizer replacement had a Shannon＇s diversity index （H） of 2.18,which was higher than that of other modes of single N fertilizer application.The results suggested that reducing N fertilizer by 20% and applying organic manure in the experimental areas could effectively lower the production costs and significantly improve soil fertility and biological properties.展开更多
The changes in humic substances （HS） is fundamental in detecting soil carbon sequestration mechanisms in natural and cultivated environments. Based on a long-term trial, the amounts of water dissolved substances （...The changes in humic substances （HS） is fundamental in detecting soil carbon sequestration mechanisms in natural and cultivated environments. Based on a long-term trial, the amounts of water dissolved substances （WSS）, humic acid （HA）, fulvic acid （FA） and humin （HU） were determined to explore the impact of long-term fertilization on HS. Increases in the amounts of WSS, HA, FA and HU were significant different among the treatments with manure. A significant correlation was found between the increased soil organic carbon （SOC） and HS （R^2=0.98, P〈0.01）. The change in the E4/E6 ratio was significantly correlated with the increased SOC （R2=0.88, P〈0.01）, HA （R^2=0.91, P〈0.01）, FA （R^2=0.91, P〈0.01） and HU （R^2=0.88, P〈0.01）. The cluster was mainly divided into two parts as manure fertilization and inorganic fertilization, based on the increases in HA, FA and HU. These results suggest that long term fertilization with manure favours carbon sequestration in HS and is mainly stabilized as HU, while the HA becomes more aliphatic. We conclude that increases in SOC can be linked to changes in the molecular characteristics of HS fractions under long term fertilization.展开更多
A systematic approach was adopted to investigate the nutrient limiting factors in gray-brown purple soils and yellow soils derived from limestone in Chongqing, China, to study balanced fertilization for corn, sweet po...A systematic approach was adopted to investigate the nutrient limiting factors in gray-brown purple soils and yellow soils derived from limestone in Chongqing, China, to study balanced fertilization for corn, sweet potato and wheat in rotation. The results showed that N, P and K were deficient in both soils, Cu, Mn, S andZn in the gray-brown purple soils and Ca, Mg, Mo and Zn for the yellow soils. Balanced fertilizer application increased yields of corn, sweet potato and wheat by 28.4%, 28.7% and 4.4%, respectively, as compared to the local farmers' practice. The systematic approach can be considered as one of the most efficient and reliable methods in fertility study.展开更多
Orchard target-oriented fertilizing with on-board sensor technology can improve fertilizer efficiency and reduce environmental pollution.Photoelectric sensors are widely used for object detection because of their low ...Orchard target-oriented fertilizing with on-board sensor technology can improve fertilizer efficiency and reduce environmental pollution.Photoelectric sensors are widely used for object detection because of their low cost and fast response time.This paper presents a Wolfberry tree dual-model detection method and the design of an orchard target-oriented variable-rate fertilization system based on photoelectric sensors.The dual-model detection method includes the Trunk Detection Model(TDM)and Canopy Detection Model(CDM),which can be applied for Wolfberry orchards at the green cluster and mature stages,respectively.A target-oriented fertilization system was designed using the dual-model method,and tested in the lab and Chinese Wolfberry orchard.The laboratory test results showed that the average center offset distances on the condition of detecting trunks,continuous canopies,and discontinuous canopies were 4.1 cm,9.1 cm and 13.1 cm,respectively.The system could ignore the signals from canes when their diameters were less than 16 mm,and also could determine the gaps within a tree when they were less than 21 cm.The orchard test results showed that the system accomplished target-oriented fertilization 95 times for 92 trees at the mature stage.The results indicated that the dual-model detection method could be used for Wolfberry trees or other trees with similar canopy changes at different growth stages.展开更多
In the traditional fertilization method,a large amount of fertilizer is applied,which causes congestion easily.It is not conducive to the sustainable development of agriculture.In this work,a vertical pneumatic fertil...In the traditional fertilization method,a large amount of fertilizer is applied,which causes congestion easily.It is not conducive to the sustainable development of agriculture.In this work,a vertical pneumatic fertilization system with a spiral Geneva mechanism was designed according to the operational requirements of variable-rate and smooth fertilization.The uniformity in discharging fertilizer with different spiral angles was simulated and analyzed by extended discrete element method(EDEM)based simulation software,from where the spiral angle of the fertilizer discharge wheel was determined to be 45°.The fertilization system includes a fertilizer apparatus with a spiral Geneva mechanism,whose optimal performance parameters were obtained from the bench experiment.The accuracy and uniformity of the fertilizer application system were taken as the evaluation indicators.The linear relationships of the discharged amount of fertilizer with the rotational speed and the opening of the fertilizer discharging wheel were verified by both static blowing fertilization and field experiments.The static blowing experimental results show that the discharged amount of fertilizer has a high linear correlation and accuracy with both the opening and rotational speed,and the highest correlation occurs with the rotational speed.The rotational speed and opening have significant effects on the discharged amount of fertilizer and the average coefficient of variation.The effect of the rotational speed was the most significant.According to the model obtained by multiple regression fittings,the optimal parameters were determined when the average coefficient of variation was small,the rotational speed was 15.9 r/min and the opening was 34.4 mm.Therefore,the purpose of precise fertilization can be achieved by adjusting the opening or rotational speed in a way to get the exact amount of fertilizer discharged as required by the corresponding crops.The field experiment showed that the variation coefficient of each fertilizer discharged decreases first and then increases with an increasing opening under different rotational speeds,which is consistent with the theoretical value.When the opening was 40 mm or 50 mm,the variation coefficient reached the minimum value,which is far less than the qualified index of 7.8%.In the static blowing experiment and the dynamic field experiment,the stability of the fertilizer discharging device can be significantly enhanced with the utilization of the pneumatic conveying fertilizer.This study can provide a theoretical reference for parameter selection and optimization of vertical spiral fertilization systems.展开更多
