Poor Fertility Research Articles

曲柄摇杆式深施机构的设计与施肥性能试验研究

In response to the poor fertilization performance of the deep application mechanism of the deep application liquid fertilizer applicator under multiple parameters, the fertilization variation of the crank rocker deep application mechanism under multiple working parameters is explored. To obtain the fertilization variation of the crank rocker deep application mechanism, a fertilization performance test bench for the crank rocker deep application mechanism is developed. On this test bench, the crank speed, liquid pump pressure, and spray hole diameter are used as experimental factors, and fertilizer application rate is used as experimental indicators. A composite design scheme of rotation center is adopted to establish a relationship model and response surface diagram between experimental influencing factors and influencing indicators. Design Expert 8.0.10 software is used to analyze and optimize the experimental data. The optimal results are a crank speed of 145.80 r/min, a liquid pump pressure of 0.25 MPa, a spray hole diameter of 3.02 mm, a fertilizer application rate of 28.6 mL, and a fertilizer loss rate of 1.9%. At this time, the fertilization performance of the mechanism is optimal. This parameter combination is applied for testing and verification to verify its rationality. The results can ensure that the crank rocker deep application mechanism has good working performance when working under multiple parameters, providing theoretical reference for designing deep application liquid fertilizer machines with simple structure and optimal fertilization performance.

Edaphic Factors Modulating Phosphorus Availability in Lowland Rice Systems, Nigeria

ABSTRACT The low rice production level in Africa is attributed to poor soil fertility despite the potential for rice cultivation in the inland valleys. This study was conducted to evaluate soil characteristics in some lowlands that have been continuously and intensively used for rice production for over two decades in southwestern Nigeria. Soil physical, chemical, and mineralogical properties, as well as phosphorus sorption characteristics, were assessed in soil samples collected from diagnostic horizons of profiles in six benchmark soils. The results show kaolinite, quartz, potassium(K)-feldspars, and mixed-layered smectite as the predominant minerals. The iron oxide fractions indicate that the soils are at varying degrees of development where the soils at the advanced stage of development are predominantly rich in kaolinite and quartz with a high concentration of total pedogenic iron oxide and generally low in soil fertility. Soil phosphorus buffering capacity is low and varies inversely with pH, confirming the deficiency of phosphorus at low pH. Short-range-order (SRO) iron (Fe) oxides show a strong affinity for phosphorus and this is stronger at lower soil horizons and mediated by some redoxomorphic reactions. The SRO iron oxide concentration has more influence on phosphorus retention in soils rather than the absolute concentration of iron oxides. The study concludes that SRO Fe oxides and soil pH are the major edaphic factors playing a prominent role in phosphorus retention and availability in the wetland soils rather than the clay minerals.

P-060 When is it the sperm’s fault? The incidence of sperm-related poor fertilization after ICSI in 13,859 matched oocyte donation cycles

Abstract Study question What is the true incidence and impact of male factor-related poor fertilization in ICSI cycles when analyzed using matched pairs of high quality donor oocytes? Summary answer In ICSI cycles with donor oocytes, male factor-related poor fertilization occurs in 3.3% of cases and contributes to 86.7% of all poor (<30%) fertilization outcomes. What is known already Opting for oocyte donation is a complex decision for couples, involving significant financial and long-term implications. This decision is typically prompted by presumed female infertility as male fertility diagnostics remain limited. Although ICSI is a highly effective treatment, cases of poor or complete fertilization failure can still occur, even when sperm parameters appear normal. This suggests the presence of unidentified male-related factors. However, the precise incidence of such factors remains poorly understood. This study aims to address this gap, offering a unique perspective, by employing a matched oocyte donation model to investigate the influence of sperm-related factors on fertilization outcomes. Study design, size, duration This retrospective cohort study analyzed 14,928 oocyte donation ICSI cycles, derived from 7,519 ovarian stimulations (OS) of 2,963 unique oocyte donors. The data were from a single center from January 2015 to December 2022. Sibling oocytes from the same OS were utilized for at least two different recipients (n = 13,859), facilitating comparisons under varying paternal conditions. Participants/materials, setting, methods Cases from the same oocyte lot with poor (<30%) and good (>65%) fertilization rates were matched to isolate sperm-related factors influencing fertilization success. Paired t-tests were used to compare outcomes. Ordinary least squares regression was used to isolate variables associated with poor fertilization, such as oocyte status (fresh versus vitrified), sperm origin (partner versus donor) and the presence of severe male factor (defined as a concentration of < 1 million/mL and/or <1% progressive motility). Main results and the role of chance The mean fertilization rate was 73.0% across all cycles analyzed. The incidence of poor fertilization (≤30%) was found to be 3.8% across the entire cohort (532 out of 13,859 cycles). Of these, 86.7% (461/532) cases using the same oocyte lot could be matched to cases with high fertilization rates (>65%) in other recipient cycles (n = 1,441), indicating that poor fertilization was male-related. We observed comparable numbers of inseminated oocytes between matched cases with high and low fertilization (7.23 ± 1.32 and 7.42 ± 1.42, respectively, p = 0.011), while the mean number of fertilized oocytes (1.44 ± 0.77 versus 6.12 ± 1.36, p = <0.001) and mean fertilization rates (20% versus 83%, p < 0.001) differed significantly. Notably, oocyte vitrification and the presence of a severe male factor negatively affected fertilization outcomes (coeff. -0.0898, p < 0.001 and coeff. -0.1500, p < 0.001, respectively). Nevertheless, the majority of poor fertilization cases (92.7%) occurred in the absence of these factors, underscoring the limitations of conventional semen diagnosis tests as predictors of poor fertilization. Across the entire cohort male factor alone accounted for 3.3% (461/13,859) of cycles with <30% fertilization rates. Furthermore, sperm-related factors were the primary cause of poor fertilization outcomes in oocyte donation cycles, accounting for 86.7% of cases. Limitations, reasons for caution Certain variables were not analyzed due to the retrospective nature and extended timeframe of the study. The matched oocyte model may overlook certain non-male factor-related instances of poor fertilization, such as procedural or technical issues. Wider implications of the findings This extensive analysis emphasizes the clinical relevance of male factor in fertilization outcomes, highlighting the need for improved semen diagnosis. It also indicates the importance of considering male-related factors in treatment decisions and shifting the focus from female-centric to more balanced fertility evaluations. Trial registration number Not applicable

