Effects of nitrogen fertilization on soil fauna – A global meta-analysis

Author(s):  
Bibiana Betancur Corredor ◽  
Birgit Lang ◽  
David Russell

<p>The impact of agricultural activities on soil fauna can be highly variable, depending on the management options adopted. High-input agricultural practices can promote a reduction in diversity of soil microarthropod communities but, at the same time can also favor bacterial-feeding fauna through the increase of bacterial food web pathways. In contrast, low-input practices can increase the dominance of fungal-feeding fauna through the promotion of fungal pathways. Responses also vary with time after fertilizer application and are strongly dependent on crop species or shifts in plant species composition due to fertilization. The type of fertilizer, organic or inorganic, can also have diverse effects on soil organisms. Organic fertilizers can increase the population of soil decomposers serving as nutrient sources for other soil organisms. Nitrogen fertilization may disturb soil organisms in a manner that affects ecosystem functioning, but the links are not yet well quantified. Therefore, a systematic compilation of available experimental data on the effects of nitrogen fertilization on taxonomic and functional groups of soil fauna is needed to clarify the patterns and mechanisms of responses. </p><p>Paired observations for meta-analysis were collected from 198 studies published in the last 30 years across 37 countries. First results show that nitrogen fertilization increased the biomass of earthworms (mean increase of 19.7%), the abundance of nematodes (mean increase of 36.6%), springtails (mean increase of 29.7%), and mites (mean increase of 35.2%), and reduced the abundance of earthworms (mean reduction of 9.2%) compared to when no fertilizer was applied. The population responses of all organisms were larger when organic fertilizers were applied. The meta-analyses for different earthworm ecological groups showed that the biomass of epigeic and endogeic earthworms were most sensitive to organic fertilization, and this effect was magnified when higher rates of nitrogen are applied. The meta-analyses for different nematode feeding groups, life-form groups of springtails and mite suborders showed that each group is affected differently by organic and inorganic fertilization. Additional meta-analysis also showed that the responses of the soil organisms to nitrogen fertilization can also be modulated by physicochemical properties of the soil as well as climatic conditions. </p>

2020 ◽  
Author(s):  
Bibiana Betancur Corredor ◽  
Birgit Lang ◽  
David Russell

<p>The impact of agricultural activities on soil fauna can be highly variable, depending on the management options adopted. High-input agricultural practices can promote a reduction in diversity of soil microarthropod communities but, at the same time can also favor bacterial-feeding fauna through the increase of bacterial foodweb pathways. In contrast, low-input practices can increase the dominance of fungal-feeding fauna through the promotion of fungal pathways. Responses also vary with time after fertilizer application and are strongly dependent on crop species or shifts in plant species composition due to fertilization.</p><p>The type of fertilizer, organic or inorganic, can also have diverse effects on soil organisms. Organic fertilizers can increase the population of soil decomposers serving as nutrient sources for other soil organisms. Inorganic fertilizers can indirectly affect the soil organisms by increasing crop growth, potentially leading to higher soil organic matter generation. However, inorganic fertilizers can also reduce species richness and abundance of microarthropods and earthworms due to acidification. Other soil fauna such as collembolan may not be particularly sensitive to nitrogen fertilization types. Nitrogen fertilization may disturb soil organisms in a manner that affects ecosystem functioning, but the links are not yet well quantified. Therefore, a compilation of available experimental field data on the effects of nitrogen fertilization on taxonomic and functional groups of soil fauna is needed to clarify the patterns and mechanisms of responses.</p><p>We are currently working on a quantitative review based on a global meta-analysis that will use paired observations from studies published across several countries. With this review, we aim to synthesize and discuss the current global knowledge on the effects of nitrogen organic and inorganic fertilization on soil fauna. Depending on data availability, we aim to quantify the responses of several groups of soil organisms to synthetic and organic nitrogen inputs, considering factors such as application rate or crop type. Our findings will be used for the development of modeling tools for the prediction of the impacts of agricultural management practices on soil functions.</p>


Agriculture ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 823
Author(s):  
Mohamed Allam ◽  
Emanuele Radicetti ◽  
Verdiana Petroselli ◽  
Roberto Mancinelli

Crop yield under reduced tillage (RT) practices is a concern for sustainable production worldwide because it is related to different environmental and agronomic factors than conventionally tilled soils. This study aimed to evaluate how climate, soil, and farming practices could affect crop yield under RT, especially under different sources of fertilisation [mineral (M), mineral + organic (MO), and organic (O)]. Multilevel meta-analysis was adopted. The analysis was performed taking into consideration environmental conditions, soil properties, crop rotation, and crop species. Only studies that reported the interaction effect of soil tillage and nutrients management on grain yield were included. The results suggest that the impact of soil tillage and fertilisation sources on crop yield depended on crop species. Using reduced tillage practices, adopting only organic nutrient sources could produce enough grains for legume crops. However, combining both inorganic and organic fertilizers added benefits for cereal crops in terms of grain yield production. This study highlights how conservation tillage practices could be affected by environmental and agronomic factors.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alejandro Garcia ◽  
M. Estrella Santamaria ◽  
Isabel Diaz ◽  
Manuel Martinez