The effects of fertilization on the distributions of organic carbon(OC) and nitrogen(N) in soil aggregates and whether these effects vary with cropping system have not been well addressed.Such information is important...The effects of fertilization on the distributions of organic carbon(OC) and nitrogen(N) in soil aggregates and whether these effects vary with cropping system have not been well addressed.Such information is important for understanding the sequestration of OC and N in agricultural soils.In this study,the distributions of OC and N associated with soil aggregates were analyzed in different fertilization treatments in a continuous winter wheat cropping system and a legume-grain rotation system in a 27-year field experiment,to understand the effects of long-term fertilization on the distributions of OC and N in aggregates and to examine the recovery of soil OC and N in a highland agroecosystem.Manure fertilizer significantly decreased soil bulk density but increased the amount of coarse fractions and their associated OC and N stocks in the soils of both systems.Fertilizers N+phosphorus(P) and manure had similar effects on total soil OC and N stocks in both systems,but had larger effects on the OC and N stocks in>2 mm aggregates in the legume-grain rotation system than in the continuous winter wheat system.The application of P increased the OC and N stocks in>2 mm aggregates and decreased the loss of N from chemical fertilizers in the legume-grain rotation system.The results from this study suggested that P fertilizer should be applied for legume-included cropping systems and that manure with or without chemical fertilizers should be applied for semiarid cropping systems in order to enhance OC and N accumulation in soils.展开更多
Mechanisms controlling phosphorus(P) availability and the roles of microorganisms in the efficient utilization of soil P in the wheat–maize double cropping system are poorly understood.In the present study,we conduct...Mechanisms controlling phosphorus(P) availability and the roles of microorganisms in the efficient utilization of soil P in the wheat–maize double cropping system are poorly understood.In the present study,we conducted a pot experiment for four consecutive wheat–maize seasons(2016–2018) using calcareous soils with high(30.36 mg kg^(–1)) and low(9.78 mg kg^(–1)) initial Olsen-P content to evaluate the effects of conventional P fertilizer application to both wheat and maize(Pwm) along with a reduced P fertilizer application only to wheat(Pw).The microbial community structure along with soil P availability parameters and crop yield were determined.The results showed that the Pw treatment reduces the annual P input by 33.3% without affecting the total yield for at least two consecutive years as compared with the Pwm treatment in the high Olsen-P soil.Soil water-soluble P concentrations in the Pw treatment were similar to those in the Pwm treatment at the 12-leaf collar stage when maize requires the most P.Furthermore,the soil P content significantly affected soil microbial communities,especially fungal communities.Meanwhile,the relative abundances of Proteobacteria and alkaline phosphatase(ALP) activity of Pw were significantly higher(by 11.4 and 13.3%) than those of Pwm in soil with high Olsen-P.The microfloral contribution to yield was greater than that of soil P content in soil with high Olsen-P.Relative abundances of Bacillus and Rhizobium were enriched in the Pw treatment compared with the Pwm treatment.Bacillus showed a significant positive correlation with acid phosphatase(ACP) activity,and Rhizobium displayed significant positive correlations with ACP and ALP in soil with high Olsen-P,which may enhance P availability.Our findings suggested that the application of P fertilization only to wheat is practical in high P soils to ensure optimal production in the wheat and maize double cropping system and that the soil P availability and microbial community may collaborate to maintain optimal yield in a wheat–maize double cropping system.展开更多
The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).Whil...The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).While such DRFEs have been explored at low to middle latitudes,the aerosol impacts on pan-Arctic ecosystems and the contributions by anthropogenic and natural emission sources remain less quantified.Here,we perform regional simulations at 0.2o×0.2ousing a well-validated vegetation model(Yale Interactive terrestrial Biosphere,YIBs)in combination with multi-source of observations to quantify the impacts of aerosol DRFEs on the net primary productivity(NPP)in the pan-Arctic during 2001-19.Results show that aerosol DRFEs increase pan-Arctic NPP by 2.19 Pg C(12.8%)yr^(-1)under clear-sky conditions,in which natural and anthropogenic sources contribute to 8.9% and 3.9%,respectively.Under all-sky conditions,such DRFEs are largely dampened by cloud to only 0.26 Pg C(1.24%)yr^(-1),with contributions of 0.65% by natural and 0.59% by anthropogenic species.Natural aerosols cause a positive NPP trend of 0.022% yr^(-1)following the increased fire activities in the pan-Arctic.In contrast,anthropogenic aerosols induce a negative trend of-0.01% yr^(-1)due to reduced emissions from the middle latitudes.Such trends in aerosol DRFEs show a turning point in the year of 2007 with more positive NPP trends by natural aerosols but negative NPP trends by anthropogenic aerosols thereafter.Though affected by modeling uncertainties,this study suggests a likely increasing impact of aerosols on terrestrial ecosystems in the pan-Arctic under global warming.展开更多
Understanding the mechanism of soil organic carbon(SOC)sequestration is of paramount importance in sustaining crop productivity and mitigating climate change.Long-term trials were employed to investigate the responses...Understanding the mechanism of soil organic carbon(SOC)sequestration is of paramount importance in sustaining crop productivity and mitigating climate change.Long-term trials were employed to investigate the responses of total SOC and its pools,i.e.,mineral-associated OC(MOC),particulate OC(POC,containing Light-POC and Heavy-POC),to fertilization regimes at Yangling(25-year),Tianshui(35-year)and Pingliang(37-year)under a rain-fed cropping system in the Loess Plateau.The fertilization regimes in each trial included three treatments,i.e.,control(no nutrient input,CK),chemical fertilizers(CF),and organic manure plus chemical fertilizers(MCF).Relative to the CK,long-term fertilization appreciably increased SOC storage by 134,89 and 129 kg ha^(–1)yr^(–1)under CF,and 418,153 and 384 kg ha^(–1)yr^(–1)under MCF in plough layer soils(0–20 cm),respectively,at the Yangling,Tianshui and Pingliang sites.The MOC pools accounted for 72,67 and 64%of the total SOC at the above three sites with sequestration rates of 76,57 and 83 kg ha^(–1)yr^(–1)under CF and 238,118 and 156 kg ha^(–1)yr^(–1)under MCF,respectively.Moreover,the MOC pool displayed a saturation behavior under MCF conditions.The POC accordingly constituted 27,33 and 36%of SOC,of which Light-POC accounted for 11,17 and 22%and Heavy-POC for 17,16 and 15%of SOC,respectively.The sequestration rates of POC were 58,32 and 46 kg ha^(–1)yr^(–1)under CF,and 181,90 and 228 kg ha^(–1)yr^(–1)under MCF at the three respective sites,in which Light-POC explained 59,81 and 72%of POC under CF,and 60,40 and 69%of POC under MCF,with Heavy-POC accounting for the balance.Compared with CK,the application of CF alone did not affect the proportions of MOC or total POC to SOC,whereas MCF application markedly reduced the proportion of MOC and increased the POC ratio,mainly in the Light-POC pool.The distribution of SOC among different pools was closely related to the distribution and stability of aggregates.The present study confirmed that organic manure amendment not only sequestered more SOC but also significantly altered the composition of SOC,thus improving SOC quality,which is possibly related to the SOC saturation level.展开更多
