Drip irrigation and flood irrigation are major irrigation methods for maize crops in the Hetao Irrigation District,Inner Mongolia Autonomous Region,China.This research delves into the effects of these irrigation metho...Drip irrigation and flood irrigation are major irrigation methods for maize crops in the Hetao Irrigation District,Inner Mongolia Autonomous Region,China.This research delves into the effects of these irrigation methods on carbon dioxide(CO_(2))exchange and crop growth in this region.The experimental site was divided into drip and flood irrigation zones.The irrigation schedules of this study aligned with the local commonly used irrigation schedule.We employed a developed chamber system to measure the diurnal CO_(2)exchange of maize plants during various growth stages under both drip and flood irrigation methods.From May to September in 2020 and 2021,two sets of repeated experiments were conducted.In each experiment,a total of nine measurements of CO_(2)exchange were performed to obtain carbon exchange data at different growth stages of maize crop.During each CO_(2)exchange measurement event,CO_(2)flux data were collected every two hours over a day-long period to capture the diurnal variations in CO_(2)exchange.During each CO_(2)exchange measurement event,the biological parameters(aboveground biomass and crop growth rate)of maize and environmental parameters(including air humidity,air temperature,precipitation,soil water content,and photosynthetically active radiation)were measured.The results indicated a V-shaped trend in net ecosystem CO_(2)exchange in daytime,reducing slowly at night,while the net assimilation rate(net primary productivity)exhibited a contrasting trend.Notably,compared with flood irrigation,drip irrigation demonstrated significantly higher average daily soil CO_(2)emission and greater average daily CO_(2)absorption by maize plants.Consequently,within the maize ecosystem,drip irrigation appeared more conducive to absorbing atmospheric CO_(2).Furthermore,drip irrigation demonstrated a faster crop growth rate and increased aboveground biomass compared with flood irrigation.A strong linear relationship existed between leaf area index and light utilization efficiency,irrespective of the irrigation method.Notably,drip irrigation displayed superior light use efficiency compared with flood irrigation.The final yield results corroborated these findings,indicating that drip irrigation yielded higher harvest index and overall yield than flood irrigation.The results of this study provide a basis for the selection of optimal irrigation methods commonly used in the Hetao Irrigation District.This research also serves as a reference for future irrigation studies that consider measurements of both carbon emissions and yield simultaneously.展开更多
A field experiment was carried out to evaluate the effects of drip fertigation combined with plant hedgerows on nitrogen and phosphorus runoff losses in intensive pear orchards in the Tai Lake Basin.Nitrogen and phosp...A field experiment was carried out to evaluate the effects of drip fertigation combined with plant hedgerows on nitrogen and phosphorus runoff losses in intensive pear orchards in the Tai Lake Basin.Nitrogen and phosphorus runoff over a whole year were measured by using successional runoff water collection devices.The four experimental treatments were conventional fertilization(CK),drip fertigation(DF),conventional fertilization combined with plant hedgerows(C+H),and drip fertigation combined with plant hedgerows(D+H).The results from one year of continuous monitoring showed a significant positive correlation between precipitation and surface runoff discharge.Surface runoff discharge under the treatments without plant hedgerows totaled 15.86%of precipitation,while surface runoff discharge under the treatments with plant hedgerows totaled 12.82%of precipitation.Plant hedgerows reduced the number of runoff events and the amount of surface runoff.Precipitation is the main driving force for the loss of nitrogen and phosphorus in surface runoff,and fertilization is an important factor affecting the losses of nitrogen and phosphorus.In CK,approximately 7.36%of nitrogen and 2.63%of phosphorus from fertilization entered the surface water through runoff.Drip fertigation reduced the accumulation of nitrogen and phosphorus in the surface soil and lowered the runoff loss concentrations of total nitrogen(TN)and total phosphorus(TP).Drip fertigation combined with plant hedgerows significantly reduced the overall TN and TP losses by 45.38 and 36.81%,respectively,in comparison to the CK totals.Drip fertigation increased the vertical migration depth of nitrogen and phosphorus nutrients and reduced the accumulation of nitrogen and phosphorus in the surface soil,which increased the pear yield.The promotion of drip fertigation combined with plant hedgerows will greatly reduce the losses of nitrogen and phosphorus to runoff and maintain the high fruit yields in the intensive orchards of the Tai Lake Basin.展开更多
Alternate partial root-zone drip fertigation (ADF) is a combination of alternating irrigation and drip fertigation,with the potential to save water and increase nitrogen (N) fertilizer efficiency.A 2-year greenhouse e...Alternate partial root-zone drip fertigation (ADF) is a combination of alternating irrigation and drip fertigation,with the potential to save water and increase nitrogen (N) fertilizer efficiency.A 2-year greenhouse experiment was conducted to evaluate the effect of different fertigation frequencies on the distribution of soil moisture and nutrients and tomato yield under ADF.The treatments included three ADF frequencies with intervals of 3 days (F3),6 days (F6) and 12 days (F12),and conventional drip fertigation as a control (CK),which was fertilized once every 6 days.For the ADF treatments,two drip tapes were placed 10 cm away on each side of the tomato row,and alternate drip irrigation was realized using a manual valve on the distribution tapes.For the CK treatment,a drip tape was located close to the roots of the tomato plants.The total N application rate of all treatments was 180 kg ha^(-1).The total irrigation amounts applied to the CK treatment were450.6 and 446.1 mm in 2019 and 2020,respectively;and the irrigation amounts applied to the ADF treatments were 60%of those of the CK treatment.The F3 treatment resulted in water and N being distributed mainly in the 0–40-cm soil layer with less water and N being distributed in the 40–60-cm soil layer.The F6 treatment led to 21.0 and 29.0%higher 2-year average concentration of mineral N in the 0–20 and 20–40-cm soil layer,respectively and a 23.0%lower N concentration in the 40–60-cm soil layer than in the CK treatment.The 2-year average tomato yields of the F3,F6,F12,and CK treatments were 107.5,102.6,87.2,and 98.7 t ha^(-1),respectively.The tomato yield of F3 was significantly higher (23.3%) than that in the F12 treatment,whereas there was no significant difference between the F3 and F6 treatment.The F6 treatment resulted in yield similar to the CK treatment,indicating that ADF could maintain tomato yield with a 40%saving in water use.Based on the distribution of water and N,and tomato yield,a fertigation frequency of 6 days under ADF should be considered as a water-saving strategy for greenhouse tomato production.展开更多
Excessive application of nitrogen (N) fertilizer is the main cause of N loss and poor use efficiency in winter wheat (Triticum aestivum L.) production in the North China Plain (NCP).Drip fertigation is considered to b...Excessive application of nitrogen (N) fertilizer is the main cause of N loss and poor use efficiency in winter wheat (Triticum aestivum L.) production in the North China Plain (NCP).Drip fertigation is considered to be an effective method for improving N use efficiency and reducing losses,while the performance of drip fertigation in winter wheat is limited by poor N scheduling.A two-year field experiment was conducted to evaluate the growth,development and yield of drip-fertigated winter wheat under different split urea (46%N,240 kg ha^(-1)) applications.The six treatments consisted of five fertigation N application scheduling programs and one slow-release fertilizer (SRF) application.The five N scheduling treatments were N0–100 (0%at sowing and 100%at jointing/booting),N25–75 (25%at sowing and 75%at jointing and booting),N50–50(50%at sowing and 50%at jointing/booting),N75–25 (75%at sowing and 25 at jointing/booting),and N100–0 (100%at sowing and 0%at jointing/booting).The SRF (43%N,240 kg ha^(-1)) was only used as fertilizer at sowing.Split N application significantly (P<0.05) affected wheat grain yield,yield components,aboveground biomass (ABM),water use efficiency(WUE) and nitrogen partial factor productivity (NPFP).The N50–50 and SRF treatments respectively had the highest yield(8.84 and 8.85 t ha^(-1)),ABM (20.67 and 20.83 t ha^(-1)),WUE (2.28 and 2.17 kg m^(-3)) and NPFP (36.82 and 36.88 kg kg^(-1)).This work provided substantial evidence that urea-N applied in equal splits between basal and topdressing doses compete economically with the highly expensive SRF for fertilization of winter wheat crops.Although the single-dose SRF could reduce labor costs involved with the traditional method of manual spreading,the drip fertigation system used in this study with the N50–50 treatment provides an option for farmers to maintain wheat production in the NCP.展开更多
