Three-year Study Research Articles

Thyroid Hormone Replacement Dosing after Bariatric Surgery in Patients with Primary Hypothyroidism And Severe Obesity: Tehran Obesity Treatment Study.

Background: Obesity and hypothyroidism are common medical conditions that are associated with each other. Bariatric surgery (BS) is a common approach used to achieve substantial weight loss in obese patients. However, there is limited evidence regarding the need for postsurgery levothyroxine (LT4) dose adjustment in patients with hypothyroidism undergoing BS. Methods: This was a three-year prospective cohort study assessing postsurgery LT4 requirements with attention to body composition changes. The current study included 1030 patients with hypothyroidism, who underwent sleeve gastrectomy (SG) (n = 707, 88.3% women) or one anastomosis gastric bypass (OAGB) (n = 323, 92% women). Patients were followed for 36 months after surgery. A bioelectrical impedance analyzer was used for body composition assessment. LT4 requirements were assessed by generalized estimating equation (GEE) methods adjusted for weight as a time-varying covariate. Results: During the follow-up, TSH (mIU/L) and T4 (ng/dL) measurements did not significantly change in the OAGB group over time. However, in the SG group, TSH measurement decreased over time (ptrend = <0.001). In the third year of the follow-up, 56.1% and 33.3% of patients in the SG and OAGB groups experienced LT4 (μg/day) dose reduction, while 24.4% and 9.1% of the participants experienced LT4 dose increments, respectively. GEE analysis showed a significant increase in the LT4/fat mass (FM) (μg/kg) ratio after 36 months of follow-up compared with the baseline in both the SG [1.8 (1.5-2.2) to 2.7 (2.0-3.5), ptrend = 0.039)] and OAGB [1.7 (1.4-2.2) to 3.2 (2.7-4.8), ptrend = <0.001)] groups. Moreover, patients who underwent OAGB experienced greater LT4/FM (μg/kg) dose adjustments compared to those undergoing SG (pbetween = 0.060). In both groups, after the first year, the increase in LT4/FM (μg/kg) plateaued (pinteraction = 0.009). Conclusion: Most hypothyroid patients experienced either a reduction or no change in LT4 (μg/day) dosage after 36 months in both surgical groups. The LT4/FM (μg/kg) was significantly increased in patients undergoing either SG or OAGB with greater alterations in the latter. Further studies on larger populations and with longer duration of follow-up are needed to confirm our results.

53592 Intervention to improve diversity in dermatology: Review of a three-year study

53592 Intervention to improve diversity in dermatology: Review of a three-year study

Herbal Companion Crops as an Example of Implementation of Sustainable Plant Protection Practices in Soybean Cultivation

This study aimed to assess the effect of using selected herbs as companion crops in soybean cultivation on the yield and overall health of soybeans. A three-year field experiment (2021–2023) was conducted using a randomized block design with three replications, where the primary experimental variable was the sowing method. The innovative cropping system involved cultivating soybeans alongside different companion herbs, such as alyssum (Lobularia maritima L.), fennel (Foeniculum vulgare Mill.), borage (Borago officinalis L.), French marigold (Tagetes patula L.), calendula (Calendula officinalis L.), and a herbal mixture referred to as ‘MIX’. The study showed that cultivation of soybean with fennel improved the quantitative and qualitative characteristics of the yield, with a significant increase in seed yield (on average by 0.27 t ha−1) as well as protein (7.67%) and oil yield (8.57%) compared to the pure soybean crop. The following fungal diseases were identified during the three-year study period (2021–2023): Cercospora leaf blight, Ascochyta blight, Fusarium wilt, and downy mildew. Cultivation of soybean with herbs as companion crops was implemented to improve the health of soybean to a varied extent. Borage, marigold, and calendula companion crops reduced infection of soybean by the fungi C. kikuchii and F. oxysporum. Cultivation with fennel and marigold was also beneficial for soybean health. On the other hand, cultivation with sweet alyssum and a mixture of herbs increased the occurrence of the fungus A. sojaecola. Cultivation of soybean in association with herbs is legitimate and requires further research given the priorities facing 21st-century agriculture.

