Comparing the Effects of Lime Soil and Yellow Soil on Cadmium Accumulation in Rice during Grain-Filling and Maturation Periods.

The karst area has become a high-risk area for Cadmium (Cd) exposure. Interestingly, the high levels of Cd in soils do not result in an excessive bioaccumulation of Cd in rice. Carbonate rock dissolution ions (CRIs) could limit the accumulation and translocation of Cd in rice. CRIs can become a major bottleneck in the remediation and management of farmlands in karst areas. However, there is limited research on the effects of CRIs in soils on Cd accumulation in rice. The karst area of lime soil (LS) and the non-karst areas of yellow soil (YS) were collected, and an external Cd was added to conduct rice cultivation experiments. Cd and CRIs (Ca2+, Mg2+, CO32-/HCO3-, and OH-) in the rice-soil system were investigated from the grain-filling to maturity periods. The results showed that CRIs of LS were significantly higher than that of YS in different treatments. CRIs of LS were 2.05 mg·kg-1 for Ca2+, 0.90 mg·kg-1 for Mg2+, and 42.29 mg·kg-1 for CO32- in LS. CRIs could influence DTPA Cd, resulting in DTPA Cd of LS being lower than that of YS. DTPA Cd of YS was one to three times larger than that of YS. Cd content in different parts of rice in YS was higher than that of LS. Cd in rice grains of YS was one to six times larger than that of LS. The uptake of Cd from the soil during Filling III was critical in determining rice Cd accumulation. CRIs in the soil could affect Cd accumulation in rice. Ca2+ and Mg2+ had significant negative effects on Cd accumulation of rice at maturity and filling, respectively. CO32-/HCO3- and OH- had significant negative effects on DTPA Cd in soil.

Effect of mineral and organic fertilizer on N dynamics upon erosion-induced topsoil dilution.

Erosion-induced topsoil dilution strongly affects cropland biogeochemistry and is associated with a negative effect on soil health and crop productivity. While its impact on soil C cycling has been widely recognized, there is little information about its impact on soil N cycling and N fertilizer dynamics. Here, we studied three factors potentially influencing N cycling and N fertilizer dynamics in cropping systems, namely: 1.) soil type, 2.) erosion-induced topsoil dilution and 3.) N fertilizer form, in a full-factorial pot experiment using canola plants. We studied three erosion affected soil types (Luvisol, eroded Luvisol, calcaric Regosol) and performed topsoil dilution in all three soils by admixing 20 % of the respective subsoil into its topsoil. N fertilizer dynamics were investigated using either mineral (calcium ammonium nitrate) or organic (biogas digestate) fertilizer, labeled with 15N. The fertilizer 15N recovery and the distribution of the fertilizer N in different soil fractions was quantified after plant maturity. Fertilizer N dynamics and utilization were influenced by all three factors investigated. 15N recovery in the plant-soil system was higher and fertilizer N utilization was lower in the treatments with diluted topsoil than in the non-diluted controls. Similarly, plants of the organic fertilizer N treatments took up significantly less fertilizer N in comparison to mineral fertilizer treatments. Both topsoil dilution and organic fertilizer application promoted 15N recovery and N accumulation in the soil fractions, with strong differences between soil types. Our study reveals an innovative insight: topsoil dilution due to soil erosion has a negligible impact on N cycling and dynamics in the plant-soil system. The crucial factors influencing these processes are found to be the choice of fertilizer form and the specific soil type. Recognizing these aspects is essential for a precise and comprehensive assessment of the environmental continuum, emphasizing the novelty of our findings.

Understanding Environmental Fate: Soil Variability and Rainfall Influence on Triafamone and Ethoxysulfuron Leaching.