The green high-yield and high-efficiency cultivation techniques of integrated management of water and fertilizer for maize under mulch drip irrigation are described from the aspects of high yield target of maize and i...The green high-yield and high-efficiency cultivation techniques of integrated management of water and fertilizer for maize under mulch drip irrigation are described from the aspects of high yield target of maize and its component factor indexes,pre-sowing preparation,sowing,post-sowing management,field management at the seedling stage,integrated management of water and fertilizer for target yield of maize,rational application of micro-fertilizer,comprehensive prevention and control of diseases and pests,timely harvest,etc.,in order to provide a reference for agricultural technicians,maize farmers and maize industry development in northern Xinjiang.展开更多
Background:Liqi Huoxue dripping pill(LQHXDP),a traditional Chinese drug for coronary heart disease,has a protective effect on the heart of rats with myocardial ischemia-reperfusion injury(MIRI)in previous studies;howe...Background:Liqi Huoxue dripping pill(LQHXDP),a traditional Chinese drug for coronary heart disease,has a protective effect on the heart of rats with myocardial ischemia-reperfusion injury(MIRI)in previous studies;however,its mechanism of action remains unclear.The purpose of this study was to investigate the protective mechanism of LQHXDP on MIRI in rats and its relationship with the PI3K/Akt signaling pathway.Methods:In this study,Sprague-Dawley rats were pre-infused with LQHXDP(175 mg/kg/d)for 10 days.PI3K inhibitor LY294002(0.3 mg/kg)was intravenously injected 15 minutes before ischemia.The rat model of MIRI was established by ligating the left anterior descending coronary artery.Subsequently,cardiac hemodynamics,serum myocardial injury markers,inflammatory factors,myocardial infarct size,antioxidant indexes,myocardial histopathology,and phosphorylation levels of key proteins of PI3K/Akt signaling pathway were assessed in rats.Results:LQHXDP was found to improve cardiac hemodynamic indexes,reduce serum creatine kinase MB isoenzyme activity and cardiac troponin and heart-type fatty acid binding protein levels,lower serum interleukin-1 beta,interleukin-6 and tumour necrosis factorαlevels,reduce the myocardial infarct size and enhance the antioxidant capacity of myocardial tissue in MIRI rats.Pathological analysis revealed that LQHXDP attenuated the extent of myocardial injury and protected mitochondria from damage in MIRI rats.Immunoblot analysis revealed that LQHXDP increased the expression levels of p-Akt and p-GSK-3βin MIRI rat cardiomyocytes.PI3K inhibitor LY294002 could impair these effects of LQHXDP.Conclusion:LQHXDP attenuated myocardial injury,attenuated oxidative stress injury and reduced inflammatory response in MIRI rats,and its protective effects were mediated by activating of PI3K/Akt/GSK-3βsignaling pathway.展开更多
Yuepuhu County in Xinjiang has a long history of cotton planting and is a national high-quality cotton base county.In 2002,it was appraised by the Ministry of Agriculture as the"Hometown of High-yield Cotton Prod...Yuepuhu County in Xinjiang has a long history of cotton planting and is a national high-quality cotton base county.In 2002,it was appraised by the Ministry of Agriculture as the"Hometown of High-yield Cotton Production in China",with an annual cotton planting area of about 43000 ha.Traditional cotton planting has disadvantages such as waste of water resources,low water use efficiency,easy breeding of diseases and insect pests,and unfavorable ground temperature recovery at the seedling stage.In order to solve the low water use efficiency in cotton planting in Yuepuhu County,reduce the occurrence of diseases and insect pests,promote sustainable cotton production,and improve the economic benefits and local ecological benefits of cotton planting,Yuepuhu County promoted the application of the resource-saving technology drip irrigation under ground membrane cotton comprehensive cultivation technology mainly promoted by the Ministry of Agriculture.This paper mainly discusses the disadvantages of traditional cotton planting,the main technical content of drip irrigation under ground membrane technology,the problems found in the practice process and the solutions,so as make cotton growers in Yuepuhu County better understand the planting technology under plastic film,and to better promote the development of cotton industry in Yuepuhu County and the surrounding regions.展开更多
The formation of controllable size and dripping frequency in electrohydrodynamic(EHD)atomization with electric periodic dripping regime are of much interest and importance because of significant and wide applications,...The formation of controllable size and dripping frequency in electrohydrodynamic(EHD)atomization with electric periodic dripping regime are of much interest and importance because of significant and wide applications,such as micro-encapsulation and ink-printing.In the present study,the experimental and theoretical works were carried out to explore droplet formation in periodic dripping regime in presence of an electric field.The dimensionless electric charge carried by each droplet produced is smaller than the 50%of critical value of the Rayleigh limit,where charge-to-mass ratio of droplets was obtained through the deflection distance in the presence of an electric field.The droplet in electric periodic dripping regime usually undergoes oscillating deformation,and finally forms a spherical droplet below the tip no more than ten times out diameter of tube.The droplet size tens of microns to one hundreds of microns decreases with an increase in applied potential.In the electric dripping mode,droplets size is independent of flow rate and affected by flow rate due to adsorption of surface active species in micro-dripping.The simplified model to predict droplets size was derived from the balance of electric,surface tension and gravity forces.The droplets size calculated in good agreement with the experiments.Meanwhile,the dripping frequency of droplets with rang of a few to several hundred hertz obtained from timeresolved images is highly dependent of liquid flow rate and electric potential.The largest dripping frequency was predicted and in reasonable agreement with the experimental results.In electric periodic dripping regime drop-on-demand droplets in size and dripping frequency further our understanding on the formation of identical droplets and are beneficial to many practical applications.展开更多
This study was conducted to investigate the effects of different fertilizers on nitrogen,phosphorus and potassium absorption and distribution by celery and the changes of soil nutrients in the 0-40 cm soil layer under...This study was conducted to investigate the effects of different fertilizers on nitrogen,phosphorus and potassium absorption and distribution by celery and the changes of soil nutrients in the 0-40 cm soil layer under drip irrigation,so as to provide a theoretical basis for nutrient management of greenhouse celery cultivation and special fertilizer development.With celery as an experiment material and the ratio of conventional fertilization as control treatment,the effects of different ratios of nitrogen,phosphorus and potassium on nutrient absorption by celery and changes of soil nutrients were investigated by plot experiment in greenhouse.The results showed that the contents and distribution proportions of N and P in leaf were higher than those in stem,while for K,the content and distribution proportion were higher in stem than in leaf.The absorption amount of K was the highest in celery,followed by N,and the absorption amount of P element was the least.The mean ratio of N,P and K in celery was 1∶0.556∶1.609.There were evident dynamic changes in contents of soil available nutrients in the 0-20 cm soil layer in various growth stages of celery under different drip irrigation fertilizers.The contents of soil available nutrients were higher on the28^(th),47^(th) and 83^(th) d after field planting,while those before field planting and after harvest were lower.So the amounts of soil available nutrients were closely related to the growth stage of celery.In the whole growth period of celery,the mean input amounts of N,P_2O_5 and K_2O were 805,1 049 and 916kg/hm^2,respectively,but the absorption amounts of nutrients by celery were far less than inputs,and the amounts of N,P_2O_5 and K_2O absorbed by celery were only 23%-26%,10%and 31%-35% of the application amounts,respectively.The apparent balance of N,P_2O_5 and K_2O were 613,943 and 609kg/hm2,respectively,indicating excess fertilization in this experiment.Under this experiment condition,T1(N∶P_2O_5∶K_2O=1∶0.63∶1.08)favored increase of celery yield and absorption of nitrogen,phosphorus and potassium by celery.The results will provide a scientific basis for study and utilization of special fertilizer for drip irrigation on celery.展开更多