Distribution of HCV Genotypes in Patients with Chronic Hepatitis C Infection: A Three-Year Single-Center Retrospective Study

Objective: Hepatitis C virus (HCV) is a single-stranded, positive-sense RNA virus belonging to the genus Hepacivirus in the Flaviviridae family. It has eight known genotypes and 93 subtypes. HCV can be transmitted through various routes, including blood transfusion, surgical procedures, sexual contact, and intravenous drug use, leading to both acute and chronic hepatitis. Genotype (GT) determination and viral load assessment are essential for selecting an appropriate antiviral treatment regimen and duration, and for monitoring treatment efficacy. We aimed to ascertain the genotype distribution over a three-year period. Methods: In this study, patients diagnosed with chronic HCV infection and followed at Afyonkarahisar Health Sciences University Health Practice and Research Hospital between July 1, 2020, and June 30, 2023, were retrospectively evaluated for their age, gender, and HCV genotype data. Results: A total of 91 patients’ HCV genotype data were included in the study. The study revealed that 95.6% of the patients were Turkish citizens, while 4.4% were of foreign nationality. Among the 91 patients, 60 (65.9%) were found to have genotype 1b, 12 (13.2%) had genotype 1a, 10 (11%) had genotype 3, 6 (6.6%) had genotype 4, 2 (2.2%) had genotype 2, and one patient (1.1%) had a co-infection of genotypes 3 and 4. Conclusion: Genotype 1b was dominant in our region. Identifying HCV genotypes is important in guiding the prognosis and treatment of chronic HCV infections and monitoring the epidemiologic changes. This information will be of great value in the health policy that targets HCV and in elimination efforts.

For cash, the planet, or for both: Evaluating an informational intervention for energy consumption reduction

Reductions in residential energy demand (especially by high-consuming households) are critical for climate change mitigation. Interventions that inform people about their energy use and its consequences may encourage them to reduce energy consumption, but such informational interventions have not always been found to be effective. In addition, little is known about the factors that determine the effectiveness of informational interventions. Here, we examined the effect of an informational intervention campaign on household energy use (electricity and gas) in Mechelen, Belgium. Neighborhoods were randomized to different variants of the intervention that emphasized the monetary, environmental, or monetary and environmental consequences of saving energy. Across a three-year study period, we observed significantly larger reductions (two additional percentage points) in gas consumption in the intervention city than in four comparable control cities. This effect was largely driven by reductions in neighborhoods with high baseline levels of gas consumption. No substantial changes were found between neighborhoods that received monetary information, environmental information, or both. Our findings support the effectiveness of informational interventions for the reduction of energy use, point to the special role of high-consuming households, and can inform the design of future intervention campaigns.

Exploring Emotional Vulnerability and Sense of Agency in the Digital Realm: A Three-Year Case Study of an EFL Teacher in South Korea

This study presents the findings from a longitudinal case study on a Korean English teacher’s experience of emotional vulnerability and professional development in online teaching. Grounded in an ecological perspective on teacher agency and emotional vulnerability, the study investigates how and why the teacher exercised agency in navigating her emotional challenges and adapting to the virtual teaching environment. Data were collected from various sources, including interviews, observations, field notes, and artifacts, for three years. The findings showed that the intricate connection between the teacher’s multiple and dynamic emotions, beliefs, and concurrent working environments significantly influences her engagement in digital teaching practices. Furthermore, the teacher’s emotional vulnerability in virtual teaching facilitated her engagement in reflective and action-oriented practices, leading to a more proactive approach to exploring and implementing alternative teaching methods online. The findings highlight the interplay between emotions, agency, and identity development, emphasizing the importance of experiencing, understanding, negotiating, and expressing emotions to discover potential alternative teaching resources and methods in ever-changing teaching environments. This study provides insights into how teachers can leverage their emotions and exercise teacher agency to enhance their professional growth and adaptability in digital learning environments.

