Cumulative live birth rates of in vitro fertilization/intracytoplasmic sperm injection after multiple complete cycles in China

There were few studies of cumulative live birth rates(CLBRs) based on multicenter reproductive clinical data from the general Chinese population.Here we report a retrospective cohort study,including 14 311 women with17 315 cycles,in three reproductive centers to evaluate two estimated parameters of CLBRs with multiple transfer cycles of in vitro fertilization(IVF)/intracytoplasmic sperm injection(ICSI) in a Chinese population.We found that CLBRs were related to female age and endometrial thickness.By the fourth transfer cycle,the conservative and optimal estimates of CLBRs were 52.95% and 77.30% in women under 30 years of age,and 18.17% and26.51% in those 37 years of age or older,respectively.The two estimates were 44.70% and 63.15% in women with endometrial thickness more than 7 mm,and 32.05% and 46.18% in those with less than 7 mm,respectively.In addition,body mass index(BMI),duration of infertility,and infertility diagnoses may also be related to CLBRs on certain conditions.The findings from this study on CLBRs after multiple transfer cycles of IVF/ICSI treatment on different conditions in the Chinese population should be beneficial to both infertile couples and clinicians.

Effect of Fasting of Ramadan on Infertile Women Undergoing In-Vitro Fertilization/Intracytoplasmic Sperm Injection Cycles: A Prospective Cohort Study

Objective: To determine the effects of fasting of Ramadan in patients undergoing in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles. Design: A prospective cohort study conducted during Ramadan. Setting: Ain Shams University IVF centre. Population: Three hundred fasting, infertile women undergoing their first trial of IVF/ICSI and 300 non-fasting matched controls undergoing the same procedure during Ramadan. Methods: Anxiety and depression were measured by the Hospital Anxiety and Depression Scale, at the start of the induction protocol. All the successful pregnant women were followed up until delivery. Main Outcome Measures: The primary outcome measure was the live birth rate. Results: The live birth rate was higher in the fasting group than in the non-fasting group;this was not significant (43% vs. 40%, P = 0.46). The fasting group needed higher doses and durations of induction. Embryo quality did not differ between both groups. The pregnancy complication rate among successful cases was higher in the fasting group (52.9% vs. 40.4%, P = 0.03);however, the frequencies of anxiety and depression were significantly lower than those in the non-fasting group (18% vs. 38%, P P < 0.00001, respectively). Conclusion: Fasting during Ramadan does not seem to significantly affect the IVF/ICSI outcome;however, it significantly decreased the anxiety and depression usually associated with these procedures.

Real value oftheoocyteswith smooth endoplasmic reticulum aggregates in in vitro fertilization/intracytoplasmic sperm injection cycle: a retrospective cohort study

objective:The management of oocytes affected by smooth endoplasmic reticulum aggregates(SERa)remains debatable.To understand how to manage SERa+oocytes and cycles,we performed a retrospective cohort study and analyzed the impact of SERa+cycles and oocytes on clinical and neonatal outcomes.Methods:We included 4856 cycles(149 SERa+and 4707 SERa-)from 4201 women(age:21-42 years)who received in vitro fertilization/intracytoplasmic sperm injection(IVF/ICSl)treatments at the Center of Reproductive Medicine,First Affliated Hospital of Army Military University,from 2016 to 2019.SERa+cycles had at least one SERa oocyte in the oocyte cohort.All 1722 oocytes in the SERa+cycle were divided into SERa+(405)and SERa-(1317)oocytes.Results:The rates of two pronuclei(2PN)and high-quality embryos were lower in SERa+cycles than in SERa-cycles,regardless of IVF or ICSI(P<0.05).As the proportion of SERa+oocytes increased in the SERa+cycles,the rate of high-quality embryos declined gradually(P<0.05).Furthermore,the rate of 2PN in SERa+oocytes was significantly lower than that in SERa-oocytes(P<0.05).Regardless of whether IVF or ICSl insemination was performed,no significant differences in terms of clinical pregnancy rate and spontaneous abortion rate were observed between SERa+and SERa-cycles or between SERa+and SERa-oocytes(P>0.05).conclusion:Normal fertilization with SERa+cycles and oocytes was substantially reduced,regardless of the insemination method.Embryos originating from SERa+oocytes can be transferred when there are no other options,but fully informed consent and strict follow-up of fetal development are mandatory.

