Accurate spatio-temporal land cover information in agricultural irrigation districts is crucial for effective agricultural management and crop production.Therefore,a spectralphenological-based land cover classificatio...Accurate spatio-temporal land cover information in agricultural irrigation districts is crucial for effective agricultural management and crop production.Therefore,a spectralphenological-based land cover classification(SPLC)method combined with a fusion model(flexible spatiotemporal data fusion,FSDAF)(abbreviated as SPLC-F)was proposed to map multi-year land cover and crop type(LC-CT)distribution in agricultural irrigated areas with complex landscapes and cropping system,using time series optical images(Landsat and MODIS).The SPLC-F method was well validated and applied in a super-large irrigated area(Hetao)of the upper Yellow River Basin(YRB).Results showed that the SPLC-F method had a satisfactory performance in producing long-term LC-CT maps in Hetao,without the requirement of field sampling.Then,the spatio-temporal variation and the driving factors of the cropping systems were further analyzed with the aid of detailed household surveys and statistics.We clarified that irrigation and salinity conditions were the main factors that had impacts on crop spatial distribution in the upper YRB.Investment costs,market demand,and crop price are the main driving factors in determining the temporal variations in cropping distribution.Overall,this study provided essential multi-year LC-CT maps for sustainable management of agriculture,eco-environments,and food security in the upper YRB.展开更多
Both straw incorporation and irrigation practices affect biological nitrogen(N)fixation(BNF),but it is still unclear how straw incorporation impacts BNF under continuous(CFI)or intermittent(IFI)flooding irrigation in ...Both straw incorporation and irrigation practices affect biological nitrogen(N)fixation(BNF),but it is still unclear how straw incorporation impacts BNF under continuous(CFI)or intermittent(IFI)flooding irrigation in a rice cropping system.A15N2-labeling chamber system was placed in a rice field to evaluate BNF with straw incorporation under CFI or IFI for 90 d.The nif H(gene encoding the nitrogenase reductase subunit)DNA and c DNA in soil were amplified using real-time quantitative polymerase chain reaction,and high-throughput sequencing was applied to the nif H gene.The total fixed N in the straw incorporation treatment was 14.3 kg ha^(-1)under CFI,being 116%higher than that under IFI(6.62 kg ha^(-1)).Straw incorporation and CFI showed significant interactive effects on the total fixed N and abundances of nif H DNA and c DNA.The increase in BNF was mainly due to the increase in the abundances of heterotrophic diazotrophs such as Desulfovibrio,Azonexus,and Azotobacter.These results indicated that straw incorporation stimulated BNF under CFI relative to IFI,which might ultimately lead to a rapid enhancement of soil fertility.展开更多
Sediment particles,as one of the key components of drip irrigation technology,significantly affect the service life of emitters and restrict the popularization of drip irrigation technology.Hence,two types of patch dr...Sediment particles,as one of the key components of drip irrigation technology,significantly affect the service life of emitters and restrict the popularization of drip irrigation technology.Hence,two types of patch drip irrigation emitters,focusing on the anti-clogging performance through the experiment,were investigated.The dynamic variations in the clogging characteristics of emitters,specifically were subjected to statistical analysis.The movement mechanism of emitter clogging and discharging sediment was studied.The effects of emitter structure and position factors on emitter clogging were analyzed.The results show that the pressure-compensated emitter exhibits superior anti-clogging perfor-mance,with a service life that is 227.8%greater than that of the labyrinth channel emitter.A single structural factor cannot completely evaluate the anti-clogging performance of emitters.All factors causing emitter clogging should be considered comprehensively.Emitters contain sensitive sediment prone to clogging,however,significant blockage occurs primarily when the sediment content is elevated.The discharge of sediment,denoted as V90,from the emitter is affected by the accumulative effect of clogged sediment.These results may offer valuable insights for the application and advancement of drip irrigation technology.展开更多
Irrigated agriculture in Cameroon is practiced on a large scale by large private firms and parastatals, and on a small scale by individual producers in different production areas of the country. Although small-scale i...Irrigated agriculture in Cameroon is practiced on a large scale by large private firms and parastatals, and on a small scale by individual producers in different production areas of the country. Although small-scale irrigation can supply local and sub-regional markets with food in the off-season, it has received little research and its challenges are therefore rarely addressed. In order to contribute to the knowledge of these small-scale irrigation systems, with a view to improving their structure and the management of irrigation water and energy, an assessment of small-scale irrigation in the southern slopes of the Bamboutos Mountains has been done. After direct observations, field measurements, surveys of 100 irrigators with questionnaires and interviews with administrative managers, analyses were carried out using Xlstat software. It was found out that about 226 small-scale irrigation systems designed and managed by producers have been installed on this slope between the end of December 2022 and mid-March 2023. Intended for market garden crops, 84.96% of these irrigation systems use sprinklers and 15.04% surface irrigation (furrow irrigation). Surface or underground water is mobilized using gravity (50%), fossil fuels (34.51%), electricity (14.6%) or solar energy (0.9%). Sprinkler irrigation is mainly carried out using locally manufactured hydraulic turnstiles. There is a lack of formal associations of irrigators in an environment marked by conflicts between water users, when there is not allocation for water withdrawal. Apart from the high cost of pumping energy ($1.32 per liter of fuel), the main constraint identified, which has become more acute over the years, is the lack of irrigation water during the water shortage period (from mid-January to mid-March). These constraints have led to a transition from surface irrigation to sprinkler irrigation, and the adoption of new energy supply and water mobilization technologies. The construction of collective surface and groundwater catchment structures with solar-powered pumping systems, the setting up of formal irrigators’ associations and an irrigation support service, could improve the availability of water throughout the irrigation season, thereby helping to improve the income generated by irrigated market-garden farming on the southern slopes of the Bamboutos Mountains.展开更多
Moistube irrigation is a newly-developed irrigation technique that utilizes a semipermeable membrane to release water slowly and continuously into the plant root zone.Alternate Moistube Irrigation(AMI)is a combination...Moistube irrigation is a newly-developed irrigation technique that utilizes a semipermeable membrane to release water slowly and continuously into the plant root zone.Alternate Moistube Irrigation(AMI)is a combination of alternative irrigation and moistube irrigation.In order to investigate the effects of AMI on plant growth,greenhouse experiments were conducted on spinach(Spinacia oleracea)and water spinach(Ipomoea aquatica)plants at different time.We measured soil water content at a depth of 20 cm in the planting boxes,and also determined seed emergence rate,plant height,largest leaf area,fresh weight per plant,yield,and irrigation water productivity(IWP)for both spinach and water spinach.The results showed that the AMI treatments had significantly higher soil water content than the conventional surface irrigation control(CK).The emergence rates of spinach and water spinach were significantly higher in the AMI treatments than in the CK,and the plant height,largest leaf area,and fresh weight during the middle and late stages of spinach and water spinach growth were also significantly higher than those of the CK.Both spinach and water spinach grew well and produced high yield with high IWP under AMI with a high water head pressure of 1.5 m at tube spacing of 20 or 30 cm.We found that AMI with a suitable combination of head pressure and tube spacing can promote plant growth and increase yield and IWP under controlled conditions.展开更多
Integrating sprinkler with deficit irrigation system is a new approach to improve crop water productivity and ensure water and food security in arid areas of India.This study undertook a field experiment of sprinkler-...Integrating sprinkler with deficit irrigation system is a new approach to improve crop water productivity and ensure water and food security in arid areas of India.This study undertook a field experiment of sprinkler-irrigated cumin(variety GC-4)with a mini-lysimeter setup at an experimental research farm in Jodhpur,India during 2019-2022.Four irrigation treatments T_(1),T_(2),T_(3),and T4 were designed at irrigation water/cumulative pan evaporation(IW/CPE)of 1.0,0.8,0.6,and 0.4,respectively,with three replications.Daily actual crop evapotranspiration(ETc)was recorded and weekly soil moisture was monitored over the crop growth period.Quantities of applied water and drainage from mini-lysimeters were also measured at every irrigation event.Yield of cumin was recorded at crop maturity.Furthermore,change in farmer's net income from 1-hm2 land was computed based on the cost of applying irrigation water and considering yield variations among the treatments.Results indicated the highest mean seasonal actual ETc(371.7 mm)and cumin yield(952.47 kg/hm2)under T_(1)(with full irrigation).Under T_(2),T_(3),and T4,the seasonal actual ETc decreased by 10.4%,27.6%,and 41.3%,respectively,while yield declined by 5.0%,28.4%,and 50.8%,respectively,as compared to the values under T_(1).Furthermore,crop water productivity of 0.272(±0.068)kg/m3 under T_(2)was found relatively higher in comparison to other irrigation treatments,indicating that T_(2)can achieve improved water productivity of cumin in arid areas at an optimum level of deficit irrigation.The results of cost-economics indicated that positive change in farmer's net income from 1-hm2 land was 108.82 USD under T_(2),while T_(3)and T4 showed net losses of 5.33 and 209.67 USD,respectively.Moreover,value of yield response factor and ratio of relative yield reductions to relative ETc deficits were found to be less than 1.00 under T_(2)(0.48),and more than 1.00 under T_(3)(1.07)and T4(1.23).This finding further supports that T_(2)shows the optimized level of deficit irrigation that saves 20.0%of water with sacrificing 5.0%yield in the arid areas of India.Findings of this study provide useful strategies to save irrigation water,bring additional area under irrigation,and improve crop water productivity in India and other similar arid areas in the world.展开更多