Although the application of inorganic fertilizer is a widespread agronomic practice used to boost soil productivity and crop yields,the effects on soil microbiome and the metabolic mechanisms involved in the high-yiel...Although the application of inorganic fertilizer is a widespread agronomic practice used to boost soil productivity and crop yields,the effects on soil microbiome and the metabolic mechanisms involved in the high-yield response of crops to long-term fertilization remain poorly described.In this study,combined metagenomic and metabolomic analyses were used to explore the mechanism of crop yield response to the 20-year application of nitrogen-phosphorus-potassium fertilizers in a subtropical agroecosystem in Southwest China.Soil bacterial and fungal communities were monitored using16S r RNA(bacteria)and internal transcribed spacer 1(ITS1)full-length gene(fungi)amplicon sequencing technologies,and metabolites were detected using a liquid chromatograph mass spectrometer.The results revealed that,in addition to providing nutrients,long-term fertilization shaped the compositions of bacteria and fungi to increase crop yields.Long-term fertilization significantly increased the relative abundances of plant growth-promoting rhizobacteria and arbuscular mycorrhizal fungi and promoted the secretion of soil metabolites such as carbohydrates,organic acids,and organic nitrogen compounds,which were primarily enriched in amino acid metabolism pathways.The increases in carbon and nitrogen sources and bioactive substances in soil promoted the increases in plant biomass and thereby maintained soil quality and production capacity.The findings highlighted the importance of soil metabolites in maintaining soil productivity as well as crop yields,and suggested that regulating key metabolites could increase crop yields in agroecosystems.展开更多
On basis of “3414” experiment, regression analysis was conducted on rel- ative yield and fertilizer quant;.ty, and a regression equation was established, as fol- lows： Y=I 699,09 ＋52.89N -3i82P ＋59.27K-1.17N2 -0....On basis of “3414” experiment, regression analysis was conducted on rel- ative yield and fertilizer quant;.ty, and a regression equation was established, as fol- lows： Y=I 699,09 ＋52.89N -3i82P ＋59.27K-1.17N2 -0.11 p2 ＋0.06K2 ＋2.02NP-2.16NK- 1.97PK （FF=0,98）. The results of regression analysis showed F〉F0.05, indicating that fertilizer quantity is of significant regression relationship with yield. It was analyzed that yield-increasing range of N fertilizer was directly proportional to fertilizer quanti- ty, and negative yield even occurs if excessive P fertilizer is applied. In general, fertilizer effects from high to low were N fertilizer〉K ferUlizer〉P fertilizer. Besides, on equation aralysls, it was proposed the optimal fertilizer quantities included N fertilizer （N） of 270 kg, P fertilizer （PUs） of 165 kg and K fertilizer （K20） of 225 kg for achieving ideal yield of 2 500 kg/hm2 of luffa in Foshan. Key words Foshan; Luffa; Index system of fertilization; Efficiency analysis展开更多
[ Objective] To investigate the optimal culture system for in vitro fertilization （IVF） of oocyte in bovine. [ Method] The IVF of mature bovine oocytes was conducted and the fertilized eggs were cultured in vitro wi...[ Objective] To investigate the optimal culture system for in vitro fertilization （IVF） of oocyte in bovine. [ Method] The IVF of mature bovine oocytes was conducted and the fertilized eggs were cultured in vitro with different culture systems. In the traditional culture system, the TALP medium and BO medium were used as fertilization medium, respectively; and M-199 medium supplemented with 5% FCS was used as fertilized egg culture medium. In the transitional culture system, the TALP medium and BO medium were used as fertilization medium; 60% TALP and 40% M-199 supplemented with 5% FCS and 60% BO and 40% M-199 supplemented with 5% FCS were used as fertilized egg culture medium, respectively. The effects of different culture systems on fertilization rate and cleavage rate were observed. E Result] In the transitional culture system （with TALP medium as fertilization medium and with 60% TALP and 40% M-199 supplemented with 5% FCS as fertilized egg culture medium）, the fertilization rate and cleavage rate were increased to 77.8% and 55.6%, respectively. [ Conclusion] The transitional culture system （with TALP medium as fertilization medium and with 60% TALP and 40% M-199 supplemented with 5% FCS as fertilized egg culture medium） is the optimal culture system for IVF of bovine oocyte.展开更多
Influenced by animal welfare requirements and expensive labor cost, producers tend to feed layers in non-cage system such as floor rearing. With the development of commercial lines of dwarf layers, the property of dwa...Influenced by animal welfare requirements and expensive labor cost, producers tend to feed layers in non-cage system such as floor rearing. With the development of commercial lines of dwarf layers, the property of dwarf layers＇ natural mating is drawing more and more attention. In this study, the authors hybridized Nongda Ill dwarf layers with White Leghorn chickens in floor-rearing system to research whether dwarf layers had defect in natural mating. Two steps of experiments were performed. The authors detected the fertilization rate of collected eggs, observed chickens＇ behavior in step I when a hen from other group was suddenly put into and recorded copulation number of every group in step II from 7：30 to 19：30. The results indicated that drawf cocks were as good as Leghorn cocks in natrual mating under floor-rearing system while drawf hens were better than Leghorn hens. Observation results showed no difference on reaction to intermixed hens between drawf layers and Leghorn layers. The best proportion of male to female for drawf layers was 1：8 in this experiment and dwarf cocks tended to mate dwarf hens rather than Leghorn hens.展开更多
This paper conducted comparative study of the index system of ecological balanced fertilization for rice,wheat and maize by data mining method based on data of"3414 fertilizer field trials"of rice,wheat and ...This paper conducted comparative study of the index system of ecological balanced fertilization for rice,wheat and maize by data mining method based on data of"3414 fertilizer field trials"of rice,wheat and maize by published papers from national soil testing and recommendation since 2005.The main conclusions of this paper were as follow:①since the three crops all belonged to Gramineae,they were consistent in variation trends of fertilizer utilization ratio,nutrient conversion rate,relative abundance-deficiency value of soil nutrient,optimum fertilization amount in most cases.②Due to the influence of the economic production,biological production,different water conditions in paddy field and dry farmland,length of growing season,cropping system(one year before and after the rotation)and so on,sometimes the laws of four aspects above mentioned for the three crops had opposite and gradient variations.展开更多
文摘Molybdenum （Mo） and Cobalt （Co） play an important role in nitrogen （N） metabolism of grain legumes. Their applications to alkaline soils have been scarcely studied. A field experiment was set up to evaluate the Mo and Co application in common bean cv. Canario Centenario under two fertilization systems： inorganic fertilization and inoculation with Rhizobium etli. In each system, Mo and Mo ＋ Co were applied by seed impregnation at doses of 1.36 g/kg of seed for Mo and 0.26 g/kg of seed for Co; a control for each fertilization system and an absolute control were included. Yield components, nodules characteristics and N content by grains and foliage were evaluated. A completely randomized block design with seven treatments and five replications was used. Mo application increased the grain yield, grain size, nodulation and N accumulation in grains under both fertilization systems. Mo increased the total N uptake by the plant in 35.4% and 26%, for N fertilized and inoculated plants, respectively. Co application increased only nodules number and weight, and N content under inoculation. Mo application to beans cultivated in alkaline soils is recommended, but Co application is suitable only when beans are inoculated with rhizobia.
