Previous Fertilization Research Articles

P-206 An evaluation of the incidence of total failed fertilization (TFF) following conventional IVF (cIVF) and the outcome of subsequent intracytoplasmic sperm injection (ICSI) cycles

Abstract Study question What is the incidence of TFF following conventional IVF (cIVF) and the chance of live birth in subsequent ICSI treatment cycles after TFF? Summary answer The incidence of TFF might be higher than previously reported and establishment of in-house benchmarks are recommended. Treatment continuation results in acceptable live birth rates. What is known already TFF following a cIVF is a devastating outcome for patients and physicians. The fear of this unfortunate event is assumable one of the main drivers for overutilizing ICSI. The incidence of TFF after cIVF should be less than 5 % of stimulated cycles based on ESHREs recommended performance indicators. Data on TFF of an unselected population is indeed however only available from an era when ICSI was not in use and showed a higher rate. We investigated the incidence of TFF and evaluated the chance of live birth following of such event at the first cycle. Study design, size, duration A single center, retrospective chart review for the time period of 2010-2021 was done to identify all cycles where cIVF did not result in at least one oocyte with ≥ 2 pronuclei. Also, patients who had more than 2 oocytes retrieved in their first cycle and continued their treatment using ICSI as a fertilization method in their upcoming cycles were selected. Participants/materials, setting, methods A total of 5772 initiated IVF cycles were identified in the electronic database for the examined time period. Criterion for cIVF was normozoospermia and applied as fertilization method in 1001 (17.3%) cycles. All the cases where TFF was noted following cIVF were retrieved and the number of oocytes, the rank of the cycle, female age and the result of upcoming cycles if any were recorded. Data was analyzed using Chi-Square test, p < 0.05 was considered significant. Main results and the role of chance A total of 125 TFF cycles were identified out of the 1001 cIVF cycles (12.49% failed fertilization rate per cIVF). A significantly higher frequency of TFF was seen in cycles where less than 3 oocytes were retrieved compared to those with more than two oocytes (38/99 [38.38%] vs. 87/902 [9.65%], p < 0.001). No statistical difference was detected between the risk of TFF occurring at the first, second or the third rank cIVF cycle (87/664 [13.10%], 30/224 [13.39%], 5/75 [6.67%] respectively; p > 0.05). The differences remained non-significant when only cycles with more than 2 oocytes were analyzed (67/608 [11.02%], 16/199 [8.04%], 4/68 [5.88%] respectively; p > 0.05). Also, different age groups showed similar incidence of TFF (16/157 [10.19%], 41/362 [11.33%], 54/381 [14.17%] and 14/101 [13.86%] in < 30, 31-35, 36-40 and >40 years of age respectively; p > 0.05). A total number of 56 patients were identified who continued their treatment using ICSI as fertilization method in their upcoming cycles. These patients completed 101 cycles resulting in 3 TFF cases (3%) and a fertilization rate of 75.1% (524/698) which was significantly higher to our baseline ICSI fertilization rate (70.9% [25231/35568]; p < 0.05). Nineteen of these 56 patients (33.9%) ended up giving at least one live birth following treatment continuation. Limitations, reasons for caution Selection criteria, e.g. patient characteristics and treatment type such as PGT-A, for choice of fertilization method are probably a source of variation in TFF incidence between centers. It is recommended that laboratories establish their own benchmark values based on their own data for the incidence of TFF. Wider implications of the findings Previous studies identified serum luteinizing hormone and progesterone levels at trigger and the number of oocytes as critical predictors for TFF. The similar chance of TFF after previous successful fertilization suggests more involvement of female factors in TFF. Acceptable live birth rates can be achieved following treatment continuation. Trial registration number not applicable

O-022 Shall we go “natural” for endometrial preparation in egg donation programs? Live birth rates and obstetrical outcome from 797 frozen single-blastocyst transfers cycles