Considering the environmental impact of triafamone and ethoxysulfuron, it is crucial to investigate their leaching behaviour under different geographical conditions. The present study evaluates the effects of application rate, soil properties and rainfall conditions on leaching of these herbicides and their metabolites. Ethoxysulfuron leached up to 50-60 cm with 82.95 to 89.23% detected in leachates while triafamone leached only to 10-20 cm and was < 0.01 µg mL-1 in leachates. Highest leachability was observed in loamy sand followed by sandy loam and clay loam soil. M1 metabolite (N-(2-((4,6-dimethoxy-1,3,5-triazin-2-yl) (hydroxy) methyl) -6-fluorophenyl) -1,1-difluoro-N-methyl methane sulfonamide) was majorly present in 0 to 10 cm soil depth. With increase in rainfall, downward mobility of both parent and M1 increased. Amendment of loamy sand soil with farmyard manure reduced the leachability indicating it could mitigate groundwater pollution. However, the effect of different exogenous OM amendments on leaching behaviour of herbicides needs to be evaluated.

How can we quantify, explain, and apply the uncertainty of complex soil maps predicted with neural networks?

Artificial neural networks (ANNs) have proven to be a useful tool for complex questions that involve large amounts of data. Our use case of predicting soil maps with ANNs is in high demand by government agencies, construction companies, or farmers, given cost and time intensive field work. However, there are two main challenges when applying ANNs. In their most common form, deep learning algorithms do not provide interpretable predictive uncertainty. This means that properties of an ANN such as the certainty and plausibility of the predicted variables, rely on the interpretation by experts rather than being quantified by evaluation metrics validating the ANNs. Further, these algorithms have shown a high confidence in their predictions in areas geographically distant from the training area or areas sparsely covered by training data. To tackle these challenges, we use the Bayesian deep learning approach "last-layer Laplace approximation", which is specifically designed to quantify uncertainty into deep networks, in our explorative study on soil classification. It corrects the overconfident areas without reducing the accuracy of the predictions, giving us a more realistic uncertainty expression of the model's prediction. In our study area in southern Germany, we subdivide the soils into soil regions and as a test case we explicitly exclude two soil regions in the training area but include these regions in the prediction. Our results emphasize the need for uncertainty measurement to obtain more reliable and interpretable results of ANNs, especially for regions far away from the training area. Moreover, the knowledge gained from this research addresses the problem of overconfidence of ANNs and provides valuable information on the predictability of soil types and the identification of knowledge gaps. By analyzing regions where the model has limited data support and, consequently, high uncertainty, stakeholders can recognize the areas that require more data collection efforts.

Phosphorus uptake and rhizosphere properties of alfalfa in response to phosphorus fertilizer types in sandy soil and saline-alkali soil.

Introduction: Phosphorus (P) fertilizer is critical to maintain a high yield and quality of alfalfa (Medicago sativa L.). There are several fertilizer types and soil types in China, and the application of a single type of P fertilizer may not be suitable for present-day alfalfa production. Methods: In order to select the optimal combination of alfalfa and soil type and fertilizer type for improving P utilization efficiency. We conducted a greenhouse pot experiment, calcium superphosphate (SSP), diammonium phosphate (DAP), ammonium polyphosphate (APP), potassium dihydrogen phosphate (KP), and no-fertilizer control treatments were applied to alfalfa in sandy and saline-alkali soils. The response of alfalfa root morphology and rhizosphere processes to different P fertilizers was investigated. Results and discussion: The results showed that shoot biomass of alfalfa was slightly higher in sandy soil than in saline-alkali soil. Shoot biomass of alfalfa increased by 223%-354% in sandy soil under P treatments compared with the control, and total root length increased significantly by 74% and 53% in DAP and SSP treatments, respectively. In saline-alkali soil, alfalfa shoot biomass was significantly increased by 229% and 275% in KP and DAP treatments, and total root length was increased by 109% only in DAP treatment. Net P uptake of alfalfa in DAP treatment was the highest in both soils, which were 0.73 and 0.54 mg plant-1, respectively. Alfalfa shoot P concentration was significantly positively correlated with shoot and root biomass (P < 0.05, 0.01 or 0.001) whereas negatively correlated with acid phosphatase concentration (P < 0.05). Improvement of plant growth and P uptake induced by P fertilizer application was greater in sandy soil than in saline-alkali soil. DAP and KP was the most efficient P fertilizers in both sandy soil and saline-alkali soil.