In recent years, the rational utilization of saline water resources for agricultural irrigation has emerged as an effective strategy to alleviate water scarcity. To safely and efficiently exploit saline water resource...In recent years, the rational utilization of saline water resources for agricultural irrigation has emerged as an effective strategy to alleviate water scarcity. To safely and efficiently exploit saline water resources over the long term, it is crucial to understand the effects of salinity on crops and develop optimal water-salinity irrigation strategies for processing tomatoes. A two-year field experiment was conducted in 2018 and 2019 to explore the impact of water salinity levels(S1: 1 g L^(–1), S2: 3 g L^(–1), and S3: 5 g L^(–1)) and irrigation amounts(W1: 305 mm, W2: 485 mm, and W3: 611 mm) on the soil volumetric water content and soil salinity, as well as processing tomato growth, yield, and water use efficiency. The results showed that irrigation with low to moderately saline water(<3 g L^(–1)) enhanced plant wateruptake and utilization capacity, with the soil water content(SWC) reduced by 6.5–7.62% and 10.52–13.23% for the S1 and S2 levels, respectively, compared to the S3 level in 2018. Under S1 condition, the soil salt content(SSC) accumulation rate gradually declined with an increase in the irrigation amount. For example, W3 decreased by 85.00 and 77.94% compared with W1 and W2 in 2018, and by 82.60 and 73.68% in 2019, respectively. Leaching effects were observed at the W3 level under S1, which gradually diminished with increasing water salinity and duration. In 2019, the salt contents of soil under each of the treatments increased by 10.81–89.72% compared with the contents in 2018. The yield of processing tomatoes increased with an increasing irrigation amount and peaked in the S1W3 treatment for the two years, reaching 125,304.85 kg ha^(–1)in 2018 and 128,329.71 kg ha^(–1)in 2019. Notably, in the first year, the S2W3 treatment achieved relatively high yields, exhibiting only a 2.85% reduction compared to the S1W3 treatment. However, the yield of the S2W3 treatment declined significantly in two years, and it was 15.88% less than that of the S1W3 treatment. Structural equation modeling(SEM) revealed that soil environmental factors(SWC and SSC) directly influence yield while also exerting indirect impacts on the growth indicators of processing tomatoes(plant height, stem diameter, and leaf area index). The TOPSIS method identified S1W3, S1W2, and S2W2 as the top three treatments. The single-factor marginal effect function also revealed that irrigation water salinity contributed to the composite evaluation scores(CES) when it was below 0.96 g L^(–1). Using brackish water with a salinity of 3 g L^(–1)at an irrigation amount of 485 mm over one year ensured that processing tomatoes maintained high yields with a relatively high CES(0.709). However, using brackish water for more than one year proved unfeasible.展开更多
To elucidate the fracturing mechanism of deep hard rock under complex disturbance environments,this study investigates the dynamic failure behavior of pre-damaged granite subjected to multi-source dynamic disturbances...To elucidate the fracturing mechanism of deep hard rock under complex disturbance environments,this study investigates the dynamic failure behavior of pre-damaged granite subjected to multi-source dynamic disturbances.Blasting vibration monitoring was conducted in a deep-buried drill-and-blast tunnel to characterize in-situ dynamic loading conditions.Subsequently,true triaxial compression tests incorporating multi-source disturbances were performed using a self-developed wide-low-frequency true triaxial system to simulate disturbance accumulation and damage evolution in granite.The results demonstrate that combined dynamic disturbances and unloading damage significantly accelerate strength degradation and trigger shear-slip failure along preferentially oriented blast-induced fractures,with strength reductions up to 16.7%.Layered failure was observed on the free surface of pre-damaged granite under biaxial loading,indicating a disturbance-induced fracture localization mechanism.Time-stress-fracture-energy coupling fields were constructed to reveal the spatiotemporal characteristics of fracture evolution.Critical precursor frequency bands(105-150,185-225,and 300-325 kHz)were identified,which serve as diagnostic signatures of impending failure.A dynamic instability mechanism driven by multi-source disturbance superposition and pre-damage evolution was established.Furthermore,a grouting-based wave-absorption control strategy was proposed to mitigate deep dynamic disasters by attenuating disturbance amplitude and reducing excitation frequency.展开更多
A growing global demand exists to formulate plans to lessen the greenhouse gas emissions produced by agricultural activities.The purpose of this study was to uncovered the changes in soil CO_(2)fluxes under varying sc...A growing global demand exists to formulate plans to lessen the greenhouse gas emissions produced by agricultural activities.The purpose of this study was to uncovered the changes in soil CO_(2)fluxes under varying scenarios including nitrogen fertilization rates,irrigation rates,and air temperatures in the Hetao Irrigation District(HID)over the 38-year period.DAYCENT model was used to predict carbon dioxide(CO_(2))fluxes from cultivated soils in the HID,Inner Mongolia from^(2)023 to 2060(the year of achieving the"carbon neutrality"goal)in this study.Results showed that mean soil CO_(2)fluxes in the sunflower field[1035.13 g/(m^(2).yr)]were significantly lower than those in the maize field[1405.54 g/(m^(2).yr)].An increase in nitrogen fertilization rate led to a significant escalation in soil CO_(2)fluxes.Moreover,elevating irrigation rates for washing salts by irrigation(WSBI)diminished soil CO_(2)fluxes in the sunflower field while amplifying them in the maize field.A rise in air temperature resulted in an increase in soil CO_(2)fluxes from the maize field,with annual increases observed,but a reduction in soil CO_(2)fluxes from the sunflower field.The sunflower fields in the HID have a more substantial advantage than the corn fields in mitigating soil CO_(2)emissions.展开更多
The SiO_(2) inverse opal photonic crystals(PC)with a three-dimensional macroporous structure were fabricated by the sacrificial template method,followed by infiltration of a pyrene derivative,1-(pyren-8-yl)but-3-en-1-...The SiO_(2) inverse opal photonic crystals(PC)with a three-dimensional macroporous structure were fabricated by the sacrificial template method,followed by infiltration of a pyrene derivative,1-(pyren-8-yl)but-3-en-1-amine(PEA),to achieve a formaldehyde(FA)-sensitive and fluorescence-enhanced sensing film.Utilizing the specific Aza-Cope rearrangement reaction of allylamine of PEA and FA to generate a strong fluorescent product emitted at approximately 480 nm,we chose a PC whose blue band edge of stopband overlapped with the fluorescence emission wavelength.In virtue of the fluorescence enhancement property derived from slow photon effect of PC,FA was detected highly selectively and sensitively.The limit of detection(LoD)was calculated to be 1.38 nmol/L.Furthermore,the fast detection of FA(within 1 min)is realized due to the interconnected three-dimensional macroporous structure of the inverse opal PC and its high specific surface area.The prepared sensing film can be used for the detection of FA in air,aquatic products and living cells.The very close FA content in indoor air to the result from FA detector,the recovery rate of 101.5%for detecting FA in aquatic products and fast fluorescence imaging in 2 min for living cells demonstrate the reliability and accuracy of our method in practical applications.展开更多
Due to the development of cloud computing and machine learning,users can upload their data to the cloud for machine learning model training.However,dishonest clouds may infer user data,resulting in user data leakage.P...Due to the development of cloud computing and machine learning,users can upload their data to the cloud for machine learning model training.However,dishonest clouds may infer user data,resulting in user data leakage.Previous schemes have achieved secure outsourced computing,but they suffer from low computational accuracy,difficult-to-handle heterogeneous distribution of data from multiple sources,and high computational cost,which result in extremely poor user experience and expensive cloud computing costs.To address the above problems,we propose amulti-precision,multi-sourced,andmulti-key outsourcing neural network training scheme.Firstly,we design a multi-precision functional encryption computation based on Euclidean division.Second,we design the outsourcing model training algorithm based on a multi-precision functional encryption with multi-sourced heterogeneity.Finally,we conduct experiments on three datasets.The results indicate that our framework achieves an accuracy improvement of 6%to 30%.Additionally,it offers a memory space optimization of 1.0×2^(24) times compared to the previous best approach.展开更多