Cynodon dactylon and Sediment Interaction in the Three Gorges Reservoir: Insights from a Three-Year Study

Sediment deposition is critical in maintaining riparian plant communities by providing essential nutrients and posing growth challenges. This study focuses on Cynodon dactylon, a dominant clonal species in the riparian zones of the Three Gorges Reservoir, and its interaction with sediment deposition over three years. Results indicated an average sediment deposition depth of 2.85 cm in the lower riparian regions. Observations revealed that C. dactylon coverage increased progressively at lower elevations despite its dominance diminishing with rising elevation levels. Additionally, positive linear correlations between C. dactylon coverage and sediment deposition depths were identified during flood periods, underscoring the species’ role in enhancing sediment deposition. These findings suggest that C. dactylon plays a significant role in sediment accumulation, which may bolster its growth and survival prospects during subsequent growing cycles. The study highlights the importance of riparian vegetation, mainly perennial clonal species like C. dactylon, in promoting sediment accumulation and contributing to the stability and functionality of riparian ecosystems.

Identification of Enterococcus spp. by MALDI-TOF mass spectrometry isolated from clinical mastitis and bulk tank milk samples

BackgroundThroughout a three-year study period, 1,577 bovine clinical mastitis samples and 302 bulk tank samples were analyzed from ten Brazilian dairy herds. Enterococcus spp. was isolated and identified in 93 (5.9%) clinical mastitis samples. In addition, 258 Enterococcus spp. were isolated from the bulk tank samples of the same herds. The identification of Enterococcus spp. isolated from bulk tanks and milk samples of clinical mastitis were accomplished by phenotypic characteristics and confirmed by MALDI-TOF Mass Spectrometry (MS). Fisher test was performed to verify the difference between bulk tanks and mastitis samples.ResultsThe following species were identified from clinical mastitis: E. saccharolyticus (62.4%), E. faecalis (19.4%), E. faecium (15.1%), E. hirae (1.1%), E. mundtii (1.1%), E. durans (1.1%). Furthermore, from 258 bulk tank milk samples, eight enterococci species were isolated: E. faecalis (67.8%), E. hirae (15.1%), E. faecium (4.6%), E. saccharolyticus (4.6%), E. mundtii (3.1%), E. caseliflavus ( 2.7%), E. durans (1.2%), E. galinarum (0.8%).ConclusionsThe difference in species predominance in bulk tank samples (67.8% of E. faecalis) and clinical mastitis (62.4% of E. saccharolyticus) was unexpected and caught our attention. Although Enterococcus spp. are traditionally classified as an environmental mastitis agent, in the present study, E. saccharolyticus behaved as a contagious agent of mastitis, which consequently changed the control patterns to be implemented.

Indigenous Early Career Researcher’s Perspectives of ‘safe spaces’’ in Higher Education

The Developing Indigenous Early Career Researchers Project is a three-year longitudinal study funded by the Australian Research Council that ran from January 2020 to December 2022. Its main focus was to investigate the experiences and perspectives of Indigenous Early Career Researchers working in universities across Australia. This article presents four main attributes identified by Indigenous Early Career Researchers as necessary to creating culturally safe spaces in Australian universities. These attributes include, safe to: (a) be Indigenous; (b) seek advice and make mistakes; (c) speak openly; and (d) trust. The successful implementation of these attributes requires institutional support and commitment in the form of relevant higher education policies and practices. Importantly, an overarching perspective of this article is that effective implementation of culturally safe spaces for Indigenous Early Career Researchers requires a significant shift in institutional discourse from the inclusion of Indigenous Peoples and Knowledges to recognising Indigenous Peoples as sovereign.