Shining a Light on How Soil Organic Carbon Behaves at Fine Scales under Long-Term Elevated CO2: An 8 Year Free-Air Carbon Dioxide Enrichment Study.

Building and protecting soil organic carbon (SOC) are critical to agricultural productivity, soil health, and climate change mitigation. We aim to understand how mechanisms at the organo-mineral interfaces influence SOC persistence in three contrasting soils (Luvisol, Vertisol, and Calcisol) under long-term free air CO2 enrichment conditions. A continuous wheat-field pea-canola rotation was maintained. For the first time, we provided evidence to a novel notion that persistent SOC is molecularly simple even under elevated CO2 conditions. We found that the elevated CO2 condition did not change the total SOC content or C forms compared with the soils under ambient CO2 as identified by synchrotron-based soft X-ray analyses. Furthermore, synchrotron-based infrared microspectroscopy confirmed a two-dimensional microscale distribution of similar and less diverse C forms in intact microaggregates under long-term elevated CO2 conditions. Strong correlations between the distribution of C forms and O-H groups of clays can explain the steady state of the total SOC content. However, the correlations between C forms and clay minerals were weakened in the coarse-textured Calcisol under long-term elevated CO2. Our findings suggested that we should emphasize identifying management practices that increase the physical protection of SOC instead of increasing complexity of C. Such information is valuable in developing more accurate C prediction models under elevated CO2 conditions and shift our thinking in developing management practices for maintaining and building SOC for better soil fertility and future environmental sustainability.

Soil quality assessment in low human activity disturbance zones: a study on the Qinghai-Tibet Plateau.

The Qinghai-Tibet Plateau, located at the Third Pole and known as the "Asian water tower," serves as a crucial ecological barrier for China. Grasping the soil quality on the Qinghai-Tibet Plateau holds paramount importance for the rational and scientific exploitation of soil resources within the region and is essential for vegetation restoration and ecological reconstruction. This study, conducted in Maqin County, Qinghai Province, collected 1647 soil samples (0-20 cm) within a study area of 6300 km2. Sixteen soil indicators were selected that were split into beneficial (N, P, S, and B), harmful (Cr, Hg, As, Pb, Ni, and Cd), and essential (Cu, Zn, Se, Ga, K, and Ca) elements. The Soil Quality Index (SQI) was computed to assess soil quality across diverse geological contexts, land cover classifications, and soil profiles. The results indicate that the overall SQI in the study area was comparatively high, with most regions having an SQI between 0.4 and 0.6, categorized as moderately to highly satisfactory. Among the different geological backgrounds, the highest SQI was found in the Quaternary alluvium (0.555) and the lowest in the Precambrian Jinshuikou Formation (0.481). Regarding different land-use types, the highest SQI was observed in glacier- and snow-covered areas (0.582) and the lowest in other types of grassland (0.461). The highest SQI was recorded in typical alpine meadow soil (0.521) and the lowest in leached brown soil (0.460). The evaluation results have significant reference value for the sustainable utilization and management of soil in Maqin County, Qinghai Province, China.

Difference in the Effect of Applying Bacillus to Control Tomato Verticillium Wilt in Black and Red Soil.