AbstractThe success in the response of a plant to a pest depends on the regulatory networks that connect plant perception and plant response. Meta-analyses of transcriptomic responses are valuable tools to discover novel mechanisms in the plant/herbivore interplay. Considering the quantity and quality of available transcriptomic analyses, Arabidopsis thaliana was selected to test the ability of comprehensive meta-analyses to disentangle plant responses. The analysis of the transcriptomic data showed a general induction of biological processes commonly associated with the response to herbivory, like jasmonate signaling or glucosinolate biosynthesis. However, an uneven induction of many genes belonging to these biological categories was found, which was likely associated with the particularities of each specific Arabidopsis-herbivore interaction. A thorough analysis of the responses to the lepidopteran Pieris rapae and the spider mite Tetranychus urticae highlighted specificities in the perception and signaling pathways associated with the expression of receptors and transcription factors. This information was translated to a variable alteration of secondary metabolic pathways. In conclusion, transcriptomic meta-analysis has been revealed as a potent way to sort out relevant physiological processes in the plant response to herbivores. Translation of these transcriptomic-based analyses to crop species will permit a more appropriate design of biotechnological programs.


2021 ◽  
Vol 11 (6) ◽  
pp. 755
Author(s):  
Falonn Contreras-Osorio ◽  
Christian Campos-Jara ◽  
Cristian Martínez-Salazar ◽  
Luis Chirosa-Ríos ◽  
Darío Martínez-García

One of the most studied aspects of children’s cognitive development is that of the development of the executive function, and research has shown that physical activity has been demonstrated as a key factor in its enhancement. This meta-analysis aims to assess the impact of specific sports interventions on the executive function of children and teenagers. A systematic review was carried out on 1 November 2020 to search for published scientific evidence that analysed different sports programs that possibly affected executive function in students. Longitudinal studies, which assessed the effects of sports interventions on subjects between 6 and 18 years old, were identified through a systematic search of the four principal electronic databases: Web of Science, PubMed, Scopus, and EBSCO. A total of eight studies, with 424 subjects overall, met the inclusion criteria and were classified based on one or more of the following categories: working memory, inhibitory control, and cognitive flexibility. The random-effects model for meta-analyses was performed with RevMan version 5.3 to facilitate the analysis of the studies. Large effect sizes were found in all categories: working memory (ES −1.25; 95% CI −1.70; −0.79; p < 0.0001); inhibitory control (ES −1.30; 95% CI −1.98; −0.63; p < 0.00001); and cognitive flexibility (ES −1.52; 95% CI −2.20; −0.83; p < 0.00001). Our analysis concluded that healthy children and teenagers should be encouraged to practice sports in order to improve their executive function at every stage of their development.


2021 ◽  
Vol 5 (1) ◽  
pp. e100135
Author(s):  
Xue Ying Zhang ◽  
Jan Vollert ◽  
Emily S Sena ◽  
Andrew SC Rice ◽  
Nadia Soliman

ObjectiveThigmotaxis is an innate predator avoidance behaviour of rodents and is enhanced when animals are under stress. It is characterised by the preference of a rodent to seek shelter, rather than expose itself to the aversive open area. The behaviour has been proposed to be a measurable construct that can address the impact of pain on rodent behaviour. This systematic review will assess whether thigmotaxis can be influenced by experimental persistent pain and attenuated by pharmacological interventions in rodents.Search strategyWe will conduct search on three electronic databases to identify studies in which thigmotaxis was used as an outcome measure contextualised to a rodent model associated with persistent pain. All studies published until the date of the search will be considered.Screening and annotationTwo independent reviewers will screen studies based on the order of (1) titles and abstracts, and (2) full texts.Data management and reportingFor meta-analysis, we will extract thigmotactic behavioural data and calculate effect sizes. Effect sizes will be combined using a random-effects model. We will assess heterogeneity and identify sources of heterogeneity. A risk-of-bias assessment will be conducted to evaluate study quality. Publication bias will be assessed using funnel plots, Egger’s regression and trim-and-fill analysis. We will also extract stimulus-evoked limb withdrawal data to assess its correlation with thigmotaxis in the same animals. The evidence obtained will provide a comprehensive understanding of the strengths and limitations of using thigmotactic outcome measure in animal pain research so that future experimental designs can be optimised. We will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines and disseminate the review findings through publication and conference presentation.