Optimizing Sweet Cherry Attributes through Magnesium and Potassium Fertilization

Plant nutrition through fertilizer application plays a crucial role in enhancing crop quality and yield, necessitating a balanced fertilization approach. Sweet cherry, esteemed as one of the most prized crops worldwide, was the focus of this three-year study spanning from 2019 to 2021, involving the sweet cherry cultivar Burlat. This study investigated the foliar application of magnesium (Mg) and potassium (K) to enhance fruit quality parameters. Different doses of Mg (250 g hL−1 and 125 g hL−1) and K (100 g hL−1 and 50 g hL−1) and a control treatment were administered to sweet cherry trees to assess their impact on fruit quality. At the commercial ripening stage, fruits from each treatment were harvested for comprehensive evaluation, including biometric and chromatic parameters, fruit firmness, routine parameters, sensory profile, and nutrient content analysis. Results from the study revealed notable enhancements in fruit weight and dimensions, particularly in the control treatment in 2020. Furthermore, Mg125 and Mg250 treatments exhibited improved color development and accelerated maturity by increasing the total soluble solids content while decreasing titratable acidity. Sensorial profiling indicated that Mg125 and Mg250 treatments intensified color intensity and sweet taste while mitigating sour taste perceptions. Conversely, potassium fertilization, especially the K50 treatment, led to increased fruit firmness and nutrient content. These findings offer valuable insights into optimizing sweet cherry production practices globally.

Three-year questionnaire study on human papillomavirus vaccination targeting new female college school students: Follow-up to a 2021 report to reveal the impact of a policy change in Japan.

The purpose of this study was to examine the trend in human papillomavirus (HPV) vaccination rates in Japan before and after a policy change in 2022, involving resumption of active recommendation and start of catch-up vaccination. From 2021 to 2023, a web-based questionnaire survey was administered to newly enrolled female college students in Yokohama, Japan. The questionnaire included items such as age, HPV vaccination status, HPV vaccine awareness, and awareness of catch-up vaccination. We compared knowledge about the HPV vaccine and cervical cancer in 2021 and 2023, before and after resumption of the national vaccination program. The HPV vaccination rates were 5.4% in 2021, 7.5% in 2022, and 35.3% in 2023, with a significant upward trend (p < 0.001). A similar upward trend was observed for HPV vaccine awareness (p < 0.001). Comparing 2022 and 2023 after the start of catch-up vaccination, there was no significant difference in awareness of catch-up vaccination (p = 0.669), but there was a significant increase in awareness of free vaccination tickets (p < 0.001). After resumption of the national vaccination program with adoption of the catch-up vaccination program, there was no difference in knowledge of cervical cancer, but there was a difference in knowledge of the HPV vaccine. Although the HPV vaccination rate has increased after the policy change, it has not recovered to the level before the suspension of active recommendation. It is important for healthcare providers and school educators to actively communicate the safety and effectiveness of the HPV vaccine.

Trajectory model to analyze the effect of multi-metal exposures on sperm parameters and sex hormones of the MARHCS cohort in China

BackgroundAt present, several cross-sectional studies have found that exposure to metal/metalloid elements is closely associated with male reproduction. However, the long-term effects of metal exposure on male reproduction have not been explored. MethodsIn 2013, 796 volunteers were recruited, followed by first and second follow-ups in 2014 and 2015. Urine, semen, and blood samples were collected at each stage to examine urinary metal/metalloid levels, sperm parameters, and sex hormones. Initially, the latent class trajectory model (LCTM) was utilized to analyze the trajectories of urinary metals. Subsequently, the effects of urinary metal trajectories on semen parameters and sex hormones were examined using the linear mixed model. Finally, the impact of urinary metal trajectories on the classification of semen quality (normal or abnormal) was evaluated using the generalized linear mixed model. ResultsAmong the 18 metals/metalloids studied, trajectories were formed by 6 of them (Li, Al, Fe, Zn, As, Rb). Further analysis using the linear mixed model and the generalized linear mixed model revealed that Li was negatively correlated with semen volume, and sperm motility (P < 0.05). The maximum-decreasing trajectory group had a detrimental effect on semen quality (OR = 1.75, 95%CI: 1.22, 2.53) compared to the minimum-stable trajectory group. Al showed negative associations with sperm concentration, total sperm count, and normal morphology (P < 0.05). Rb was positively associated with progressive motility (P < 0.05). The high-stable trajectory group exhibited a protective effect on semen quality (OR = 0.66, 95%CI: 0.49, 0.90) compared to the low-stable trajectory group. Additionally, Fe was observed to have a negative relationship with follicle-stimulating hormone (FSH) (P < 0.05), and Rb exhibited a negative correlation with progesterone (P) (P < 0.05). ConclusionOur three-year cohort study provides new evidence that Li and Al have a negative impact on semen quality, whereas Rb is associated with beneficial effects. Additionally, Rb and Fe are endocrine disruptors of sex hormones.