The increase of human population generates the need to improve the efficiency of food production. A thorough planning is required following the scope of economic and sustainable development, being irrigation a basic t...The increase of human population generates the need to improve the efficiency of food production. A thorough planning is required following the scope of economic and sustainable development, being irrigation a basic tool, however water availability is restricted and it obliges farmers to progress increasing water productivity. Irrigation uses around 70% of total available fresh water, while irrigation water application efficiency is around 40%. Irrigation systems must follow strong criteria at the design stage to achieve high values of water productivity. Maintenance is indispensable to follow the original functioning level of those systems. At last the daily precise management of systems, following soil water potential, considering the effective rain storage at root depth of the crop and the evolution of daily evapotranspiration, preserving natural resources, are relevant to achieve low values of water footprint of this crop. In an 8 year drip irrigation system, the Uniformity Coefficient of Christiansen (UCC) measured was 95.14%;the Uniform Coefficient of the Minor Quart (UCMQ) was 93.16%. The Total Distribution Efficiency (EDT) was 95.13% when measurements finished while the irrigation systems is of. When measurements also considered the volume collected during the “recession phase in drip irrigation” and the “volume of water collected during recession phase in drip irrigation” collected at different points, EDT was 95.13%. Moreover it can be seen that when three different typical soil of the area were considered, the EDT was, 91.85%, 91.47% and 90.30% respectively, according with different water storage capacity of each soil. The Total Distribution Efficient is a strong method, to evaluate the design and management of drip irrigation systems, under different design criteria, management practices and maintenance of the systems. Water footprint in a blueberry (Vaccinium corymbosum L.) crop with drip and sprinkler anti-frost system, were measure and values obtained were 846, 310, 223, 212, 172 and 218 liters per kg of fresh fruit in the period 2010-2015. The UCC and the UCMQ reflects properly the irrigation design, while the EDT reflects irrigation design, management and maintenance. Water footprint is at last the strong tool to evaluate design and operation of the irrigation system and crop management.展开更多
The objective of this study was to investigate the effects of applying different amounts of water and nitrogen on yield, fruit quality, water use efficiency(WUE), irrigation water use efficiency(IWUE) and nitrogen use...The objective of this study was to investigate the effects of applying different amounts of water and nitrogen on yield, fruit quality, water use efficiency(WUE), irrigation water use efficiency(IWUE) and nitrogen use efficiency(NUE) of drip-irrigated greenhouse tomatoes in northwestern China. The plants were irrigated every seven days at various proportions of 20-cm pan evaporation(E_p). The experiment consisted of three irrigation levels(I1, 50% E_p; I2, 75% E_p; and I3, 100% E_p) and three N application levels(N1, 150 kg N ha^(–1); N2, 250 kg N ha^(–1); and N3, 350 kg N ha^(–1)). Tomato yield increased with the amount of applied irrigation water in I2 and then decreased in I3. WUE and IWUE were the highest in I1. WUE was 16.5% lower in I2 than that in I1, but yield was 26.6% higher in I2 than that in I1. Tomato yield, WUE, and IWUE were significantly higher in N2 than that in N1 and N3. NUE decreased with increasing N levels but NUE increased with increase the amount of water applied. Increasing both water and N levels increased the foliar net photosynthetic rate. I1 and I2 treatments significantly increased the contents of total soluble solids(TSS), vitamin C(VC), lycopene, soluble sugars(SS), and organic acids(OA) and the sugar:acid ratio in the fruit and decreased the nitrate content. TSS, VC, lycopene, and SS contents were the highest in N2. The harvest index(HI) was the highest in I2N2. I2N2 provided the optimal combination of tomato yield, fruit quality, and WUE. The irrigation and fertilisation regime of 75% E_p and 250 kg N ha^(–1) was the best strategy of water and N management for the production of drip-irrigated greenhouse tomato.展开更多
Developing effective irrigation and drainage strategies to improve the quality of saline-alkali soil is vital for enhancing agricultural production and increasing economic returns. In this study, we explored how irrig...Developing effective irrigation and drainage strategies to improve the quality of saline-alkali soil is vital for enhancing agricultural production and increasing economic returns. In this study, we explored how irrigation and drainage modes (flood irrigation, drip irrigation, and sub-surface pipe drainage under drip irrigation) improve the saline-alkali soil in Xinjiang, China. We aimed to study the transport characteristics of soil water and salt under different irrigation and drainage modes, and analyze the effects of the combination of irrigation and drainage on soil salt leaching, as well as its impacts on the growth of oil sunflower. Our results show that sub-surface pipe drainage under drip irrigation significantly reduced the soil salt content and soil water content at the 0–200 cm soil depth. Under sub-surface pipe drainage combined with drip irrigation, the mean soil salt content was reduced to below 10 g/kg after the second irrigation, and the soil salt content decreased as sub-surface pipe distance decreased. The mean soil salt content of flood irrigation exceeded 25 g/kg, and the mean soil desalination efficiency was 3.28%, which was lower than that of drip irrigation. The mean soil desalination rate under drip irrigation and sub-surface pipe drainage under drip irrigation was 19.30% and 58.12%, respectively. After sub-surface drainage regulation under drip irrigation, the germination percentage of oil sunflower seedlings was increased to more than 50%, which further confirmed that combined drip irrigation and sub-surface pipe drainage is very effective in improving the quality of saline-alkali soil and increasing the productivity of agricultural crops.展开更多
Effects of soil moisture on cotton root length density (total root length per unit soil volume) and yield under drip irrigation with plastic mulch were studied through field experiments. The results indicate that spat...Effects of soil moisture on cotton root length density (total root length per unit soil volume) and yield under drip irrigation with plastic mulch were studied through field experiments. The results indicate that spatial distributions of root length density of cotton under various water treatments were basically similar. Horizontally, both root length densities of cotton in wide and narrow rows were similar, and higher than that between mulches. Vertically, root length density of cotton decreased with increasing soil depth. The distribution of root length density is different under different irrigation treatments. In conditions of over-irrigation, the root length density of cotton between mulches would increase. However, it would decrease in both the wide rows and narrow rows. The mean root length density of cotton increased with increasing irrigation water. Water stress caused the root length density to increase in lower soil layers. There is a significant correlation between root length density and yields of cotton at the flower-boll and wadding stages. The regression between irrigation amount and yield of cotton can be expressed as y = -0.0026x2+18.015x-24845 (R2 = 0.959). It showed that the irrigation volume of 3,464.4 m3/hm2 led to op-timal root length density. The yield of cotton was 6,360 .8 kg/hm2 under that amount of irrigation.展开更多
Biochar addition can improve the physical and hydraulic characteristics of sandy soil.This study investigated the effects of biochar on water holding capacity and water movement in sandy soil under drip irrigation.By ...Biochar addition can improve the physical and hydraulic characteristics of sandy soil.This study investigated the effects of biochar on water holding capacity and water movement in sandy soil under drip irrigation.By indoor simulation experiments,the effects of biochar application at five levels(0%,1%,2%,4%and 6%)on the soil water retention curve,infiltration characteristics of drip irrigation and water distribution were tested and analyzed.The results showed that biochar addition rate was positively correlated with water holding capacity of sandy soil and soil available water.Within the same infiltration time,with an increasing amount of added biochar,the diffusion distance of the horizontal wetting front(HWF)tended to decrease,while the infiltration distance of vertical wetting front(VWF)initially declined and then rose.The features of wetted bodies changed from"broad-shallow"to"narrow-deep"type.The relationship between the transport distances of HWF and VWF and the infiltration time was described by a power function.At the same distance from the point source,the larger the amount of added biochar,the higher the soil water content.Biochar had a great influence on the water content of the layer with biochar(0–200 mm)and had some effects at 200–250 mm without biochar;but it had less influence on the soil water content deeper than 250 mm.For the application rate of biochar of 4%,most water was retained within 0–250 mm soil layer.However,when biochar application amount was high(6%),it would be helpful for water infiltration.During the improvement of sandy soil,biochar application rate of 4%in the plow layer had the best effect.展开更多
