Rotation System Research Articles

12-year continuous biochar application: Mitigating reactive nitrogen loss in paddy fields but without rice yield enhancement

Numerous studies have documented the beneficial effects of short-term biochar application on soil carbon sequestration, greenhouse gas emissions reduction, and ecological functions enhancement. However, concerns persist regarding the impacts on soil reactive nitrogen (N) loss and crop yields under long-term biochar application (more than ten years), due to the irreversibility once biochar is incorporated into soils. This study presents the results of a 12-year field experiment in a rice-wheat rotation system with treatments including a control (CK, no corn straw or biochar), annual corn straw returning (CS, 6 Mg·ha−1·yr−1), and annual application of corn straw biochar pyrolyzed at 400°C at rates of 2.4, 6, and 12 Mg·ha−1·yr−1 (BC1, BC2, and BC3), investigating rice yields (2011–2022) and reactive N loss (2021–2022). The results showed that after 11 years of continuous biochar application until the 2021 rice season, alkaline hydrolysis N (AN, equivalent to an average of 347 kg N ha−1) within the 0–15 cm soil layer in biochar treatments was significantly higher than that of the CK (200 kg N ha−1), attributable to the biochar-induced enhancement of cation exchange capacity (CEC). The application of biochar reduced inorganic N leaching and NH3 volatilization losses by an average of 42.21 % and 30.85 %, respectively. However, N2O emission in the BC3 treatment was over 2 times as high as in the CK. Continuous biochar applications did not increase rice yield over the 12 rice seasons, as excessive soil AN level under biochar application reduced the rice harvest index. The results indicated that continuous biochar application was effective in reducing reactive N losses and increasing plant-available N supply, suggesting a potential to sustain rice production with lower fertilizer N inputs.

Simulated herbicide mixtures delay both specialist monogenic and generalist polygenic resistance evolution in weeds.

Evolution of herbicide-resistant weed populations is a major challenge to world food production. Using different herbicides in rotation and/or using different herbicides together as mixtures are strategies that may delay the selection of resistance. This study used simulation modelling to investigate whether mixtures and rotations can delay the selection of both generalist polygenic and specialist monogenic herbicide resistance, and whether these strategies are more likely to lead to the selection of generalist resistance in weed types with varying biological characteristics. Our simulations suggest that well-designed effective herbicide mixtures should delay evolution of both polygenic and monogenic resistance better than rotations and single herbicides across all weed types. Both mixture and rotation strategies increased the likelihood of polygenic resistance compared to single-herbicide use, and the likelihood of polygenic resistance increased as the fecundity and competitiveness of the weed increased. Whether monogenic or polygenic resistance occurred in each case depended most on the relative initial allele frequencies. We did not find that herbicide mixtures were more likely than rotations to lead to the selection of generalist polygenic resistance. The simulated efficacy of mixtures over rotations decreased if components were used at reduced rates or when individual components had already been used solo. Herbicide rotations and particularly well-designed mixtures should delay evolution of both polygenic and monogenic resistance, especially if used as part of an effective integrated weed management programme. However, herbicide mixtures and rotations may also increase the risk that resistance will be generalist polygenic rather than specialist monogenic. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of hot air-assisted radio frequency rotation heating system on improving heating uniformity of dried black fungus (Auricularia auricula)

A large-capacity radio frequency (RF) rotation heating system was employed in this study to heat dried black fungus, and hot air was used for assistance treatment. The effects of electrode gap, rotation rate and hot air on the uniformity of RF heating of dried black fungus were explored. The optimal heating process parameters were obtained, and the sterilization effect was validated. The results showed that the rotation system could significantly enhance the RF heating uniformity of black fungus (P > 0.05). The optimal heating process for heating a large-capacity (480 g) black fungus was to utilize RF heating assisted by 70 °C hot air with an electrode gap of 175 mm and a rotation rate of 60 rpm, followed by 30 min of heat preservation at 70 °C hot air with a rotation rate of 40 rpm. After the entire sterilization treatment, the heating uniformity index λ of black fungus was reduced to 0.027 ± 0.004, the total plate count decreased by 3 log CFU/g, and the moisture content dropped to below 13 %. The ideal RF heating uniformity and sterilization effect of black fungus were obtained in this study through the simultaneous use of hot air and rotation, providing a theoretical foundation for the application of RF technology in the processing of black fungus.