Clomiphene Citrate or Medroxyprogesterone Acetate with Human Menopausal Gonadotropin in Poor Responders during In vitro Fertilization/Intracytoplasmic Sperm Injection Treatments Combined with Embryo Cryopreservation?

Objective:This study aimed to compare the efficacy of clomiphene citrate(CC)with human menopausal gonadotropin(hMG)and that of medroxyprogesterone acetate(MPA)with hMG in poor responders defined according to the Bologna criteria.Methods:The data of patients with poor ovarian response(POR)according to the Bologna criteria from September 2016 to November 2017 were retrospectively reviewed.All participants received either CC+hMG or the progesterone-primed ovarian stimulation protocol(PPOS)protocol.Results:A total of 340 patients and 563 in vitro fertilization cycles were analyzed in this study.The incidence of spontaneous luteinizing hormone(LH)surge and the mean LH level on trigger day were significantly lower in the PPOS group than in the CC+HMG group(0.04%vs.3.49%and 4.26±3.59 vs.9.38±6.92 mIU/mL,respectively,P<0.05);however,the incidence of premature ovulation was similar between the two groups.The number of viable embryos harvested was not statistically different between the two groups(1.7±1.1 vs.1.5±0.8,P=0.06).The mean dose and duration of hMG were significantly higher in the PPOS group than in the CC+hMG group(908.7±556.6 vs.177.9±214.5 IU and 6.0±3.4 vs.1.2±1.5 days,respectively,P<0.05).However,the number of oocytes retrieved,number of metaphase II oocytes,and fertilization rate were comparable between the two groups.Conclusions:The CC with low-dose gonadotropin strategy was superior to the MPA with hMG protocol for POR.

A Modified Ultra-Long Downregulation Protocol Improves Pregnancy Outcomes in High Body Mass Index Patients Undergoing In vitro Fertilization/Intracytoplasmic Sperm Injection Treatment

Objective:Overweight and obesity are increasingly epidemic and negatively related to reproductive outcome.The aim of this study was to investigate the advantages of a modified ultra-long downregulation protocol on pregnancy outcomes of patients with high body mass index(BMI)undergoingin vitro fertilization(IVF)/intracytoplasmic sperm injection(ICSI),compared to the long protocol(LP).Methods:We retrospectively analyzed the clinical data of 3,920 infertile patients at the Reproductive and Genetic Hospital of Citic-Xiangya from January 2012 to December 2017 by propensity score matching(PSM).Patients were divided into two groups:modified ultra-LP(MULP)(n=1,960)and LP(n=1,960).Results:In the MULP group,live birth rate(52.65%vs.46.79%,P<0.001,odds ratio[OR]:1.784,95%confidence interval[CI]:1.563-2.036),clinical pregnancy rate(62.50%vs.57.91%,P=0.003,OR:1.211,95%CI:1.066-1.377),and implantation rate(53.24%vs.49.65%,P=0.004,OR:1.155,95%CI:1.048-1.272)were statistically significantly higher than those of the LP group.Moreover,the cycle cancellation rates(12.70%vs.15.15%,P=0.027,OR:0.815,95%CI:0.68-0.977),abortion rates(12%vs.14.8%,P=0.046,OR:0.785,95%CI:0.619-0.996),and ectopic pregnancy rates(1.06%vs.2.11%,P=0.04,OR:0.497,95%CI:0.252-0.98)were lower than those in the LP group.Conclusion:The modified ultra-long downregulation protocol improved the pregnancy outcomes in patients with high BMI undergoing IVF/ICSI treatment,providing a potential option for physicians when deciding an optimized ovary stimulation protocol for high BMI patients.