In practical applications, the effectiveness of biological control agents such as Bacillus is often unstable due to different soil environments. Herein, we aimed to explore the control effect and intrinsic mechanism of Bacillus in black soil and red soil in combination with tomato Verticillium wilt. Bacillus application effectively controlled the occurrence of Verticillium wilt in red soil, reducing the incidence by 19.83%, but played a limited role in black soil. Bacillus colonized red soil more efficiently. The Verticillium pathogen decreased by 71.13% and 76.09% after the application of Bacillus combinations in the rhizosphere and bulk of the red soil, respectively, while there was no significant difference in the black soil. Additionally, Bacillus application to red soil significantly promoted phosphorus absorption. Furthermore, it significantly altered the bacterial community in red soil and enriched genes related to pathogen antagonism and phosphorus activation, which jointly participated in soil nutrient activation and disease prevention, promoting tomato plant growth in red soil. This study revealed that the shaping of the bacterial community by native soil may be the key factor affecting the colonization and function of exogenous Bacillus.

Soil type and moisture content alter soil microbial responses to manure from cattle administered antibiotics.

Growing concerns about the global antimicrobial resistance crisis require a better understanding of how antibiotic resistance persists in soil and how antibiotic exposure impacts soil microbial communities. In agroecosystems, these responses are complex because environmental factors may influence how soil microbial communities respond to manure and antibiotic exposure. The study aimed to determine how soil type and moisture alter responses of microbial communities to additions of manure from cattle treated with antibiotics. Soil microcosms were constructed using two soil types at 15, 30, or 45% moisture. Microcosms received biweekly additions of manure from cattle given cephapirin or pirlimycin, antibiotic-free manure, or no manure. While soil type and moisture had the largest effects on microbiome structure, impacts of manure treatments on community structure and individual ARG abundances were observed across varying soil conditions. Activity was also affected, as respiration increased in the cephapirin treatment but decreased with pirlimycin. Manure from cattle antibiotics also increased NH4+ and decreased NO3- availability in some scenarios, but the effects were heavily influenced by soil type and moisture. Overall, this work demonstrates that environmental conditions can alter how manure from cattle administered antibiotics impact the soil microbiome. A nuanced approach that considers environmental variability may benefit the long-term management of antibiotic resistance in soil systems.

Responses of soil bacterial communities and maize yields to sulfur application across four soil types.

Introduction: This study assessed the effects of S application on maize yields and soil bacterial communities across four sites with different soil types and three S application rates (0 kg ha-1, 30 kg ha-1, and 90 kg ha-1). Methods: Changes in soil properties, bacterial community diversity, structure, and their contributions to maize production were evaluated post-S application treatments. Results: (1) S application decreased soil pH, increased available sulfur (AS), and boosted maize yields in all soil types. (2) Reduced Chao1 and Shannon diversity indices were observed in black soil after S application. (3) Bacterial community structure was significantly affected by S application, except in sandy soil, impacting key stone taxa abundance. (4) Black soil showed higher sensitivity to S application due to less stable bacterial community structure. (5) Soil physicochemical indicators altered by S application, such as AS and pH, mediated bacterial diversity, influencing maize yield. Organic matter (OM) had the most significant direct positive effect on yield, followed by AS and bacterial community diversity. Discussion: This study emphasizes the impact of S application on soil properties and bacterial communities in diverse soil types. Understanding these mechanisms can guide precision S application practices for maize yield regulation.

Reduction of nitrous oxide emission by using stearic acid combined zinc coated urea in silty clay and sandy loam soils under bare and planted conditions.

Overuse of chemical fertilizers in agroecosystems leads to the increased economic burden, low crop production in terms of input and environmental pollution. Due to its improved nutrient management and degrading properties, synthetic slow release fertilizers have become a significant advancement in the fertilizer sector. In this study we evaluated the effect of slow release urea on nitrous oxide (N2O) emission, crop growth and crop nutrient contents. Measurements were carried out in two different texture soils (sandy loam and silty clay) under two different conditions (bare soil and planted). The N2O emission was measured for 15 days from bare soils and 48 days from planted soil. Plant fresh weight, dry weight, chlorophyll contents, N and Zn were measured in the end of the experiment. The results showed that N2O emission was reduced 33-39 % from coated urea as compared to conventional urea in bare soil. In planted soil, the coated urea reduced the N2O emission 29-33 %. The deep placement of urea in silty clay soil reduced the N2O emission up to 22.8 % as compared to surface placement. Plant fresh matter, dry matter, N and Zn contents were significantly (p ≤ 0.05) higher with coated urea as compared to conventional urea. It is concluded that the coating of urea with hydrophobic materials like stearic acid, along with Zn sources i.e. Zn fortified nano-bentonite or the ZnO nanoparticles (NPs) presents opportunities to overcome the environmental pollution and increasing the crop production and quality.