Dynamically documenting archaeological excavations based on 3D modeling: a case study of the excavation of the #3 fossil of hominin cranium from Yunxian, Hubei, China

Documenting tangible cultural heritage using 3D modeling techniques is gradually becoming an indispensable component of archaeological practice. The 3D modeling techniques based on photogrammetry and LiDAR scanning enable high-accuracy and high-realistic reconstruction of archaeological sites, and have been proven a powerful tool for documenting archaeological excavations. However, dynamically documenting an ongoing excavation using these techniques is still considered tedious, time-consuming, expensive, and dependent on expertise. Moreover, the application of 3D modeling techniques in archaeological excavations still faces some technical challenges, such as modeling with multi-source and multi-scale data, fusing local models at different times into a whole, achieving fast modeling while GPU workstations are not available in the field, and evaluating the quality of 3D models. As a result, there are still very few archaeological teams deeply engaged in dynamic documentation with 3D modeling techniques, and traditional drawing sketches and taking photographs still dominate. In these senses, documenting the archaeological excavation at the Yunxian Man site (located in Hubei, China) is an invaluable opportunity for exploration and practice. Archaeologists determined to conduct dynamically documenting at the beginning of the 6th excavation project for the site, and established a rotation system to reconcile physical excavation with digital preservation. Through repeated practice and communication, we proposed a workflow and pursued several new methods to enhance the feasibility of dynamically documenting, and obtained 4D models of the ongoing archaeological excavations. In 2022, the Yunxian Man site unearthed the most intact fossil of hominin cranium from about one million years ago in the Eurasian continent, preserving important and scarce anatomical features of early humans in Asia. As the original taphonomic context of the fossil corroded away during physical excavations, the digital documentation consisting of 4D models serves as permanent original data source in subsequent archaeological research. Moreover, we obtained cross-scale 3D models from geographical environment to archaeological site, excavation area, and cultural remains, and all of these 3D models are in an actual, unified coordinate framework. Thus, we can contribute to multidisciplinary cross-collaborative research through data sharing. Considering that digital documentations serve a great value in archaeological research, this paper focuses on sharing the workflow and methods to facilitate digital preservation for more archaeological projects.

Optimizing the Dosing Regimen During Rotation From Subcutaneous to Transdermal Administration of Fentanyl

ContextSubcutaneous (SC) administration of fentanyl allows for rapid dose titration to treat urgent cancer-related pain. After establishing the optimal fentanyl dose, patients typically rotate towards transdermal (TD) fentanyl patches. Continuing the SC fentanyl up to 12h after application of the patch led to elevated fentanyl concentrations and fentanyl-related toxicities. Based on these findings, and simulations using a pharmacokinetic (PK) model, SC fentanyl administration was discontinued immediately following the application of the patch. ObjectivesTo validate the fentanyl rotation schedule by assessing the PK equivalence in fentanyl exposure before and after rotation. MethodsPK samples and clinical data were prospectively collected from 12 hours prior to rotation until 12 hours after rotation in patients with cancer-related pain undergoing fentanyl rotation. ResultsBetween December 2021 and September 2023, 29 evaluable patients were enrolled in the study. The 90% confidence interval (CI) of the geometric mean ratio between the post- over pre-rotation area under the curve (AUC) fell within the prespecified 0.8–1.25 equivalence interval (90% CI 1.05–1.16). Patient-reported intensity of both nausea (P = 0.047) and transpiration (P = 0.034) decreased post-rotation. Pain intensity and other adverse events did not differ significantly pre and post-rotation. One patient needed adjustment of opioid therapy 40 hours after rotation due to fentanyl-related toxicities. ConclusionThe updated rotation scheme, implying a 1:1 dose conversion and discontinuation of SC fentanyl directly after rotation, resulted in equivalent fentanyl exposure pre and post-rotation. Moreover, the dosing regimen showed to be safe and efficacious during rotation. The new dosing regimen when rotating from SC to TD fentanyl can be effectively and safely implemented in routine palliative care.