P-225 Implementing a more physiological method to trigger oocyte activation in cases of extremely poor fertilization with ICSI

Abstract Study question Can we utilize a more physiological compound to induce oocyte activation in couples with history of complete/partial fertilization failure with ICSI? Summary answer Recombinant human phospholipase-C-zeta (rhPLCζ) successfully activated oocytes with same efficiency as ionomycin, consistently normalized fertilization and enhanced clinical outcomes. What is known already While ICSI overcomes most aspects of male gamete dysfunction, partial or complete fertilization failure may seldomly occur mostly due absence of sperm-specific protein, known as PLCζ, which is required to trigger oocyte activation. Assisted oocyte activation (AOA), most often performed with an antibiotic (ionomycin), activates oocytes by triggering calcium release from intracellular storage. This agent induces indiscriminate permeabilization of ooplasmic membrane-bound organelles. This action has been considered nonspecific and may have possible deleterious effects on subsequent embryo development. Therefore, we propose a physiological alternative that employs a recombinant form of PLCζ, the native protein residing in the sperm perinuclear theca. Study design, size, duration In the past 12 months, couples with poor ICSI fertilization were included. PLCζ were assessed to confirm sperm-related oocyte activation deficiency with a normal threshold of ≥ 30%. In a preliminary comparison, sibling oocytes were equally allocated to AOA by ionomycin or to rhPLCζ at time of ICSI. Fertilization, embryo development, and clinical outcomes between the two cohorts. Subsequently, we describe the clinical outcomes of couples treated solely by rhPLCζ. Participants/materials, setting, methods Thirty couples, confirmed with low level of PLCζ in the ejaculates, were offered AOA with their subsequent ICSI cycles (IRB#0712009553). Conventional AOA was performed by exposing post-ICSI oocytes to 50 µM ionomycin. The rhPLCζ-AOA method was performed by co-injecting spermatozoa with 0.4pL of a rhPLCζ (5 µg/µL) during ICSI. Chi-square tests were utilized to compare rhPLCζ-AOA versus ionomycin-AOA and rhPLCζ-AOA versus history cycles. Main results and the role of chance In the preliminary study, 9 patients were included (maternal age: 35.7 ± 6, paternal age: 36.7 ± 6). PLCζ positivity was 11.7±3.6% confirming a sperm-related oocyte activation deficiency. A total of 123 oocytes were retrieved in 9 cycles, with maturity of 78.0% (96/123). The 96 MII oocytes were allocated to be treated with ionomycin-AOA (n = 58) or rhPLCζ-AOA (n = 38). While conventional ionomycin-AOA yielded a fertilization rate at 55.2% (32/58), rhPLCζ-AOA resulted in 63.1% (24/38). Both compounds generated embryos at similar rates and one pregnancy was achieve in each cohort. On the bases of such comparable outcomes, 21 couples had 40 previous cycles that generated a fertilization rate of 18.3% (60/327), cleavage rate of 51.7% (31/60), Following the replacement of 23 embryos in 14 transfer cycles, these cycles yielded 2 clinical pregnancies, but all resulted in pregnancy loss. In the subsequent cycles with rhPLCζ-AOA (n = 32), an enhanced fertilization rate was achieved at 41.1% (116/280, P<0.00001). The treatment cycle yielded a higher cleavage rate at 80.2% (93/116, P<0.0001), and after replacing 25 embryos in 17 embryo transfer cycles, yielded 6 pregnancies and 5 of them resulted in delivered or are ongoing. Limitations, reasons for caution We demonstrated that physiological rhPLCζ-AOA achieved an excelled fertilization and clinical outcomes comparing to the traditional ionomycin method. Although further observation is needed to confirm its safety, this approach represents a more physiological method capable of achieving fertilization, higher embryo cleavage and ultimately better pregnancy outcomes. Wider implications of the findings While ICSI has gained large popularity, poor fertilization may occasionally occur. The availability of an assisted oocyte activation that utilize a native compound capable of restoring fertilization capability of the male gamete is appealing and holds great promises. Trial registration number N/A

P-067 A physiological approach for oocyte activation when using testicular spermatozoa