Abstract Study question Frozen single blastocyst transfer in modified natural cycle (mNC) increases success rates reducing obstetric risks in egg recipients, compared to Hormone Replacement Therapy (HRT) protocols? Summary answer In egg recipients, single-blastocyst transfer in mNC showed higher pregnancy rates, lower miscarriage rates, higher new-born rates compared to HRT, being preterm birth rate comparable. What is known already When choosing endometrial preparation protocols for egg recipients, we must consider medication safety and costs, cycle’s cancellation rate, clinical outcomes as maternal and fetal risks. The superiority of mNC over HRT for frozen embryo transfers (FET) has been reported in terms of delivery and miscarriage rates as well as obstetrical complications, but few data are available on egg recipients, being HRT protocols the routine treatment in most cases. In donor programs, when a blastocyst freeze-all strategy or egg banking is applied, there is no longer need for donor-recipient synchronization and many FET could be performed in mNC cycles. Study design, size, duration Retrospective single-centre comparative clinical study, including 797 frozen single-blastocyst transfer (FSBT) initiated cycles between January 2020 and December 2021: 590 (74%) in HRT protocol and 207 (26%) in mNC protocol. The two groups were homogeneous for donor’s age (25,4 yo HRT Vs 25,8 yo mNC), recipient’s age (42,1 yo HRT Vs 42,4 yo mNC), severe male factor (6% HRT Vs 4% mNC), and the need for a sperm donor (28% HRT Vs 22% mNC). Participants/materials, setting, methods Among 797 started cycles, we compared cancellation rates between HRT and mNC groups due to either medical reasons (inadequate endometrium, bleeding, ovulatory leak) or other issues (no embryo survival, flight cancellations, COVID-19 restrictions). We studied the clinical outcomes of the 683 FSBT performed, comparing HRT and mNC cycles for pregnancy rate, clinical pregnancy rate, miscarriage rate, live birth rate, and preterm birth rate <35 weeks. We used Chi-square test to compare groups (p < 0,05). Main results and the role of chance CANCELLATION RATES: Out of the 797 endometrial preparation cycles started, the overall cancellation rate was 14% from which 72,8% due to medical reasons (inadequate endometrium, bleeding, ovulatory leak) and 27,2% due to other issues (no embryo survival, SARS-Cov-2 related issues, flight cancellations, etc.); when evaluating cancellation for medical reasons, we didn’t find significant differences between HRT protocol cycles (9%) and mNC protocol cycles (7%), p = 0,33. CLINICAL OUTCOMES: Out of the 683 frozen single blastocyst transfers performed, no twin pregnancies occurred as expected. There were no statistically significant differences between HRT Vs mNC endometrial preparation protocol when comparing pregnancy rates (59% Vs 63%, p = 0,35), clinical pregnancy rates (49% Vs 57%, p = 0,10) and miscarriage rates (19% Vs 16%, p = 0,48). Live birth rate was significantly higher in the mNC (47%) compared to HRT (38%), p = 0,046. Overall preterm birth rate <35 weeks was 3,9%, including <32 weeks 1,1% and <28 weeks 0,3%. There were no significant differences between HRT and mNC endometrial preparation protocol for preterm birth rate <35 weeks (3,6% Vs 4,6%, p = 0,75). Limitations, reasons for caution Single-centre retrospective comparative trial. Homogeneity studies included several confounding variables, but other bias could have been studied such as uterine factor, PGT-A rate or previous fertility treatments. Wider implications of the findings In donor programs, the use of modified natural cycle should be encouraged as first option irrespectively from recipient’s age for FET in normo-ovulatory patients, considering the increased live birth rates when compared to HRT-FET cycles. Moreover, mNC cycles are more patient’s friendly and cost-effective. Trial registration number not applicable

ICSI for non-male factor infertility: time to reappraise IVF?

Intracytoplasmic sperm injection (ICSI) was initially introduced to overcome problems due of severe male factor infertility not being solved with conventional in-vitro fertilization (cIVF). However, recent years have witnessed an increasing use of ICSI by most assisted reproductive technique laboratories for non-male factor indications. Examples of the latter include previous fertilization failure after cIVF, few or poor-quality oocytes, immature oocytes, advanced maternal age, preimplantation genetics test (PGT), cryopreserved oocytes, and unexplained infertility. The replacement of cIVF with ICSI in several non-male factor infertility cases is probably because some reproductive specialists consider that ICSI is associated with better reproductive outcomes. Unfortunately, data on reproductive outcomes in favor of ICSI over cIVF are limited or absent. Therefore, the factors that can help define the use of one technique over the other should be identified. These should include the likelihood of fertilization failure, potential risks of the procedure, and its costs. In this review, we aim to highlight the current guidelines, advantages, and limitations of the use of cIVF/ICSI for infertility treatment. Additionally, we provide a comprehensive review of the use of ICSI in indications other than severe male factor infertility.