A retained bile duct stone after operation for cholelithiasis still occurs and causes symptoms such as biliary colic and obstructive jaundice.An endoscopic retrograde cholangiopancreatography with endoscopic sphincter...A retained bile duct stone after operation for cholelithiasis still occurs and causes symptoms such as biliary colic and obstructive jaundice.An endoscopic retrograde cholangiopancreatography with endoscopic sphincterotomy(EST),followed by stone extraction,are usually an effective treatment for this condition.However,these procedures are associated with severe complications including pancreatitis,bleeding,and duodenal perforation.Nitrates such as glyceryl trinitrate(GTN) and isosorbide dinitrate(ISDN) are known to relax the sphincter of Oddi.In 6 cases in which a retained stone was detected following cholecystectomy,topical nitrate drip infusion via cystic duct tube(C-tube) was carried out.Retained stones of 2-3 mm diameter and no dilated common bile duct in 3 patients were removed by drip infusion of 50 mg GTN or 10 mg ISDN,which was the regular dose of intravenous injection.Three other cases failed,and EST in 2 cases and endoscopic biliary balloon dilatation in 1 case were performed.One patient developed an adverse event of nausea.Severe complications were not observed.We consider the topical nitrate drip infusion via C-tube to be old but safe,easy,and inexpensive procedure for retained bile duct stone following cholecystectomy,inasmuch as removal rate was about 50% in our cases.展开更多
Drip irrigation can produce high rice yields with significant water savings;therefore,it is widely used in arid area water-scarce northern China.However,high-frequency irrigation of drip irrigation with low temperatur...Drip irrigation can produce high rice yields with significant water savings;therefore,it is widely used in arid area water-scarce northern China.However,high-frequency irrigation of drip irrigation with low temperature well water leads to low root zone temperature and significantly reduce the rice yield compared to normal temperature water irrigated rice,for example,reservoir water.The main purpose of this paper is to investigate the effects of low soil temperature on the yield reduction of drip irrigated rice in the spike differentiation stage.The experiment set the soil temperatures at 18℃,24℃and 30℃under two irrigation methods(flood and drip irrigation),respectively.The results showed that,at the 30℃soil temperature,drip irrigation increased total root length by 53%but reduced root water conductivity by 9%compared with flood irrigation.Drip irrigation also increased leaf abscisic acid and proline concentrations by 13%and 5%,respectively.These results indicated that drip irrigated rice was under mild water stress.In the 18℃soil temperature,drip irrigation reduced hydraulic conductivity by 58%,leaf water potential by 40%and leaf net photosynthesis by 25%compared with flood irrigation.The starch concentration in male gametes was also 30%less in the drip irrigation treatment than in the flood irrigation treatment at soil temperature 18℃.Therefore,the main reason for the yield reduction of drip irrigated rice was that the low temperature aggravates the physiological drought of rice and leads to the decrease of starch content in male gametes and low pollination fertilization rate.Low temperature aggravates physiological water deficit in drip irrigated rice and leads to lower starch content in male gametes and low pollination fertilization rate,which is the main reason for the reduced yield of drip irrigated rice.Overall,the results indicated that the low soil temperatures aggravated the water stress that rice was under in the drip irrigated environment,causing declines both in the starch content of male gametes and in pollination rate.Low temperature will ultimately affect the rice yield under drip irrigation.展开更多
The objective of this study was to obtain the water-saving and efficient production mode of Arabica coffee. The effects of three drip irrigation modes,conventional drip irrigation( CDI),alternate drip irrigation( ADI)...The objective of this study was to obtain the water-saving and efficient production mode of Arabica coffee. The effects of three drip irrigation modes,conventional drip irrigation( CDI),alternate drip irrigation( ADI) and fixed drip irrigation( FDI) on growth,photosynthetic characteristics,biomass accumulation and irrigation water use efficiency of Arabica coffee were investigated under three nitrogen levels,high nitrogen( NH),middle nitrogen( NM) and low nitrogen( NL). The results show that there was a significant Logistic curve between the plant height,the stem diameter of Arabica coffee and growth days. Compared with CDI,ADI had no significant effects on leaf net photosynthetic rate,stomatal conductance,instantaneous water use efficiency and biomass accumulation above ground of Arabica coffee,while FDI decreased significantly,ADI and FDI increased irrigation water use efficiency by 50. 59% and 32. 85%,respectively. Compared with NH,with the reduction of N application rate,net photosynthetic rate,stomatal conductance,biomass accumulation above ground and irrigation water use efficiency decreased by 6. 81%-12. 30%,13. 70%-22. 69%,9. 61%-16. 67% and 9. 78%-15. 64%,respectively. Compared with CDINH,ADINHdecreased net photosynthesis rate and the stomatal conductance not significantly,other treatments decreased by 9. 16%-19. 22%,14. 49%-32. 91%,and decreased biomass accumulation above ground by 8. 26%-27. 34% except ADINH,and increased irrigation water use efficiency by 16. 46%-60. 95% except CDINMand CDINL. Therefore,alternate drip irrigation under high N level( ADINH) is the best water and nitrogen coupling mode of young Arabica coffee tree for water efficiency.展开更多
The Northeast Plain is the largest maize production area in China,and drip irrigation has recently been proposed to cope with the effects of frequent droughts and to improve water use efficiency(WUE).In order to devel...The Northeast Plain is the largest maize production area in China,and drip irrigation has recently been proposed to cope with the effects of frequent droughts and to improve water use efficiency(WUE).In order to develop an efficient and environmentally friendly irrigation system,drip irrigation experiments were conducted in 2016-2018 incorporating different soil water conservation measures as follows:(1)drip irrigation under plastic film mulch(PI),(2)drip irrigation under biodegradable film mulch(BI),(3)drip irrigation incorporating straw returning(SI),and(4)drip irrigation with the tape buried at a shallow soil depth(OI);with furrow irrigation(FI)used as the control.The results showed that PI and Bl gave the highest maize yield,as well as the highest WUE and nitrogen use efficiency(NUE)because of the higher root length density(RLD)and better heat conditions during the vegetative stage.But compared with BI,PI consumed more soil water in the 20-60 and 60-100 cm soil layers,and accelerated the progress of root and leaf senescence due to a larger root system in the top 0-20 cm soil layer and a higher soil temperature during the reproductive stage.SI was effective in improving soil water and nitrate contents,and promoted RLD in deeper soil layers,thereby maintaining higher physiological activity during the reproductive stage.FI resulted in higher nitrate levels in the deep 60-100 cm soil layer,which increased the risk of nitrogen losses by leaching compared with the drip irrigation treatments.RLD in the 0-20 cm soil layer was highly positively correlated with yield,WUE and NUE(P<0.001),but it was negatively correlated with root nitrogen use efficiency(NRE)(P<0.05),and the correlation was weaker in deeper soil layers.We concluded that Bl had advantages in water-nitrogen utilization and yield stability response to drought stress,and thus is recommended for environmentally friendly and sustainable maize production in Northeast China.展开更多