Chemistry of soil-type dependent soil matrices and its influence on behaviors of pharmaceutical compounds (PCs) in soils.

Behaviors of pharmaceutical compounds (PCs) in soil are usually determined by experimental extrapolation of results from separate constitutes to the soil, or from a special soil to other regional soil conditions. However, such extrapolation is problematic due to variations in soil clay mineral and organic matter (OM) compositions with soil types, which dominate the interaction mechanisms of PCs in soil. It is essential to review current literature to enhance our understanding of the soil-type dependent surface chemistry of soil matrices and the environmental behavior of PCs in different soil types. Major types of soils occur globally in parallel to the latitudinal or altitudinal zonation due to regional climate conditions with distinct clay mineral and OM compositions. The soil-type dependent surface chemistry results in variations in retention, distribution, transport, and transformation PCs in soil. The mixture of PCs of different classes usually exhibited enhanced sorption due to the cooperative multilayer sorption on soil constituents, and that of the same class often caused differential adsorption capacity compared to the sorption from single compound due to competitive sorption. PCs preferentially adsorb to a soil component, or to a special soil type, and exhibit notably soil-type dependent sorption affinity, mobility, and dissipation. The soil-dependent surface chemistry of soil is critical to predict the persistence and bioavailability of PCs in soil. In the future, more detailed studies of influence of individual soil factor on the behaviors of PCs and especially the practical field site investigation are required to better understand the sorption, transport, transformation, and ecotoxicology of PCs in typical soil types.

Substrate and Moisture Affect the Pupation Depth of the Corn Silk Flies Chaetopsis massyla and Euxesta eluta (Diptera: Ulidiidae).

Corn silk flies, or picture-winged flies (Diptera: Ulidiidae), are important pests of fresh market sweet corn in commercial production areas in southern Florida. Issues with pest management related to insecticide resistance, problems in insecticide application, and alternate crop population sources constitute a significant challenge for the protection of developing corn ears. Developed larvae leave cobs and pupate in the soil; however, relatively little is known about these behaviors. In this study, two soil types collected from fields were compared with sand under six different moisture levels in the laboratory to determine the pupation depths of the larvae. Comparisons were carried out concerning the pupation depth of Chaetopsis massyla and Euxesta eluta, which are major pest species in Florida. Both soil type (muck, loamy sand, and sand) and moisture levels (0, 10, 25, 50, 75, 100% field holding capacity) significantly affected pupation depth, with shallow pupation observed under dry or saturated wet conditions. The addition of structures such as pipe cleaners simulating corn roots resulted in deeper pupation under most conditions.

Changes in grassland soil types lead to different characteristics of bacterial and fungal communities in Northwest Liaoning, China.