This paper deeply discusses the causes of gear howling noise,the identification and analysis of multi-source excitation,the transmission path of dynamic noise,simulation and experimental research,case analysis,optimiz...This paper deeply discusses the causes of gear howling noise,the identification and analysis of multi-source excitation,the transmission path of dynamic noise,simulation and experimental research,case analysis,optimization effect,etc.,aiming to better provide a certain guideline and reference for relevant researchers.展开更多
The eutrophication of rivers and lakes is becoming increasingly common,primarily because of pollution from agricultural non-point sources.We investigated the effects of optimized water and fertilizer treatments on agr...The eutrophication of rivers and lakes is becoming increasingly common,primarily because of pollution from agricultural non-point sources.We investigated the effects of optimized water and fertilizer treatments on agricultural non-point source pollution in the Nansi Lake basin.The water heat carbon nitrogen simulator model(WHCNS model)was used to analyze water and nitrogen transport in wheat fields in Nansi Lake basin.Four water and fertilizer treatments were set up:conventional fertilization and irrigation(CK),reduced controlled-release fertilizer and conventional irrigation(F2W1),an equal amount of controlled-release fertilizer and reduced irrigation(F1W2),and reduced controlled-release fertilizer and reduced irrigation(F2W2).The results indicated that the replacement of conventional fertilizers with controlled-release fertilizers,combined with reduced irrigation,led to reduced nitrogen loss.Compared with those of the CK,the cumulative nitrogen leaching and ammonia volatilization of F2W1 were reduced by 8.90 and 41.67%,respectively;under F1W2,the same parameters were reduced by 12.50 and 15.99%,respectively.Compared with the other treatments,F2W2 significantly reduced nitrogen loss while producing a stable yield.Compared with those of the CK,ammonia volatilization and nitrogen loss due to leaching were reduced by 29.17 and 27.13%,respectively,water and nitrogen use efficiencies increased by 11.38 and 17.80%,respectively.F2W2 showed the best performance among the treatments,considering water and fertilizer management.Our findings highlight the effectiveness of optimizing water and fertilizer application in improving the water and nitrogen use efficiency of wheat,which is of great significance for mitigating nitrogen loss from farmland in the Nansi Lake basin.展开更多
Improving cotton fiber quality can increase the economic income of cotton farmers, but achieving high fiber quality without decreasing cotton fiber yield remains a major challenge in saline-alkaline cotton fields. A f...Improving cotton fiber quality can increase the economic income of cotton farmers, but achieving high fiber quality without decreasing cotton fiber yield remains a major challenge in saline-alkaline cotton fields. A field experiment was conducted in 2020 and 2021 on saline-alkaline soil with cotton under drip irrigation to examine how amount and timing of leaching affected soils salinity, cotton fiber yield and quality. There were five leaching amounts(CK: 0 mm, W1: 75 mm, W2: 150 mm, W3: 225 mm and W4: 300 mm) and three leaching timings(T1: once at the seedling stage, T2: twice at the seedling and budding stages, and T3: thrice at the seedling, budding and pollen-setting stages). Soil salinity, soil nitrate nitrogen(NO_(3)-N), cotton nitrogen(N) uptake, irrigation water productivity(IWP), cotton fiber yield, fiber length, fiber uniformity, fiber strength, fiber elongation, micronaire and fiber quality index(FQI) were investigated. The results indicated that soil salinity and NO_(3)-N reduced with increasing leaching amount. The N uptake of cotton bolls was greater than in cotton leaves, stems and roots, and total N accumulation increased with increasing leaching amount. The optimal cotton fiber yield and IWP occurred in treatment W3T2, and were 3,199 and 2,771 kg ha^(-1), and 0.5482 and 0.4912 kg m-3in 2020 and 2021, respectively. Fiber length, strength, elongation, and uniformity increased with increasing leaching amount, while there was a negative relationship between fiber micronaire and leaching amount. Soil salinity, NO_(3)-N and fiber micronaire were negatively correlated with fiber quality(i.e., length, strength, elongation and uniformity) and yield, nitrogen uptake of various organs(i.e., root, stems and leaves) and whole plant nitrogen uptake. Pearson correlation analysis revealed that fiber elongation was most sensitive to soil salinity. The method of Entropy–Order Preference by Similarity to Ideal Solution(EM–TOPSIS) indicated that leaching of 300 mm of water applied equally at the seedling and budding periods was the optimal treatment to maintain soil salinity and nutrient levels and achieve high cotton fiber yield and quality. In conclusion, the optimal level of leaching treatment decreased soil salinity and improved nitrogen uptake and was beneficial to achieve high fiber yield and quality. Our results will be significant for guiding drip irrigation practice of leaching on saline-alkaline soils for sustainable cotton fiber production.展开更多
Greenhouse planting is a key method for increasing the yield of agricultural products in China.The Academy of Agricultural Sciences has conducted extensive research on the water requirements of greenhouse crops during...Greenhouse planting is a key method for increasing the yield of agricultural products in China.The Academy of Agricultural Sciences has conducted extensive research on the water requirements of greenhouse crops during various growth stages.Studies indicate that crops in the germination stage,seedling stage,and other stages of their growth cycle have different water needs.Proper irrigation can significantly enhance both crop quality and yield.To apply the Academy of Agricultural Sciences’expertise on irrigation during different growth stages to practical farming,and to avoid improper irrigation at specific stages that could reduce crop production and quality,our team has designed an intelligent irrigation system for agricultural greenhouses.This system adapts to the growth patterns of crops by establishing an irrigation model based on characteristic images of each growth stage and irrigation data provided by the Academy.Using image recognition technology,the system accurately identifies the growth stage of crops.It then employs a pre-set irrigation curve and data from humidity sensors to execute precise irrigation through a closed-loop Proportion-Integral-Differential(PID)control system.This ensures optimal water management,leading to improved crop quality and yield.展开更多
Taking the Ming Tombs Forest Farm in Beijing as the research object,this research applied multi-source data fusion and GIS heat-map overlay analysis techniques,systematically collected bird observation point data from...Taking the Ming Tombs Forest Farm in Beijing as the research object,this research applied multi-source data fusion and GIS heat-map overlay analysis techniques,systematically collected bird observation point data from the Global Biodiversity Information Facility(GBIF),population distribution data from the Oak Ridge National Laboratory(ORNL)in the United States,as well as information on the composition of tree species in suitable forest areas for birds and the forest geographical information of the Ming Tombs Forest Farm,which is based on literature research and field investigations.By using GIS technology,spatial processing was carried out on bird observation points and population distribution data to identify suitable bird-watching areas in different seasons.Then,according to the suitability value range,these areas were classified into different grades(from unsuitable to highly suitable).The research findings indicated that there was significant spatial heterogeneity in the bird-watching suitability of the Ming Tombs Forest Farm.The north side of the reservoir was generally a core area with high suitability in all seasons.The deep-aged broad-leaved mixed forests supported the overlapping co-existence of the ecological niches of various bird species,such as the Zosterops simplex and Urocissa erythrorhyncha.In contrast,the shallow forest-edge coniferous pure forests and mixed forests were more suitable for specialized species like Carduelis sinica.The southern urban area and the core area of the mausoleums had relatively low suitability due to ecological fragmentation or human interference.Based on these results,this paper proposed a three-level protection framework of“core area conservation—buffer zone management—isolation zone construction”and a spatio-temporal coordinated human-bird co-existence strategy.It was also suggested that the human-bird co-existence space could be optimized through measures such as constructing sound and light buffer interfaces,restoring ecological corridors,and integrating cultural heritage elements.This research provided an operational technical approach and decision-making support for the scientific planning of bird-watching sites and the coordination of ecological protection and tourism development.展开更多