Current methods for nasal spray formulations have been elementary evaluating the dripping characteristics of a formulation and have not assessed the behavior of the nasal formulation in the presence of varying types o...Current methods for nasal spray formulations have been elementary evaluating the dripping characteristics of a formulation and have not assessed the behavior of the nasal formulation in the presence of varying types of mucus depending on the indication or diseased state. This research investigated the effects of nasal mucus on the dripping behavior of nasal formulations and focused on developing an improved in vitro analytical test method that is more physiologically relevant in characterizing nasal formulation dripping behavior. Method development was performed using simulated nasal mucus preparations for both healthy and diseased states as coatings for the dripping experiment representing a wide range of viscosity. Factors evaluated during development of this in vitro test method included amount of mucus, application of mucus, drying times, and compatibility of the mucus on a C18 Thin Layer Chromatography(TLC) substrate. The dripping behavior of nasal formulations containing a range of 1%Avicel to 3.5% Avicel was assessed by actuating the nasal spray on a perpendicular TLC plate coated with either healthy or diseased simulated nasal mucus. After actuation of the nasal spray, the dripping of the formulation on the coated TLC plate was measured after the plate was repositioned vertically. The method that was developed generated reproducible results on the dripping behavior of nasal formulations and provided critical information about the compatibility of the formulation with the nasal mucus for different diseased states, aiding in nasal spray formulation development and physical characterization of the nasal spray.展开更多
Laboratory tests were conducted at the Irrigation Devices and Equipment’s Test Laboratory, Agricultural Engineering Research Institute, Agriculture Research Center, Giza, Egypt. The experimental design of laboratory ...Laboratory tests were conducted at the Irrigation Devices and Equipment’s Test Laboratory, Agricultural Engineering Research Institute, Agriculture Research Center, Giza, Egypt. The experimental design of laboratory experiments was split in randomized complete block design with three replicates. Laboratory tests carried out on three irrigation lateral lines of 40, 60, 80 m under the following three drip irrigation circuit (DIC) designs;1) one manifold for lateral lines or closed circuits with one manifold of drip irrigation system (CM1DIS);2) closed circuits with two manifolds for lateral lines (CM2DIS), and 3) traditional drip irrigation system (TDIS) as a control. The aims of the work were to study the effect of drip irrigation circuits (DIC) and lateral lines lengths (LLL;where): (LLL1 = 40 m, LLL2 = 60 m, and LLL3 = 80 m) on pressure head (PH) and friction loss (FL). Regarding to LLL and according to PH values, DIC designs could be ranked in the following ascending order: TDIS 1DIS 2DIS. The differences in PH among DIC designs were significant at the 1% level. The depressive effects of LLL on PH could be ranked in the following ascending order: LLL1 2 ≤ LLL3. Differences in PH among LLL treatments were significant at the 1% level except that between LLL2 and LLL3. The effects of interactions among: DIC × LLL on PH were significant at the 1% level with some exceptions. The highest value of PH (9.5 m) and the lowest one (6.05 m) were achieved in the interactions of CM2DIS × LLL1 and TDIS × LLL3, respectively. The shapes of the energy gradient lines were affected by DIC and LLL treatments used through their effect on ?H/H ratio. However, they followed similar trends. According to the FL values, DIC and LLL treatments could be ranked in the following descending orders TDIS > CM1DIS > CM2DIS and LLL1 > LLL2 > LLL3. The differences in FL among DIC and LLL were significant and the effects of interactions among DIC × LLL on FL were significant at the 1% level. The maximum and minimum values of FL were obtained in the interactions: TDIS × LLL3 and CM2DIS × LLL1, respectively. Therefore, the CM2DIS system is recommended for use where technically feasible.展开更多
基金supported by the Shandong Province Natural Science Foundation Youth Branch(ZR2023QC157)the National Natural Science Foundation of China(51979233)+1 种基金the Key Research and Development Project of Shaanxi Province(2022KW-47,2022NY-220)the Heze University Doctoral Research Fund(XY21BS24,XY22BS17).
文摘Drip irrigation and flood irrigation are major irrigation methods for maize crops in the Hetao Irrigation District,Inner Mongolia Autonomous Region,China.This research delves into the effects of these irrigation methods on carbon dioxide(CO_(2))exchange and crop growth in this region.The experimental site was divided into drip and flood irrigation zones.The irrigation schedules of this study aligned with the local commonly used irrigation schedule.We employed a developed chamber system to measure the diurnal CO_(2)exchange of maize plants during various growth stages under both drip and flood irrigation methods.From May to September in 2020 and 2021,two sets of repeated experiments were conducted.In each experiment,a total of nine measurements of CO_(2)exchange were performed to obtain carbon exchange data at different growth stages of maize crop.During each CO_(2)exchange measurement event,CO_(2)flux data were collected every two hours over a day-long period to capture the diurnal variations in CO_(2)exchange.During each CO_(2)exchange measurement event,the biological parameters(aboveground biomass and crop growth rate)of maize and environmental parameters(including air humidity,air temperature,precipitation,soil water content,and photosynthetically active radiation)were measured.The results indicated a V-shaped trend in net ecosystem CO_(2)exchange in daytime,reducing slowly at night,while the net assimilation rate(net primary productivity)exhibited a contrasting trend.Notably,compared with flood irrigation,drip irrigation demonstrated significantly higher average daily soil CO_(2)emission and greater average daily CO_(2)absorption by maize plants.Consequently,within the maize ecosystem,drip irrigation appeared more conducive to absorbing atmospheric CO_(2).Furthermore,drip irrigation demonstrated a faster crop growth rate and increased aboveground biomass compared with flood irrigation.A strong linear relationship existed between leaf area index and light utilization efficiency,irrespective of the irrigation method.Notably,drip irrigation displayed superior light use efficiency compared with flood irrigation.The final yield results corroborated these findings,indicating that drip irrigation yielded higher harvest index and overall yield than flood irrigation.The results of this study provide a basis for the selection of optimal irrigation methods commonly used in the Hetao Irrigation District.This research also serves as a reference for future irrigation studies that consider measurements of both carbon emissions and yield simultaneously.
基金supported by the International S&T Cooperation Program of Shanghai,China(20390731200)the Major Science and Technology Program for Water Pollution Control and Treatment,China(2017ZX07205)。
文摘A field experiment was carried out to evaluate the effects of drip fertigation combined with plant hedgerows on nitrogen and phosphorus runoff losses in intensive pear orchards in the Tai Lake Basin.Nitrogen and phosphorus runoff over a whole year were measured by using successional runoff water collection devices.The four experimental treatments were conventional fertilization(CK),drip fertigation(DF),conventional fertilization combined with plant hedgerows(C+H),and drip fertigation combined with plant hedgerows(D+H).The results from one year of continuous monitoring showed a significant positive correlation between precipitation and surface runoff discharge.Surface runoff discharge under the treatments without plant hedgerows totaled 15.86%of precipitation,while surface runoff discharge under the treatments with plant hedgerows totaled 12.82%of precipitation.Plant hedgerows reduced the number of runoff events and the amount of surface runoff.Precipitation is the main driving force for the loss of nitrogen and phosphorus in surface runoff,and fertilization is an important factor affecting the losses of nitrogen and phosphorus.In CK,approximately 7.36%of nitrogen and 2.63%of phosphorus from fertilization entered the surface water through runoff.Drip fertigation reduced the accumulation of nitrogen and phosphorus in the surface soil and lowered the runoff loss concentrations of total nitrogen(TN)and total phosphorus(TP).Drip fertigation combined with plant hedgerows significantly reduced the overall TN and TP losses by 45.38 and 36.81%,respectively,in comparison to the CK totals.Drip fertigation increased the vertical migration depth of nitrogen and phosphorus nutrients and reduced the accumulation of nitrogen and phosphorus in the surface soil,which increased the pear yield.The promotion of drip fertigation combined with plant hedgerows will greatly reduce the losses of nitrogen and phosphorus to runoff and maintain the high fruit yields in the intensive orchards of the Tai Lake Basin.