Conservative management of early-stage endometrial cancer for fertility preservation: a survey study among Swedish gynecologists and gynecological oncologists

Conservative management of endometrial cancer (CMEC) is viable for women with early-stage disease wishing to preserve fertility, but there is poor knowledge regarding clinicians’ attitudes towards treatment or guidelines adherence. This 55-item survey study investigated CMEC-related experience, practice and attitudes among clinically active Swedish gynecologists and gynecological oncologists, focusing on reproductive eligibility criteria. The survey consisted of a general and two specific subsets, selectively delivered to clinicians active in infertility (subset A) and endometrial cancer (subset B) care. Answers from 218 clinicians were included. More than half agreed on CMEC whereas only 5% explicitly disagreed. The majority supported a fertility work-up to substantiate reasonable chances to pregnancy and live birth. Most disagreed about CMEC in case of previous unsuccessful fertility treatments, while more than 1/3 disagreed about CMEC in known fertility problems, recurrent miscarriages or previous children. Over 50% of respondents in subset A (n = 107) found it applicable with fertility investigations such as ovarian reserve testing or, in case of male partner, semen analysis. Respondents in subset B (n = 165) agreed on items based on existing recommendations regarding the oncological management of CMEC, including the use of continuous progestins, hysteroscopic resection of macroscopic lesions, control biopsy with curettage or hysteroscopy after 6 months of treatment, pursuing pregnancy as soon as possible after complete response, and performing a hysterectomy once live birth is achieved. While many clinicians were familiar with CMEC, the overall experience is limited. Fertility specialists seem less involved than oncologists in patient care but there is broad support for fertility-related eligibility criteria.

Short Interpregnancy Interval Following a Multifetal Pregnancy: Maternal and Neonatal Outcomes

To evaluate the maternal and neonatal outcomes of women with short interpregnancy intervals (IPI < 6 months) following a multifetal pregnancy. A multicenter retrospective cohort study of women with an index multifetal delivery and a subsequent singleton gestation between 2005 and 2021. The obstetrical outcomes of pregnancies following short IPI (<6 months) were compared to those with an IPI of 18-48 months. Additional analyses were also conducted for the other IPI groups: 7-17 months, and longer than 49 months, while women with an IPI of 18-48 months served as the reference group. The primary outcome was preterm birth (<37 weeks) rate. Secondary outcomes were other adverse maternal and neonatal outcomes. Univariate and multiple logistic regression analyses were performed. Overall, 2514 women had a primary multifetal delivery with a subsequent singleton gestation at our medical centers; 160 (6.4%) had a short IPI, and 1142 (45.4%) had an optimal IPI. Women with a singleton gestation following a short IPI were younger, with lower rates of previous cesarean and fertility treatments. Women in the short IPI group had significantly higher rates of preterm birth <37 weeks, anemia (Hb < 11 gr%) on admission to the delivery room, and placental abruption. Multivariable logistic regression analysis demonstrated that short IPI is associated with an increased risk for preterm birth (aOR 2.39, 95% CI 1.12-5.11, p = 0.03). Short IPI following a multifetal gestation is associated with an increased risk for preterm birth in subsequent singleton pregnancy.

Comparing endometrial preparation methods in frozen embryo transfers – Does a previous live birth make a difference?

Research questionDoes the outcome of a medicated or natural endometrial preparation for a frozen cycle differ if a patient has previously experienced a failed fresh cycle? DesignRetrospective matched case-controlled study to investigate frozen embryo transfer (FET) outcomes in women undergone medicated or natural endometrial preparation, with adjustment to the history of previous live birth. 878 frozen cycles were included for analysis, over a period of 2 years. ResultsAfter adjusting for the number of embryos transferred, endometrial thickness and the number of previous embryo transfers, there was no difference in live birth rate (LBR) between medicated-FET and natural-FET groups regardless of the previous fertility outcome (p = 0.08). ConclusionsA previous live birth does not affect the outcome of a subsequent frozen cycle, regardless of whether medicated- or natural endometrial preparation is used.