Methane and nitrous oxide emissions in the rice-shrimp rotation system of the Vietnamese Mekong Delta

Rice-shrimp rotation systems are one of the widespread farming practices in the Vietnamese Mekong Delta coastal areas. However, greenhouse gas (GHG) emissions in the system have remained unclear. This study aimed to examine methane (CH4) and nitrous oxide (N2O) emissions from the system, including (i) land-based versus high-density polyethylene-lined (HDPE) nursery ponds and (ii) conventional versus improved grow-out ponds inoculated with effective microorganisms (EM) bioproducts. The results showed that CH4 flux in land-based and HDPE-lined nursery ponds were 1.04 and 0.25 mgCH4 m−2 h−1, respectively, while the N2O flux was 8.37 and 6.62 μgN2O m−2 h−1, respectively. Global warming potential (GWP) from land-based nursery ponds (18.3 g CO2eq m−2) was approximately 3 folds higher than that of the HDPE-lined nursery pond (6.1 g CO2eq m−2). Similarly, the mean CH4 and N2O fluxes were 15.84 mg CH4 m−2 h−1 and 7.17 μg N2O m−2 h−1 for the conventional ponds, and 10.51 mg CH4 m−2 h−1 and 7.72 μg N2O m−2 h−1 for the improved grow-out ponds. Conventional practices (2388 g CO2eq m−2) had a higher 1.5-fold GWP compared to the improved grow-out pond (1635 g CO2eq m−2). The continuation of the land-based nursery pond and conventional aquacultural farming practices increase CH4 emission and GWP, while applying HDPE-lined nursery ponds combined with improved grow-out ponds could be a promising approach for reducing GHG emissions in rice-shrimp rotation systems. This study recommends further works in the rice-shrimp rotation systems, including (i) an examination of the effects of remaining rice stubbles in the platform on the availability of TOC levels and GHG emissions and (ii) ameliorating dissolved oxygen (DO) concentration on the effectiveness of GHG emission reduction.

Effects of straw application on soil hydrothermal conditions and crop yield in a maize and wheat rotation system

Effects of straw application on soil hydrothermal conditions and crop yield in a maize and wheat rotation system

Effects of dry bio-slurry and nitrogen fertilizer on potato and wheat yields under rotation cropping system.

Integrated nutrient management and crop rotation are important farming practices, which enhance the nutrient use efficiency of crops and reduce the incidence of diseases and insect pests. The study was carried out to address the gap in using integrated nutrient management in crop rotation systems for soil qualities and crop yield improvement. That was done by adjusting the balance ratio of dry bio-slurry and nitrogen fertilizers. The experiment was containing ten levels; Control (0,0), recommended nitrogen, 50% dry-bio slurry, 100% dry-bio slurry, 75% dry-bio slurry, 75% dry-bio slurry+25% recommended nitrogen, 50% dry-bio slurry+50% recommended nitrogen, 25% dry-bio slurry+75% recommended nitrogen, 100% dry-bio slurry + 25% recommended nitrogen and 100% dry-bio slurry + 50% recommended nitrogen that was laid out in randomized complete block design with three replications for three years. The data on soil properties and yield components of potatoes and wheat were collected and analyzed using statistical analysis system software 9.4. An application of dry bio-slurry with nitrogen fertilizer was significantly affected both crop yield and soil properties in the rotation system. The application of 25% dry bio-slurry with 75% recommended nitrogen gave the highest tuber yield of potato (27.6 tha-1) as compared to control. Similarly, using 100% and 75% sole dry bio-slurry resulted in the highest grain yield (3.85 tha-1) and above-ground biomass (9.59 tha-1) of wheat. The combination of 25% dry bio-slurry with 75% recommended nitrogen scored the highest net benefit (2889.2 US$) with an acceptable marginal return (4463.3%) via by improving crops yield in the system. So, an application of 25% dry bio-slurry with 75% recommended nitrogen could be promoted for yield-soil improvement in the study area and similar agroecology.