基金supported by the National Natural Science Foundation of China(51809189)the Shanxi Province Key Laboratory of Soil Environment and Nutrient Resources,China(2019002)。
文摘Alternate partial root-zone drip fertigation (ADF) is a combination of alternating irrigation and drip fertigation,with the potential to save water and increase nitrogen (N) fertilizer efficiency.A 2-year greenhouse experiment was conducted to evaluate the effect of different fertigation frequencies on the distribution of soil moisture and nutrients and tomato yield under ADF.The treatments included three ADF frequencies with intervals of 3 days (F3),6 days (F6) and 12 days (F12),and conventional drip fertigation as a control (CK),which was fertilized once every 6 days.For the ADF treatments,two drip tapes were placed 10 cm away on each side of the tomato row,and alternate drip irrigation was realized using a manual valve on the distribution tapes.For the CK treatment,a drip tape was located close to the roots of the tomato plants.The total N application rate of all treatments was 180 kg ha^(-1).The total irrigation amounts applied to the CK treatment were450.6 and 446.1 mm in 2019 and 2020,respectively;and the irrigation amounts applied to the ADF treatments were 60%of those of the CK treatment.The F3 treatment resulted in water and N being distributed mainly in the 0–40-cm soil layer with less water and N being distributed in the 40–60-cm soil layer.The F6 treatment led to 21.0 and 29.0%higher 2-year average concentration of mineral N in the 0–20 and 20–40-cm soil layer,respectively and a 23.0%lower N concentration in the 40–60-cm soil layer than in the CK treatment.The 2-year average tomato yields of the F3,F6,F12,and CK treatments were 107.5,102.6,87.2,and 98.7 t ha^(-1),respectively.The tomato yield of F3 was significantly higher (23.3%) than that in the F12 treatment,whereas there was no significant difference between the F3 and F6 treatment.The F6 treatment resulted in yield similar to the CK treatment,indicating that ADF could maintain tomato yield with a 40%saving in water use.Based on the distribution of water and N,and tomato yield,a fertigation frequency of 6 days under ADF should be considered as a water-saving strategy for greenhouse tomato production.
基金funded by the earmarked fund for China Agriculture Research System(CARS-03-19)the National Natural Science Foundation of China(51879267 and 51709264)+1 种基金the Open Fund Projects of the Agricultural Environment Experimental Station of Minstry of Agriculture and Rural Affairs,China(FIRI2021040103)the Agricultural Science and Technology Innovation Program(ASTIP)of Chinese Academy of Agricultural Sciences。
文摘Excessive application of nitrogen (N) fertilizer is the main cause of N loss and poor use efficiency in winter wheat (Triticum aestivum L.) production in the North China Plain (NCP).Drip fertigation is considered to be an effective method for improving N use efficiency and reducing losses,while the performance of drip fertigation in winter wheat is limited by poor N scheduling.A two-year field experiment was conducted to evaluate the growth,development and yield of drip-fertigated winter wheat under different split urea (46%N,240 kg ha^(-1)) applications.The six treatments consisted of five fertigation N application scheduling programs and one slow-release fertilizer (SRF) application.The five N scheduling treatments were N0–100 (0%at sowing and 100%at jointing/booting),N25–75 (25%at sowing and 75%at jointing and booting),N50–50(50%at sowing and 50%at jointing/booting),N75–25 (75%at sowing and 25 at jointing/booting),and N100–0 (100%at sowing and 0%at jointing/booting).The SRF (43%N,240 kg ha^(-1)) was only used as fertilizer at sowing.Split N application significantly (P<0.05) affected wheat grain yield,yield components,aboveground biomass (ABM),water use efficiency(WUE) and nitrogen partial factor productivity (NPFP).The N50–50 and SRF treatments respectively had the highest yield(8.84 and 8.85 t ha^(-1)),ABM (20.67 and 20.83 t ha^(-1)),WUE (2.28 and 2.17 kg m^(-3)) and NPFP (36.82 and 36.88 kg kg^(-1)).This work provided substantial evidence that urea-N applied in equal splits between basal and topdressing doses compete economically with the highly expensive SRF for fertilization of winter wheat crops.Although the single-dose SRF could reduce labor costs involved with the traditional method of manual spreading,the drip fertigation system used in this study with the N50–50 treatment provides an option for farmers to maintain wheat production in the NCP.
文摘The green high-yield and high-efficiency cultivation techniques of integrated management of water and fertilizer for maize under mulch drip irrigation are described from the aspects of high yield target of maize and its component factor indexes,pre-sowing preparation,sowing,post-sowing management,field management at the seedling stage,integrated management of water and fertilizer for target yield of maize,rational application of micro-fertilizer,comprehensive prevention and control of diseases and pests,timely harvest,etc.,in order to provide a reference for agricultural technicians,maize farmers and maize industry development in northern Xinjiang.
基金supported by National Natural Science Foundation of China(Grant No.81860873 and 81960864)the Scientific and Technological Projects of Guizhou Province(Qian Kehe Jichu(2016)1401)High-level Talents Project of Guizhou Province(GUTCM(ZQ2018005)).
文摘Background:Liqi Huoxue dripping pill(LQHXDP),a traditional Chinese drug for coronary heart disease,has a protective effect on the heart of rats with myocardial ischemia-reperfusion injury(MIRI)in previous studies;however,its mechanism of action remains unclear.The purpose of this study was to investigate the protective mechanism of LQHXDP on MIRI in rats and its relationship with the PI3K/Akt signaling pathway.Methods:In this study,Sprague-Dawley rats were pre-infused with LQHXDP(175 mg/kg/d)for 10 days.PI3K inhibitor LY294002(0.3 mg/kg)was intravenously injected 15 minutes before ischemia.The rat model of MIRI was established by ligating the left anterior descending coronary artery.Subsequently,cardiac hemodynamics,serum myocardial injury markers,inflammatory factors,myocardial infarct size,antioxidant indexes,myocardial histopathology,and phosphorylation levels of key proteins of PI3K/Akt signaling pathway were assessed in rats.Results:LQHXDP was found to improve cardiac hemodynamic indexes,reduce serum creatine kinase MB isoenzyme activity and cardiac troponin and heart-type fatty acid binding protein levels,lower serum interleukin-1 beta,interleukin-6 and tumour necrosis factorαlevels,reduce the myocardial infarct size and enhance the antioxidant capacity of myocardial tissue in MIRI rats.Pathological analysis revealed that LQHXDP attenuated the extent of myocardial injury and protected mitochondria from damage in MIRI rats.Immunoblot analysis revealed that LQHXDP increased the expression levels of p-Akt and p-GSK-3βin MIRI rat cardiomyocytes.PI3K inhibitor LY294002 could impair these effects of LQHXDP.Conclusion:LQHXDP attenuated myocardial injury,attenuated oxidative stress injury and reduced inflammatory response in MIRI rats,and its protective effects were mediated by activating of PI3K/Akt/GSK-3βsignaling pathway.
文摘Yuepuhu County in Xinjiang has a long history of cotton planting and is a national high-quality cotton base county.In 2002,it was appraised by the Ministry of Agriculture as the"Hometown of High-yield Cotton Production in China",with an annual cotton planting area of about 43000 ha.Traditional cotton planting has disadvantages such as waste of water resources,low water use efficiency,easy breeding of diseases and insect pests,and unfavorable ground temperature recovery at the seedling stage.In order to solve the low water use efficiency in cotton planting in Yuepuhu County,reduce the occurrence of diseases and insect pests,promote sustainable cotton production,and improve the economic benefits and local ecological benefits of cotton planting,Yuepuhu County promoted the application of the resource-saving technology drip irrigation under ground membrane cotton comprehensive cultivation technology mainly promoted by the Ministry of Agriculture.This paper mainly discusses the disadvantages of traditional cotton planting,the main technical content of drip irrigation under ground membrane technology,the problems found in the practice process and the solutions,so as make cotton growers in Yuepuhu County better understand the planting technology under plastic film,and to better promote the development of cotton industry in Yuepuhu County and the surrounding regions.