基金supported by research grants from the Natural Science Foundation of Shandong Province,China(ZR2020MC092)the Key Research and Development Project of Shandong Province,China(2019TSCYCX-33)the Key Research and Development Project of Shandong Province,China(LJNY202025).
文摘To make agricultural systems sustainable in terms of their greenness and efficiency,optimizing the tillage and fertilization practices is essential.To assess the effects of tilling and fertilization practices in wheat-maize cropping systems,a three-year field experiment was designed to quantify the carbon footprint(CF)and energy efficiency of the cropping systems in the North China Plain.The study parameters included four tillage practices(no tillage(NT),conventional tillage(CT),rotary tillage(RT),and subsoiling rotary tillage(SRT))and two fertilizer regimes(inorganic fertilizer(IF)and hybrid fertilizer with organic and inorganic components(HF)).The results indicated that the most prominent energy inputs and greenhouse gas(GHG)emissions could be ascribed to the use of fertilizers and fuel consumption.Under the same fertilization regime,ranking the tillage patterns with respect to the value of the crop yield,profit,CF,energy use efficiency(EUE)or energy productivity(EP)for either wheat or maize always gave the same sequence of SRT>RT>CT>NT.For the same tillage,the energy consumption associated with HF was higher than IF,but its GHG emissions and CF were lower while the yield and profit were higher.In terms of overall performance,tilling is more beneficial than NT,and reduced tillage practices(RT and SRT)are more beneficial than CT.The fertilization regime with the best overall performance was HF.Combining SRT with HF has significant potential for reducing CF and increasing EUE,thereby improving sustainability.Adopting measures that promote these optimizations can help to overcome the challenges posed by a lack of food security,energy crises and ecological stress.
基金supported by the Natural Science Foundation of Shandong Province,China(Nos.ZR2022MD118 and ZR2022MD050)the Beijing Academy of Agricultural and Forestry Sciences Science and Technology Innovation Capacity Construction Project,China(No.20230207)+3 种基金the Humanities and Social Science Foundation Project of Ministry of Education,China(No.22YJCZH166)the Technical System of Ecological Agriculture of Modern Agricultural Technology System in Shandong Province,China(No.SDAIT-30-02)the National Key Research and Development Program of China(No.2023YFD1701901)the Fundamental Research Funds for Central Non-profit Scientific Institution of China(No.1610132023006).
文摘Controlled-release/stable nitrogen(N)fertilizers can improve vegetable yields and achieve lower greenhouse gas emissions,resulting in cost-effective and environmentally friendly vegetable production.However,there has been limited research on the controlled-release/stable N fertilization in long-term fixed-position vegetable rotation fields.In this study,a five-year field experiment was conducted to examine the effects of long-term controlled-release/stable N fertilization in reducing greenhouse gas emissions and increasing lettuce yield.Six distinct treatments were employed for N fertilization:the control without N fertilizer(CK),normal local farming practices with application of urea fertilizer at 400 kg N ha^(-1)(T1),optimized application of urea at 320 kg N ha^(-1)(T2),optimized application of urea at 320 kg N ha^(-1)with supplementation of 1.0 kg ha^(-1)3,4-dimethylpyrazole phosphate(DMPP)as N inhibitor(T3),application of polyurethane-coated urea at 320 kg N ha^(-1)(T4),and application of polyurethane-coated urea at 320 kg N ha^(-1)with supplementation of 1.0 kg ha^(-1)DMPP(T5).The results showed that the T3,T4,and T5 treatments using controlled-release/stable N fertilization emitted about 12.2%-56.7%less average annual cumulative nitrous oxide(N_(2)O)and 1.31%-10.0%less carbon dioxide(CO_(2))than the T2 treatment.Nitrous oxide and CO_(2)emissions from the T4 and T5 treatments were considerably lower than those from the T3 treatment.No significant seasonal or interannual variability was observed in N_(2)O and CO_(2)emissions.The observed phenomena were attributed to the fluctuations in soil ammonium-and nitrate-N contents.The findings in this study revealed that long-term controlled-release/stable N fertilization resulted in reduced field N loss,benefitting vegetable yields without increasing CO_(2)emissions and highlighting the application potential of this technique for sustainable agricultural production.
基金supported by the Jiangsu Agricultural Science and Technology Innovation Fund(CX(22)2015)the Fundamental Research Funds for the Central Universities(XUEKEN2022008)+1 种基金the Innovation Center for Modern Crop Production Cosponsored by Province and Ministry(CIC-MCP)the Cotton Industry Technology Research System of Shandong Province(SDAIT-03).