Numerous steep slopes resulting from infrastructure construction drastically affect ecological landscapes.The vegetation concrete(VC)ecological slope protection method efficiently rehabilitates slope ecosystems.Despit...Numerous steep slopes resulting from infrastructure construction drastically affect ecological landscapes.The vegetation concrete(VC)ecological slope protection method efficiently rehabilitates slope ecosystems.Despite advancements in the construction process,the standard irrigation maintenance method for slope vegetation remains unspecified.Three principal factors affecting VC water diffusion from production to application are:site conditions,irrigation design parameters,and substrate preparation standards.This study employed an energy-efficient porous ceramic emitter in buried irrigation equipment to investigate the effect of slope,water head,and bulk density on water diffusion patterns,analyzing both apparent and fine-scale dynamics through laboratory experiments and numerical simulations.The results demonstrated a positive correlation between slope and water head with the distance of wetted front.However,bulk density showed a negative correlation.The power function exhibited optimal fitting for wetted front advancement over time,with the'power0-type'function most precisely representing the VC wetted front movement(R2>0.99).The water content,utilized to assess the precision of the HYDRUS simulation grounded in the van Genuchten model and the centrifuge method(p<0.05),exhibited discrepancies with the wetted front while revealing a robust logistic correlation with irrigation duration.The root-mean-square error,mean absolute error,and percent bias between the observed and simulated water contents were 0.85%,0.74%,and-3.50%,respectively.The VC soil hydrodynamic parameters,specifically the inverse of the intake suction,the pore-size distribution exponent,and the shape factor,were quantified as 0.019,1.329,and 0.248,respectively.Water head significantly influenced water transport more than slope;yet,irrespective of their combination,extended irrigation generally intensified the'instability'of water diffusion.To regulate slope substrate moisture through water diffusion in practical conditions,it is advisable to prioritize the modification of VC preparations,followed by the design of an appropriate irrigation pressure,and finally the selection of an optimal location for the irrigator's deployment.The findings of water diffusion through a semi-rigid composite substrate broaden the applicability of soil hydrodynamics theory to composite soils and enhance its implications through conceptual and practical advice.展开更多
Understanding the infiltration process and quantifying recharge are critical for effective water resources management,particularly in arid and semi-arid regions.However,factors influencing on recharge process under di...Understanding the infiltration process and quantifying recharge are critical for effective water resources management,particularly in arid and semi-arid regions.However,factors influencing on recharge process under different land use types in irrigation districts remain unclear.In this study,a Brilliant Blue FCF dye tracer experiment was conducted to investigate infiltration pathways under the cotton field,pear orchard,and bare land conditions in the Kongque Rive Irrigation District of Xinjiang,China.Recharge rates were estimated using the chloride mass balance method.The results show that the average preferential flow ratio was highest in the bare land(50.42%),followed by the cotton field(30.09%)and pear orchard(23.59%).Matrix flow was the dominant infiltration pathway in the pear orchard and cotton field.Irrigation method was a primary factor influencing recharge rates,with surface irrigation promoting deeper infiltration compared to drip irrigation.Under the drip irrigation mode,the recharge of cotton fields ranged from 23.47 mm/a to 59.16 mm/a.In comparison,the recharge of surface irrigation in pear orchards contributed between 154.30 mm/a and 401.65 mm/a.These findings provide valuable insights into soil water infiltration and recharge processes under typical land use conditions in the Kongque River Irrigation District,supporting improved irrigation management and sustainable water resource utilization.展开更多
BACKGROUND Gastric cancer(GC)is one of the most common malignancies and types of cancer worldwide.AIM To compare the differences in tumor markers of GC with GC dissection,we evaluated the efficacy of recent tumor remo...BACKGROUND Gastric cancer(GC)is one of the most common malignancies and types of cancer worldwide.AIM To compare the differences in tumor markers of GC with GC dissection,we evaluated the efficacy of recent tumor removal.METHODS A prospective cohort study was conducted to analyze the clinical data of patients with GC.Patients were divided into two groups based on the surgical approach:The membrane dissection(MD)group,which underwent membrane-guided laparoscopic radical gastrectomy with D2 lymph node dissection plus complete mesocolic excision,and the D2 group,which underwent traditional laparoscopic radical gastrectomy with D2 lymph node dissection.Abdominal lavage fluid was collected pre-and postoperatively from patients in both groups.The expression of carcinoembryonic antigen(CEA)and cytokeratin-19(CK-19)message RNAs in the abdominal lavage fluid was detected using reverse transcription polymerase chain reaction.The factors influencing the increase of the tumor markers were analyzed,and the short-term efficacy of the two surgery types was compared.RESULTS In total,135 eligible patients were included in this study,with 69 and 66 cases in the MD and D2 groups,respectively.Fourteen patients with benign gastric lesions were selected to detect tumor marker expression.After excluding patients positive for preoperative cancer leakage,we found that 9.52%and 26.67%of patients in the MD and D2 groups developed postoperative CEA positivity,respectively.Multivariate analysis revealed that the degree of differentiation and surgical approach were independent risk factors for postoperative CEA positivity.The surgical approach was an independent risk factor affecting postoperative CK-19 positivity and postoperative CEA and CK-19 positivity.Surgical time,intraoperative blood loss,number of lymph nodes dissected,time to first postoperative flatus,and time to first liquid intake were all significantly different between the two surgical approaches.There were no significant differences in the incision length,duration of postoperative hospital stays,or postoperative complications.CONCLUSION MD is a better radical surgical treatment than traditional D2 surgery and is worthy of further clinical promotion and application.展开更多
Drought is one of the most severe environmental stresses affecting soybean growth and development,especially in arid and semi-arid areas.The aim of this experiment is to evaluate the effect of regulated deficit irriga...Drought is one of the most severe environmental stresses affecting soybean growth and development,especially in arid and semi-arid areas.The aim of this experiment is to evaluate the effect of regulated deficit irrigation during the vegetative stages on soybean plants and determine the amount irrigation water can be reduced without affecting the physiological parameters,the crop phenology,and the yield of the soybean crop.The field experiments were conducted during two irrigation crop seasons(2021 and 2022)in Louata,Morocco.The results showed that regulated deficit irrigation regimes during the vegetative stages was combined with high temperatures and low air humidities during the beginning of flowering and the pod filling stage during 2021 in comparison with 2022,especially for 25%CWR(crop water requirements).Regulated deficit irrigation regimes reduced the stomatal conductance by 46%and 52%respectively during the first and second growing seasons by limiting CO_(2) intake for the Calvin cycle.The stomata closure increased the leaf temperature and affected the functioning of the photosynthetic apparatus by damaging the chlorophyll pigments and impairment of electron transport chains in chloroplasts.The transition from regulated deficit irrigation to 100%CWR at the beginning of flowering(R1)compensated for the photosynthetic loss,improved the growth and development of soybean plants and enhanced the yield and its components for 50%and 75%CWR.The adaptative mechanism such as the remobilization of the carbon reserved in the stems and leaves(vegetative tissues)to the grains improved the grain yield by 36.7%during 2021 and by 32.2%during 2022 and.This consequently improved the water use efficiency,the water productivity of soybean for 50%and 75%CWR and contributed to water saving with an average of 60 mm per growing season.展开更多
基金National Natural Science Foundation of China,No.52379053,No.52022108The Key Research Project of Science and Technology in Inner Mongolia Autonomous Region of China,No.NMKJXM202208,No.NMKJXM202301The Project Funded by the Water Resources Department of Inner Mongolia Autonomous Region of China,No.NSK202103。
文摘Accurate spatio-temporal land cover information in agricultural irrigation districts is crucial for effective agricultural management and crop production.Therefore,a spectralphenological-based land cover classification(SPLC)method combined with a fusion model(flexible spatiotemporal data fusion,FSDAF)(abbreviated as SPLC-F)was proposed to map multi-year land cover and crop type(LC-CT)distribution in agricultural irrigated areas with complex landscapes and cropping system,using time series optical images(Landsat and MODIS).The SPLC-F method was well validated and applied in a super-large irrigated area(Hetao)of the upper Yellow River Basin(YRB).Results showed that the SPLC-F method had a satisfactory performance in producing long-term LC-CT maps in Hetao,without the requirement of field sampling.Then,the spatio-temporal variation and the driving factors of the cropping systems were further analyzed with the aid of detailed household surveys and statistics.We clarified that irrigation and salinity conditions were the main factors that had impacts on crop spatial distribution in the upper YRB.Investment costs,market demand,and crop price are the main driving factors in determining the temporal variations in cropping distribution.Overall,this study provided essential multi-year LC-CT maps for sustainable management of agriculture,eco-environments,and food security in the upper YRB.