基金National Natural Science Foundation of China(51106064)Natural Science Foundation of Jiangsu Province,China(BK20171301)+1 种基金China Postdoctoral Science Foundation(2018M632245)a project supported by Jiangsu University for NSFC(FCJJ2015001)。
文摘The formation of controllable size and dripping frequency in electrohydrodynamic(EHD)atomization with electric periodic dripping regime are of much interest and importance because of significant and wide applications,such as micro-encapsulation and ink-printing.In the present study,the experimental and theoretical works were carried out to explore droplet formation in periodic dripping regime in presence of an electric field.The dimensionless electric charge carried by each droplet produced is smaller than the 50%of critical value of the Rayleigh limit,where charge-to-mass ratio of droplets was obtained through the deflection distance in the presence of an electric field.The droplet in electric periodic dripping regime usually undergoes oscillating deformation,and finally forms a spherical droplet below the tip no more than ten times out diameter of tube.The droplet size tens of microns to one hundreds of microns decreases with an increase in applied potential.In the electric dripping mode,droplets size is independent of flow rate and affected by flow rate due to adsorption of surface active species in micro-dripping.The simplified model to predict droplets size was derived from the balance of electric,surface tension and gravity forces.The droplets size calculated in good agreement with the experiments.Meanwhile,the dripping frequency of droplets with rang of a few to several hundred hertz obtained from timeresolved images is highly dependent of liquid flow rate and electric potential.The largest dripping frequency was predicted and in reasonable agreement with the experimental results.In electric periodic dripping regime drop-on-demand droplets in size and dripping frequency further our understanding on the formation of identical droplets and are beneficial to many practical applications.
基金Supported by Special Fund of Agro-scientific Research in Public Interest(201303133-3)Fund for Commercialization and Extension of Scientific and Technologic Achievements in Agriculture in Tianjin City(201203030)
文摘This study was conducted to investigate the effects of different fertilizers on nitrogen,phosphorus and potassium absorption and distribution by celery and the changes of soil nutrients in the 0-40 cm soil layer under drip irrigation,so as to provide a theoretical basis for nutrient management of greenhouse celery cultivation and special fertilizer development.With celery as an experiment material and the ratio of conventional fertilization as control treatment,the effects of different ratios of nitrogen,phosphorus and potassium on nutrient absorption by celery and changes of soil nutrients were investigated by plot experiment in greenhouse.The results showed that the contents and distribution proportions of N and P in leaf were higher than those in stem,while for K,the content and distribution proportion were higher in stem than in leaf.The absorption amount of K was the highest in celery,followed by N,and the absorption amount of P element was the least.The mean ratio of N,P and K in celery was 1∶0.556∶1.609.There were evident dynamic changes in contents of soil available nutrients in the 0-20 cm soil layer in various growth stages of celery under different drip irrigation fertilizers.The contents of soil available nutrients were higher on the28^(th),47^(th) and 83^(th) d after field planting,while those before field planting and after harvest were lower.So the amounts of soil available nutrients were closely related to the growth stage of celery.In the whole growth period of celery,the mean input amounts of N,P_2O_5 and K_2O were 805,1 049 and 916kg/hm^2,respectively,but the absorption amounts of nutrients by celery were far less than inputs,and the amounts of N,P_2O_5 and K_2O absorbed by celery were only 23%-26%,10%and 31%-35% of the application amounts,respectively.The apparent balance of N,P_2O_5 and K_2O were 613,943 and 609kg/hm2,respectively,indicating excess fertilization in this experiment.Under this experiment condition,T1(N∶P_2O_5∶K_2O=1∶0.63∶1.08)favored increase of celery yield and absorption of nitrogen,phosphorus and potassium by celery.The results will provide a scientific basis for study and utilization of special fertilizer for drip irrigation on celery.
文摘The increase of human population generates the need to improve the efficiency of food production. A thorough planning is required following the scope of economic and sustainable development, being irrigation a basic tool, however water availability is restricted and it obliges farmers to progress increasing water productivity. Irrigation uses around 70% of total available fresh water, while irrigation water application efficiency is around 40%. Irrigation systems must follow strong criteria at the design stage to achieve high values of water productivity. Maintenance is indispensable to follow the original functioning level of those systems. At last the daily precise management of systems, following soil water potential, considering the effective rain storage at root depth of the crop and the evolution of daily evapotranspiration, preserving natural resources, are relevant to achieve low values of water footprint of this crop. In an 8 year drip irrigation system, the Uniformity Coefficient of Christiansen (UCC) measured was 95.14%;the Uniform Coefficient of the Minor Quart (UCMQ) was 93.16%. The Total Distribution Efficiency (EDT) was 95.13% when measurements finished while the irrigation systems is of. When measurements also considered the volume collected during the “recession phase in drip irrigation” and the “volume of water collected during recession phase in drip irrigation” collected at different points, EDT was 95.13%. Moreover it can be seen that when three different typical soil of the area were considered, the EDT was, 91.85%, 91.47% and 90.30% respectively, according with different water storage capacity of each soil. The Total Distribution Efficient is a strong method, to evaluate the design and management of drip irrigation systems, under different design criteria, management practices and maintenance of the systems. Water footprint in a blueberry (Vaccinium corymbosum L.) crop with drip and sprinkler anti-frost system, were measure and values obtained were 846, 310, 223, 212, 172 and 218 liters per kg of fresh fruit in the period 2010-2015. The UCC and the UCMQ reflects properly the irrigation design, while the EDT reflects irrigation design, management and maintenance. Water footprint is at last the strong tool to evaluate design and operation of the irrigation system and crop management.
基金supported by grants from the National High-Tech R&D Program of China(863 Program)(2013AA103004)the Water and Technology Support Plan of Shaanxi Province,China(2014slkj-17)
文摘The objective of this study was to investigate the effects of applying different amounts of water and nitrogen on yield, fruit quality, water use efficiency(WUE), irrigation water use efficiency(IWUE) and nitrogen use efficiency(NUE) of drip-irrigated greenhouse tomatoes in northwestern China. The plants were irrigated every seven days at various proportions of 20-cm pan evaporation(E_p). The experiment consisted of three irrigation levels(I1, 50% E_p; I2, 75% E_p; and I3, 100% E_p) and three N application levels(N1, 150 kg N ha^(–1); N2, 250 kg N ha^(–1); and N3, 350 kg N ha^(–1)). Tomato yield increased with the amount of applied irrigation water in I2 and then decreased in I3. WUE and IWUE were the highest in I1. WUE was 16.5% lower in I2 than that in I1, but yield was 26.6% higher in I2 than that in I1. Tomato yield, WUE, and IWUE were significantly higher in N2 than that in N1 and N3. NUE decreased with increasing N levels but NUE increased with increase the amount of water applied. Increasing both water and N levels increased the foliar net photosynthetic rate. I1 and I2 treatments significantly increased the contents of total soluble solids(TSS), vitamin C(VC), lycopene, soluble sugars(SS), and organic acids(OA) and the sugar:acid ratio in the fruit and decreased the nitrate content. TSS, VC, lycopene, and SS contents were the highest in N2. The harvest index(HI) was the highest in I2N2. I2N2 provided the optimal combination of tomato yield, fruit quality, and WUE. The irrigation and fertilisation regime of 75% E_p and 250 kg N ha^(–1) was the best strategy of water and N management for the production of drip-irrigated greenhouse tomato.