Introduction: Soil microbial communities are critical in regulating grassland biogeochemical cycles and ecosystem functions, but the mechanisms of how environmental factors affect changes in the structural composition and diversity of soil microbial communities in different grassland soil types is not fully understood in northwest Liaoning, China. Methods: We investigated the characteristics and drivers of bacterial and fungal communities in 4 grassland soil types with 11 sites across this region using high-throughput Illumina sequencing. Results and Discussion: Actinobacteria and Ascomycota were the dominant phyla of bacterial and fungal communities, respectively, but their relative abundances were not significantly different among different grassland soil types. The abundance, number of OTUs, number of species and diversity of both bacterial and fungal communities in warm and temperate ecotone soil were the highest, while the warm-temperate shrub soil had the lowest microbial diversity. Besides, environmental factors were not significantly correlated with soil bacterial Alpha diversity index. However, there was a highly significant negative correlation between soil pH and Shannon index of fungal communities, and a highly significant positive correlation between plant cover and Chao1 index as well as Observed species of fungal communities. Analysis of similarities showed that the structural composition of microbial communities differed significantly among different grassland soil types. Meanwhile, the microbial community structure of temperate steppe-sandy soil was significantly different from that of other grassland soil types. Redundancy analysis revealed that soil total nitrogen content, pH and conductivity were important influencing factors causing changes in soil bacterial communities, while soil organic carbon, total nitrogen content and conductivity mainly drove the differentiation of soil fungal communities. In addition, the degree of connection in the soil bacterial network of grassland was much higher than that in the fungal network and soil bacterial and fungal communities were inconsistently limited by environmental factors. Our results showed that the microbial community structure, composition and diversity of different grassland soil types in northwest Liaoning differed significantly and were significantly influenced by environmental factors. Microbial community structure and the observation of soil total nitrogen and organic carbon content can predict the health changes of grassland ecosystems to a certain extent.

Plant-Parasitic Nematodes Associated with Cannabis sativa in Florida.

The subtropical climate of Florida allows for a wide range of crops to be grown. With the classification of hemp (Cannabis sativa L., <0.3% delta-9-tetrahydrocannabinol) as an agricultural commodity, hemp has become a potential alternative crop in Florida. Hemp cultivars of different geographies (Europe, China, and North America), and uses (fiber, oil and CBD), were evaluated in three field experiments. The field experiments evaluated a total of 26 cultivars and were conducted for two consecutive seasons at three different locations (soil types) in North (sandy loam), Central (fine sand), and South Florida (gravelly loam). Nematode soil populations were measured at the end of each season. A diverse population of plant-parasitic nematodes was found, with reniform nematodes (RN, Rotylenchulus reniformis) the dominant species in North and South Florida (up to 27.5 nematodes/cc soil), and RKN (Meloidogne javanica) the main species in central Florida (up to 4.7 nematodes/cc soil). Other nematodes that were commonly found in south Florida (and to a lesser extent north Florida) were spiral (Helicotylenchus spp.), stunt (Tylenchorhynchus spp.) and ring nematodes (Criconemoids), while in central Florida, stubby root (Nanidorus minor) and sting nematodes (Belonolaimus longicaduatus) were found. No significant difference among hemp cultivars was noted at any of the locations. RKN were found in all three regions and soils, while RN were only found in North and South Florida. This is the first report on plant-parasitic nematodes associated with hemp in Florida fields. Natural nematode populations varied greatly, depending on where in Florida hemp was grown. Growers who wish to include hemp in their crop rotation need to be aware of potential pest pressure from nematodes. More research is needed to determine to what extent nematodes, especially RKN and RN, can reduce hemp growth and yield.

Stability of exogenous Cadmium in different vineyard soils and its effect on grape seedlings.