2018 ◽  
Vol 10 (4) ◽  
pp. 387-405 ◽  
Author(s):  
C. J. Bennett ◽  
R. E. Walker ◽  
M. L. Blumfield ◽  
J. Ma ◽  
F. Wang ◽  
...  

AbstractDespite many interventions aiming to reduce excessive gestational weight gain (GWG), it is currently unclear the impact on infant anthropometric outcomes. The aim of this review was to evaluate offspring anthropometric outcomes in studies designed to reduce GWG. A systematic search of seven international databases, one clinical trial registry and three Chinese databases was conducted without date limits. Studies were categorised by intervention type: diet, physical activity (PA), lifestyle (diet + PA), other, gestational diabetes mellitus (GDM) (diet, PA, lifestyle, metformin and other). Meta-analyses were reported as weighted mean difference (WMD) for birthweight and birth length, and risk ratio (RR) for small for gestational age (SGA), large for gestational age (LGA), macrosomia and low birth weight (LBW). Collectively, interventions reduced birthweight, risk of macrosomia and LGA by 71 g (WMD: −70.67, 95% CI −101.90 to −39.43,P<0.001), 16% (RR: 0.84, 95% CI 0.73–0.98,P=0.026) and 19% (RR: 0.81, 95% CI 0.69–0.96,P=0.015), respectively. Diet interventions decreased birthweight and LGA by 99 g (WMD −98.80, 95% CI −178.85 to −18.76,P=0.016) and 65% (RR: 0.35, 95% CI 0.17–0.72,P=0.004). PA interventions reduced the risk of macrosomia by 51% (RR: 0.49, 95% CI 0.26–0.92,P=0.036). In women with GDM, diet and lifestyle interventions reduced birthweight by 211 and 296 g, respectively (WMD: −210.93, 95% CI −374.77 to −46.71,P=0.012 and WMD:−295.93, 95% CI −501.76 to −90.10,P=0.005, respectively). Interventions designed to reduce excessive GWG lead to a small reduction in infant birthweight and risk of macrosomia and LGA, without influencing the risk of adverse outcomes including LBW and SGA.


2021 ◽  
Author(s):  
Xu Tian ◽  
Yan-Fei Jin ◽  
Zhao-Li Zhang ◽  
Hui Chen ◽  
Wei-Qing Chen ◽  
...  

Abstract Background: Enteral immunonutrition (EIN) has been extensively applied in cancer patients, however its role in esophageal cancer (EC) patients receiving esophagectomy remains unclear. We performed this network meta-analysis to investigate the impact of EIN on patients undergoing surgery for EC and further determine the optimal time of applying EIN.Methods: We searched PubMed, EMBASE, Cochrane library, and China National Knowledgement Infrastructure (CNKI) to identify eligible studies. Categorical data was expressed as the odds ratio with 95% confidence interval (CI), and continuous data was expressed as mean difference (MD) with 95% CI. Pair-wise and network meta-analysis was performed to evaluate the impact of EIN on clinical outcomes using RevMan 5.3 and ADDIS V.1.16.8 softwares. The surface under the cumulative ranking curve (SUCRA) was calculated to rank all nutritional regimes.Results: Total 14 studies involving 1071 patients were included. Pair-wise meta-analysis indicated no difference between EIN regardless of the application time and standard EN (SEN), however subgroup analyses found that postoperative EIN was associated with decreased incidence of total infectious complications (OR=0.47; 95%CI=0.26 to 0.84; p=0.01) and pneumonia (OR=0.47; 95%CI=0.25 to 0.90; p=0.02) and shortened LOH (MD=-1.01; 95%CI=-1.44 to -0.57; p<0.001) compared to SEN, which were all supported by network meta-analyses. Ranking probability analysis further indicated that postoperative EIN has the highest probability of being the optimal option in terms of these three outcomes.Conclusions: Postoperative EIN should be preferentially utilized in EC patients undergoing esophagectomy because it has optimal potential of decreasing the risk of total infectious complications and pneumonia and shortening LOH.OSF registration number: 10.17605/OSF.IO/KJ9UY.


2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S280-S281
Author(s):  
M Attauabi ◽  
M Zhao ◽  
F Bendtsen ◽  
J Burisch