文摘Long-term straw return with appropriate nitrogen(N)fertilization increases seedcotton yield and fiber quality,and the root system plays an important role in cotton production.However,under straw return and N fertilization,the relationship between the cotton boll-loading capacity of the root system and seedcotton yield remains unclear.In this study,a ten years of long-term field experiment was conducted in a wheat-cotton rotation system.The effects of straw treatments(straw return and straw removal)and N rates(N0,N75,N150 and N300 representing 0,75,150 and 300 kg N ha^(-1),respectively)on cotton root activity,boll-loading capacity of the root system and their relationship to seedcotton yield from 2019 to 2022 were quantified.The results showed that straw return with an appropriate N fertilization of N150 increased root biomass,the rate and components of root-bleeding sap,as well as boll-loading capacity of the root system and seedcotton yield,but decreased the ratio of root to shoot biomass.Furthermore,the root-bleeding sap rate reached the maximum at 30 d post anthesis(DPA)during the peak boll setting stage.However,the contents of nitrate-N,free amino acids and soluble sugar in root-bleeding sap decreased from 10 DPA.Notably,in 2021 and at 30 DPA,the highest contents of nitrate-N(4.8μg mL^(-1))and free amino acids(8.3μg mL^(-1)),as well as soluble sugar(3.4μg mL^(-1))were observed at N150 under straw return.The increase in seedcotton yield is positively correlated to the soluble sugar content.Straw return significantly increased the boll-loading capacity of the root system,which first increased but then decreased with the increase in N fertilization.Under straw return with N150,the maximum seecotton yield(3455-4544 kg ha^(-1))was recorded,and the largest boll loading(49-54 boll 100 g^(-1))and boll capacity(242-292 g 100 g^(-1))of root system at the boll opening stage were observed.Therefore,straw return with appropriate N fertilization improved root activity and the boll-loading capacity of the root system,thereby increasing seedcotton yield.This study provides new insights into improving seedcotton yield from the perspective of coordinating cotton growth.
文摘Rationale:This case report describes a couple with recurrent fertilization failure despite undergoing multiple cycles of intracytoplasmic sperm injection(ICSI).The principal clinical concern was suspected oocyte activation deficiency(OAD),in which fertilization is impeded due to the oocyte’s inability to initiate embryogenesis,commonly attributed to inadequate intracellular calcium(Ca^(2+))release following sperm injection.Patient concerns:The couple repeatedly experienced complete or near-complete fertilization failure in previous ICSI cycles,raising suspicion of an underlying oocyte activation defect.Diagnosis:Based on the repeated absence of fertilization post-ICSI and clinical history,a diagnosis of suspected OAD leading to recurrent ICSI fertilization failure was considered.Interventions:Artificial oocyte activation(AOA)using the calcium ionophore A23187 was performed.After ICSI,unfertilized oocytes were exposed to the ionophore to induce Ca^(2+)influx,simulating physiological calcium oscillations essential for oocyte activation.The efficacy of intervention was evaluated through subsequent embryonic development,morphological grading,and chromosomal integrity.Outcomes:Following AOA treatment,successful oocyte activation occurred,resulting in the formation of high-grade embryos with normal developmental progression.Chromosomal analysis revealed no detectable abnormalities,indicating genomic stability.Lessons:Calcium ionophore–mediated AOA may serve as an effective adjunct in cases of recurrent ICSI failure attributed to OAD.This case highlights the importance of individualized therapeutic strategies in assisted reproduction;however,further research is needed to refine protocols,validate broader clinical efficacy,and assess long-term safety,including potential epigenetic risks.
基金We acknowledge that the research is supported by the National Key Technology Research and Development Program(No.2012BAK17B15).
文摘This paper presented a novel variable rate fertilization system based on the method of adjusting the active feed-roll length of a fluted roller.The feasibility of this method was discussed using analysis of the fluted roller model.One seed drill produced by Kuhn Company(France),which could sow and fertilize simultaneously,was used as a test platform to implement the mechanical structure of variable rate fertilization.The design methods for the variable rate fertilization mechanical structure and actuator were introduced in detail.A low-cost and stable embedded support decision subsystem and corresponding software were developed.The support decision subsystem is based on grid management.Each grid field cell contains information about corresponding spatial position and fertilizer application rate.A SpatiaLite database was employed to solve the spatial location search and spatial data query.Experiments were conducted to evaluate the fertilization uniformity and dynamic response time.The average value of coefficient of variation is 8.4%in five different active feed-roll lengths which reflects good uniformity.The dynamic response times for the adjustment of variable rate fertilization system from 204 kg/hm^(2) to 319 kg/hm^(2) and 319 kg/hm^(2) to 204 kg/hm^(2) are about 4.2 s.The results suggest that the variable rate fertilization system performs well in dynamic adjustment and stability.
基金supported by the National Basic Research Program of China (973 Program,2007CB109308)the National High-Tech R&D Program of China (2007AA06Z332)a special grant of Application of Nuclear Techniques in Agriculture from the Ministry of Agriculture of China (200803034)
文摘Rational application of nitrogen （N） fertilizers is an important measure to raise N fertilizer recovery rate and reduce N loss.A two-year field experiment of rice-wheat rotation was employed to study the effects of N fertilization modes including a N fertilizer reduction and an organic manure replacement on crop yield,nutrient uptake,soil enzyme activity,and number of microbes as well as diversity of microbes.The result showed that 20% reduction of traditional N fertilizer dose of local farmers did not significantly change crop yield,N uptake,soil enzyme activity,and the number of microbes （bacteria,actinomycetes,and fungi）.On the basis of 20% reduction of N fertilizer,50% replacement of N fertilizer by organic manure increased the activity of sucrose,protease,urease,and phosphatase by 46-62,27-89,33-46,and 35-74%,respectively,and the number of microbes,i.e.,bacteria,actinomycetes,and fungi by 36-150,11-153,and 43-56%,respectively.Further,organic fertilizer replacement had a Shannon＇s diversity index （H） of 2.18,which was higher than that of other modes of single N fertilizer application.The results suggested that reducing N fertilizer by 20% and applying organic manure in the experimental areas could effectively lower the production costs and significantly improve soil fertility and biological properties.