Abstract Study question Can poor fertilization with testicular spermatozoa be rescued by oocyte activation? We propose a more physiological approach to the standard method. Summary answer Couples who utilized testicular spermatozoa benefitted from assisted oocyte activation (AOA), particularly when a more physiological approach such as recombinant human phospholipase-C-zeta (rhPLCζ) was utilized. What is known already ICSI overcomes sperm acrosomal dysfunction and other inherent defects of the male gamete. However, partial or complete fertilization failure may still occur, often attributable to the absence of PLCζ. These cases are often treated by calcium ionophore, a very popular method that is considered quite safe, however it still raises concerns because it induces intracellular calcium oscillations in a very aspecific manner. Testicular spermatozoa are particularly at risk of suboptimal fertilization; therefore, the availability of a more physiological method would be welcome. Study design, size, duration Over a period of 12 months, 21 couples utilizing testicular spermatozoa for ICSI, that resulted in poor fertilization, were identified and treated in subsequent ICSI cycles with assisted oocyte activation (AOA), either by exposure to ionomycin or co-injection of rhPLCζ at the time of ICSI. Embryology and clinical outcomes were recorded and compared between the two AOA methods as well as the couples’ historical and subsequent cycles. Participants/materials, setting, methods Couples with a history of poor/absent fertilization after undergoing ICSI using testicular spermatozoa were counseled for AOA in subsequent cycles (IRB 0712009553). For consenting couples, AOA was performed either by exposing post-ICSI oocytes to 50mM of ionomycin (Ionomycin-AOA), or by co-injecting spermatozoa with 0.4pL of rhPLCζ (5mg/mL) during ICSI (rhPLCζ-AOA). Fertilization, embryo development, and clinical outcomes were compared between the couples’ historical and AOA cycles. Main results and the role of chance We included 21 couples (maternal age, 35.1±4 yrs; paternal age, 36.8±7 yrs). Female partners all had negative infertility workups that consisted of a comprehensive review of their medical history as well as a targeted physical examination and tests assessing ovarian reserve, ovulatory function, and absence of uterine and tubule structural abnormalities. The couples underwent 53 historical ICSI cycles using poor testicular spermatozoa (concentration, 0.04±0.1x106/ml, 0.5±1% motility) that yielded a 22.5% (94/417) fertilization and only an 11.5% (3/26) clinical pregnancy rate. All couples subsequently underwent ICSI-AOA cycles. Fourteen couples (maternal age, 35.5±4 yrs; paternal age, 37.6±6 yrs) who were treated with Ionomycin-AOA obtained a higher fertilization of 44.4% (99/223) (P<0.00001), which resulted in a clinical pregnancy rate of 26.3% (5/19). Thus far, four couples have delivered 1 boy and 3 girls, with no major or minor congenital malformations. The remaining 7 couples (maternal age, 35.8±4 yrs; paternal age, 37.9±7 yrs) underwent subsequent ICSI cycles with rhPLCζ-AOA, which yielded a remarkably higher fertilization of 50.0% (50/134) (P<0.00001). These couples went on to achieve a clinical pregnancy rate of 27.3% (3/11), resulting in the delivery of 1 girl and 2 boys. Initial follow-up has confirmed normal neonatal development. Limitations, reasons for caution The effectiveness of AOA in ICSI cycles with testicular spermatozoa is very encouraging, particularly when a more physiological method is utilized. Nonetheless, these findings need to be validated in a larger cohort, confirming successful outcome and children health. Wider implications of the findings ICSI utilizing surgically retrieved spermatozoa, particularly testicular, are plagued by suboptimal fertilization, and using AOA may represent a way to normalize the generation of conceptuses. Moreover, a broader adoption of AOA would certainly benefit from the use of a recombinant cytosolic factor normally present in the sperm perinuclear theca. Trial registration number n/a

P-066 A multi-bioassay approach to identify male gamete fertilization dysfunction

Abstract Study question Can a multi-bioassay approach identify a specific male gamete dysfunction often overlooked by a standard semen analysis? Summary answer In cases of persistent fertilization failure, additional testing may assist in pinpointing underlying factors contributing to compromised sperm embryo developmental competence and tailor treatment. What is known already Conventional semen analysis, while informative, ineffectively captures the complete spectrum of male gamete dysfunction. Despite adequate sperm concentration and motility, some couples may still experience fertilization failure with Intracytoplasmic Sperm Injection (ICSI). This highlights the complexity of male infertility, that extends beyond standard parameters. In addressing sperm-related fertilization challenges, various assisted oocyte activation (AOA) methods have been proposed to trigger intracellular Ca2+ release, leading to calcium spikes and meiosis initiation. Study design, size, duration In the past 10 months, we identified couples (n = 50) with a history of poor ICSI fertilization, exhibiting suboptimal head morphology. Screening for acrosomal dysfunction involved assessing the presence of PLCxand related gene mutations. We measured the degree of chromatin compaction by histone-to-protamine ratio and evaluated sperm chromatin fragmentation (SCF). To correct for eventual acrosomal dysfunction, couples were counseled to undergo subsequent ICSI cycles with AOA. Clinical outcome was compared between historical and treatment cycles. Participants/materials, setting, methods Fifty men with a history of poor ICSI fertilization were included. A standard semen analysis was conducted according to WHO guidelines. The presence of PLCx was measured through immunofluorescent staining (normal threshold, ≥ 30%), corroborated by gene mutation detection though DNA-seq. Sperm histone-to-protamine ratio was evaluated by Aniline Blue (normal threshold, <15% histone retention). SCF was assessed utilizing the TUNEL assay (normal threshold, ≤15%). AOA was performed using ionomycin or recombinant PLCx protein. Main results and the role of chance Fifty men experienced a poor clinical outcome following ICSI with a fertilization of 7.4% (48/647), embryo implantation of 6.6% (1/15), clinical pregnancy of 6.6% (1/15), and pregnancy loss rate of 100% (1/1). Their semen analysis, interestingly, revealed the following semen parameters: 3.0±1 mL volume, 50.0±20 x106/mL concentration, 41.4±21% motility, and 1.9±1% normal morphology. Nonetheless, PLCx content was diminished, with values ranging from 2-27%. Genomic assessment confirmed mutations in PLCx, DPY19L2, SPATA16 and PICK1 genes, all implicated in sperm nuclear remodeling and acrosome formation. An elevated histone content at 29.7% was positively correlated with an increased SCF at 18.0% (R2=0.6, P<0.001). In subsequent cycles employing AOA, the normal fertilization increased to 42.3% (305/721), the embryo implantation reached 13.0% (9/69), the clinical pregnancy rose to 21.1% (8/38), and the delivery rate was 21.1% (8/38), without any pregnancy loss. (P<0.001). Limitations, reasons for caution While this study affirms the effectiveness of a multifaceted assessment in pinpointing specific sperm dysfunctions and customizing treatment, it is still a retrospective observation requiring independent validation in a larger population. Wider implications of the findings Semen analysis alone fails to address specific aspects of male gamete dysfunction. Incorporating additional bioassays to assess chromatin structure, integrity, and acrosomal function offers valuable insights for fertility management in tailoring personalized treatments. This comprehensive approach enhances the understanding of male reproductive health, maximizing the potential for successful clinical outcome. Trial registration number not applicable