Abstract Background Several studies have shown an association between inflammatory bowel diseases [IBD] and immune-mediated diseases [IMIDs], but data on the impact of co-occurring IMIDs on IBD course are inconsistent. The aim of this study was to investigate the impact of co-occurring IMIDs on IBD phenotype and disease course. Methods PubMed and EMBASE were searched from database inception through December 2018 and updated in October 2019 for studies reporting prevalences or odds, risks or hazard ratios of IBD-related disease outcomes in patients with and without co-existing IMIDs. Meta-analyses were performed to estimate summary prevalences and risks of the outcomes which included disease extension, IBD-related surgery and hospitalisation, malignancy, mortality and need of medication (biologic therapy, steroids and immunomodulators). IMIDs were stratified into primary sclerosing cholangitis [PSC] and ‘IMIDs other than PSC’. Results A total of 93 studies comprising 14,307 IBD patients with IMIDs and 3,409,914 IBD patients without IMIDs were included in the study. Summary risks and prevalences with 95% confidence intervals for each outcome are presented in figures 1 and 2, respectively. The following results are all significant (p &lt; 0.05). Compared with patients without co-occurring IMIDs, patients with ulcerative colitis [UC] and co-occurring IMIDs other than PSC more frequently received immunomodulators and steroids, and patients with Crohn’s disease [CD] and concomitant IMIDs other than PSC more often received biologic therapy. UC patients with co-existing IMIDs other than PSC more often underwent IBD-related surgery, while patients with CD and PSC received fewer surgeries. In addition, UC patients with co-occurring PSC were at increased risk for having extensive colitis, pancolitis, and malignancies. Patients with UC and PSC had a higher mortality rate, but no difference was found among patients with IMIDs other than PSC. PSC did not influence hospitalisation rates among IBD patients. Conclusion This meta-analysis found that IBD patients with co-existing IMIDs have a different disease course than patients without concomitant IMIDs. This study emphasises the importance of multidisciplinary care of IBD and that physicians caring for IBD patients need to be aware of IMIDs as a prognostic factor.


Rheumatology ◽  
2020 ◽  
Vol 59 (9) ◽  
pp. 2199-2206 ◽  
Author(s):  
Bradley Pittam ◽  
Sonal Gupta ◽  
Nicholas L Harrison ◽  
Selina Robertson ◽  
David M Hughes ◽  
...  

Abstract Objective To describe the prevalence of extra-articular manifestations—enthesitis, dactylitis, nail disease, uveitis and IBD—in PsA, and their impact on longitudinal disease outcomes. Methods We searched Medline, PubMed, Scopus and Web of Science using a predefined protocol in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies using imaging to define extra-articular manifestations (EAMs) were excluded. Where possible, we performed meta-analyses of prevalence estimates, reported as percentages (95% CI). Heterogeneity (I2 statistic) was examined according to study characteristics. Results We identified 65 studies amounting to a total of 163 299 PsA patients. Enthesitis was assessed in 29 studies with an average prevalence of 30% (95% CI: 24%, 38%). Dactylitis was reported in 35 studies with an average prevalence of 25% (95% CI: 20%, 31%). Nail disease was present in 60% (95% CI: 52%, 68%) across 26 studies, but definitions were often unclear. Uveitis (3.2%; 95% CI: 1.9%, 5.3%) and IBD (3.3%; 95% CI: 1.5%, 7.1%) were less common. Heterogeneity was high (&gt;95%) in all meta-analyses, but could not be explained by study characteristics. No studies examined the impact of EAMs on longitudinal disease outcomes, except that dactylitis increases radiographic progression. Conclusion Enthesitis, dactylitis and nail disease are highly prevalent in PsA, but not uveitis and IBD. EAM patterns differ from axial SpA despite their shared disease mechanisms, which may help further understand differences between spondyloarthritides. More studies are needed on the impact of EAMs on disease outcomes such as response to treatment.


BMJ Open ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. e035287
Author(s):  
Min Chen ◽  
Tai-Chun Tang ◽  
Tao-Hong He ◽  
Yong-Jun Du ◽  
Di Qin ◽  
...  

IntroductionThe prevalence of haemorrhoidal diseases was high in general population, and many treatments are proposed for the management of haemorrhoids. The treatments include conservative and surgical interventions; the credibility and strength of current evidence of their effectiveness are not comprehensively evaluated. We aim to evaluate the credibility of systematic reviews and meta-analyses that assess the effectiveness of the treatments for haemorrhoidal diseases through an umbrella review.Methods and analysisWe will search Ovid Medline, Embase, Cochrane library and Web of Science from inception to March 2020 without any language restriction. We will include meta-analyses that examine the effectiveness of treatments in the management of haemorrhoids. Two reviewers will independently screen the titles and abstracts of retrieved articles, and they will extract data from the included meta-analyses. For each meta-analysis, we will estimate the effect size of a treatment through the random-effect model and the fixed-effect model, and we will evaluate between-study heterogeneity (Cochrane’s Q and I2statistics) and small-study effect (Egger’s test); we will also estimate the evidence of excess significance bias. Evidence of each treatment will be graded according to prespecified criteria. Methodological quality of each meta-analysis will be evaluated by using Assessment of Multiple Systematic Reviews 2. The corrected cover area method will be used to assess the impact of overlap in reviews on the findings of the umbrella review.Ethics and disseminationWe will present the results of the umbrella review at conferences and publish the final report in a peer-reviewed journal. The umbrella review does not require ethical approval.PROSPERO registration numberCRD42019140702.


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