Impact of COVID-19 pandemic on microplastic occurrence in aquatic environments: A three-year study in Taihu Lake Basin, China

The impact of the Coronavirus Disease 2019 (COVID-19) pandemic on microplastic (MP) occurrence in aquatic environments deserves an in-depth study. In this study, the occurrence of MPs and environmental flux of plastics before (2019) and during (2020 and 2021) the pandemic were comparatively investigated in various aquatic compartments in the Taihu Lake Basin in China. The field-based investigations from 2019 to 2021 for Taihu Lake have shown that, at the onset of the outbreak, the MP abundance declined at a rate of 62.3 %, but gradually recovered to the pre-pandemic level. However, the amount of plastics being released into aquatic environments showed a declining trend in 2020 and 2021 compared to those in 2019, with decrease rates of 13.7 % and 15.8 %, respectively. Characterization analysis of MP particles and source apportionment framework implied that while the contributions of tire abrasion and domestic waste to MP occurrence were depleted owing to the reduction in human activity during the pandemic, weathering and fragmentation of retained plastics contributed to the recovery of stored MPs. This study provides insights into the anthropogenic influences on MP occurrence, and supports policymakers in managing and controlling plastic contamination in large freshwater systems in the “new normal” phase.

Evaluating maize (Zea mays L.) management practices implementing sensitivity analysis of vegetation indices

Conservation agriculture and sustainable agronomic principles include several management practices such as cover cropping, no-till, and alternative fertilization rates. Each of these practices can result in changes among agricultural productivity, sustainability for future farming, and protections for the environment. These management practices are important concepts that can be applied in the production of maize (Zea mays L., corn). The aim of this three-year study (2018–2020) was to compare maize health across two fields located in Riesel, TX under varying management approaches and precipitation conditions. The first field utilized ‘business as usual’ operations characterized by the implementation of tillage, fertilization at a maximum rate (10.06 Mg/ha), and no cover crops. The second field utilized ‘aspirational’ cultivation techniques categorized by no tillage, cover crops, and an alternative method for rate of fertilization. Each field was subject to satellite-based remote sensing methods incorporating Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and Normalized Difference Red Edge (NDRE). Indices were subject to sensitivity analyses to determine the most sensitive index for maize under various managements and precipitation conditions. The most sensitive index (EVI) served as a proxy for time series analysis for maize health under the varying managements and rainfall conditions. The results suggest improvements to maize health are experienced over time when aspirational managements are employed, even though business as usual management resulted in higher yields. However, studies with greater duration could point to these perceived benefits over a long-term implementation. Nevertheless, productivity comparisons considering amount of input (i.e. fertilizer) suggests an increase in efficiency each year for the aspirational management. These findings suggest factors such as improved soil health from implementation of no-till and cover crops contribute to field health, efficiencies, and resiliency across varying precipitation conditions.

Factors associated with mental health and quality of life among Brazilian medical students: a three-year longitudinal study

Background Despite several studies on the mental health of medical students, there is insufficient research on long-term follow-ups. Aims To investigate the associated factors and changes in the quality of life and mental health of a group of medical students followed-up for three years. Methods An observational, prospective cohort study was conducted. Four classes were followed during the first three years of the medical course. The study included sociodemographic data, mental health data using the DASS-21 scale, and quality-of-life data using the WHOQOL-BREF scale. Linear regression models were used for analysis. Results A total of 201 (66.1%) medical students responded to both data collection waves after a three-year follow-up. Depressive symptoms(p < 0.001), anxiety(p = 0.037), and stress(p < 0.001) increased. Additionally, physical(p < 0.001), psychological(p < 0.001), and social(p = 0.003) quality of life decreased. Worse mental health at baseline and being a woman were associated with worse mental health after three years, while higher income at baseline was associated with better quality of life after three years. Conclusions The mental health and quality of life of the medical students worsened after three years, being influenced by gender, income, and mental health at baseline. Educators and managers must be aware of these factors to minimize suffering in medical schools.