Cadmium (Cd) being potentially toxic heavy metal, has become increasingly serious to vineyard soil and grapes in recent years. Soil type is one of the main factors affecting the absorption of Cd in grapes. To investigate the stabilization characteristics and form changes of Cd in different types of vineyard soils, a 90-days incubation experiment was conducted after exogenous Cd addition to 12 vineyard soils from typical vineyards in China. The inhibition of exogenous Cd on grape seedlings was determined based on the pit-pot incubation experiment (200 kg soil per pot). The results demonstrate that Cd concentration in all the sampling sites did not exceed the national screening values (GB15618-2018; i.e., 0.3 mg/kg when pH was lower than 7.5, 0.6 mg/kg when pH was higher than 7.5);. Cd in Fluvo-aquic soil 2, Red soils1, 2, 3 and Grey-Cinnamon soil is dominated by acid-soluble fraction, but was mainly in residual fraction in the remain soils. Throughout the aging process, proportion of the acid-soluble fraction increased and then decreased, while proportion of the residual fraction decreased and then increased, after exogenous Cd was added. The mobility coefficients of Cd in Fluvo-aquic soil 2 and Red soil 1, 2 increased 2.5, 3 and 2 folds, after exogenous Cd addition, respectively. Compared with CK (control), the correlation between total Cd content and its different fractions was relatively weak in the Cdl (low concentration) and Cdh (high concentration) groups. Poor Cd stabilization and strong inhibition of seedling growth rate were observed in Brown soil 1, black soil, red soil 1 and cinnamomic soil. Fluvo-aquic soil 2, 3 and Brown soil 2 showed good Cd stability and small inhibition effect on grape seedlings. These results show that Cd stability in soils and inhibition rate of grape seedlings by Cd are strongly influenced by soil type.

Effects of different soil types on gas exhange parameters and fruits of Hippophae rhamnoides ssp. mongolica "Ulanshalin" plants.

Background: This study aims to explore the growth and production potential of Hippophae rhamnoides ssp. mongolica "Ulanshalin," a pioneer species of soil and water conservation, after being planted in the Yellow River Basin area with serious soil erosion. An analysis of the differences in photosynthesis and fruit yield of H. rhamnoides plants grown in two typical soils in the watershed is key to understanding whether local conditions are suitable for the growth and yield of H. rhamnoides, as well as the impact of the plants on soil and water conservation. Methods: During the growing season, diurnal changes in the gas exchange parameters of Hippophae rhamnoides-like plants growing in Loess soil and Aeolian soil were continuously monitored, and the effects of total nitrogen (TN) and other elements on the net photosynthetic rate (P N) of the plants were analyzed and compared in the two different soil types. The morphological and quality differences of Hippophae rhamnoides fruits were also compared after reaching the ripening stage. Results: (1) There was a significant difference in the composition of Loess soil and of Aeolian soil. The organic matter content and AK content of the Loess soil was significantly higher than in the Aeolian soil, and the pH was closer to neutral. However, the TK content, TP content, and AP content of the Aeolian soil were slightly higher than in the Loess soil, the pH was higher, and it was alkaline. (2) After controlling the light and temperature, with all other external factors consistent, the daily variation trend of P N, T r, and G s in the leaves of H. rhamnoides plants growing in the two different soils were basically the same. There were differences, however, in when these factors reached their peaks. Soil composition had an impact on the photosynthetic characteristics of H. rhamnoides, with TN, TP, AP, and SOM being the main factors promoting the photosynthetic rate of H. rhamnoides P N. The peaks of P N, T r, and G s of H. rhamnoides plants growing in Aeolian soil were higher than those growing in Loess soil. (3) The average stem length of H. rhamnoides plants growing in Aeolian soil was higher than the plants growing in Loess soil. The number of thorns in the branches of plants in the Aeolian soil was relatively low, and the weight of 100 fruits (28.28 g) was significantly higher than the weight of 100 fruits of the H. rhamnoides plants grown in Loess soil (11.14 g). Conclusions: The results of this study show that in the Yellow River Basin area, Aeolian soil is more conducive to the growth of H. rhamnoides plants than Loess soil. H. rhamnoides plants growing in Aeolian soil had good adaptability and stress resistance, and a larger potential for fruit production. These findings provide insights for ecological restoration and the creation of economic value in the Yellow River Basin area.

Effects of sulfadiazine and Cu on soil potential nitrification and ammonia-oxidizing archaea and bacteria communities across different soils.