P-027 Sperm motility and calcium ionophore treatment influence fertilization and pregnancy outcomes in TESE-ICSI

Abstract Study question Are there differences in fertilization and pregnancy rates post-TESE-ICSI between motile and immotile sperm, and do these vary in treatments with and without calcium ionophore? Summary answer Post-TESE-ICSI data reveals differences in fertilization and pregnancy rates when comparing motile vs. immotile sperm and treatments with and without calcium ionophore after TESE-ICSI. What is known already Testicular sperm extraction (TESE) followed by intracytoplasmic sperm injection (ICSI) poses a challenge for every IVF laboratory. This is particularly true in patients exhibiting azoospermia, where only a few and mostly immotile sperm are present in testicular tissue. In these cases, a calcium ionophore treatment for activation of the oocyte may help to overcome poor prognosis fertilization outcome, and thereby enhancing the likelihood to achieve a transfer leading to a successful pregnancy. Although both techniques, TESE-ICSI and activating substances are commonly applied, detailed analyses for individual counselling of couples are missing. Study design, size, duration This study analyzed 787 TESE-ICSI cycles (2015-2023) regarding patient age, number of attempts, oocyte maturity, fertilization and pregnancy rate after fresh embryo transfer. Cycles were split into four groups: (A) at least one motile sperm was injected (n = 493); (B) only immotile sperm were used (n = 294); (C) calcium ionophore (n = 474); (D) no calcium ionophore (n = 313). 17 cycles were excluded from the study because no sperm were found on the day of TESE-ICSI and oocytes were vitrified. Participants/materials, setting, methods In our IVF clinic, calcium ionophore treatments are only offered if a pre-screening of TESE samples reveals the absence of motile spermatozoa or if a previously conducted TESE-ICSI attempt resulted in a low fertilization rate (<30%) or a total fertilization failure. Statistical analyses was performed to compare the motile and immotile sperm group and the groups with or without calcium ionophore treatment. Main results and the role of chance No differences were found in all groups (A-D) regarding age of female or male patient and number of collected oocytes per group. However, our results demonstrate a difference in the mean number of ICSI attempts when comparing motile sperm and immotile sperm (2.0±1.3 vs. 2.3±1.6, p < 0.05), and when comparing attempts with calcium ionophore treatment and those without (2.4±1.6 vs. 1.8±1.8, p < 0.0005). The mean fertilization rate (2PN stage) was higher in the motile sperm group (A) compared to the immotile group (B) (57.8% vs. 28.4%, p < 0.0005) and also higher in attempts of group (D) in comparison to attempts of group C (56.8% vs. 40.2%, p < 0.0005). While fertilization failure occurred less often in group (A) (3.2%) it occurred to a higher rate in group (B) (19.4%), followed by group (C) (12.0%). Biochemical (BPR) and clinical pregnancy rates (CPR) showed a significant difference between the motile and immotile sperm group (BCR: 33.2% vs. 12.3%, p < 0.0005; CPR: 25.6% vs. 9.3%, p < 0.0005), but no differences between the two calcium ionophore groups. Limitations, reasons for caution This analysis was done retrospectively. A potential subgroup analysis of groups (A) and (B) into calcium ionophore use and of groups (C) and (D) into motile or immotile sperm will reveal the effect of calcium ionophore on success rates regardless of sperm motility. Wider implications of the findings Our data provides insight into success rates of TESE-ICSI cycles, especially if only immotile sperm were present. This will serve as a helpful guide for physicians when counseling patients about their success rates and to optimize the outcome in cases with poor prognosis by using a calcium ionophore treatment. Trial registration number not applicable

P-164 The impact of oocyte morphological abnormalities on fertilization rate and blastocyst quality