基金supported by the National Natural Science Foundation of China(Nos.42177333 and 31870500)the National Special Program for Key Basic Research of the Ministry of Science and Technology of China(No.2015FY110700)the Jiangsu Agriculture Science and Technology Innovation Fund,China(No.JASTIFCX(20)2003)。
文摘Both straw incorporation and irrigation practices affect biological nitrogen(N)fixation(BNF),but it is still unclear how straw incorporation impacts BNF under continuous(CFI)or intermittent(IFI)flooding irrigation in a rice cropping system.A15N2-labeling chamber system was placed in a rice field to evaluate BNF with straw incorporation under CFI or IFI for 90 d.The nif H(gene encoding the nitrogenase reductase subunit)DNA and c DNA in soil were amplified using real-time quantitative polymerase chain reaction,and high-throughput sequencing was applied to the nif H gene.The total fixed N in the straw incorporation treatment was 14.3 kg ha^(-1)under CFI,being 116%higher than that under IFI(6.62 kg ha^(-1)).Straw incorporation and CFI showed significant interactive effects on the total fixed N and abundances of nif H DNA and c DNA.The increase in BNF was mainly due to the increase in the abundances of heterotrophic diazotrophs such as Desulfovibrio,Azonexus,and Azotobacter.These results indicated that straw incorporation stimulated BNF under CFI relative to IFI,which might ultimately lead to a rapid enhancement of soil fertility.
基金National Natural Science Foundation of China(52269011,52469008)。
文摘Sediment particles,as one of the key components of drip irrigation technology,significantly affect the service life of emitters and restrict the popularization of drip irrigation technology.Hence,two types of patch drip irrigation emitters,focusing on the anti-clogging performance through the experiment,were investigated.The dynamic variations in the clogging characteristics of emitters,specifically were subjected to statistical analysis.The movement mechanism of emitter clogging and discharging sediment was studied.The effects of emitter structure and position factors on emitter clogging were analyzed.The results show that the pressure-compensated emitter exhibits superior anti-clogging perfor-mance,with a service life that is 227.8%greater than that of the labyrinth channel emitter.A single structural factor cannot completely evaluate the anti-clogging performance of emitters.All factors causing emitter clogging should be considered comprehensively.Emitters contain sensitive sediment prone to clogging,however,significant blockage occurs primarily when the sediment content is elevated.The discharge of sediment,denoted as V90,from the emitter is affected by the accumulative effect of clogged sediment.These results may offer valuable insights for the application and advancement of drip irrigation technology.
文摘Irrigated agriculture in Cameroon is practiced on a large scale by large private firms and parastatals, and on a small scale by individual producers in different production areas of the country. Although small-scale irrigation can supply local and sub-regional markets with food in the off-season, it has received little research and its challenges are therefore rarely addressed. In order to contribute to the knowledge of these small-scale irrigation systems, with a view to improving their structure and the management of irrigation water and energy, an assessment of small-scale irrigation in the southern slopes of the Bamboutos Mountains has been done. After direct observations, field measurements, surveys of 100 irrigators with questionnaires and interviews with administrative managers, analyses were carried out using Xlstat software. It was found out that about 226 small-scale irrigation systems designed and managed by producers have been installed on this slope between the end of December 2022 and mid-March 2023. Intended for market garden crops, 84.96% of these irrigation systems use sprinklers and 15.04% surface irrigation (furrow irrigation). Surface or underground water is mobilized using gravity (50%), fossil fuels (34.51%), electricity (14.6%) or solar energy (0.9%). Sprinkler irrigation is mainly carried out using locally manufactured hydraulic turnstiles. There is a lack of formal associations of irrigators in an environment marked by conflicts between water users, when there is not allocation for water withdrawal. Apart from the high cost of pumping energy ($1.32 per liter of fuel), the main constraint identified, which has become more acute over the years, is the lack of irrigation water during the water shortage period (from mid-January to mid-March). These constraints have led to a transition from surface irrigation to sprinkler irrigation, and the adoption of new energy supply and water mobilization technologies. The construction of collective surface and groundwater catchment structures with solar-powered pumping systems, the setting up of formal irrigators’ associations and an irrigation support service, could improve the availability of water throughout the irrigation season, thereby helping to improve the income generated by irrigated market-garden farming on the southern slopes of the Bamboutos Mountains.
基金Supported by Key Research and Development Program of Shanxi Province(202302140601009).
文摘Moistube irrigation is a newly-developed irrigation technique that utilizes a semipermeable membrane to release water slowly and continuously into the plant root zone.Alternate Moistube Irrigation(AMI)is a combination of alternative irrigation and moistube irrigation.In order to investigate the effects of AMI on plant growth,greenhouse experiments were conducted on spinach(Spinacia oleracea)and water spinach(Ipomoea aquatica)plants at different time.We measured soil water content at a depth of 20 cm in the planting boxes,and also determined seed emergence rate,plant height,largest leaf area,fresh weight per plant,yield,and irrigation water productivity(IWP)for both spinach and water spinach.The results showed that the AMI treatments had significantly higher soil water content than the conventional surface irrigation control(CK).The emergence rates of spinach and water spinach were significantly higher in the AMI treatments than in the CK,and the plant height,largest leaf area,and fresh weight during the middle and late stages of spinach and water spinach growth were also significantly higher than those of the CK.Both spinach and water spinach grew well and produced high yield with high IWP under AMI with a high water head pressure of 1.5 m at tube spacing of 20 or 30 cm.We found that AMI with a suitable combination of head pressure and tube spacing can promote plant growth and increase yield and IWP under controlled conditions.
文摘Integrating sprinkler with deficit irrigation system is a new approach to improve crop water productivity and ensure water and food security in arid areas of India.This study undertook a field experiment of sprinkler-irrigated cumin(variety GC-4)with a mini-lysimeter setup at an experimental research farm in Jodhpur,India during 2019-2022.Four irrigation treatments T_(1),T_(2),T_(3),and T4 were designed at irrigation water/cumulative pan evaporation(IW/CPE)of 1.0,0.8,0.6,and 0.4,respectively,with three replications.Daily actual crop evapotranspiration(ETc)was recorded and weekly soil moisture was monitored over the crop growth period.Quantities of applied water and drainage from mini-lysimeters were also measured at every irrigation event.Yield of cumin was recorded at crop maturity.Furthermore,change in farmer's net income from 1-hm2 land was computed based on the cost of applying irrigation water and considering yield variations among the treatments.Results indicated the highest mean seasonal actual ETc(371.7 mm)and cumin yield(952.47 kg/hm2)under T_(1)(with full irrigation).Under T_(2),T_(3),and T4,the seasonal actual ETc decreased by 10.4%,27.6%,and 41.3%,respectively,while yield declined by 5.0%,28.4%,and 50.8%,respectively,as compared to the values under T_(1).Furthermore,crop water productivity of 0.272(±0.068)kg/m3 under T_(2)was found relatively higher in comparison to other irrigation treatments,indicating that T_(2)can achieve improved water productivity of cumin in arid areas at an optimum level of deficit irrigation.The results of cost-economics indicated that positive change in farmer's net income from 1-hm2 land was 108.82 USD under T_(2),while T_(3)and T4 showed net losses of 5.33 and 209.67 USD,respectively.Moreover,value of yield response factor and ratio of relative yield reductions to relative ETc deficits were found to be less than 1.00 under T_(2)(0.48),and more than 1.00 under T_(3)(1.07)and T4(1.23).This finding further supports that T_(2)shows the optimized level of deficit irrigation that saves 20.0%of water with sacrificing 5.0%yield in the arid areas of India.Findings of this study provide useful strategies to save irrigation water,bring additional area under irrigation,and improve crop water productivity in India and other similar arid areas in the world.