The Clinical Outcomes of In Vitro Fertilization/Intracytoplasmic Sperm Injection Treatments in 43 Women with a History of Gestational Trophoblastic Disease

Background:To analyze the clinical outcomes of in vitro fertilization(IVF)/intracytoplasmic sperm injection treatments in women with a history of gestational trophoblastic disease(GTD).Methods:This retrospective study included 43 patients with a history of GTD as the study group and 43 matched patients as the control group.The patients in the study group were divided into two groups according to the therapy received.Patients in Subgroup A(n=32)underwent uterine curettage treatment only.Patients in Subgroup B(n=11)underwent uterine curettage combined with chemotherapy.The characteristics of ovarian stimulation and outcomes of embryos and pregnancy were compared.Results:In the first cycle,there was a higher number of retrieved oocytes and normal fertilized oocytes in the control group than those in the study group(9.2 vs.6.2 and 6.0 vs.4.0,respectively;P<0.05);however,a similar mature oocyte rate(83.5%vs.85.0%),normal fertilization rate(84.5%vs.80.1%),number of good-quality embryos(1 vs.2),and viable embryos(2 vs.2)were found between the two groups(P>0.05).There was no difference in the outcomes between Subgroup A and Subgroup B.There was a significant difference in thickness of the endometrium between the control group and study group(10.9 mm vs.9.2 mm,respectively;P<0.05).The biochemical pregnancy rate and ongoing pregnancy rate in the control group were significantly higher than those in the study group(51.4%vs.31.7%and 37.8%vs.18.3%,respectively;P<0.05).In the study group,28(93.3%)patients had intrauterine adhesion(IUA)and 23(76.7%)patients used an intrauterine device(IUD),which were both significantly higher than those in control group(P<0.05).In addition,the rate of IUA in second-look hysteroscopy was lower than that in the first surgery in the study group(P<0.05).Conclusions:Patients with a history of GTD can present with a similar normal fertilization rate and number of viable embryos.However,patients with a history of GTD may have a thinner endometrium and lower ongoing pregnancy rate.Hysteroscopy before frozen embryo transfer and usage of an IUD can improve the occurrence of IUA.

Synergistic effects of planting density and nitrogen fertilization on chlorophyll degradation and leaf senescence after silking in maize

Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the activities of Chl a-degrading enzymes after silking,and the post-silking dry matter accumulation and grain yield under multiple planting densities and N fertilization rates.The dynamic change of GLA_(ear)after silking fitted to the logistic model,and the GLA_(ear) duration and the GLAearat 42 d after silking were affected mainly by the duration of the initial senescence period(T_(1))which was a key factor of the leaf senescence.The average chlorophyllase(CLH)activity was 8.3 times higher than pheophytinase activity and contributed most to the Chl content,indicating that CLH is a key enzyme for degrading Chl a in maize.Increasing density increased the CLH activity and decreased the Chl content,T1,GLAear,and GLA_(ear) duration.Under high density,appropriate N application reduced CLH activity,increased Chl content,prolonged T1,alleviated high-density-induced leaf senescence,and increased post-silking dry matter accumulation and grain yield.

Simulation of the Ecosystem Productivity Responses to Aerosol Diffuse Radiation Fertilization Effects over the Pan-Arctic during 2001–19

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.

Persistence of fertilization effects on soil organic carbon in degraded alpine wetlands in the Yellow River source region

In the restoration of degraded wetlands,fertilization can improve the vegetation-soil-microorganisms complex,thereby affecting the organic carbon content.However,it is currently unclear whether these effects are sustainable.This study employed Biolog-Eco surveys to investigate the changes in vegetation characteristics,soil physicochemical properties,and soil microbial functional diversity in degraded alpine wetlands of the source region of the Yellow River at 3 and 15 months after the application of nitrogen,phosphorus,and organic mixed fertilizer.The following results were obtained:The addition of nitrogen fertilizer and organic compost significantly affects the soil organic carbon content in degraded wetlands.Three months after fertilization,nitrogen addition increases soil organic carbon in both lightly and severely degraded wetlands,whereas after 15 months,organic compost enhanced the soil organic carbon level in severely degraded wetlands.Structural equation modeling indicates that fertilization decreases the soil pH and directly or indirectly influences the soil organic carbon levels through variations in the soil water content and the aboveground biomass of vegetation.Three months after fertilization,nitrogen fertilizer showed a direct positive effect on soil organic carbon.However,organic mixed fertilizer indirectly reduced soil organic carbon by increasing biomass and decreasing soil moisture.After 15 months,none of the fertilizers significantly affected the soil organic carbon level.In summary,it can be inferred that the addition of nitrogen fertilizer lacks sustainability in positively influencing the organic carbon content.