Findings on celestial pole offsets predictions in the second earth orientation parameters prediction comparison campaign (2nd EOP PCC)

In 2021, the International Earth Rotation and Reference Systems Service (IERS) established a working group tasked with conducting the Second Earth Orientation Parameters Prediction Comparison Campaign (2nd EOP PCC) to assess the current accuracy of EOP forecasts. From September 2021 to December 2022, EOP predictions submitted by participants from various institutes worldwide were systematically collected and evaluated. This article summarizes the campaign's outcomes, concentrating on the forecasts of the dX, dY, and dψ, dε components of celestial pole offsets (CPO). After detailing the campaign participants and the methodologies employed, we conduct an in-depth analysis of the collected forecasts. We examine the discrepancies between observed and predicted CPO values and analyze their statistical characteristics such as mean, standard deviation, and range. To evaluate CPO forecasts, we computed the mean absolute error (MAE) using the IERS EOP 14 C04 solution as the reference dataset. We then compared the results obtained with forecasts provided by the IERS. The main goal of this study was to show the influence of different methods used on predictions accuracy. Depending on the evaluated prediction approach, the MAE values computed for day 10 of forecast were between 0.03 and 0.16 mas for dX, between 0.03 and 0.12 mas for dY, between 0.07 and 0.91 mas for dψ, and between 0.04 and 0.41 mas for dε. For day 30 of prediction, the corresponding MAE values ranged between 0.03 and 0.12 for dX, and between 0.03 and 0.14 mas for dY. This research shows that machine learning algorithms are the most promising approach in CPO forecasting and provide the highest prediction accuracy (0.06 mas for dX and 0.08 mas for dY for day 10 of prediction).Graphical abstract

Analysis of the beneficial effects of prior soybean cultivation to the field on corn yield and soil nitrogen content.

Corn-soybean rotation is a cropping pattern to optimize crop structure and improve resource use efficiency, and nitrogen (N) fertilizer application is an indispensable tool to increase corn yields. However, the effects of N fertilizer application levels on corn yield and soil N storage under corn-soybean rotation have not been systematically studied. The experimental located in the central part of the Songnen Plain, a split-zone experimental design was used with two planting patterns of continuous corn (CC) and corn-soybean rotations (RC) in the main zone and three N application rates of 0, 180, and 360 kg hm-2 of urea in the secondary zone. The research has shown that RC treatments can enhance plant growth and increase corn yield by 4.76% to 79.92% compared to CC treatments. The amount of N fertilizer applied has a negative correlation with yield increase range, and N application above 180 kg hm-2 has a significantly lower effect on corn yield increase. Therefore, a reduction in N fertilizer application may be appropriate. RC increased soil N storage by improving soil N-transforming enzyme activity, improving soil N content and the proportion of soil organic N fractions. Additionally, it can improve plant N use efficiency by 1.4%-5.6%. Soybeans grown in corn-soybean rotations systems have the potential to replace more than 180 kg hm-2 of urea application. Corn-soybean rotation with low N inputs is an efficient and sustainable agricultural strategy.

Non-invasive glucose extraction by a single polarization rotator system in patients with diabetes.

This study utilizes a Mueller matrix-based system to extract accurate glucose levels from human fingertips, addressing challenges in skin complexity. Integration of domain knowledge and data science aims to enhance prediction accuracy using a Random Forest model. The primary goal is to improve glucose level predictions by selecting effective features based on the Pearson product-moment correlation coefficient (PPMCC). The interpolation compensates for delayed glucose concentration. This study integrates domain knowledge and data science, combining a Mueller matrix-based system and a random forest model. It is noted that 16 effective features were identified from 27 test points collected from a healthy volunteer in the laboratory. These features were divided into training and prediction sets in a ratio of 8:2. As a result, the regression coefficient, R2, was 0.8907 and the mean absolute relative difference (MARD) was 6.8%, respectively. This significantly improves prediction accuracy, demonstrating the model's robustness and reliability in accurately forecasting outcomes based on the identified features. In addition, in the Institutional Review Board (IRB) tests at NCKU's hospital, all data passed the same preprocessing and model. The measurement results from an individual diabetic patient demonstrate high accuracy for blood glucose concentrations below 150 mg/dL, with acceptable deviation at higher levels and no severe error zones. Over a three-month period, data from the participating diabetic patient showed a MARD of 4.44% with the R2 of 0.836, and the other patient recorded a MARD of 7.79% with the R2 of 0.855. The study shows the proposed approach accurately extracts glucose levels. Integrating domain knowledge, data science, and effective strategies significantly improves prediction accuracy.