Assisted Oocyte Activation following Intracytoplasmic Sperm Injection: A Sensible Option for Infertile Couples with Severe Teratozoospermia.

The intracytoplasmic sperm injection (ICSI) has significantly improved male factor infertility treatment; however, complete fertilization failure still occurs in 1-5% of ICSI treatment cycles mainly due to oocyte activation failure. It is estimated that around 40-70% of oocyte activation failure is associated with sperm factors after ICSI. Assisted oocyte activation (AOA) as an effective approach to avoid total fertilization failure (TFF) has been proposed following ICSI. In the literature, several procedures have been described to overcome failed oocyte activation. These include mechanical, electrical, or chemical stimuli initiating artificial Ca2+ rises in the cytoplasm of oocytes. AOA in couples with previous failed fertilization and those with globozoospermia has resulted in varying degrees of success. The aim of this review is to examine the available literature on AOA in teratozoospermic men undergoing ICSI-AOA and determine whether the ICSI-AOA should be considered as an adjunct fertility procedure for these patients.

Protective Effect of L-carnitine against Cefquinome Sulfate Induced Testicular Damage and Oxidative Stress in Male Albino Rats

The present study was conducted to evaluate the protective effect of L-carnitine (LC) against possible deleterious effects of cefquinome sulfate (CS) on antioxidant capacity, fertility parameters and histopathological findings of reproductive organs in male rats. Therefore, seventy two mature male rats were equally divided into four equal groups as following: The control group of rats was administered two s.c. doses of physiological saline (vehicle of other drugs) (2ml/kg b.wt. once daily for 5 successive days and 2ml/kg b.wt. once daily for 8 successive weeks), the second group was s.c. administered LC (200 mg/kg b.wt. once daily for 8 successive weeks), the third group was s.c. administered CS (50 mg/kg b.wt. once daily for 5 successive days) and the fourth group was s.c. administered CS concomitantly with LC by the same doses. The obtained results showed that administration of CS induced a significant (P≤ 0.05) increase in serum level of Malondialdehyde (MDA) and total sperm abnormalities with significant (P≤ 0.05) decrease in serum level of total antioxidant capacity (TAC), sperm motility and total sperm count. Moreover, CS induced histopathological changes in tissues of testes and epididymis. Conversely, administration of LC concomitantly with CS ameliorates all the previous antioxidant, fertility and histopathological alterations induced by CS. It could be concluded that CS induced some undesired effects on antioxidant activity, fertility parameters and histopathological findings which could be ameliorated by LC in male albino rats.

INTERFERENCE OF ABORTION LAW ON THE RELATIONSHIP BETWEEN ECONOMIC DEVELOPMENT AND FERTILITY RATE OF WOMEN

The last few decades have seen unprecedented economic growth and fertility decline. However, the relationship between economic development and fertility rate varies across the countries due to country-specific characteristics. There are two schools of thought in the existing literature: the first holds that women's fertility declines with economic development, which happens in tandem with industrialization, while the second holds that fertility rises with economic development because it encourages early marriage, coupled with, increase in economic security. However, there is a dearth of information in the literature regarding how various birth control regulatory systems affect the connection between fertility and economic development. Therefore, the present study attempts to analyze the relationship between birthrate and growth of GDP per capita in 182 nations (using panel data from 1990 to 2012). The study has three major findings. First, it implies the U-shaped association between economic progress and fertility rate is not universal. Second, the law affects women's fertility. More abortion restrictions boost a woman's fertility. Finally, cultural influences like previous periods' fertility rates affect the current period's fertility, indicating an intertemporal link. The study contributes to the in-depth understanding of the determinants of fertility rate. It identified how the abortion law influence the relationship between economic development and fertility rate. The findings can help in designing the fertility control measures, based on a country’s status of economic development.

The effects of previous summer drought and fertilization on winter non-structural carbon reserves and spring leaf development of downy oak saplings.