基金supported by the National Natural Science Foundation of China (30873470)the National Special Research Fund for Non-Profit Sector (Agriculture) (201203030)the grant from Qingdao Agricultural University, China (631214)
文摘The changes in humic substances （HS） is fundamental in detecting soil carbon sequestration mechanisms in natural and cultivated environments. Based on a long-term trial, the amounts of water dissolved substances （WSS）, humic acid （HA）, fulvic acid （FA） and humin （HU） were determined to explore the impact of long-term fertilization on HS. Increases in the amounts of WSS, HA, FA and HU were significant different among the treatments with manure. A significant correlation was found between the increased soil organic carbon （SOC） and HS （R^2=0.98, P〈0.01）. The change in the E4/E6 ratio was significantly correlated with the increased SOC （R2=0.88, P〈0.01）, HA （R^2=0.91, P〈0.01）, FA （R^2=0.91, P〈0.01） and HU （R^2=0.88, P〈0.01）. The cluster was mainly divided into two parts as manure fertilization and inorganic fertilization, based on the increases in HA, FA and HU. These results suggest that long term fertilization with manure favours carbon sequestration in HS and is mainly stabilized as HU, while the HA becomes more aliphatic. We conclude that increases in SOC can be linked to changes in the molecular characteristics of HS fractions under long term fertilization.
文摘A systematic approach was adopted to investigate the nutrient limiting factors in gray-brown purple soils and yellow soils derived from limestone in Chongqing, China, to study balanced fertilization for corn, sweet potato and wheat in rotation. The results showed that N, P and K were deficient in both soils, Cu, Mn, S andZn in the gray-brown purple soils and Ca, Mg, Mo and Zn for the yellow soils. Balanced fertilizer application increased yields of corn, sweet potato and wheat by 28.4%, 28.7% and 4.4%, respectively, as compared to the local farmers' practice. The systematic approach can be considered as one of the most efficient and reliable methods in fertility study.
基金This work was supported by Shaanxi Science and Technology Projects(2017KJXX-54 and 2014KTCL02-15)Science and Technology Project of Northwest A&F University(Z222021560)the"Young Faculty Study Abroad Program"of Northwest A&F University Scholarship Fund.
文摘Orchard target-oriented fertilizing with on-board sensor technology can improve fertilizer efficiency and reduce environmental pollution.Photoelectric sensors are widely used for object detection because of their low cost and fast response time.This paper presents a Wolfberry tree dual-model detection method and the design of an orchard target-oriented variable-rate fertilization system based on photoelectric sensors.The dual-model detection method includes the Trunk Detection Model(TDM)and Canopy Detection Model(CDM),which can be applied for Wolfberry orchards at the green cluster and mature stages,respectively.A target-oriented fertilization system was designed using the dual-model method,and tested in the lab and Chinese Wolfberry orchard.The laboratory test results showed that the average center offset distances on the condition of detecting trunks,continuous canopies,and discontinuous canopies were 4.1 cm,9.1 cm and 13.1 cm,respectively.The system could ignore the signals from canes when their diameters were less than 16 mm,and also could determine the gaps within a tree when they were less than 21 cm.The orchard test results showed that the system accomplished target-oriented fertilization 95 times for 92 trees at the mature stage.The results indicated that the dual-model detection method could be used for Wolfberry trees or other trees with similar canopy changes at different growth stages.
基金The authors gratefully acknowledge the support was provided by the National Key Research and Development Program of China(Grant No.2017YFD0700700,2017YFD0700704,2016YFD0200600,2016YFD0200606,2018YFD0200700).
文摘In the traditional fertilization method,a large amount of fertilizer is applied,which causes congestion easily.It is not conducive to the sustainable development of agriculture.In this work,a vertical pneumatic fertilization system with a spiral Geneva mechanism was designed according to the operational requirements of variable-rate and smooth fertilization.The uniformity in discharging fertilizer with different spiral angles was simulated and analyzed by extended discrete element method(EDEM)based simulation software,from where the spiral angle of the fertilizer discharge wheel was determined to be 45°.The fertilization system includes a fertilizer apparatus with a spiral Geneva mechanism,whose optimal performance parameters were obtained from the bench experiment.The accuracy and uniformity of the fertilizer application system were taken as the evaluation indicators.The linear relationships of the discharged amount of fertilizer with the rotational speed and the opening of the fertilizer discharging wheel were verified by both static blowing fertilization and field experiments.The static blowing experimental results show that the discharged amount of fertilizer has a high linear correlation and accuracy with both the opening and rotational speed,and the highest correlation occurs with the rotational speed.The rotational speed and opening have significant effects on the discharged amount of fertilizer and the average coefficient of variation.The effect of the rotational speed was the most significant.According to the model obtained by multiple regression fittings,the optimal parameters were determined when the average coefficient of variation was small,the rotational speed was 15.9 r/min and the opening was 34.4 mm.Therefore,the purpose of precise fertilization can be achieved by adjusting the opening or rotational speed in a way to get the exact amount of fertilizer discharged as required by the corresponding crops.The field experiment showed that the variation coefficient of each fertilizer discharged decreases first and then increases with an increasing opening under different rotational speeds,which is consistent with the theoretical value.When the opening was 40 mm or 50 mm,the variation coefficient reached the minimum value,which is far less than the qualified index of 7.8%.In the static blowing experiment and the dynamic field experiment,the stability of the fertilizer discharging device can be significantly enhanced with the utilization of the pneumatic conveying fertilizer.This study can provide a theoretical reference for parameter selection and optimization of vertical spiral fertilization systems.
基金supported by the National Natural Science Foundation of China(Nos.41571296,41622105,and 41571130082)the program from Northwest A&F University,China(No.2452017028)the program from State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,China(No.A314021403-Q5)
文摘The effects of fertilization on the distributions of organic carbon(OC) and nitrogen(N) in soil aggregates and whether these effects vary with cropping system have not been well addressed.Such information is important for understanding the sequestration of OC and N in agricultural soils.In this study,the distributions of OC and N associated with soil aggregates were analyzed in different fertilization treatments in a continuous winter wheat cropping system and a legume-grain rotation system in a 27-year field experiment,to understand the effects of long-term fertilization on the distributions of OC and N in aggregates and to examine the recovery of soil OC and N in a highland agroecosystem.Manure fertilizer significantly decreased soil bulk density but increased the amount of coarse fractions and their associated OC and N stocks in the soils of both systems.Fertilizers N+phosphorus(P) and manure had similar effects on total soil OC and N stocks in both systems,but had larger effects on the OC and N stocks in>2 mm aggregates in the legume-grain rotation system than in the continuous winter wheat system.The application of P increased the OC and N stocks in>2 mm aggregates and decreased the loss of N from chemical fertilizers in the legume-grain rotation system.The results from this study suggested that P fertilizer should be applied for legume-included cropping systems and that manure with or without chemical fertilizers should be applied for semiarid cropping systems in order to enhance OC and N accumulation in soils.