Study on the wear characteristics of a 3D printed tool in flat lapping of Al2O3 ceramic materials

Widespread and popular use of ceramic products in various industry sectors necessitates the search for methods of their efficient processing. Lapping technology, which enables obtaining high dimensional and shape accuracy and high surface flatness, is one of the basic methods of finishing hard and brittle technical ceramics with a porous structure. This study analyzed the characteristics and wear value of an SLS-printed abrasive tool intended for single-sided lapping of Al2O3 technical ceramics. As earlier research demonstrated, introduction of a 3D printed lapping plate by selective laser sintering (SLS), leads to a significant development in the field of precision machining technology. This method showed not only efficient machining performance on oxide technical materials, but was also characterized by relatively low abrasive wear. Straightness errors were evaluated with the use of a least-squares method (LSQ) and minimum zone method based on control line rotation scheme (CLRS). The proposed model proved the experimental results by identifying a similar location of a higher contact density on the lapping tool, where this location is expected to be the one for bigger wear. Surface topography of the lapping tool depends on the tool wear intensity and as a consequence on its shape error. An SLS-printed lapping plate, by obtaining good technological effects, revealed its potential ability in machining hard and brittle technical ceramics.

Screw Motion Used in Semiconstrained Rotational Plate Systems for Anterior Cervical Discectomy and Fusion.

Retrospective observational study. To scrutinize screw motion used in semiconstrained rotational plate systems for anterior cervical discectomy and fusion (ACDF). Semiconstrained rotational plate systems are supposed to control graft subsidence and facilitate lordosis acquisition and maintenance by toggling the instrumented vertebrae via variable-angle screws. However, their benefits may be unrealized if the screws move within the vertebrae. We reviewed medical records of 119 patients who underwent 1-level, 2-level, 3-level, or 4-level ACDF, divided them into the short-segment (n=62, 1-level or 2-level ACDF) and long-segment (n=59, 3- level or 4-level ACDF) groups, and investigated their immediate and 1-year postoperative lateral radiographs. We measured the fused segmental angle, screw angles at the upper-instrumented vertebra (UIV) and lower-instrumented vertebra (LIV), distance from the screw base to the endplate of UIV/LIV (SBE), and distance from the screw tip to the endplate of UIV/LIV (STE) to analyze the screw motion used in these plate systems. The differences between the immediate and 1-year postoperative values were statistically analyzed. The nonunion level was also investigated. Screw angle and SBE at the LIV significantly decreased in the long-segment group (-14.5±9.8 degrees and -2.8±1.8mm, respectively) compared with those in the short-segment group (-4.6±6.0 degrees and -1.0±1.5mm, respectively). Thus, the long-segment group could not maintain the immediate-postoperative segmental angle. Overall, 27 patients developed nonunion, with 19 (70.4%) in the long-segment group and 21 (77.8%) at the lowest fused level. Semiconstrained rotational plate systems provide only vertical forces to the fused segment rather than toggling the instrumented vertebrae. Postoperatively in multilevel ACDF, LIV screws migrate caudally, suggesting that these plate systems are not always effective in maintaining lordosis. Moreover, LIV screws and the anterior wall of the LIV are subject to overloading, resulting in a high rate of nonunion at the lowest fused level. Level III.

Another approach to Planar Cover Conjecture focusing on rotation systems

Another approach to Planar Cover Conjecture focusing on rotation systems

Phacelia and Buckwheat Cover Crops’ Effects on Soil Quality in Organic Vegetable Production in a High Tunnel System

Cover crops (CCs) are regarded as beneficial to agricultural practice as an option for soil quality improvement in field production systems. The main goal of this study was to assess the impact of spring phacelia (Phacelia tanacetifolia Benth.) and buckwheat (Fagopyrum Mill.) in a crop rotation (CC–leek–parsley, 2020–2021) on the physicochemical and biological properties of the soil in an organic high tunnel system. Soil analyses involved measurements of bulk density, water capacity, soil aggregation, soil organic carbon (SOC), available soil nutrients, as well as microbial abundance and diversity. Phacelia generated more aboveground biomass (58.2 t fresh matter ha−1) than buckwheat (33.0 t ha−1), and their biomass contained 161 kg N ha−1 and 67 kg N ha−1, respectively. A large quantity of elements, such as N, Ca, P, S, B, and Cu, were found in phacelia biomass. More Mg and Na were found in buckwheat plants. The results showed that CC biomass significantly improved some of the soil physical and chemical properties, such as soil organic carbon stock and wet aggregate stability, and decreased soil bulk density. Cover crop treatments changed the dynamics of soil bacterial and fungus populations in a high tunnel system. Phacelia increased the quantity of ammonifiers and nitrifiers in the soil substantially. Further research with a long-term focus is needed to assess the impact of cover crops on soil properties, soil quality, and subsequent crop yields in high tunnel crop rotation and management systems.