It is still unknown whether the previous summer season drought and fertilization will affect the winter non-structural carbohydrate (NSC) reserves, spring leaf development, and mortality of trees in the next year. We, therefore, conducted an experiment with Quercus pubescens (downy oaks) saplings grown under four drought levels from field capacity (well-watered; ~25% volumetric water content) to wilting point (extreme drought; ~6%), in combination with two fertilizer treatments (0 vs. 50kg/ha/year blended) for one growing season to answer this question. We measured the pre- and post-winter NSC, and calculated the over-winter NSC consumption in storage tissues (i.e. shoots and roots) following drought and fertilization treatment, and recorded the spring leaf phenology, leaf biomass, and mortality next year. The results showed that, irrespective of drought intensity, carbon reserves were abundant in storage tissues, especially in roots. Extreme drought did not significantly alter NSC levels in tissues, but delayed the spring leaf expansion and reduced the leaf biomass. Previous season fertilization promoted shoot NSC use in extreme drought-stressed saplings over winter (showing reduced carbon reserves in shoots after winter), but it also showed positive effects on survival next year. We conclude that: (1) drought-stressed downy oak saplings seem to be able to maintain sufficient mobile carbohydrates for survival, (2) fertilization can alleviate the negative effects of extreme drought on survival and recovery growth of tree saplings.

Drivers of sorghum response to fertilizer microdosing on smallholder farms across Burkina Faso

Fertilizer microdosing (FM) is being disseminated to resource-limited smallholder farmers within the framework of sustainable intensification in order to boost crop productivity. However, scaling up of this technology revealed that yield response variability may be a barrier to its adoption. A total of 351 on-farm trials across three agro-climatic zones (Sissili: 800–1000 mm, Oubritenga: 600–800 mm and Zandoma: ≤ 600 mm mean annual rainfall) over two years in Burkina Faso were therefore conducted in order to identify the factors driving sorghum (Sorghum bicolor (L.) Moench) yield response to FM (2 g/hill of N-P-K 14–23–14 and 1 g/hill of urea). The trials were stratified to consider soil types (indigenous classification) as well as the distance between homesteads and fields as a criterion of fertility. Additional variables included previous crop management practices and weed pressure. On average, FM application increased yields by 385, 571 and 388 kg/ha in Sissili, Oubritenga and Zandoma, respectively. The proportion of fields with a value-cost ratio (VCR) ≥ 2 was 34% in Sissili, 56% in Oubritenga, and 30% in Zandoma. In the three zones, yield response to FM tended to increase with increasing soil depth and plot duration of cultivation, as well as with the proper timing of weeding and fertilizer application. Within Sissili lower responses were observed on stony-gravelly and sandy soils compared to black soils, and also on plots previously amended with high amounts of fertilizer compared to soils with moderate or no previous fertilizer application. For plots with no previous fertilizer application, better responses were observed on plots with legumes as antecedent crop. In Oubritenga, responses were greater on clayey soils compared to other soil types. In Zandoma, yield response was greatest in lower floodplain soils compared to other soils, and increased with increasing delay in sowing. Overall, crop response to FM was affected by (i) soil type and topographic position, (ii) plot history through the duration of cultivation, the antecedent crop and the previous fertilization rate, and (iii) plot management. The relative importance of these factors was site-specific and can be easily communicated to farmers.

THE INFLUENCE OF PATIENT EDUCATION LEVEL, PREGNANCY/BREASTFEEDING, AND INFERTILITY TREATMENT ON PERCEPTIONS OF THE COVID-19 VACCINE: A MIXED METHODS STUDY