Introduction: Sulfadiazine (SDZ) and copper (Cu) are frequently detected in agricultural soils, but little is known on their single or combined impact on ammonia oxidizing microbial community and function across different soils. Methods: In this study, a microcosm was conducted to distinguish the microbial ecotoxicity of SDZ and Cu across different soils by analyzing soil potential nitrification rate (PNR) and the amoA gene sequences. Results: The results showed that the single spiking of SDZ caused a consistent decrease of soil PNR among three tested soils, but no consistent synergistic inhibition of SDZ and Cu was observed across these soils. Moreover, across three tested soils, the distinct responses to the single or joint exposure of SDZ and Cu were found in amoA gene abundance, and diversity as well as the identified genus taxa of ammonia-oxidizing archaea (AOA) and bacteria (AOB). Meanwhile, only the specific genus taxa of AOA or AOB consistently corresponded to the variation of soil PNR across different treated soils. The further principal component analysis (PCA) exhibited that the variable influence of SDZ and Cu on ammonia oxidizing microbial community and function was greatly dependent on soil type. Discussion: Therefore, in addition to ecological functionality and the specific prokaryotic taxa, soil microbial ecotoxicity of SDZ and Cu also was dependent on edaphic factors derived from soil types. This study proposes an integrative assessment of soil properties and multiple microbial targets to soil contamination management.

Soil Quality Enhances Seed Germination Success in Ephedra major-A Pilot Experiment.

There are currently knowledge gaps in the environmental context related to successful seed germination of Ephedra major. Therefore, we herein explore the influence of soil quality and water availability on the germination performance through a garden experiment that mimics natural site conditions. One hundred seeds were extracted from fifty ripe strobili collected randomly from the ramets of a single female plant. Ten seeds per pot were sown in ten pots, which were equally split by receiving different watering treatments (watered versus control) and soil types (S0-shallow and stony; S1-like S0 but slightly deeper; S2-like S0 but even deeper and rich in woodland humus; S3-clay-layered alluvial; S4-anthropogenic). No significant interaction effect was detected between the two manipulated factors. Watering only had a marginal effect on the germination rate, but the latter was significantly higher in S2 when compared to the other soil types. These outcomes suggest that soil quality is more important than moisture for the germination success. Its rate is expected to be higher under the open canopy of woodlands compared to open rupicolous habitats, since seeds can benefit from higher humus availability and reduced evapotranspiration.

Soil properties drive the bacterial community to cadmium contamination in the rhizosphere of two contrasting wheat (Triticum aestivum L.) genotypes.

Cadmium (Cd) bioavailability in the rhizosphere makes an important difference in grain Cd accumulation in wheat. Here, pot experiments combined with 16S rRNA gene sequencing were conducted to compare the Cd bioavailability and bacterial community in the rhizosphere of two wheat (Triticum aestivum L.) genotypes, a low-Cd-accumulating genotype in grains (LT) and a high-Cd-accumulating genotype in grains (HT), grown on four different soils with Cd contamination. Results showed that there was non-significant difference in total Cd concentration among four soils. However, except for black soil, DTPA-Cd concentrations in HT rhizospheres were higher than those of LT in fluvisol, paddy soil and purple soil. Results of 16S rRNA gene sequencing showed that soil type (52.7%) was the strongest determinant of root-associated community, while there were still some differences in rhizosphere bacterial community composition between two wheat genotypes. Taxa specifically colonized in HT rhizosphere (Acidobacteria, Gemmatimonadetes, Bacteroidetes and Deltaproteobacteria) could participate in metal activation, whereas LT rhizosphere was highly enriched by plant growth-promoting taxa. In addition, PICRUSt2 analysis also predicted high relative abundances of imputed functional profiles related to membrane transport and amino acid metabolism in HT rhizosphere. These results revealed that the rhizosphere bacterial community may be an important factor regulating Cd uptake and accumulation in wheat and indicated that the high Cd-accumulating cultivar might improve Cd bioavailability in the rhizosphere by recruiting taxa related to Cd activation, thus promoting Cd uptake and accumulation.