Effects of the rice-mushroom rotation pattern on soil properties and microbial community succession in paddy fields.

Currently, straw biodegradation and soil improvement in rice-mushroom rotation systems have attracted much attention. However, there is still a lack of studies on the effects of rice-mushroom rotation on yield, soil properties and microbial succession. In this study, no treatment (CK), green manure return (GM) and rice straw return (RS) were used as controls to fully evaluate the effect of Stropharia rugosoannulata cultivation substrate return (SRS) on soil properties and microorganisms. The results indicated that rice yield, soil nutrient (organic matter, organic carbon, total nitrogen, available nitrogen and available potassium) and soil enzyme (urease, saccharase, lignin peroxidase and laccase) activities had positive responses to the rice-mushroom rotation. At the interannual level, microbial diversity varied significantly among treatments, with the rice-mushroom rotation significantly increasing the relative alpha diversity index of soil bacteria and enriching beneficial microbial communities such as Rhizobium, Bacillus and Trichoderma for rice growth. Soil nutrients and enzymatic activities were significantly correlated with microbial communities during rice-mushroom rotation. The fungal-bacterial co-occurrence networks were modular, and Latescibacterota, Chloroflexi, Gemmatimonadota and Patescibacteria were closely related to the accumulation of nutrients in the soil. The structural equation model (SEM) showed that fungal diversity responded more to changes in soil nutrients than did bacterial diversity. Overall, the rice-mushroom rotation model improved soil nutrients and rice yields, enriched beneficial microorganisms and maintained microbial diversity. This study provides new insights into the use of S. rugosoannulata cultivation substrates in the sustainable development of agroecosystems.

Profiling of rhizosphere bacterial community associated with sugarcane and banana rotation system

BackgroundGuangxi is the leading sugarcane-producing area in China. Due to the Panama disease outbreak in banana gardens, sugarcane and banana rotation was recommended. A field experiment with the newly released sugarcane cultivar Zhongzhe 1 (ZZ1) was conducted to understand the role of the sugarcane–banana rotation system in shaping the rhizosphere microbiota. Fields in the region possess characteristics of red laterite soil.ResultsUsing Illumina HiSeq sequencing to analyze soil samples’ 16S rRNA V3-V4 region, the preceding banana rotation field had relatively greater bacterial diversity than the monoculture sugarcane field. Proteobacteria, Chloroflexi, Actinobacteria, and Acidobacteria were the dominant phyla, with distinct taxa enriched in each environment. However, the preceding sugarcane monoculture field enriched functional groups related to nitrogen fixation and cellulolysis. Network analysis highlighted contrasting network structures between sugarcane and banana rhizospheres, suggesting differential stability and susceptibility to environmental influences. Furthermore, correlations between soil properties and bacterial alpha-diversity underscored the influence of preceding crops on rhizosphere microbial communities.ConclusionThis research enhances our understanding of crop rotation effects on soil microbial ecology and provides insights into optimizing agricultural practices for enhanced soil health and crop productivity. Future studies should explore the underlying mechanisms driving these interactions and evaluate the long-term impacts of crop rotation on soil microbial dynamics.Graphical abstract

Adaptive integumentary features of beef cattle raised on afforested or non-shaded tropical pastures

