Background and aims
It has been confirmed that the declines in arbuscular mycorrhizal fungi (AMF) populations and agroecosystem diversity are largely due to nutrient enrichment caused by ...fertilization. Replacing chemical-only fertilization with organic fertilization is widely considered a possible approach for maintaining soil biodiversity and a healthy functioning ecosystem. Here we aim to examine the effects of organic fertilizer on AMF occurrence.
Methods
We conducted a meta-analysis of 162 field experiments from 54 published studies conducted over the last 20 years. Our dataset included two groups: organic fertilization (OF)
vs
chemical-only fertilization (CF) and OF
vs
no fertilization (NF).
Results
We found that organic fertilizer increased AM fungal biomass and was less detrimental to AMF richness than mineral-only fertilization. AMF responses to organic fertilizer were generally positive when AMF and host plants had a strong mutualistic symbiosis such as in phosphorus-deficient soil, drought and semi-drought areas, at low latitudes, and at testing sites that contained two or more plant species or included legume. In conditions other than these, the responses were generally negative. Organic carbon input, increased soil phosphorus and the ratio of fertilizer N and P jointly explain the effects of organic fertilizer on AMF occurrence.
Conclusions
Our analysis indicates that, although some limiting factors exist, application of organic fertilizer can be an effective practice to protect AM symbiosis from the negative effects of nutrient enrichment in current cropping systems.
Severe early defoliation has become an important factor restricting the development of the pear industry in southern China. However, the assembly patterns of microbial communities and their ...functional activities in response to the application of bioorganic fertilizer (BIO) or humic acid (HA) in southern China’s pear orchards remain poorly understood, particularly the impact on the early defoliation of the trees. We conducted a 3-year field experiment (2017–2019) in an 18-year-old ‘Cuiguan’ pear orchard. Four fertilization schemes were tested: local custom fertilization as control (CK), CK plus HA (CK-HA), BIO, and BIO plus HA (BIO-HA). Results showed that BIO and BIO-HA application decreased the early defoliation rate by 50–60%, and increased pear yield by 40% compared with the CK and CK-HA treatments. The BIO and BIO-HA application significantly improved soil pH, available nutrient content, total enzyme activity and ecosystem multifunctionality, and also changed the structure of soil bacterial and fungal communities. The genus
Acidothermus
was positively correlated with the early defoliation rate, while the genus
Rhodanobacter
was negatively correlated. Additionally, random forest models revealed that the early defoliation rate could be best explained by soil pH, ammonium content, available phosphorus, and total enzyme activity. In conclusion, application of BIO or BIO mixed with HA could have assembled distinct microbial communities and increased total enzyme activity, leading to significant improvement of soil physicochemical traits. The increased availability of soil nutrient thus changed leaf nutrient concentrations and alleviated the early defoliation rate of pear trees in acid red soil in southern China.
Utilization of arbuscular mycorrhizal (AM) resources to improve, or even maintain agroecosystem sustainability requires a thorough understanding of the biotic and abiotic factors that impact AM ...fungal communities. AM symbiosis is important in mango and litchi trees, two economically important fruit crops in China, but there is little information on the AM fungi associated with these trees or their responses to organic fertilizer. Using Illumina high-throughput sequencing we analyzed AM colonization, spore density, and community composition and diversity in the rhizospheric soil from 16 mango orchards and 16 litchi orchards located in southern China. Ours was a regional scale study and in general, we found that the majority of AM fungi OTUs belonged to the families Glomeraceae, followed by Gigasporaceae, Paraglomeraceae, Acaulosporaceae and Diversisporaceae. Glomus and Paraglomus were the genera that differed most in abundance between the rhizospheric soil of mango and litchi. AMF community composition was impacted by latitude and longitude and soil characteristics such as, NO3−-N, NH4+-N, available-P, and soil organic carbon (SOC). The sampling sites were in areas of medium to low altitude, and there was no significant correlation between altitude and AM fungal richness. We found that higher soil nutrient content, particularly available-P, was negatively correlated with AM colonization. Our results also showed that some of the AM genera responded differently to environmental variables. Structural equation modeling (SEM) demonstrated that SOC not only had a direct positive effect on AMF richness, but also an indirect negative effect, due to increased soil fertility. Our findings have enabled a deeper insight into the impacts of organic fertilizer on AM fungal communities, which will be valuable when considering AM symbiosis in orchard management.
•The abundance of Glomus and Paraglomus differed greatly between the rhizospheric soil of mango and litchi.•Geographical distances and soil properties jointly shaped the AM fungal communities.•Some AM genera responded differently to environmental variables.•SOC resulting from increased manure input had a direct positive effect on AMF richness.•Excessive use of manure is detrimental to AMF occurrence.