Calcium-Magnesium Ca/Mg Ratios and Their Agronomic Implications for the Optimization of Phosphate Fertilization in Rainfed Rice Farming on Acidic Ferralsol in the Forest Zone of Ivory Coast

This study is a contribution to improving rice productivity on acidic plateau soils of the tropical rainforest zone. It is based on taking into account the cationic balances of the soil in order to optimize the phosphorus (P) nutrition of rice on these acidic soils, where this nutrient constitutes a limiting factor for agricultural production. Three (3) pot trials were conducted in Adiopodoumé in the forested south of Côte d’Ivoire. The interactive effects of calcium carbonate (0, 25, 50 and 75 kg Ca ha−1) and magnesium sulfate (0, 25, 50 and 75 kg Mg ha−1) were evaluated on the response of NERICA 5 rice at doses 0, 25, 50 and 75 kg P ha−1 of natural phosphate from Togo, applied only once at the start of the experiment. Additional fertilizers of nitrogen (N) (100 kg N ha−1) and potassium (K) (50 kg KCl ha−1) were added to each of the tests in a split-plot device. The test results revealed a paddy production potential of approximately 3 to 5 t⋅ha−1 for NERICA 5 on an acidic soil, under the effect of the interaction of P, Ca and Mg. The quadratic response of rice yield to the doses of these fertilizers would be more dependent on their balance, itself influenced by Ca nutrition. For the sustainability and maintenance of rice production in agro-ecology studied, it was recommended doses of 38 kg Ca ha−1, 34 kg Mg ha−1 in a Ca/Mg ratio (1/1) with intakes of 41 kg P ha−1, overall in a ratio 1/1/1 (P/Ca/Mg) more favorable to the availability of free iron considered a guiding element of mineral nutrition. Thus, these promising results should be confirmed in a real environment for better management of the fertilization of rice cultivated on acidic plateau soils in Côte d’Ivoire.

Intracytoplasmic sperm injection in cases with a history of in vitro fertilization failure

<abstract>Aim: To evaluate the effect of intracytoplasmic sperm injection (ICSI) in the management of cases with a history of conventional in vitro fertilization (IVF) failure. Methods: Two groups of patients, 19 with normal semen parameters and a history of IVF failure (metaphase Ⅱ oocytes: 0~30 %) and 28 with severe male factor infertility received ICSI technology during the same period. Ovarian stimulation was achieved by conventional procedure. Transvaginal ultrasound-guided oocyte collection was done 35~37 h after human chorionic gonadotrophin (hCG) injection. Only metaphase Ⅱ oocytes were selected for microinjection. Results: Fertilization was achieved with ICSI in all the patients. The fertilization rate (75.6 %±21.1 % vs. 73.9 %±19.2 %), cleavage rate (85.1 %±19.3 % vs. 82.7 %±22.1 %), clinical pregnancy rate per embryo transfer cycle (31.6 % vs. 28.6 %) and implantation rate per embryo (15.3 % vs. 14.4 %) did not differ significantly between the two groups. Conclusion: ICSI is a valuable method for couples with a history of IVF failure. These patients may have a similar ICSI result as in severe male infertility.

Varicocele management in the era of in vitro fertilization/intracytoplasmic sperm injection

Varicocele is the most common surgically treatable cause of male infertility, and often results in alterations in semen parameters, sperm DNA damage, and changes to the seminal milieu. Varicocele repair can result in improvement in these parameters in the majority of men with clinical varicocele; data supporting repair in men with subclinical varicocele are less definitive. In couples seeking fertility using assisted reproductive technologies （ARTs）, varicocele repair may offer improvement in semen parameters and sperm health that can increase the likelihood of successful fertilization using techniques such as in vitro fertilization （IVF） or intracytoplasmic sperm injection （ICSI）, or may decrease the level of ART needed to achieve successful pregnancy. Male infertility is an indicator of general male health, and evaluation of the infertile male with an eye toward future health can facilitate optimal screening and treatment of these men. Furthermore, varicocele may represent a progressive lesion, offering an argument for its repair, although this is currently unclear.