Abstract Study question Do distinct morphological abnormalities in oocytes have an adverse effect on both fertilization rates and the quality of resulting blastocyst? Summary answer While most oocyte morphological abnormalities did not significantly affect outcomes, dark cytoplasmic color correlated with lower fertilization rates and the absence of good quality blastocysts What is known already Variability exists in the fertilization and developmental potential of mature (metaphase II - MII) human oocytes. A high-quality MII oocyte is characterized by a spherical shape, homogeneous cytoplasm, smooth appearance, a uniform zona pellucida (ZP), a normal-sized perivitelline space (PVS), and a single unfragmented polar body (PB). Dysmorphisms, such as variations in cytoplasmic features and anomalies in PVS size and PB regularity may occur. There are conflicting reports on the relationship between oocyte morphology and IVF outcomes. A recent meta-analysis highlighted associations between poor fertilization potential and specific dysmorphisms, including large/irregular PB, a large PVS, refractile bodies, and vacuoles. Study design, size, duration This study analyzed 367 MII oocytes obtained from 40 young patients. The fertilization rate (FR) and blastocyst quality (BQ) were compared among 132 dysmorphic and 235 normal MII oocytes (from October 2023 to January 2024). Dysmorphic oocytes were categorized as having a non-spherical shape, large PVS, PVS debris, abnormal ZP, fragmented PB, excess cytoplasmic granules, vacuoles, and dark cytoplasmic color. Participants/materials, setting, methods All MII oocyte denuded were examined under the microscope at x-400 magnification. Dysmorphic and normal oocytes were separated, injected, and cultured individually until day 5 under conditions of 37oC and 6% CO2. Fertilization was assessed 14 to 18 hours post-injection, and subsequent embryonic development was evaluated on day 2 and day 5. Blastocysts graded 4AA to 4BC are considered good quality, while those graded 4CC to 3CC are classified as fair quality. Main results and the role of chance The mean age of patients was 24.14 ± 3.77. In total, 36% of all oocytes exhibit at least one dysmorphism (n = 132). From the overall dataset analyzed, there was no significant difference (p > 0.9999) in FR between the normal 77.87% (183/235) and dysmorphic group of oocytes 78.03 (103/132). The odd ratio and 95% confidence interval are 0.9909 and 0.5957 to 1.633 respectively. However, this was not the same for oocytes with dark color cytoplasm. The presence of this dysmorphism significantly lowered FR (p = 0.0176) with an odd ratio of 5.544 (95% CI: 1.419 to 21.67). Similarly, the result showed no statistically significant difference (p = 0.1073) in the likelihood of obtaining a fair quality blastocyst between the normal oocytes 23.40% (55/235) and dysmorphic group of oocytes 15.79 (21/133). This was also the same for the likelihood of obtaining good quality blastocyst. There was no statistically significant difference (p = 0.1536) between the normal group 20.00% (47/235) and the dysmorphic group 26.52 (35/132). Oocyte with dark color cytoplasm gave no good quality blastocyst. Limitations, reasons for caution The exclusive use of oocytes from young patients may limit the generalizability of findings to a broader population of IVF patients. Also, the sample size may limit the study’s ability to detect subtle associations. A reason for caution when interpreting this study is its focus on morphological assessments alone. Wider implications of the findings The knowledge from our findings may contribute to optimizing oocyte selection strategies for intracytoplasmic sperm injection. Also, the knowledge could potentially be integrated into AI modules for oocyte morphological assessment. However, more studies would be required to develop a robust and scalable system Trial registration number Not applicable

The role of Zai pits and integrated soil fertility management options in improving crop productivity for smallholder farmers in the drylands of Sub-Saharan Africa

The drylands of Africa are experiencing food insecurity due to prolonged drought and water scarcity which has a negative effect on crop production. In the drylands of Sub-Saharan Africa, many small holder farmers are experiencing low crop yields and economic returns as a result of poor soil fertility and water scarcity. This is because of the inappropriate soil and water conservation strategies used in the region. Zai pits have been used as a soil and water conservation strategy in the drylands of Africa in combination with integrated soil fertility management (ISFM) options to improve soil fertility, increase the overall crop yields and the economic returns. This review deals on the role of zai pits and integrated soil fertility management options in improving productivity for the small holder farmers in the drylands of Sub-Saharan Africa. Zai pits have been used to harvest water which ultimately improves soil moisture for crop production with the different fertility inputs applied in the pits for nutrient efficiency. To evaluate productivity and profitability in zai tillage system, yield, benefit cost ratio (BCR) and net benefits are used. In this study, different studies by researchers on the use of zai pits and integrated soil fertility management options have been discussed and this would be beneficial for other researchers who have interest in this field. Most studies have indicated that the zai pit technology is an important soil and water conservation strategy which in combination with the integrated soil fertility management (ISFM) options improves crop productivity in terms of yield and economic returns.

Totally extraperitoneal laparoscopy-assisted microsurgical vasovasostomy for the treatment of obstructive azoospermia caused by pediatric bilateral inguinal herniorrhaphy.

Pediatric inguinal hernia repair (IHR) is a common cause of obstructive azoospermia (OA). Yet, the surgical treatment for this kind of OA remains difficult with poor fertility outcome. To evaluate the safety and effectiveness of totally extraperitoneal laparoscopy-assisted microsurgical vasovasostomy (VV) in the treatment of OA caused by pediatric bilateral IHR. Totally, 37 patients with OA caused by pediatric bilateral IHR were enrolled in this study from March 2015 to December 2020 in Shanghai General Hospital. The clinical data and fertility outcomes were collected and analyzed. All patients enrolled had a history of bilateral IHR at the age of 1-10 years old. The mean age of patients was 27±4.31 (range: 18-35) years. Totally extraperitoneal laparoscopy (TEP) was applied in 31 patients for the exploration and retrieval of pelvic vas deferens end, and 30 of them underwent microsurgical VV successfully. Among the six cases where TEP was not applied, five cases underwent microsurgical anastomosis. Intraoperative exploration revealed that the location of vas deferens injuries included scrotum (2.70%, 1/37), inguinal canal (5.41%, 2/37), pelvic cavity (78.37%, 29/37), and multiple sites (13.51%, 5/37). The mean operation time was 339±96.73 min (range: 130-510 min). There were no surgical complications. Thirty-three cases were followed up for 5-48 months with four cases lost to follow-up. The overall patency rate, pregnancy rate, and natural pregnancy rate were 75.86% (22/29), 46.67% (14/30), and 36.84% (7/19, 3 patients without family planning), respectively. And seven couples conceived through the assisted reproductive technique, two of which using fresh sperm in the ejaculate. TEP laparoscopy-assisted microscopic VV is an effective treatment for patients with OA caused by pediatric bilateral IHR.