Bioorganic fertilizers are widely used in fruit orchards to improve soil properties and increase productivity. To investigate the effects of bioorganic fertilizer (BIO) and chemical fertilizer (CF) ...on the root system architecture and above-ground growth of pear trees, a split-root experiment was conducted. To this end, six soil amendment combinations were investigated: NF–NF (no fertilizer), NF-CF, NF-BIO, CF-CF, BIO-BIO, and BIO-CF. Roots of 1-year old ‘Cuiguan’ pear trees were distributed as evenly as possible into split-root chambers containing the aforementioned amendment combinations and maintained for 210 days after budding. Results showed that in boxes containing the same fertilizer in both chambers (NF–NF, CF-CF and BIO-BIO), the BIO chambers had an improved soil pH, by 0.6–0.8 units, and 23%–65.5% greater SOM than the soils in the NF and CF chambers. We also found that in these BIO chambers the lateral root number was 2.1–3.5 times greater than in NF and CF chambers and the maximum order of lateral roots was greater than 9. BIO application promoted lateral root growth in the paired NF and CF chambers, increasing specific root length and reducing root tissue density. In BIO-CF boxes, the 4th to 6th lateral root number and length accounted for the largest proportion of total lateral root number and length respectively. Moreover, compared with trees grown in CF-CF, those grown in BIO-BIO and BIO-CF had greater mean xylem, phloem, and cork layer thicknesses, as well as greater mean vessel density and number. BIO-CF treated soils had significantly reduced (50%) available phosphorus content compared to CF-CF treated soils, and consistently, BIO-CF resulted in the greatest growth of trunk girth (by 5–29%) among all the treatments. Soil organic matter and nitrate nitrogen concentration had significantly positive effects on root growth and activity, while branching intensity was significantly related to available phosphorus content and total nitrogen, followed by available potassium content and ammonia nitrogen content. In conclusion, local application of bioorganic fertilizer is a promising technique to sustainably maintain pear tree productivity because it accelerates the root proliferation and activity in either nutrient-deficient or -sufficient soil.
Monoclonal antibody drugs that inhibit programmed death 1 (PD-1) or programmed death ligand 1 (PD-L1) have been widely used in esophageal cancer (EC) and yielded significant therapeutic responses. ...However, only a few patients obtain lasting clinical benefits due to primary or acquired drug resistance, and new treatment schemes are urgently needed. The tumor immune microenvironment is the main factor that affects patients' response to immunosuppressive agents. This article will discuss the role of immunosuppressive cells and non-cellular components in the immune process to provide ideas for the next research direction of EC.
Anti-motion artifact is one of the most important properties of ambulatory ECG monitoring equipment. At present, there is a lack of standardized means to test the performance of anti-motion artifact. ...ECG simulator and special conductive leather are used to build the simulator, it is used to simulate human skin, to generate ECG signal input for the ECG monitoring equipment attached to it. The mechanical arm and fixed support are used to build a motion simulation system to fix the conductive leather. The mechanical arm is programmed to simulate various motion states of the human body, so that the ECG monitoring equipment can produce corresponding motion artifacts. The collected ECG signals are read wirelessly, observed, analyzed and compared, and the anti-motion artifact performance of ECG monitoring equipment is evaluated. The test results show that by artificially creating the small difference between the two groups of ambulatory ECG monitoring equipment, the system can accurately test the interference signal
Objective The temporal and spatial variation characteristics and driving factors of vegetation in the Guanzhong Plain urban agglomeration from 2000 to 2020 were studied in order to provide scientific ...guidance for the construction of regional ecological civilization. Methods Based on the Google Earth Engine (GEE) cloud platform, we used the enhanced vegetation index (EVI) data calculated from Landsat images from 2000 to 2020 combined with trend analysis, hot spot analysis, geographic detector model, and other methods to analyze the change pattern and driving factors of the annual maximum EVI (EVImax) in the Guanzhong Plain urban agglomeration. Results ① Annual EVImax showed a significant upward trend in the Guanzhong Plain urban agglomeration from 2000 to 2020. Annual EVImax values for the unchanged land use/cover types showed a fluctuating upward trend, among which the rate of increase for grassland was the largest. ② Spatially, the EVImax values showed a decreasing trend from south to north, and the hi
In the process of underground excavation, the surrounding rock is in a very complex stress environment, especially under the influence of its anisotropy, the occurrence of dynamic disaster is hidden. ...In this paper, the loading and unloading tests of sandstone in different principal stress directions were carried out by using the true triaxial unloading disturbed rock test system. The mechanical properties and failure characteristics of true triaxial under different principal stresses were studied, the energy evolution mechanism in other directions induced by loading and unloading of different principal stresses was analyzed. Results showed that under the influence of rock mass secondary stress anisotropy, during the cyclic loading and unloading process of the first principal stress, the strain in other directions shows opposite deformation. The volumetric strain compresses first and then expands, and the final volumetric strain shows a macroscopic phenomenon of expansion. When the third principal stress of hi
To construct a model for predicting recidivism in violence in community-based schizophrenia spectrum disorder patients (SSDP) by adopting a joint modeling method.ObjectiveTo construct a model for ...predicting recidivism in violence in community-based schizophrenia spectrum disorder patients (SSDP) by adopting a joint modeling method.Based on the basic data on severe mental illness in Southwest China between January 2017 and June 2018, 4565 community-based SSDP with baseline violent behaviors were selected as the research subjects. We used a growth mixture model (GMM) to identify patterns of medication adherence and social functioning. We then fitted the joint model using a zero-inflated negative binomial regression model and compared it with traditional static models. Finally, we used a 10-fold training-test cross validation framework to evaluate the models' fitting and predictive performance.MethodsBased on the basic data on severe mental illness in Southwest China between January 2017 and June 2018, 4565 comm
To study the energy evolution of rocks under uniaxial compression, uniaxial compression and uniaxial step loading and unloading tests were performed on granite, sandstone, and coal, and the ...stress-strain curves under different conditions were obtained. The total energy density, elastic energy density and dissipation energy density for the whole process of rock specimens under different conditions were obtained by using the integral and formula. The energy evolution characteristics of rock specimens before and after the peak were analyzed, and the relationship between elastic energy density and total energy density under uniaxial compression were investigated. The results show that the outer envelope of the uniaxial step loading and unloading stress-strain curves have the same trend as the uniaxial compression curves, and the overall deviation exists to a certain extent, and the greater the density of the rock, the smaller the deviation is. The elastic energy density and total energy density of the rock specim
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