基金funded by the National Key R&D Program of China (2022YFD1900405)。
文摘In recent years, the rational utilization of saline water resources for agricultural irrigation has emerged as an effective strategy to alleviate water scarcity. To safely and efficiently exploit saline water resources over the long term, it is crucial to understand the effects of salinity on crops and develop optimal water-salinity irrigation strategies for processing tomatoes. A two-year field experiment was conducted in 2018 and 2019 to explore the impact of water salinity levels(S1: 1 g L^(–1), S2: 3 g L^(–1), and S3: 5 g L^(–1)) and irrigation amounts(W1: 305 mm, W2: 485 mm, and W3: 611 mm) on the soil volumetric water content and soil salinity, as well as processing tomato growth, yield, and water use efficiency. The results showed that irrigation with low to moderately saline water(<3 g L^(–1)) enhanced plant wateruptake and utilization capacity, with the soil water content(SWC) reduced by 6.5–7.62% and 10.52–13.23% for the S1 and S2 levels, respectively, compared to the S3 level in 2018. Under S1 condition, the soil salt content(SSC) accumulation rate gradually declined with an increase in the irrigation amount. For example, W3 decreased by 85.00 and 77.94% compared with W1 and W2 in 2018, and by 82.60 and 73.68% in 2019, respectively. Leaching effects were observed at the W3 level under S1, which gradually diminished with increasing water salinity and duration. In 2019, the salt contents of soil under each of the treatments increased by 10.81–89.72% compared with the contents in 2018. The yield of processing tomatoes increased with an increasing irrigation amount and peaked in the S1W3 treatment for the two years, reaching 125,304.85 kg ha^(–1)in 2018 and 128,329.71 kg ha^(–1)in 2019. Notably, in the first year, the S2W3 treatment achieved relatively high yields, exhibiting only a 2.85% reduction compared to the S1W3 treatment. However, the yield of the S2W3 treatment declined significantly in two years, and it was 15.88% less than that of the S1W3 treatment. Structural equation modeling(SEM) revealed that soil environmental factors(SWC and SSC) directly influence yield while also exerting indirect impacts on the growth indicators of processing tomatoes(plant height, stem diameter, and leaf area index). The TOPSIS method identified S1W3, S1W2, and S2W2 as the top three treatments. The single-factor marginal effect function also revealed that irrigation water salinity contributed to the composite evaluation scores(CES) when it was below 0.96 g L^(–1). Using brackish water with a salinity of 3 g L^(–1)at an irrigation amount of 485 mm over one year ensured that processing tomatoes maintained high yields with a relatively high CES(0.709). However, using brackish water for more than one year proved unfeasible.
基金supported by the National Key R&D Program of China(No.2023YFB2603602)the National Natural Science Foundation of China(Nos.52222810 and 52178383).
文摘To elucidate the fracturing mechanism of deep hard rock under complex disturbance environments,this study investigates the dynamic failure behavior of pre-damaged granite subjected to multi-source dynamic disturbances.Blasting vibration monitoring was conducted in a deep-buried drill-and-blast tunnel to characterize in-situ dynamic loading conditions.Subsequently,true triaxial compression tests incorporating multi-source disturbances were performed using a self-developed wide-low-frequency true triaxial system to simulate disturbance accumulation and damage evolution in granite.The results demonstrate that combined dynamic disturbances and unloading damage significantly accelerate strength degradation and trigger shear-slip failure along preferentially oriented blast-induced fractures,with strength reductions up to 16.7%.Layered failure was observed on the free surface of pre-damaged granite under biaxial loading,indicating a disturbance-induced fracture localization mechanism.Time-stress-fracture-energy coupling fields were constructed to reveal the spatiotemporal characteristics of fracture evolution.Critical precursor frequency bands(105-150,185-225,and 300-325 kHz)were identified,which serve as diagnostic signatures of impending failure.A dynamic instability mechanism driven by multi-source disturbance superposition and pre-damage evolution was established.Furthermore,a grouting-based wave-absorption control strategy was proposed to mitigate deep dynamic disasters by attenuating disturbance amplitude and reducing excitation frequency.
基金Supported by Natural Science Foundation of the Inner Mongolia Autonomous Region(2020MS04001)Inner Mongolia Autonomous Region Science and Technology Program Project+1 种基金Hetao College Science and Technology Research Project(HYYB202303)Hetao College Science and Technology Innovation Team.
文摘A growing global demand exists to formulate plans to lessen the greenhouse gas emissions produced by agricultural activities.The purpose of this study was to uncovered the changes in soil CO_(2)fluxes under varying scenarios including nitrogen fertilization rates,irrigation rates,and air temperatures in the Hetao Irrigation District(HID)over the 38-year period.DAYCENT model was used to predict carbon dioxide(CO_(2))fluxes from cultivated soils in the HID,Inner Mongolia from^(2)023 to 2060(the year of achieving the"carbon neutrality"goal)in this study.Results showed that mean soil CO_(2)fluxes in the sunflower field[1035.13 g/(m^(2).yr)]were significantly lower than those in the maize field[1405.54 g/(m^(2).yr)].An increase in nitrogen fertilization rate led to a significant escalation in soil CO_(2)fluxes.Moreover,elevating irrigation rates for washing salts by irrigation(WSBI)diminished soil CO_(2)fluxes in the sunflower field while amplifying them in the maize field.A rise in air temperature resulted in an increase in soil CO_(2)fluxes from the maize field,with annual increases observed,but a reduction in soil CO_(2)fluxes from the sunflower field.The sunflower fields in the HID have a more substantial advantage than the corn fields in mitigating soil CO_(2)emissions.
基金supported by the National Natural Science Foundation of China(21663032 and 22061041)the Open Sharing Platform for Scientific and Technological Resources of Shaanxi Province(2021PT-004)the National Innovation and Entrepreneurship Training Program for College Students of China(S202110719044)。
文摘The SiO_(2) inverse opal photonic crystals(PC)with a three-dimensional macroporous structure were fabricated by the sacrificial template method,followed by infiltration of a pyrene derivative,1-(pyren-8-yl)but-3-en-1-amine(PEA),to achieve a formaldehyde(FA)-sensitive and fluorescence-enhanced sensing film.Utilizing the specific Aza-Cope rearrangement reaction of allylamine of PEA and FA to generate a strong fluorescent product emitted at approximately 480 nm,we chose a PC whose blue band edge of stopband overlapped with the fluorescence emission wavelength.In virtue of the fluorescence enhancement property derived from slow photon effect of PC,FA was detected highly selectively and sensitively.The limit of detection(LoD)was calculated to be 1.38 nmol/L.Furthermore,the fast detection of FA(within 1 min)is realized due to the interconnected three-dimensional macroporous structure of the inverse opal PC and its high specific surface area.The prepared sensing film can be used for the detection of FA in air,aquatic products and living cells.The very close FA content in indoor air to the result from FA detector,the recovery rate of 101.5%for detecting FA in aquatic products and fast fluorescence imaging in 2 min for living cells demonstrate the reliability and accuracy of our method in practical applications.