To elucidate infertile patient perceptions of the novel COVID-19 vaccine as it pertained to fertility treatments and future pregnancies. This was an IRB approved, single center mixed methods survey study. A 60-question survey was administered assessing patient perceptions regarding the novel COVID-19 vaccine as it pertained to their fertility care and future fertility treatment. The survey was offered to a total of 760 patients undergoing fertility evaluation and treatment, 192 responded (25% response rate). Fischer exact or McNemar exact tests were performed depending on quantitative data distribution. Responses to the open-ended questions were analyzed using inductive content analysis to generate qualitative themes. Quantitative: Of the 192 respondents most were white females, holding private insurance, with a college degree. Participant willingness to accept the COVID-19 vaccine was analyzed in conjunction with various demographic variables to determine trends between these variables and vaccine acceptance. Respondents’ age, marital status, income level and insurance status did not correlate with perceived willingness to accept the COVID-19 vaccine. However, respondents who reported having a college education were more likely to consider the COVID-19 vaccine when it became available to them (No Degree= 5/16 (31.3%), College Degree= 76/104 (73.1%), Post-graduate Degree= 57/67 (85.1%), N=187, P<0.001). When asked if pregnancy or breastfeeding impacted respondents' willingness to consider the COVID-19 vaccine 79 (43.9%) responded yes, while 101 (56.1%) responded no or unsure. When participants’ responses were stratified by the number of previous completed fertility treatments (either embryo transfers or intrauterine inseminations), there was a statistically significant trend of increasing willingness to receive the COVID-19 vaccine during a pregnancy or while breastfeeding (1 Treatment= 53/135 (39.2%), 2 treatments= 19/37 (51.3%), 3 treatments= 6/6(100%), N=180). Qualitative themes included participants’: fear of the unknown due to existing perceptions, beliefs, and mistrust; interpretations of medical knowledge and self-generated benefit-risk assessments, and desire for provider guidance and mindful communication. This study suggests that despite identified hesitancy of the COVID-19 vaccine, patients with higher levels of education and those who completed >2 infertility treatments were more willing to consider the COVID-19 vaccine, even with pregnancy or breastfeeding in mind. Patients unwilling to receive the vaccine reported mistrust in healthcare, lack of communication with providers, and medical misunderstanding while formulating benefit-risk assessments.

Booting stage is the key timing for split nitrogen application in improving grain yield and quality of wheat – A global meta-analysis

Wheat is one of the most important staple crops and is mainly consumed as baked goods. Late nitrogen (N) application following a previous basic fertilization is commonly conducted to increase grain protein concentration and to improve the bread-making quality of wheat. However, the effect of late N application on the yield and quality of wheat highly varied among studies and, therefore, was questioned recently. This global meta-analysis, based on reported field experiments, aimed to clarify whether, and if so under what conditions, a late N (split from the overall N fertilization rate) application that follows an earlier N application is effective in high-protein bread-wheat production. The results showed that split N application enhanced the grain protein concentration by 5.8 %, wet gluten content by 7.9 %, and dough stability time by 10.8 %, while it decreased the grain yield of wheat by 3.5 % compared to that without split N application. However, the results varied, depending on the N application methods and environmental factors. At the fertilization level of 151–200 kg N/ha which is generally recognized as the rational N recommendation rate, split N application could increase the grain protein concentration by 6.9 %, stability time by 14.0 % and wet gluten content by 7.7 % without reducing the grain yield of wheat. More importantly, both the grain yield and quality of wheat were enhanced by split N application only when late N was applied at the booting stage. Moreover, the widely observed negative correlation between grain yield and grain protein concentration was weakened by split N application at the booting stage.

Allometric equations for biomass and contents of macronutrients in a young Tectona grandis stand

Evaluations of biomass and nutrient contents in teak stands are necessary alternatives for avoiding early cutting to provide supplemental data for the plant module of fertilization recommendation systems. This study aimed to adjust allometric equations to estimate the accumulation of biomass and nutrient contents in teak plantations in the central region of Brazil. Plots in seminal and clonal stands contained 81 trees aged 75 months, that had not received previous fertilization or thinning. Additional clonal stands aged 15, 51 [...]

Effects of long-term N fertilization on nitrate leaching and vegetation responses in a spruce stand after severe wind damage

Wind damage in a forest stand can result in varying soil effects depending on the pre-history of the site, but areas with storm-felled trees can generally be expected to show more nitrate leaching than undamaged stands. Previous fertilization in such areas, especially with nitrogen (N) fertilizer, may further increase nitrate leaching. This study examined the effect of partial felling of a 42-year-old Norway spruce stand in the Skogaby experimental forest in Sweden during Storm Gudrun in 2005. Nitrate leaching was measured one year before and six years after the storm, in three experimental treatments: fertilization-irrigation with complete nutrient admixture (IF), fertilization with N-free nutrient admixture (V), and an untreated control (0). The 0 and IF treatments had some undamaged replicate plots, but V plots had no trees left after the storm. Compared with undamaged plots and the pre-disturbance level, nitrate leaching was significantly higher in all storm-felled plots, and in the soil solution nitrate dominated strongly over ammonium. Leaching peaked during the second and third post-storm years (2006–2007) and decreased to near pre-storm levels during the fifth and sixth years (2009–2010). Total nitrate leaching 2005–2010 was estimated to be 414, 233, and 218 kg N ha−1 in the damaged IF, 0, and V plots, respectively. Total nitrate leaching in undisturbed plots in the IF and 0 treatments was 37 and 0.3 kg N ha−1, respectively. Ground vegetation coverage, biomass, and biomass N increased with time and were negatively correlated with nitrate discharge. However, plant uptake of N only partly explained the significant decline in nitrate leaching between 2006 and 2010. This decrease could also be explained by N immobilization in fungi decomposing woody roots with low N concentrations.