A nomogram predicting clinical pregnancy in the first fresh embryo transfer for women undergoing in vitro fertilization and intracytoplasmic sperm injection(IVF/ICSI) treatments

The extent to which factors affect the probability of clinical pregnancy in the first fresh embryo transfer after assisted conception is unknown.In order to examine the predictors of clinical pregnancy,a retrospective cohort study was launched between January 1,2013 and December 31,2016 in four infertility clinics including 19837 in vitro fertilization and intracytoplasmic sperm injection(IVF/ICSI)fresh cycles with known outcomes and relevant records.A multivariable logistic regression was used to select the most significant predictors in the final nomogram for predicting clinical pregnancy.Furthermore,the model was validated by an independent validation set and the performance of the model was evaluated by the receiver operating characteristic(ROC)curves along with the area under the ROC curve(AUC)and calibration plots.In a training set including 17854 participants,we identified that female age,tubal factor,number of embryos transferred,endometrial thickness and number of good-quality embryos were independent predictors for clinical pregnancy.We developed a nomogram using these five factors and the predictive ability was 0.66 for AUC(95%CI=0.64−0.68),which was independently validated in the validation set(AUC=0.66,95%CI=0.65−0.68).Our results show that some specific factors can be used to provide infertile couples with an accurate assessment of clinical pregnancy following assisted conception and facilitate to guide couples and clinicians.

Fertilization of in vitro matured human oocytes by intracytoplasmic sperm injection (ICSI) using ejaculated and testicular spermatozoa

Aim: To evaluate the fertilization competence of spermatozoa from ejaculates and testicle when the oocytes were matured in vitro following intracytoplasmic sperm injection (ICSI). Methods: Fifty-six completed cycles in 46 women with polycystic ovarian syndrome were grouped according to the semen parameters of their male partners. Group 1 was 47 cycles that presented motile and normal morphology spermatozoa in ejaculates and Group 2 was the other nine cycles where male partners were diagnosed as obstructive azoospermia and spermatozoa could only be found in testicular tissue fragment. All female patients received minimal stimulation with gonadotropin. Immature oocytes were matured in vitro and inseminated by ICSI. The spermatozoa from testes were retrieved by testicular fine needle aspiration. Results: A total of 449 and 78 immature oocytes were collected and cultured for 48 hours, 75.5 % (339/449) and 84.6 % (66/78) oocytes were matured in Groups 1 and 2, respectively. The percentage of oocytes achieving normal fertilization was significantly higher in Group 1 than that in Group 2 (72.9 % vs. 54.5 %, P < 0.05). There were no significant differences in the rates of oocytes cleavage and clinical pregnancies in these two groups [87.4 % (216/247) vs. 88.9 % (32/36); 21.3 % (10/47) vs. 44.4 % (4/9)]. A total of 15 babies in the two groups were healthy delivered at term. Conclusion: It appears that IVM combined with ICSI using testicular spermatozoa can produce healthy infants, while the normal fertilization rate of in vitro matured oocytes after ICSI using testicular spermatozoa was significantly lower than using the ejaculated spermatozoa.

Effect of interval after surgery on in vitro fertilization/intracytoplasmic sperm injection outcomes in patients with stage Ⅲ/Ⅳ endometriosis

Background For patients with severe endometriosis, the spontaneous pregnancy rates have been reported to be near 0 due to extreme distortion of normal pelvic anatomy.Surgery is one of the treatment options; however, if patients failed to conceive after surgery, in vitro fertilization （IVF） is effective.The objective of this retrospective study was to determine the clinical characteristics of IVF/intracytoplasmic sperm injection （ICSI） in patients with stage Ⅲ/Ⅳ endometriosis, and to determine the impact of the interval from surgery to IVF/ICSI on outcome.Methods One hundred and sixty patients who were diagnosed with stage Ⅲ/Ⅳ endometriosis underwent IVF/ICSI cycles between February 2004 and June 2009 were enrolled.The mean interval from surgery to IVF, number of oocytes retrieved, fertilization rate, implantation rate, embryos transferred, and good embryos transferred were compared between two age groups （≤35 years and 〉 35 years）.Results The mean interval from surgery to IVF was （37.9±28.9） months for the group ≤ 35 years of age and （57.6±39.7）months for the group 〉35 years of age.Twenty-five IVF/ICSI cycles （12.8%） were performed during the first year after surgery, and 34.9% IVF/ICSI cycles were performed 2 years after surgery.No significant differences existed between the two groups with respect to the fertilization rate, implantation rate, number of embryos transferred, number of good embryos,clinical pregnancy rates, live birth rates, and cumulative clinical pregnancy rates （P 〉0.05）.The probability of cumulative clinical pregnancies was 75%, 50%, and 25% （（29.0±4.8）, （61.0±7.6）, and （120.0±16.9） months after surgery, respectively）.Conclusions For infertile patients with stage Ⅲ/Ⅳ endometriosis, the optimal time to conceive by IVF/ICSI is 〈2 years after surgery; nevertheless, most of the patients took a longer time to conceive.