基金supported by Natural Science Foundation of China(Nos.62303126,62362008,author Z.Z,https://www.nsfc.gov.cn/,accessed on 20 December 2024)Major Scientific and Technological Special Project of Guizhou Province([2024]014)+2 种基金Guizhou Provincial Science and Technology Projects(No.ZK[2022]General149) ,author Z.Z,https://kjt.guizhou.gov.cn/,accessed on 20 December 2024)The Open Project of the Key Laboratory of Computing Power Network and Information Security,Ministry of Education under Grant 2023ZD037,author Z.Z,https://www.gzu.edu.cn/,accessed on 20 December 2024)Open Research Project of the State Key Laboratory of Industrial Control Technology,Zhejiang University,China(No.ICT2024B25),author Z.Z,https://www.gzu.edu.cn/,accessed on 20 December 2024).
文摘Due to the development of cloud computing and machine learning,users can upload their data to the cloud for machine learning model training.However,dishonest clouds may infer user data,resulting in user data leakage.Previous schemes have achieved secure outsourced computing,but they suffer from low computational accuracy,difficult-to-handle heterogeneous distribution of data from multiple sources,and high computational cost,which result in extremely poor user experience and expensive cloud computing costs.To address the above problems,we propose amulti-precision,multi-sourced,andmulti-key outsourcing neural network training scheme.Firstly,we design a multi-precision functional encryption computation based on Euclidean division.Second,we design the outsourcing model training algorithm based on a multi-precision functional encryption with multi-sourced heterogeneity.Finally,we conduct experiments on three datasets.The results indicate that our framework achieves an accuracy improvement of 6%to 30%.Additionally,it offers a memory space optimization of 1.0×2^(24) times compared to the previous best approach.
文摘This paper deeply discusses the causes of gear howling noise,the identification and analysis of multi-source excitation,the transmission path of dynamic noise,simulation and experimental research,case analysis,optimization effect,etc.,aiming to better provide a certain guideline and reference for relevant researchers.
基金supported by the National Key Research and Development Program of China(2018YFD0800303)the Major Science and Technology Innovation Projects in Shandong Province,China(2021CXGC010804).
文摘The eutrophication of rivers and lakes is becoming increasingly common,primarily because of pollution from agricultural non-point sources.We investigated the effects of optimized water and fertilizer treatments on agricultural non-point source pollution in the Nansi Lake basin.The water heat carbon nitrogen simulator model(WHCNS model)was used to analyze water and nitrogen transport in wheat fields in Nansi Lake basin.Four water and fertilizer treatments were set up:conventional fertilization and irrigation(CK),reduced controlled-release fertilizer and conventional irrigation(F2W1),an equal amount of controlled-release fertilizer and reduced irrigation(F1W2),and reduced controlled-release fertilizer and reduced irrigation(F2W2).The results indicated that the replacement of conventional fertilizers with controlled-release fertilizers,combined with reduced irrigation,led to reduced nitrogen loss.Compared with those of the CK,the cumulative nitrogen leaching and ammonia volatilization of F2W1 were reduced by 8.90 and 41.67%,respectively;under F1W2,the same parameters were reduced by 12.50 and 15.99%,respectively.Compared with the other treatments,F2W2 significantly reduced nitrogen loss while producing a stable yield.Compared with those of the CK,ammonia volatilization and nitrogen loss due to leaching were reduced by 29.17 and 27.13%,respectively,water and nitrogen use efficiencies increased by 11.38 and 17.80%,respectively.F2W2 showed the best performance among the treatments,considering water and fertilizer management.Our findings highlight the effectiveness of optimizing water and fertilizer application in improving the water and nitrogen use efficiency of wheat,which is of great significance for mitigating nitrogen loss from farmland in the Nansi Lake basin.
基金financially supported by the National Key Research and Development Program of China (2022YFD1900401)the Science and Technology Project of Agriculture, Xinjiang Production and Construction Corps, China (2021AB037)。
文摘Improving cotton fiber quality can increase the economic income of cotton farmers, but achieving high fiber quality without decreasing cotton fiber yield remains a major challenge in saline-alkaline cotton fields. A field experiment was conducted in 2020 and 2021 on saline-alkaline soil with cotton under drip irrigation to examine how amount and timing of leaching affected soils salinity, cotton fiber yield and quality. There were five leaching amounts(CK: 0 mm, W1: 75 mm, W2: 150 mm, W3: 225 mm and W4: 300 mm) and three leaching timings(T1: once at the seedling stage, T2: twice at the seedling and budding stages, and T3: thrice at the seedling, budding and pollen-setting stages). Soil salinity, soil nitrate nitrogen(NO_(3)-N), cotton nitrogen(N) uptake, irrigation water productivity(IWP), cotton fiber yield, fiber length, fiber uniformity, fiber strength, fiber elongation, micronaire and fiber quality index(FQI) were investigated. The results indicated that soil salinity and NO_(3)-N reduced with increasing leaching amount. The N uptake of cotton bolls was greater than in cotton leaves, stems and roots, and total N accumulation increased with increasing leaching amount. The optimal cotton fiber yield and IWP occurred in treatment W3T2, and were 3,199 and 2,771 kg ha^(-1), and 0.5482 and 0.4912 kg m-3in 2020 and 2021, respectively. Fiber length, strength, elongation, and uniformity increased with increasing leaching amount, while there was a negative relationship between fiber micronaire and leaching amount. Soil salinity, NO_(3)-N and fiber micronaire were negatively correlated with fiber quality(i.e., length, strength, elongation and uniformity) and yield, nitrogen uptake of various organs(i.e., root, stems and leaves) and whole plant nitrogen uptake. Pearson correlation analysis revealed that fiber elongation was most sensitive to soil salinity. The method of Entropy–Order Preference by Similarity to Ideal Solution(EM–TOPSIS) indicated that leaching of 300 mm of water applied equally at the seedling and budding periods was the optimal treatment to maintain soil salinity and nutrient levels and achieve high cotton fiber yield and quality. In conclusion, the optimal level of leaching treatment decreased soil salinity and improved nitrogen uptake and was beneficial to achieve high fiber yield and quality. Our results will be significant for guiding drip irrigation practice of leaching on saline-alkaline soils for sustainable cotton fiber production.
文摘Greenhouse planting is a key method for increasing the yield of agricultural products in China.The Academy of Agricultural Sciences has conducted extensive research on the water requirements of greenhouse crops during various growth stages.Studies indicate that crops in the germination stage,seedling stage,and other stages of their growth cycle have different water needs.Proper irrigation can significantly enhance both crop quality and yield.To apply the Academy of Agricultural Sciences’expertise on irrigation during different growth stages to practical farming,and to avoid improper irrigation at specific stages that could reduce crop production and quality,our team has designed an intelligent irrigation system for agricultural greenhouses.This system adapts to the growth patterns of crops by establishing an irrigation model based on characteristic images of each growth stage and irrigation data provided by the Academy.Using image recognition technology,the system accurately identifies the growth stage of crops.It then employs a pre-set irrigation curve and data from humidity sensors to execute precise irrigation through a closed-loop Proportion-Integral-Differential(PID)control system.This ensures optimal water management,leading to improved crop quality and yield.
基金Sponsored by Beijing Youth Innovation Talent Support Program for Urban Greening and Landscaping——The 2024 Special Project for Promoting High-Quality Development of Beijing’s Landscaping through Scientific and Technological Innovation(KJCXQT202410).