Evaluation of push-pull technology for pest and soil fertility management on maize in north western Ethiopia

Maize (Zea mays L.) production in north western Ethiopia is severely constrained by the parasitic weed striga (Striga hermontica), the stemborer (Busseola fusca) pest, and poor soil fertility due to continuous mono cropping. An intercropping system known as push-pull technology is a novel soil and pest management strategy for improving soil fertility and controlling agricultural pests by using repellent "push" plants (such as desmodium, Desmodiumintortum)and trap "pull" plants (such as napier grass, Pennisetum purpureum). The aims of the study were (i) to evaluate the effectiveness of the push-pull technology against stemborer and striga infestation, (ii) to investigate the impact of the push-pull technology on improving grain yield, and (iii) to assess effect of the push-pull technology on soil fertility. The study was conducted in 2017 and 2018 cropping seasons in 3 districts in north western Ethiopia. Three farmers from each district, who practiced the technology, were randomly selected for the study. Each farmer had a set of two treatments (plots): a push-pull technology (PPT) and maize monocrop (MC) treatments. Data were collected on the percentage of maize plants damaged by stemborers, the number of striga plants that emerged, plant height, grain yield, available phosphorus (P), available potassium (K), total nitrogen (TN), organic carbon (OC), organic matter (OM) and bulk density (BD). There were significant reduction in stemborer damage (2.8 %) and striga count (4.1 Striga plants/m2) in the push-pull treatment compared to the maize monocrop plots (15.4 % and 21.8 striga plants/m2, respectively). Maize plant height (2.34 m) and grain yield (5.3 t ha−1) were significantly higher in the push-pull plots as compared to the sole crop (1.9 m and 3.0 t ha−1, respectively). Similarly, there were significantly higher P (20.06 mg/kg soil), K (406.86 mg/kg soil), TN (2.5 g/kg soil), OC (42.9 g/kg soil), OM (73.8 g/kg soil) levels considered to be moderate to high fertility status in the push-pull as compared to monocrop plots (11.17 mg/kg soil, 347.93 mg/kg soil, 1.6 g/kg soil, 29.8 g/kg soil, and 51.2 g/kg soil, respectively) which is rated from low to moderate soil fertility level. Moreover, bulk density was significantly lower in PPT (0.92 g/cm3) than in MC (0.95 g/cm3) plots. This suggests that push pull technology is effective in reducing striga and stemborer damage and improves soil fertility status which results in better grain yield.

The Effect of Liquid Organic Fertilizer from Kepok Banana Humps on Cayenne Pepper Plants' (Capsicum frutescens L.) Growth and Yield

The primary issue encountered in the cultivation of cayenne pepper is the low production levels attributed to the non-intensive cultivation system and poor soil fertility. Enhancing cultivation techniques, mainly through the application of liquid organic fertilizer derived from Kepok banana humps, has the potential to boost production yields. Kepok banana humps harbor microbes that aid in the decomposition of beneficial organic matter. The objective of this study is to assess the impact and optimal concentration of liquid organic fertilizer from Kepok banana humps on the growth and yield of cayenne pepper. Employing a Completely Randomized Design (CRD) with 4 treatments and 3 replications, the findings indicated that the utilization of liquid organic fertilizer from Kepok banana humps significantly influenced flowering age, harvest age, fruit weight per plant, and plant dry weight. At the same time, no notable effects were observed on plant height and leaf width. The most effective treatment was P3 (300 ml/plant), which yielded the most favorable outcomes across these parameters.

Evaluation of Microbe-Enriched Organic Fertilizer on Three Hybrid Corn (Zea Mays L.) Varieties in Swamp Land

Lowland areas are characterized by poor soil fertility and low nutrient content, making them suboptimal for agriculture. However, these lands have the potential to be developed for agricultural purposes, particularly for cultivating hybrid corn plants. To enhance production, organic fertilizers enriched with Azospirilium microbes and Phosphate Solubilizing Bacteria (BPF) are utilized, along with the planting of superior varieties that are tolerant to lowland conditions. Azospirilium microbes play a crucial role in providing nitrogen (N) nutrients through the nitrogenase enzyme, while BPF contributes phosphorus (P) and potassium (K) nutrients through the phosphatase enzyme. This combination of nutrients is essential for hybrid corn plants to thrive and produce effectively. The research conducted in Pulau Semambu Village, North Inderalaya District, Ogan Ilir Regency, from January to April 2023, employed a field experiment method using a Factorial Randomized Block Design with 9 treatment combinations repeated 3 times. The study involved three varieties (Pioneer 21, Bisi 816, Pertiwi) and three organic fertilizer dosages (100 kg/ha, 300 kg/ha, 500 kg/ha). The highest yield was achieved by applying 300 kg/ha of microbe-enriched organic fertilizer in combination with the Bisi 816 variety, resulting in a yield of 4.24 kg/plot or 5.65 tonnes/ha. This result represented a 60% increase compared to the Pioneer 21 variety treated with 100 kg/ha of microbial-enriched organic fertilizer.