Phosphorus fertilizer with increased efficiency affects soybean yields

Phosphate fertilization is an important tool for achieving high yields in soybean, especially in tropical soils where phosphate fertilization efficiency is low. Fertilizers with improved efficiency, such as polymer-coated fertilizers, are one of several strategies to increase P fertilization efficiency. The objective of this study was to evaluate plant growth, leaf P content, soybean yield, and P fertilization efficiency in different seasons in response to P rates and sources. A factorial experiment (2 x 4) + 1 using two P sources (monoammonium phosphate (MAP) and Policote-coated MAP), four P rates (40, 80, 120, and 160 kg P2O5 ha-1), and the control (no P fertilization) was conducted with soybean in the 2016-2020 seasons. Phosphate fertilization increased soybean yield and was affected by P rates and sources. Soybean yield increased from 1464.7 kg ha-1, 468.4 kg ha-1, and 2297.3 kg ha-1 without P fertilization to 3,638.5 kg ha-1, 3,682.1 kg ha-1, and 3,856.7 kg ha-1, respectively, when MAP was applied at 158.0, 125.3, and 160 kg ha-1 P2O5, while when Policote coated MAP, the maximum productivity was 3,950.3 kg ha-1, 4,380.5 kg ha-1 and 4,343.0 kg ha-1 with 159.0, 160.0 and 140.1 kg ha-1 P2O5, respectively, in 2017/2018, 2018/2019 and 2019/2020 seasons. Increasing phosphate fertilizer rates decreased agronomic P use efficiency (APUE), which was mitigated by P-coated fertilizer (fertilizer with improved efficiency). Lower APUE was observed in the 2019/2020 season, likely as a result of residual effects from previous phosphate fertilizer applications

Relationship between sperm quality and total fertilization failure in intracytoplasmic sperm injection and in vitro fertilization cycles: A cross-sectional study.

BackgroundTotal fertilization failure (TFF) is associated with essential mechanistic and cellular events.ObjectiveThe present study is a comprehensive examination of detrimental effects with well-known assays for predicting TFF in conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles.Materials and MethodsSemen parameters of 90 men, including 60 cases who had experienced IVF/ICSI failure and a control group of 30 individuals, were evaluated. Sperm chromatin/DNA quality assessments were done by aniline blue, toluidine blue, chromomycin A3, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assays. A lipid hydroperoxide (LPO) kit was used to measure the LPO, and JC1 staining was used to evaluate mitochondrial membrane potential (MMP).ResultsThere were statistically significant differences found between the IVF, ICSI and control groups by the toluidine blue (p = 0.01), TUNEL (p = 0.02), and chromomycin A3 (p 0.001) tests, but not by the aniline blue staining. Furthermore, there was a significant difference regarding LPO concentration and high MMP in cases of IVF fertilization failure compared to the control group (p = 0.04, p = 0.02, respectively). The logistic regression model showed that sperm viability was predictive for fertilization failure in the ICSI group. Sperm chromatin and DNA quality assays were not predictors for TFF in either group.ConclusionCellular events such as high DNA fragmentation damage, high levels of reactive oxygen species, and low MMP levels can cause TFF in IVF and ICSI programs. Diagnostic tests, especially in cases with previous fertilization failure, showed significant differences in sperm chromatin and DNA quality between groups but could not predict the risk of TFF.