We aimed to analyze the seasonal acclimatization process of Nelore and Canchim cattle raised on two production systems (non-shaded, NS, and integrated crop-livestock-forest, ICLF), based on the dynamics of the morphological and functional attributes of the hair coat and skin during winter and summer. The study was conducted in Brazil, in a low-altitude tropical climate region. A completely randomized 2 × 2 factorial design was adopted as follows: two production systems (NS and ICLF), two breeds (Nelore and Canchim) in a longitudinal structure, with measurements repeated over time through two stations (winter and summer). The experimental animals consisted of 32 Nelore (Bos indicus) and 32 Canchim (5/8 Bos taurus × 3/8 Bos indicus) bulls. The animals were equally distributed between two intensive rotational grazing systems. In both breeds, the hair coat was significantly thicker in winter but longer in summer, which increased epidermal protection. The Nelore bulls had shorter, wider, and thicker hairs, which are attributes that promote heat loss via conduction. The Canchim bulls showed significantly lower hair density and higher epithelium distance to sweat glands, which resulted in higher core temperature and respiratory rate. In turn, Nelore bulls had higher serum concentrations of triiodothyronine and lower serum concentrations of cortisol. However, Canchim bulls more frequently and intensely activated their thermoregulatory system and markedly adjusted their hair coat and hair features to reduce heat gain, especially in summer. Therefore, the anatomical plasticity and functional integumentary characteristics of Nelore and Canchim bulls reflect their acclimatization to tropical conditions.

Sheep rotational grazing strategy to improve soil organic carbon and reduce carbon dioxide emission from spring wheat in an arid region

Context Cultivating forage crops is crucial to improve feed production, and grazing is an important utilisation method to improve soil fertility. Aim Improving soil organic carbon (SOC) content and reducing carbon dioxide (CO2) emission through grazing management from a spring wheat field. Methods We compared sheep rotational grazing and control, and studied their effects on SOC and CO2 emission from a spring wheat field. Key results Sheep rotational grazing improved SOC content (by 23.5%) and soil easily oxidised organic carbon (EOC) content (by 7.7%) and reduces soil microbial biomass carbon (MBC) content (by 35.8%) compared with the control. Sheep rotational grazing reduced CO2 emission compared with the control. Sheep grazing reduced cumulative CO2 emission by 28.9% and 33.0% in May and June compared with the control. Conclusions Sheep grazing improved SOC content and reduce CO2 emission from a spring wheat field. Implications Based on our short-term study, sheep rotational grazing has a significant effect on SOC, EOC and MBC contents and CO2 emission from spring wheat fields in arid regions. For a large-scale assessment of sheep grazing on soil fertility and CO2 emission, more investigation for different soils and climates is necessary. Furthermore, a long-term study is also necessary to better understand the effect of sheep rotational grazing on soil fertility and CO2 emission from spring wheat fields in arid regions.

Hazards of toxic metal(loid)s: Exploring the ecological and health risk in soil–crops systems with long-term sewage sludge application

Sewage sludge (SS) is commonly used as agricultural fertilizer worldwide. However, the toxic metal(loid)s in SS raises concerns about soil contamination and the potential risks to human health. This study, conducted since 2007 on the North China Plain, examines the impact of SS use on crops. An experiment was designed with five treatments: conventional fertilization (CK) and four levels of SS application (W1, W2, W3, and W4: 4.5, 9.0, 18.0, and 36.0 t ha−1, respectively). Soil concentrations of eight toxic metal(loid)s (Zn, Cu, Cr, Cd, Ni, Pb, As, and Hg) were analyzed to assess pollution risk using various indices. Health risks associated with maize and wheat grains were also evaluated. Additionally, the impact of long-term SS application on crop yield, soil quality, and human health within a wheat-maize rotation system was examined. SS application increased wheat and maize yields by 5.37 to 19.08 % and 6.97 to 17.94 %, respectively, across treatments W2 to W4. Despite the toxic metal(loid)s in the grains remaining within safe limits, their concentrations showed an upward trend, especially under the W4 treatment. Moreover, SS application significantly increased the soil Zn, Cu, Cr, Cd, Pb, and Hg levels (P < 0.05) without exceeding the national standards. The geo-accumulation index values revealed rising pollution levels for Zn, Cu, Cd, and Hg, which shifted from no contamination to moderate contamination and then to moderate-to-high contamination, yet the overall pollution level remained safe. Soil ecological risks increased from moderate to serious, with Hg posing the greatest risk, particularly under the W4 treatment. Long-term crop intake from the area significantly exposed children and adults to As, contributing 42.12 % and 34.62 % to hazard index (HI), respectively. The HI values for toxic metal(loid)s in these grains surpassed one in both age groups, suggesting health risks from long-term SS cultivated crops.