Successive selection responses of tetraploid Crassostrea angulata: Comparison of growth, survival, sex ratio and ploidy composition between selected and unselected groups

Triploid Crassostrea angulata has the advantages of fast growth, poor fertility and high quality. However, due to poor fertility, direct genetic improvement is difficult. Mating between tetraploid males and diploid females has been shown to be the best method for commercial triploid production, so genetic improvement of tetraploids will directly affect the phenotypic traits of triploid offspring. However, to date, few studies have investigated the genetic improvement of tetraploid oysters. Based on the induced tetraploid C. angulata population, this study carried out three successive generations of growth selective breeding research, and systematically compared the growth, survival, ploidy composition and sex ratio of the selected group and the control group. The results showed that there was no significant difference in the survival rate from planktonic larvae to adult between the two groups. However, the growth of the selected group was significantly higher than that of the control group, that was, the shell height and whole weight of S3 were significantly higher than that of C3, and the selection advantage of shell height increased from 7.80% of S1 to 34.68% of S3. The ploidy composition of the two tetraploid groups was relatively stable before the 90th days, but on the 270th day, some tetraploids underwent chromosome loss and transformed into diploids or triploids, which might be related to gametogenesis of tetraploids. Moreover, with the increase of generations, the number of individuals with chromosome loss in the selected group gradually decreased, and their ploidy became more stable than that in the control group. In addition, both groups were fertile, with a sex ratio of more males than females, and a proportion of hermaphrodite individuals. In conclusion, this study successfully selected a fast growth line of tetraploid C. angulata, which can be used for commercial production of fast-growing triploid C. angulata, and provides a basis and reference for the genetic improvement of tetraploid oysters.

Enhancement of southern flounder (Paralichthys lethostigma) sperm velocity and fertility by direct activation of sperm epidermal growth factor and adenylyl cyclase signaling pathways

Development of southern flounder commercial aquaculture is limited by poor sperm motility and fertility, but the underlying causes and mechanisms regulating sperm motility are unknown. In vitro treatment of southern flounder sperm with progestin hormones rapidly increases velocity (swimming speed), a major component of sperm motility, and also fertility through membrane progestin receptor alpha (mPRα) and increases in Acy (adenylyl cyclase)/cAMP signaling. The progestin-induced increase of Atlantic croaker sperm velocity is also mediated through epidermal growth factor receptor (Egfr) transactivation resulting in extracellular-regulated kinase 1/2 (Erk1/2) signaling, but its role in regulating southern flounder sperm velocity is unknown. The hypotheses that Egfr transactivation and Erk1/2 signaling mediates progestin-induced increases in sperm velocity and calcium levels in southern flounder, and that direct stimulation of sperm Egfr/Erk1/2 and Acy/cAMP pathways increases sperm fertility in strip spawning trials were tested in the present study. Golf, Egfr, Erk1/2, and protein kinase A were detected on southern flounder sperm by immunocytochemistry. Involvement of Egfr/Erk1/2 signaling in increasing sperm velocity and calcium levels was investigated by preincubating sperm with two EGFR inhibitors, AG1478, and AG825, a matrix metalloproteinase inhibitor, Ilomastat, and two ERK1/2 inhibitors, PD98059, and U0126, for 30 min prior to 1 min treatment with progestins. Sperm swimming speed was observed under a microscope after activation with a hyperosmotic medium and recorded for 1 min. Whereas treatment with the inhibitors did not alter basal sperm velocity and calcium levels, all of them significantly attenuated velocity and calcium increases in response to progestins. Treatment in vitro for 1 min with the Egfr agonist, recombinant human EGF (0.1 nM and 100 nM), mimicked the stimulatory effects of progestins on sperm velocity, the increase in calcium, and also fertility in a strip spawning trials with ovulated southern flounder eggs. The results suggest Egfr/Erk1/2 signaling is involved in sperm velocity and fertility responses to progestins in southern flounder. Direct in vitro treatment with the Acy activator, forskolin (10 μM) for 1 min mimicked the stimulatory action of progestins on sperm calcium levels, velocity, and fertility, suggesting that Acy/cAMP signaling also mediates increased sperm swimming speed and fertility. Importantly, both EGF and forskolin also directly stimulated southern flounder sperm velocity and fertility at the end of the reproductive season when sperm were no longer responsive to progestins. The results suggest that EGF and forskolin could potentially be used as pharmacological agents to enhance reproductive performance of male southern flounder broodstock.

Deer grazing drove an assemblage‐level evolution of plant dwarfism in an insular system

Abstract Plant dwarfism, a syndrome characterised by a significant reduction in plant height and organ size, is a widely observed pattern of stress‐tolerant life‐form evolution that results from local adaptation to harsh environmental conditions. The drivers of assemblage‐level dwarfism have primarily been attributed to abiotic factors, such as low temperature, aridity, poor soil fertility or frequent fires. While biotic factors such as grazing pressure from herbivores can contribute to the establishment of plant dwarfism, these factors have rarely been tested at assemblage levels. Focusing on a dwarf plant assemblage comprising over 80 taxa on a small continental island in Japan with a high deer density, we hypothesised that historical deer grazing could also be a factor contributing to the large‐scale convergent evolution of dwarfism. To test this hypothesis, we measured the size of 1908 individual plants of 40 taxa pairs, comprising both palatable and unpalatable pairs from the island and their counterpart taxa from neighbouring regions, and sought to assess which factors (i.e. low solar radiation, estimated divergence time, low nutrient conditions and grazing pressure from deer) may have contributed to the formation of the dwarf plant assemblage on the island. We also performed genetic analysis to infer the time frames for the establishment of dwarf taxa. Statistical analyses revealed that plant size was significantly reduced mainly among the palatable taxa growing on the island, with preferential grazing by deer being identified as the most significant factor influencing plant size. Furthermore, genetic analyses revealed that dwarf ecotypes may have evolved over tens of thousands of years. Synthesis: To the best of our knowledge, this study is the first to demonstrate that interactions with herbivores can shape the assemblage‐level convergence of plant dwarfism. These findings enhance our current understanding of the formation of plant functional diversity.