Soil mineral nitrogen dynamics in fallow periods in a rainfed semiarid Mediterranean agricultural system

Rainfed agricultural systems in semiarid Mediterranean environments are subject to erratic but often heavy rainfall events. As an agronomic practice, fallow periods can be included even within the existing EU common policy for crop diversification. This research aimed to quantify the effects of a previous mineral fertilization on the soil mineral nitrogen (N min ) content and on potential nitrate leaching during no-tilled fallow periods of a crop rotation. Water and N min soil measurements obtained during three fallow seasons were used. Data were also used to check if the Leaching Estimation and Chemistry Model (LEACHM) can be used for the soil N min prediction after fallow. During these periods, the N min measured in the soil profile increased on average by 125 kg N ha -1 , while the model averaged an increase of 95 kg N ha -1 . The estimate of N leached ranged from 11 to 38 kg N ha -1 . The N balance simulated using LEACHM might differ from the actual processes. After a drought period followed by a soil water replenishment, the calibrated LEACHM underestimated soil N min probably due to the “Birch effect”. After occasional rainy spells when soil quickly became saturated, LEACHM overestimated soil N min probably due to occasional N 2 O emissions not being fully accounted by the model and to specific preferential water flow, which might produce a greater nitrate leaching than that simulated by LEACHM using the convection-dispersion equation . The results show that soil N min measurements by sampling after the fallow period cannot be replaced by LEACHM simulations. These samplings are of interest in fallow established inside a rotation and to avoid over-fertilization in the following cropping season, while reducing N environmental impacts.

The Application of a Bio-Stabilized Municipal Solid Waste-Based Fertilizer for Buckwheat Production

In a circular economy framework, waste valorization in crop production promotes sustainability in the agricultural sector. Buckwheat (BW; Fagopyrum esculentum Moench) has promising nutritional and economic value. Its sustainable production can be promoted by applying organic fertilizers. Aimed at determining the effect of a bio-stabilized municipal solid waste (MSW) amendment on BW, a greenhouse experiment was performed combining two different soils (clay and sandy) with three previous fertilization treatments (no fertilizer, mineral fertilizer, or MSW fertilizer) from the precedent faba bean crop and three present fertilization treatments (no fertilizer, mineral fertilizer, or MSW fertilizer) from the precedent wheat crop. The present fertilizer treatments followed the same procedure and fertilization rates (7.9 g/kg clay soil and 6.7 g/kg sandy soil of MSW amendment and 0.14 g/kg clay soil and 0.12 g/sandy soil of mineral fertilizer) as the previously fertilized treatments to study the effects on BW crop and soil. Results indicated a positive response of biomass production (on average 34.4 g/plant) and seed yield (on average 10.6 g/plant) to direct organic fertilization, obtaining comparable results with respect to the mineral fertilization treatments. Additionally, organic fertilization significantly enhanced seed quality and nutrient content compared to mineral fertilization, which resulted in a higher chlorophyll content. The findings revealed that the residual effect from the previous bio-stabilized MSW amendment was not sufficient to provide the total nutrients necessary for BW potential growth and biomass production, although slight tendencies toward increase were observed. Soil properties, such as organic matter and nitrogen content, as well as soil nutrient concentrations, were positively affected by organic fertilization, presenting adequate levels of heavy metals (Cu, Zn, Pb, Ni, Cr, and Cd). The insights of this study are valuable to determine the effects of reusing waste by-products for BW crop fertilization to reduce or substitute for chemical fertilizers.

Homozygous Loss of Septin12, but not its Haploinsufficiency, Leads to Male Infertility and Fertilization Failure.

The SEPTIN12 gene has been associated with male infertility. Male Septin12 +/− chimera mice were infertile, supporting the prevailing view that SEPTIN12 haploinsufficiency causes male infertility. In this study, we identified a heterozygous mutation on SEPTIN12, c.72C>A (p.Cys24Ter) in the male partner of a patient couple, who had a previous fertilization failure (FF) after intracytoplasmic sperm injection (ICSI) and became pregnant after ICSI together with artificial oocyte activation (AOA). To investigate the role of SEPTIN12 in FF and oocyte activation, we constructed Septin12 knockout mice. Surprisingly, Septin12 −/− male mice, but not Septin12 +/− male mice, are infertile, and have reduced sperm counts and abnormal sperm morphology. Importantly, AOA treatment enhances the 2-cell embryo rate of ICSI embryos injected with Septin12 −/− sperm, indicating that FF caused by male Septin12 deficiency is overcome by AOA. Mechanistically, loss of PLCζ around the acrosome might be the reason for FF of Septin12 −/− sperm. Taken together, our data indicated that homozygous knockout of Septin12, but not Septin12 haploinsufficiency, leads to male infertility and FF.