文摘Taking the Ming Tombs Forest Farm in Beijing as the research object,this research applied multi-source data fusion and GIS heat-map overlay analysis techniques,systematically collected bird observation point data from the Global Biodiversity Information Facility(GBIF),population distribution data from the Oak Ridge National Laboratory(ORNL)in the United States,as well as information on the composition of tree species in suitable forest areas for birds and the forest geographical information of the Ming Tombs Forest Farm,which is based on literature research and field investigations.By using GIS technology,spatial processing was carried out on bird observation points and population distribution data to identify suitable bird-watching areas in different seasons.Then,according to the suitability value range,these areas were classified into different grades(from unsuitable to highly suitable).The research findings indicated that there was significant spatial heterogeneity in the bird-watching suitability of the Ming Tombs Forest Farm.The north side of the reservoir was generally a core area with high suitability in all seasons.The deep-aged broad-leaved mixed forests supported the overlapping co-existence of the ecological niches of various bird species,such as the Zosterops simplex and Urocissa erythrorhyncha.In contrast,the shallow forest-edge coniferous pure forests and mixed forests were more suitable for specialized species like Carduelis sinica.The southern urban area and the core area of the mausoleums had relatively low suitability due to ecological fragmentation or human interference.Based on these results,this paper proposed a three-level protection framework of“core area conservation—buffer zone management—isolation zone construction”and a spatio-temporal coordinated human-bird co-existence strategy.It was also suggested that the human-bird co-existence space could be optimized through measures such as constructing sound and light buffer interfaces,restoring ecological corridors,and integrating cultural heritage elements.This research provided an operational technical approach and decision-making support for the scientific planning of bird-watching sites and the coordination of ecological protection and tourism development.
基金supported by the National Natural Science Foundation of China(Grant No.41925030)the Nyingchi National Sustainable Development Experimental Zone Project(2023-SYQ-007)the Science and Technology Research Program of Institute of Mountain Hazards and Environment,Chinese Academy of Sciences(Grant No.IMHE-ZDRW-02)。
文摘Numerous steep slopes resulting from infrastructure construction drastically affect ecological landscapes.The vegetation concrete(VC)ecological slope protection method efficiently rehabilitates slope ecosystems.Despite advancements in the construction process,the standard irrigation maintenance method for slope vegetation remains unspecified.Three principal factors affecting VC water diffusion from production to application are:site conditions,irrigation design parameters,and substrate preparation standards.This study employed an energy-efficient porous ceramic emitter in buried irrigation equipment to investigate the effect of slope,water head,and bulk density on water diffusion patterns,analyzing both apparent and fine-scale dynamics through laboratory experiments and numerical simulations.The results demonstrated a positive correlation between slope and water head with the distance of wetted front.However,bulk density showed a negative correlation.The power function exhibited optimal fitting for wetted front advancement over time,with the'power0-type'function most precisely representing the VC wetted front movement(R2>0.99).The water content,utilized to assess the precision of the HYDRUS simulation grounded in the van Genuchten model and the centrifuge method(p<0.05),exhibited discrepancies with the wetted front while revealing a robust logistic correlation with irrigation duration.The root-mean-square error,mean absolute error,and percent bias between the observed and simulated water contents were 0.85%,0.74%,and-3.50%,respectively.The VC soil hydrodynamic parameters,specifically the inverse of the intake suction,the pore-size distribution exponent,and the shape factor,were quantified as 0.019,1.329,and 0.248,respectively.Water head significantly influenced water transport more than slope;yet,irrespective of their combination,extended irrigation generally intensified the'instability'of water diffusion.To regulate slope substrate moisture through water diffusion in practical conditions,it is advisable to prioritize the modification of VC preparations,followed by the design of an appropriate irrigation pressure,and finally the selection of an optimal location for the irrigator's deployment.The findings of water diffusion through a semi-rigid composite substrate broaden the applicability of soil hydrodynamics theory to composite soils and enhance its implications through conceptual and practical advice.
基金supported by the Hydrogeological Investigation Project in Kaidu River and Kongque River Basin in Xinjiang,China(No.DD2020171)the Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shaanxi Province(No.2020006).
文摘Understanding the infiltration process and quantifying recharge are critical for effective water resources management,particularly in arid and semi-arid regions.However,factors influencing on recharge process under different land use types in irrigation districts remain unclear.In this study,a Brilliant Blue FCF dye tracer experiment was conducted to investigate infiltration pathways under the cotton field,pear orchard,and bare land conditions in the Kongque Rive Irrigation District of Xinjiang,China.Recharge rates were estimated using the chloride mass balance method.The results show that the average preferential flow ratio was highest in the bare land(50.42%),followed by the cotton field(30.09%)and pear orchard(23.59%).Matrix flow was the dominant infiltration pathway in the pear orchard and cotton field.Irrigation method was a primary factor influencing recharge rates,with surface irrigation promoting deeper infiltration compared to drip irrigation.Under the drip irrigation mode,the recharge of cotton fields ranged from 23.47 mm/a to 59.16 mm/a.In comparison,the recharge of surface irrigation in pear orchards contributed between 154.30 mm/a and 401.65 mm/a.These findings provide valuable insights into soil water infiltration and recharge processes under typical land use conditions in the Kongque River Irrigation District,supporting improved irrigation management and sustainable water resource utilization.
基金Supported by Putian Science and Technology Plan Project,No.2022SY003.
文摘BACKGROUND Gastric cancer(GC)is one of the most common malignancies and types of cancer worldwide.AIM To compare the differences in tumor markers of GC with GC dissection,we evaluated the efficacy of recent tumor removal.METHODS A prospective cohort study was conducted to analyze the clinical data of patients with GC.Patients were divided into two groups based on the surgical approach:The membrane dissection(MD)group,which underwent membrane-guided laparoscopic radical gastrectomy with D2 lymph node dissection plus complete mesocolic excision,and the D2 group,which underwent traditional laparoscopic radical gastrectomy with D2 lymph node dissection.Abdominal lavage fluid was collected pre-and postoperatively from patients in both groups.The expression of carcinoembryonic antigen(CEA)and cytokeratin-19(CK-19)message RNAs in the abdominal lavage fluid was detected using reverse transcription polymerase chain reaction.The factors influencing the increase of the tumor markers were analyzed,and the short-term efficacy of the two surgery types was compared.RESULTS In total,135 eligible patients were included in this study,with 69 and 66 cases in the MD and D2 groups,respectively.Fourteen patients with benign gastric lesions were selected to detect tumor marker expression.After excluding patients positive for preoperative cancer leakage,we found that 9.52%and 26.67%of patients in the MD and D2 groups developed postoperative CEA positivity,respectively.Multivariate analysis revealed that the degree of differentiation and surgical approach were independent risk factors for postoperative CEA positivity.The surgical approach was an independent risk factor affecting postoperative CK-19 positivity and postoperative CEA and CK-19 positivity.Surgical time,intraoperative blood loss,number of lymph nodes dissected,time to first postoperative flatus,and time to first liquid intake were all significantly different between the two surgical approaches.There were no significant differences in the incision length,duration of postoperative hospital stays,or postoperative complications.CONCLUSION MD is a better radical surgical treatment than traditional D2 surgery and is worthy of further clinical promotion and application.
基金financially supported by Domaine Louata of Providence Verte Company,Agricultural Training and Research Center.
文摘Drought is one of the most severe environmental stresses affecting soybean growth and development,especially in arid and semi-arid areas.The aim of this experiment is to evaluate the effect of regulated deficit irrigation during the vegetative stages on soybean plants and determine the amount irrigation water can be reduced without affecting the physiological parameters,the crop phenology,and the yield of the soybean crop.The field experiments were conducted during two irrigation crop seasons(2021 and 2022)in Louata,Morocco.The results showed that regulated deficit irrigation regimes during the vegetative stages was combined with high temperatures and low air humidities during the beginning of flowering and the pod filling stage during 2021 in comparison with 2022,especially for 25%CWR(crop water requirements).Regulated deficit irrigation regimes reduced the stomatal conductance by 46%and 52%respectively during the first and second growing seasons by limiting CO_(2) intake for the Calvin cycle.The stomata closure increased the leaf temperature and affected the functioning of the photosynthetic apparatus by damaging the chlorophyll pigments and impairment of electron transport chains in chloroplasts.The transition from regulated deficit irrigation to 100%CWR at the beginning of flowering(R1)compensated for the photosynthetic loss,improved the growth and development of soybean plants and enhanced the yield and its components for 50%and 75%CWR.The adaptative mechanism such as the remobilization of the carbon reserved in the stems and leaves(vegetative tissues)to the grains improved the grain yield by 36.7%during 2021 and by 32.2%during 2022 and.This consequently improved the water use efficiency,the water productivity of soybean for 50%and 75%CWR and contributed to water saving with an average of 60 mm per growing season.