The effects of contour-based rainwater harvesting and integrated nutrient management on maize yields in semi-arid regions of Zimbabwe

In the smallholder farming areas located in semi-arid regions of Zimbabwe, low and unreliable rainfall distribution and poor soil fertility are the major factors limiting crop production. The negative effects of these biophysical factors have been worsened by climate change. However, the major challenges have been the lack of sustainable, low-cost water and nutrient management technologies for these semi-arid regions. The objectives of this study were to evaluate the effects of contour-based rainwater harvesting (RWH) namely tied contours (TC), infiltration pits (IP) which were compared with the standard contour (STDC), and intergrated nutrient management (INM) where cattle manure was used as basal fertiliser and Ammonium Nitrate (AN) as top dressing, on maize yields. Results showed that fields with RWH had higher yields compared to STDC. Average maize yields were 2210 and 1792 kg ha−1 for TC and IP which were 88% and 52% above STDC (1176 kg ha−1) respectively. Increasing nitrogen (N) levels resulted in a further increase in maize yields. Return on investment was negative during drier years and was significantly higher in RWH systems compared with STDC during wet seasons. Farmers need to reduce mineral fertiliser application during dry seasons since little rainwater is captured. We conclude that contour based RWH and INM can be used as sustainable low cost methods of crop production. Higher fertiliser application rates when rainfall is limiting, do not result in increased return on investiment.

Farmers’ production constraints, preferred varietal traits and perceptions on sorghum grain mold in Senegal

Improving sorghum adoption rates by developing adapted varieties that meet end-user preferences is a major challenge in West Africa. In this study, a participatory rural appraisal was undertaken to identify the main sorghum production constraints, farmers’ preferred variety traits and their perceptions on sorghum grain mold. The study was conducted in four representative rural communities located in the main sorghum producing area of Senegal. A total of 260 farmers were interviewed and data were collected through focus group discussions and individual questionnaires. Our results indicated that Striga, insects, poor soil fertility and drought are the major sorghum producing constraints in Senegal. Grain mold was identified as the second most important sorghum disease after the damping-off. Discoloration on grain surface was the most important criteria farmers used to recognize the disease. The most important sorghum traits farmers desired in improved varieties are medium to short plant maturity cycle, medium plant height, large open or semi-compact panicle, big and white grain, and adaptation to local growing conditions. The results showed that the sorghum cropping system is dominated by male farmers who mainly grow local landraces. These results will provide updated recommendations for the breeding products profile to meet end-user preferences in Senegal.

Rhizobium leguminosarum bv.viciae Potential Assessment using Dosha faba Bean Isolates from Central and North Gondar, Ethiopia

Purpose: The objective this study was to evaluate nitrogen fixation effectiveness, survival and compatibility of the isolates of on two different soils that came from Dabat and Shentia sites at Gondar, Ethiopia. The author recommends that the isolates test their nitrogen fixing potential under field conditions in slightly acidic and neutral soil before being used as commercial biofertilzer inoculants. The present study provides potential nitrogen fixer input for agricultural research centers. Methodology: Soil physicochemical analysis and most probable number were done according to their standard procedure. Three top strains were selected as inoculants for faba beans grown on the slightly acidic Shentia soil and the slightly neutral Dabat soil with their control. The symbiotic effectiveness of the strains was evaluated based on plant agronomy and total nitrogen of the plant. The results of the strains analyzed by SPSS version 26. Findings: The highest rhizobium population size was 5.8 x102 cells g-1 soil, while the lowest was 1.7 x102 cell g-1 soil observed at the Dabat and Shentia sites, respectively. There is limited nitrogen and phosphorus content other were enough. It was significant difference inter-strain difference in the all agronomic parameter of all treatments in soil compared to each based on agronomic parameter, but across soils there was no significant different except shoot fresh weight. The result of these studies showed that two Rhizobium leguminosarum bv.viciae isolates and other combinations of them had considerable effect on agronomic properties. Unique Contribution to Theory, Practice and Policy: The application of biological nitrogen fixation through Rhizobium inoculums is promoted as a solution to the problem of poor soil fertility in areas where legumes are cultivated. In most of the developing countries, including Ethiopia, biological nitrogen fixation technology has not fully flourished, so this study was initiated to evaluate fixation potential of isolates.

What is driving the global decline of human fertility? Need for a multidisciplinary approach to the underlying mechanisms.

An intense period of human population expansion over the past 250 years is about to cease. Total fertility rates are falling dramatically all over the world such that highly industrialized nations, including China and the tiger economies of SE Asia, will see their populations decline significantly in the coming decades. The socioeconomic, geopolitical and environmental ramifications of this change are considerable and invite a multidisciplinary consideration of the underlying mechanisms. In the short-term, socioeconomic factors, particularly urbanization and delayed childbearing are powerful drivers of reduced fertility. In parallel, lifestyle factors such as obesity and the presence of numerous reproductive toxicants in the environment, including air-borne pollutants, nanoplastics and electromagnetic radiation, are seriously compromising reproductive health. In the longer term, it is hypothesized that the reduction in family size that accompanies the demographic transition will decrease selection pressure on high fertility genes leading to a progressive loss of human fecundity. Paradoxically, the uptake of assisted reproductive technologies at scale, may also contribute to such fecundity loss by encouraging the retention of poor fertility genotypes within the population. Since the decline in fertility rate that accompanies the demographic transition appears to be ubiquitous, the public health implications for our species are potentially devastating.