Prediction of Cumulative Live Birth Rate in Women Aged 40 Years and Over Undergoing In vitro Fertilization/Intracytoplasmic Sperm Injection

Objective:To investigate cumulative live birth rate (cLBR) per oocyte retrieval in infertile patients aged 40 years and over undergoing their first in vitro fertilization/intracytoplasmic sperm injection cycles and to identify the possible predictors.Methods:A total of 1,613 patients at a university hospital in China from January 2013 to May 2017 were enrolled in this retrospective study.All data for fresh and subsequent frozen-thawed cycles were analyzed.Multivariate logistic regression analysis with stepwise selection of possible predictors for cLBR was performed,and Loess curve was constructed to determine the association between cLBR and the number of oocytes retrieved.Results:cLBR significantly increased with the number of oocytes retrieved and reached up to 75% when > 20 oocytes were retrieved (P<0.001).Variables of antral follicle count (AFC) and the number of oocytes retrieved were selected using multiple logistic regression analysis with stepwise selection to predict the significance of cLBR.cLBR demonstrated an obvious upward trend as the number of oocytes retrieval increased in the Loess curve.Conclusions:For patients aged 40 years and over,AFC and the number of oocytes retrieved were two key predictors for cLBR and maximization of ovarian reserve exploitation was pivotal to increase the chance of live birth.

Effects of Fertilization on Soil CO_(2) Efflux in Chinese Hickory(Carya cathayensis)Stands

Chinese hickory(Carya cathayensis Sarg.)is a popular nut tree in China,but there is little information about the influences of fertilization on soil CO_(2) efflux and soil microbial biomass.This study evaluated the short-term effects of different fertilizer applications on soil CO_(2) efflux and soil microbial biomass in Chinese hickory stands.Four fertilizer treatments were established:control(CK,no fertilizer),inorganic fertilizer(IF),organic fertilizer(OF),and equal parts organic and inorganic N fertilizers(OIF).A field experiment was conducted to measure soil CO_(2) effluxes using closed chamber and gas chromatography techniques.Regardless of the fertilization practices,soil CO_(2) effluxes of all the treatments showed a similar temporal pattern,with the highest value in summer and the lowest in winter.The mean annual soil CO_(2) efflux in the IF treatment was significantly higher than that in the CK,OIF,and OF treatments.There was no significant difference in soil CO_(2) efflux between the OIF,OF,and CK treatments.Soil CO_(2) effluxes were significantly affected by soil temperature.Soil dissolved organic carbon(DOC)was positively correlated with soil CO_(2) efflux only in the CK treatment.Regression analysis,including soil temperature,moisture,and DOC,showed that soil temperature was the primary factor influencing soil CO_(2) effluxes.Both OF and OIF treatments increased concentrations of soil microbial biomass carbon(MBC)and microbial biomass nitrogen(MBN),but decreased the ratio of MBC:MBN.These results reveal that applying organic fertilizer,either alone or combined with inorganic fertilizer,may be the optimal strategy for mitigating soil CO_(2) emission and improving soil quality in Chinese hickory stands.

Hole fertilization in the root zone facilitates maize yield and nitrogen utilization by mitigating potential N loss and improving mineral N accumulation