Early-life gut bacterial community structure predicts disease risk and athletic performance in horses bred for racing

Gut bacterial communities have a profound influence on the health of humans and animals. Early-life gut microbial community structure influences the development of immunological competence and susceptibility to disease. For the Thoroughbred racehorse, the significance of early-life microbial colonisation events on subsequent health and athletic performance is unknown. Here we present data from a three-year cohort study of horses bred for racing designed to explore interactions between early-life gut bacterial community structure, health events in later life and athletic performance on the racetrack. Our data show that gut bacterial community structure in the first months of life predicts the risk of specific diseases and athletic performance up to three years old. Foals with lower faecal bacterial diversity at one month old had a significantly increased risk of respiratory disease in later life which was also associated with higher relative abundance of faecal Pseudomonadaceae. Surprisingly, athletic performance up to three years old, measured by three different metrics, was positively associated with higher faecal bacterial diversity at one month old and with the relative abundance of specific bacterial families. We also present data on the impact of antibiotic exposure of foals during the first month of life. This resulted in significantly lower faecal bacterial diversity at 28 days old, a significantly increased risk of respiratory disease in later life and a significant reduction in average prize money earnings, a proxy for athletic performance. Our study reveals associations between early-life bacterial community profiles and health events in later life and it provides evidence of the detrimental impact of antimicrobial treatment in the first month of life on health and performance outcomes in later life. For the first time, this study demonstrates a relationship between early-life gut bacterial communities and subsequent athletic performance that has implications for athletes of all species including humans.

Predictors of limb saving in diabetic foot ulcer.

This study was aimed to determine the various factors which could serve as predictor of saving of lower limb from amputation in patients with diabetic foot ulcer (DFU). This three-year retrospective study was conducted in the Diabetes and Endocrinology Unit of Hayatabad Medical complex Peshawar, Pakistan. Demographic, clinical, laboratory and radiological information of the diabetic patients with DFU admitted between January 2020 to December 2022 was retrieved from the hospital files. Information regarding initial and final decision regarding amputation and the outcome of the ulcer was also recorded. A total of 502 patients of diabetes mellitus (DM) with DFU were included in the study, of whom there were 279 (55.6%) males and 223 (44.4%) females. The mean age of the study population, mean duration of DM and mean HbA1c were 55.2 ± 9.8 years, 13.7 ± 6.7 years and 11.2 ± 2.4 %, respectively. Patients who had an amputation of their lower limbs had an increased age (p= 0.034), raised total leucocyte count (TLC) (p= <0.001), higher HbA1c (p= 0.025), had osteomyelitis (p= <0.001), and had a higher-grade ulcer (p= <0.001). On binary logistic regression analysis, ulcer grade (OR=7.4, p= <0.001), osteomyelitis (OR=11.8, p= <0.001), and initial decision of no amputation at the time of admission (OR=33.6, p=<0.001) were independently associated with the lower limb salvage. DFU which were of grade I to II, had no evidence of osteomyelitis and for which an initial decision was of no amputation were more likely to be salvaged.

Brokering understanding: Canadian deaf interpreters’ role and practice

ABSTRACT This article reports findings from semi-structured interviews with twelve Canadian deaf interpreter (DI) participants as part of a three-year study of language ideologies related to DIs. DIs are professional or amateur sign language interpreters and translators who are deaf and who may often but not always work as part of a team with hearing interpreters. When working with a hearing interpreter who uses the same national sign language, the DI’s role is often seen as meeting the needs of deaf clients who are viewed as lacking proficiency in a named language and/or who are viewed as monolingual in a named national sign language. This reflects normative language ideologies and conceptions of interpreting and translation. DI participants described their role in terms of their enhanced powers of understanding that elicited greater information from other deaf individuals than was apparent to a hearing interpreter. In addition, DI participants characterized their work as primarily translation, in a manner that accords with translation as the creation of meaning and as translanguaging that extends beyond named languages and deploys the individual’s full semiotic repertoire.