基金supported by the National Natural Science Foundation of China (41977019)the National Key Research and Development Program of China (2017YFD0200201 and 2017YFD0200706)+1 种基金the Shandong Key Research and Development Program, China (2019GNC106011)the Provincial Agricultural Science and Technology Park Construction Project, Shandong (LKZ2018143)。
文摘Mechanisms controlling phosphorus(P) availability and the roles of microorganisms in the efficient utilization of soil P in the wheat–maize double cropping system are poorly understood.In the present study,we conducted a pot experiment for four consecutive wheat–maize seasons(2016–2018) using calcareous soils with high(30.36 mg kg^(–1)) and low(9.78 mg kg^(–1)) initial Olsen-P content to evaluate the effects of conventional P fertilizer application to both wheat and maize(Pwm) along with a reduced P fertilizer application only to wheat(Pw).The microbial community structure along with soil P availability parameters and crop yield were determined.The results showed that the Pw treatment reduces the annual P input by 33.3% without affecting the total yield for at least two consecutive years as compared with the Pwm treatment in the high Olsen-P soil.Soil water-soluble P concentrations in the Pw treatment were similar to those in the Pwm treatment at the 12-leaf collar stage when maize requires the most P.Furthermore,the soil P content significantly affected soil microbial communities,especially fungal communities.Meanwhile,the relative abundances of Proteobacteria and alkaline phosphatase(ALP) activity of Pw were significantly higher(by 11.4 and 13.3%) than those of Pwm in soil with high Olsen-P.The microfloral contribution to yield was greater than that of soil P content in soil with high Olsen-P.Relative abundances of Bacillus and Rhizobium were enriched in the Pw treatment compared with the Pwm treatment.Bacillus showed a significant positive correlation with acid phosphatase(ACP) activity,and Rhizobium displayed significant positive correlations with ACP and ALP in soil with high Olsen-P,which may enhance P availability.Our findings suggested that the application of P fertilization only to wheat is practical in high P soils to ensure optimal production in the wheat and maize double cropping system and that the soil P availability and microbial community may collaborate to maintain optimal yield in a wheat–maize double cropping system.
基金jointly supported by the National Key Research and Development Program of China(Grant No.2022YFE0106500)Jiangsu Science Fund for Distinguished Young Scholars(Grant No.BK20200040)。
文摘The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).While such DRFEs have been explored at low to middle latitudes,the aerosol impacts on pan-Arctic ecosystems and the contributions by anthropogenic and natural emission sources remain less quantified.Here,we perform regional simulations at 0.2o×0.2ousing a well-validated vegetation model(Yale Interactive terrestrial Biosphere,YIBs)in combination with multi-source of observations to quantify the impacts of aerosol DRFEs on the net primary productivity(NPP)in the pan-Arctic during 2001-19.Results show that aerosol DRFEs increase pan-Arctic NPP by 2.19 Pg C(12.8%)yr^(-1)under clear-sky conditions,in which natural and anthropogenic sources contribute to 8.9% and 3.9%,respectively.Under all-sky conditions,such DRFEs are largely dampened by cloud to only 0.26 Pg C(1.24%)yr^(-1),with contributions of 0.65% by natural and 0.59% by anthropogenic species.Natural aerosols cause a positive NPP trend of 0.022% yr^(-1)following the increased fire activities in the pan-Arctic.In contrast,anthropogenic aerosols induce a negative trend of-0.01% yr^(-1)due to reduced emissions from the middle latitudes.Such trends in aerosol DRFEs show a turning point in the year of 2007 with more positive NPP trends by natural aerosols but negative NPP trends by anthropogenic aerosols thereafter.Though affected by modeling uncertainties,this study suggests a likely increasing impact of aerosols on terrestrial ecosystems in the pan-Arctic under global warming.
基金sponsored by the Ministry of Agriculture and Rural Affairs of China under Special funds for the Operation and Maintenance of Scientific Research Facilities(G202010-2)。
文摘Understanding the mechanism of soil organic carbon(SOC)sequestration is of paramount importance in sustaining crop productivity and mitigating climate change.Long-term trials were employed to investigate the responses of total SOC and its pools,i.e.,mineral-associated OC(MOC),particulate OC(POC,containing Light-POC and Heavy-POC),to fertilization regimes at Yangling(25-year),Tianshui(35-year)and Pingliang(37-year)under a rain-fed cropping system in the Loess Plateau.The fertilization regimes in each trial included three treatments,i.e.,control(no nutrient input,CK),chemical fertilizers(CF),and organic manure plus chemical fertilizers(MCF).Relative to the CK,long-term fertilization appreciably increased SOC storage by 134,89 and 129 kg ha^(–1)yr^(–1)under CF,and 418,153 and 384 kg ha^(–1)yr^(–1)under MCF in plough layer soils(0–20 cm),respectively,at the Yangling,Tianshui and Pingliang sites.The MOC pools accounted for 72,67 and 64%of the total SOC at the above three sites with sequestration rates of 76,57 and 83 kg ha^(–1)yr^(–1)under CF and 238,118 and 156 kg ha^(–1)yr^(–1)under MCF,respectively.Moreover,the MOC pool displayed a saturation behavior under MCF conditions.The POC accordingly constituted 27,33 and 36%of SOC,of which Light-POC accounted for 11,17 and 22%and Heavy-POC for 17,16 and 15%of SOC,respectively.The sequestration rates of POC were 58,32 and 46 kg ha^(–1)yr^(–1)under CF,and 181,90 and 228 kg ha^(–1)yr^(–1)under MCF at the three respective sites,in which Light-POC explained 59,81 and 72%of POC under CF,and 60,40 and 69%of POC under MCF,with Heavy-POC accounting for the balance.Compared with CK,the application of CF alone did not affect the proportions of MOC or total POC to SOC,whereas MCF application markedly reduced the proportion of MOC and increased the POC ratio,mainly in the Light-POC pool.The distribution of SOC among different pools was closely related to the distribution and stability of aggregates.The present study confirmed that organic manure amendment not only sequestered more SOC but also significantly altered the composition of SOC,thus improving SOC quality,which is possibly related to the SOC saturation level.