Reducing environmental impacts and improving N utilization are critical to ensuring food security in China.Although root-zone fertilization has been considered an effective strategy to improve nitrogen use efficiency (NUE),the effect of controlled-release urea (CRU) applied in conjunction with normal urea in this mode is unclear.Therefore,a 3-year field experiment was conducted using a no-N-added as a control and two fertilization modes (FF,furrow fertilization by manual trenching,i.e.,farmer fertilizer practice;HF:root-zone hole fertilization by point broadcast manually) at 210 kg N ha^(–1) (controlled-release:normal fertilizer=5:5),along with a 1-year in-situ microplot experiment.Maize yield,NUE and N loss were investigated under different fertilization modes.The results showed that compared with FF,HF improved the average yield and N recovery efficiency by 8.5 and 22.3%over three years,respectively.HF had a greater potential for application than FF treatment,which led to increases in dry matter accumulation,total N uptake,SPAD value and LAI.In addition,HF remarkably enhanced the accumulation of ^(15)N derived from fertilizer by 17.2%compared with FF,which in turn reduced the potential loss of^(15)N by 43.8%.HF increased the accumulation of N in the tillage layer of soils at harvest for potential use in the subsequent season relative to FF.Hence,HF could match the N requirement of summer maize,sustain yield,improve NUE and reduce environmental N loss simultaneously.Overall,root-zone hole fertilization with blended CRU and normal urea can represent an effective and promising practice to achieve environmental integrity and food security on the North China Plain,which deserves further application and investigation.

Evaluation of three sets of advanced backcrosses of eggplant with wild relatives from different gene pools under low N fertilization conditions

The development of new cultivars with improved nitrogen use efficiency(NUE)is key for implementing sustainable agriculture practices.Crop wild relatives(CWRs)provide valuable genetic resources for breeding programs aimed at achieving this goal.In this study,three eggplant(Solanum melongena)accessions together with their advanced backcrosses(ABs;BC3 to BC5 generations)were evaluated for 22 morpho-agronomic,physiological,and NUE traits under low nitrogen(LN)fertilization conditions.The ABs were developed with introgressions from the wild relatives Solanum insanum,Solanum dasyphyllum,and Solanum elaeagnifolium.The AB population comprised a total of 25,59,and 59 genotypes,respectively,with overall donor wild relative genome coverage percentages of 58.8%,46.3%,and 99.2%.The three S.melongena recurrent parents were also evaluated under control(normal)N fertilization.Reduction of N fertilization in the parents resulted in decreased chlorophyll content-related traits,aerial biomass,stem diameter,and yield and increased NUE,nitrogen uptake efficiency(NUpE),and nitrogen utilization efficiency(NUtE).However,the decrease in yield was moderate,ranging between 62.6%and 72.6%.A high phenotypic variation was observed within each of the three sets of ABs under LN conditions,with some individuals displaying improved transgressive characteristics over the recurrent parents.Using the single primer enrichment technology 5 k probes platform for high-throughput genotyping,we observed a variable but high degree of recurrent parent genome recovery in the ABs attributable to the lines recombination,allowing the successful identification of 16 quantitative trait loci(QTL).Different allelic effects were observed for the introgressed QTL alleles.Several candidate genes were identified in the QTL regions associated with plant growth,yield,fruit size,and NUE-related parameters.Our results show that eggplant materials with introgressions from CWRs can result in a dramatic impact in eggplant breeding for a more sustainable agriculture.

Repositioning fertilizer manufacturing subsidies for improving food security and reducing greenhouse gas emissions in China

China removed fertilizer manufacturing subsidies from 2015 to 2018 to bolster market-oriented reforms and foster environmentally sustainable practices.However,the impact of this policy reform on food security and the environment remains inadequately evaluated.Moreover,although green and low-carbon technologies offer environmental advantages,their widespread adoption is hindered by prohibitively high costs.This study analyzes the impact of removing fertilizer manufacturing subsidies and explores the potential feasibility of redirecting fertilizer manufacturing subsidies to invest in the diffusion of these technologies.Utilizing the China Agricultural University Agri-food Systems model,we analyzed the potential for achieving mutually beneficial outcomes regarding food security and environmental sustainability.The findings indicate that removing fertilizer manufacturing subsidies has reduced greenhouse gas(GHG)emissions from agricultural activities by 3.88 million metric tons,with minimal impact on food production.Redirecting fertilizer manufacturing subsidies to invest in green and low-carbon technologies,including slow and controlled-release fertilizer,organic-inorganic compound fertilizers,and machine deep placement of fertilizer,emerges as a strategy to concurrently curtail GHG emissions,ensure food security,and secure robust economic returns.Finally,we propose a comprehensive set of government interventions,including subsidies,field guidance,and improved extension systems,to promote the widespread adoption of these technologies.