The Hypogeous Roman Archeological Museum of Positano: Study of the Evolution of Biological Threaten and Development of Adequate Control Protocols.

Hypogea are natural or artificial spaces located underground often of great interest from an anthropological, archeological, religious, artistic, or historic point of view. Due to their features, these environments usually present conservative problems and biological colonization could be considered as one of the main threats. The present three-year study was carried out by specialists of the Central Institute for Restoration of Rome (ICR) in the hypogeous site preserved in the Roman Archeological Museum of Positano (Positano MAR) and focused on characterizing biological alterations present on the mural paintings; setting up efficient strategies and protocols for biodeterioration control; and monitoring the efficacy of direct and indirect interventions. Patinas with different morphologies were analyzed through microscopic observations, cultural analyses and next-generation sequencing. The results proved that the alterations comprised a great variety of microorganisms forming very distinct communities, differently distributed over space and time. The main taxa represented were bacteria of phyla Pseudomonadota and Actinomycetota, fungi belonging to the genus Fusarium and Gliocladium, and algae of the genus Chlorococcum. Preservation protocols were set up considering the alterations' composition and included the application of biocides, limiting daily temperature changes, decreasing illuminance values on painted surfaces, and the screening of natural light sources.

Legume choice and planting configuration influence intercrop nutrient and yield gains through complementarity and selection effects in legume-based wheat intercropping systems

CONTEXTBy exploiting the complementarities between intercrops, cereal/legume intercropping provides an opportunity to increase legume production with sustained cereal yield. However, little is known about how legume choice and spatial configurations affect the performance and economic viability of legume-based wheat intercropping, especially in arid-irrigated conditions. OBJECTIVEWe conducted this study to investigate the complementarity of three different legumes (chickpea, soybean, and pea) with wheat and determine the appropriate strip width for intercrops. METHODSA three-year study (2021−2023) was conducted to evaluate the effects of legume choice and spatial configuration (narrow strips of 0.6 m (NS) and partially wide strips of 1.2 m (pWS) for each intercrop) on wheat/soybean, wheat/pea, and wheat/chickpea intercropping, and results were compared with their sole systems for dry matter, nitrogen (N) and phosphorus (P) uptake, yield, and economic returns. We also quantified the intensity of the net biodiversity effect (NE), complementarity effect (CE), and selection effect (SE) for yield, N (NEN, CEN, and SEN), and P (NEP, CEP, and SEP) gains of legume-based wheat intercropping systems. RESULTS AND CONCLUSIONSOur results show that intercrops achieved the highest dry matter, nutrient uptake, and grain yield with pWS compared to NS. The intercropped chickpea, soybean, and pea achieved 67–71%, 55–62%, and 62–70% of their sole system yield. The intercropped wheat with chickpea, soybean, and pea produced 66–69%, 57–62%, and 62–66% of sole wheat yield, respectively. Results also confirmed a positive NE with both NS and pWS, mainly due to the higher CE, which ranges from 37% to 104% of NE under all intercropping systems. The nutrient uptake gain with NS and pWS ranged from −3.4 kg ha−1 to 101.5 kg ha−1 (NEN) and − 0.2 kg ha−1 to 13.8 kg ha−1 (NEP). On average, maximum LER (1.36), NE (1012 kg ha−1), NEN (86 kg ha−1), and NEP (12 kg ha−1) were obtained with pWS in wheat/chickpea, followed by wheat/pea and wheat/soybean intercropping. Overall, wheat/pea intercropping with pWS generated the highest net profit (2014, 1533, and 1394 USD ha−1 in 2021, 2022, and 2023, respectively), which was primarily linked to the high market price of pea than chickpea and soybean. SIGNIFICANCEThese results imply that legume choice and spatial configurations influenced complementary and facilitation interactions between intercrops, and wheat/chickpea and wheat/pea intercropping with pWS could be adopted as a productive cropping strategy for obtaining higher and diverse crop yields with reduced land and nutrients than the sole wheat system.