基金financially supported by the Provincial Key Research and Development Program of Yunnan,China(No.2018BB015)the Provincial Basic Application Research Project of Yunnan,China(No.2019YD096)the Research Project on Utilizing Efficiency of Nitrogen with AM Fungi about Intercropping System on Plateau Sloping Arable Land(No.31660378)。
文摘Although the application of inorganic fertilizer is a widespread agronomic practice used to boost soil productivity and crop yields,the effects on soil microbiome and the metabolic mechanisms involved in the high-yield response of crops to long-term fertilization remain poorly described.In this study,combined metagenomic and metabolomic analyses were used to explore the mechanism of crop yield response to the 20-year application of nitrogen-phosphorus-potassium fertilizers in a subtropical agroecosystem in Southwest China.Soil bacterial and fungal communities were monitored using16S r RNA(bacteria)and internal transcribed spacer 1(ITS1)full-length gene(fungi)amplicon sequencing technologies,and metabolites were detected using a liquid chromatograph mass spectrometer.The results revealed that,in addition to providing nutrients,long-term fertilization shaped the compositions of bacteria and fungi to increase crop yields.Long-term fertilization significantly increased the relative abundances of plant growth-promoting rhizobacteria and arbuscular mycorrhizal fungi and promoted the secretion of soil metabolites such as carbohydrates,organic acids,and organic nitrogen compounds,which were primarily enriched in amino acid metabolism pathways.The increases in carbon and nitrogen sources and bioactive substances in soil promoted the increases in plant biomass and thereby maintained soil quality and production capacity.The findings highlighted the importance of soil metabolites in maintaining soil productivity as well as crop yields,and suggested that regulating key metabolites could increase crop yields in agroecosystems.
基金Supported by High-efficient Cultivation Technology System Construction Project of Characteristic Vegetable in Foshan([2015]12)Special Fund of Minstry of Agriculture(201503106)~~
文摘On basis of “3414” experiment, regression analysis was conducted on rel- ative yield and fertilizer quant;.ty, and a regression equation was established, as fol- lows： Y=I 699,09 ＋52.89N -3i82P ＋59.27K-1.17N2 -0.11 p2 ＋0.06K2 ＋2.02NP-2.16NK- 1.97PK （FF=0,98）. The results of regression analysis showed F〉F0.05, indicating that fertilizer quantity is of significant regression relationship with yield. It was analyzed that yield-increasing range of N fertilizer was directly proportional to fertilizer quanti- ty, and negative yield even occurs if excessive P fertilizer is applied. In general, fertilizer effects from high to low were N fertilizer〉K ferUlizer〉P fertilizer. Besides, on equation aralysls, it was proposed the optimal fertilizer quantities included N fertilizer （N） of 270 kg, P fertilizer （PUs） of 165 kg and K fertilizer （K20） of 225 kg for achieving ideal yield of 2 500 kg/hm2 of luffa in Foshan. Key words Foshan; Luffa; Index system of fertilization; Efficiency analysis
基金supported by the Scientific Research & Development Fund of Tianjin Agricultural University
文摘[ Objective] To investigate the optimal culture system for in vitro fertilization （IVF） of oocyte in bovine. [ Method] The IVF of mature bovine oocytes was conducted and the fertilized eggs were cultured in vitro with different culture systems. In the traditional culture system, the TALP medium and BO medium were used as fertilization medium, respectively; and M-199 medium supplemented with 5% FCS was used as fertilized egg culture medium. In the transitional culture system, the TALP medium and BO medium were used as fertilization medium; 60% TALP and 40% M-199 supplemented with 5% FCS and 60% BO and 40% M-199 supplemented with 5% FCS were used as fertilized egg culture medium, respectively. The effects of different culture systems on fertilization rate and cleavage rate were observed. E Result] In the transitional culture system （with TALP medium as fertilization medium and with 60% TALP and 40% M-199 supplemented with 5% FCS as fertilized egg culture medium）, the fertilization rate and cleavage rate were increased to 77.8% and 55.6%, respectively. [ Conclusion] The transitional culture system （with TALP medium as fertilization medium and with 60% TALP and 40% M-199 supplemented with 5% FCS as fertilized egg culture medium） is the optimal culture system for IVF of bovine oocyte.
文摘Influenced by animal welfare requirements and expensive labor cost, producers tend to feed layers in non-cage system such as floor rearing. With the development of commercial lines of dwarf layers, the property of dwarf layers＇ natural mating is drawing more and more attention. In this study, the authors hybridized Nongda Ill dwarf layers with White Leghorn chickens in floor-rearing system to research whether dwarf layers had defect in natural mating. Two steps of experiments were performed. The authors detected the fertilization rate of collected eggs, observed chickens＇ behavior in step I when a hen from other group was suddenly put into and recorded copulation number of every group in step II from 7：30 to 19：30. The results indicated that drawf cocks were as good as Leghorn cocks in natrual mating under floor-rearing system while drawf hens were better than Leghorn hens. Observation results showed no difference on reaction to intermixed hens between drawf layers and Leghorn layers. The best proportion of male to female for drawf layers was 1：8 in this experiment and dwarf cocks tended to mate dwarf hens rather than Leghorn hens.
基金Major Scientific and Technological Projects in Guangxi(GUIKE AA17204077)Special Project of Guangxi Science and Technology Base and Talent(GUIKE AD18126012)+2 种基金First-class Discipline(Geography)Construction Project in GuangxiSpecial Funds for"Guangxi Bagui Scholars"Collaborative Innovation Task of Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences—Integration and Demonstration of Green and Efficient Agricultural Technology Innovation in Danjiangkou Water Conservation Area(CAAS-XTCX2016015).
文摘This paper conducted comparative study of the index system of ecological balanced fertilization for rice,wheat and maize by data mining method based on data of"3414 fertilizer field trials"of rice,wheat and maize by published papers from national soil testing and recommendation since 2005.The main conclusions of this paper were as follow:①since the three crops all belonged to Gramineae,they were consistent in variation trends of fertilizer utilization ratio,nutrient conversion rate,relative abundance-deficiency value of soil nutrient,optimum fertilization amount in most cases.②Due to the influence of the economic production,biological production,different water conditions in paddy field and dry farmland,length of growing season,cropping system(one year before and after the rotation)and so on,sometimes the laws of four aspects above mentioned for the three crops had opposite and gradient variations.