基金financially supported by the National Natural Science Foundation of China (51741908)
文摘Developing effective irrigation and drainage strategies to improve the quality of saline-alkali soil is vital for enhancing agricultural production and increasing economic returns. In this study, we explored how irrigation and drainage modes (flood irrigation, drip irrigation, and sub-surface pipe drainage under drip irrigation) improve the saline-alkali soil in Xinjiang, China. We aimed to study the transport characteristics of soil water and salt under different irrigation and drainage modes, and analyze the effects of the combination of irrigation and drainage on soil salt leaching, as well as its impacts on the growth of oil sunflower. Our results show that sub-surface pipe drainage under drip irrigation significantly reduced the soil salt content and soil water content at the 0–200 cm soil depth. Under sub-surface pipe drainage combined with drip irrigation, the mean soil salt content was reduced to below 10 g/kg after the second irrigation, and the soil salt content decreased as sub-surface pipe distance decreased. The mean soil salt content of flood irrigation exceeded 25 g/kg, and the mean soil desalination efficiency was 3.28%, which was lower than that of drip irrigation. The mean soil desalination rate under drip irrigation and sub-surface pipe drainage under drip irrigation was 19.30% and 58.12%, respectively. After sub-surface drainage regulation under drip irrigation, the germination percentage of oil sunflower seedlings was increased to more than 50%, which further confirmed that combined drip irrigation and sub-surface pipe drainage is very effective in improving the quality of saline-alkali soil and increasing the productivity of agricultural crops.
基金supported by the National 973 project (2009CB421302)the National Project (2007BAC03A0604)the key National Natural Science Foundation (40830640)
文摘Effects of soil moisture on cotton root length density (total root length per unit soil volume) and yield under drip irrigation with plastic mulch were studied through field experiments. The results indicate that spatial distributions of root length density of cotton under various water treatments were basically similar. Horizontally, both root length densities of cotton in wide and narrow rows were similar, and higher than that between mulches. Vertically, root length density of cotton decreased with increasing soil depth. The distribution of root length density is different under different irrigation treatments. In conditions of over-irrigation, the root length density of cotton between mulches would increase. However, it would decrease in both the wide rows and narrow rows. The mean root length density of cotton increased with increasing irrigation water. Water stress caused the root length density to increase in lower soil layers. There is a significant correlation between root length density and yields of cotton at the flower-boll and wadding stages. The regression between irrigation amount and yield of cotton can be expressed as y = -0.0026x2+18.015x-24845 (R2 = 0.959). It showed that the irrigation volume of 3,464.4 m3/hm2 led to op-timal root length density. The yield of cotton was 6,360 .8 kg/hm2 under that amount of irrigation.
基金supported by the Special Fund for Agro-scientific Research in the Public Interest(20130313006,201503136)the National Natural Science Foundation of China(31660073)+1 种基金the National Key Research and Development Program of China(2017YFD0200803-04,2018YFD0800804,2017YFD0201900)the Youth Foundation of Xinjiang Academy of Agricultural Sciences(xjnkq-2015002)
文摘Biochar addition can improve the physical and hydraulic characteristics of sandy soil.This study investigated the effects of biochar on water holding capacity and water movement in sandy soil under drip irrigation.By indoor simulation experiments,the effects of biochar application at five levels(0%,1%,2%,4%and 6%)on the soil water retention curve,infiltration characteristics of drip irrigation and water distribution were tested and analyzed.The results showed that biochar addition rate was positively correlated with water holding capacity of sandy soil and soil available water.Within the same infiltration time,with an increasing amount of added biochar,the diffusion distance of the horizontal wetting front(HWF)tended to decrease,while the infiltration distance of vertical wetting front(VWF)initially declined and then rose.The features of wetted bodies changed from"broad-shallow"to"narrow-deep"type.The relationship between the transport distances of HWF and VWF and the infiltration time was described by a power function.At the same distance from the point source,the larger the amount of added biochar,the higher the soil water content.Biochar had a great influence on the water content of the layer with biochar(0–200 mm)and had some effects at 200–250 mm without biochar;but it had less influence on the soil water content deeper than 250 mm.For the application rate of biochar of 4%,most water was retained within 0–250 mm soil layer.However,when biochar application amount was high(6%),it would be helpful for water infiltration.During the improvement of sandy soil,biochar application rate of 4%in the plow layer had the best effect.
文摘A retained bile duct stone after operation for cholelithiasis still occurs and causes symptoms such as biliary colic and obstructive jaundice.An endoscopic retrograde cholangiopancreatography with endoscopic sphincterotomy(EST),followed by stone extraction,are usually an effective treatment for this condition.However,these procedures are associated with severe complications including pancreatitis,bleeding,and duodenal perforation.Nitrates such as glyceryl trinitrate(GTN) and isosorbide dinitrate(ISDN) are known to relax the sphincter of Oddi.In 6 cases in which a retained stone was detected following cholecystectomy,topical nitrate drip infusion via cystic duct tube(C-tube) was carried out.Retained stones of 2-3 mm diameter and no dilated common bile duct in 3 patients were removed by drip infusion of 50 mg GTN or 10 mg ISDN,which was the regular dose of intravenous injection.Three other cases failed,and EST in 2 cases and endoscopic biliary balloon dilatation in 1 case were performed.One patient developed an adverse event of nausea.Severe complications were not observed.We consider the topical nitrate drip infusion via C-tube to be old but safe,easy,and inexpensive procedure for retained bile duct stone following cholecystectomy,inasmuch as removal rate was about 50% in our cases.
基金supported by the National High Technology Research and Development Program of China(2011AA100508)the National Natural Science Foundation of China(31471947,31860587)
文摘Drip irrigation can produce high rice yields with significant water savings;therefore,it is widely used in arid area water-scarce northern China.However,high-frequency irrigation of drip irrigation with low temperature well water leads to low root zone temperature and significantly reduce the rice yield compared to normal temperature water irrigated rice,for example,reservoir water.The main purpose of this paper is to investigate the effects of low soil temperature on the yield reduction of drip irrigated rice in the spike differentiation stage.The experiment set the soil temperatures at 18℃,24℃and 30℃under two irrigation methods(flood and drip irrigation),respectively.The results showed that,at the 30℃soil temperature,drip irrigation increased total root length by 53%but reduced root water conductivity by 9%compared with flood irrigation.Drip irrigation also increased leaf abscisic acid and proline concentrations by 13%and 5%,respectively.These results indicated that drip irrigated rice was under mild water stress.In the 18℃soil temperature,drip irrigation reduced hydraulic conductivity by 58%,leaf water potential by 40%and leaf net photosynthesis by 25%compared with flood irrigation.The starch concentration in male gametes was also 30%less in the drip irrigation treatment than in the flood irrigation treatment at soil temperature 18℃.Therefore,the main reason for the yield reduction of drip irrigated rice was that the low temperature aggravates the physiological drought of rice and leads to the decrease of starch content in male gametes and low pollination fertilization rate.Low temperature aggravates physiological water deficit in drip irrigated rice and leads to lower starch content in male gametes and low pollination fertilization rate,which is the main reason for the reduced yield of drip irrigated rice.Overall,the results indicated that the low soil temperatures aggravated the water stress that rice was under in the drip irrigated environment,causing declines both in the starch content of male gametes and in pollination rate.Low temperature will ultimately affect the rice yield under drip irrigation.
基金National Natural Science Foundation of China(51109102,51469010,51769010)the basic research project of Yunnan Province(2014FB130)key project of education department in Yunnan Province(2011Z035)
文摘The objective of this study was to obtain the water-saving and efficient production mode of Arabica coffee. The effects of three drip irrigation modes,conventional drip irrigation( CDI),alternate drip irrigation( ADI) and fixed drip irrigation( FDI) on growth,photosynthetic characteristics,biomass accumulation and irrigation water use efficiency of Arabica coffee were investigated under three nitrogen levels,high nitrogen( NH),middle nitrogen( NM) and low nitrogen( NL). The results show that there was a significant Logistic curve between the plant height,the stem diameter of Arabica coffee and growth days. Compared with CDI,ADI had no significant effects on leaf net photosynthetic rate,stomatal conductance,instantaneous water use efficiency and biomass accumulation above ground of Arabica coffee,while FDI decreased significantly,ADI and FDI increased irrigation water use efficiency by 50. 59% and 32. 85%,respectively. Compared with NH,with the reduction of N application rate,net photosynthetic rate,stomatal conductance,biomass accumulation above ground and irrigation water use efficiency decreased by 6. 81%-12. 30%,13. 70%-22. 69%,9. 61%-16. 67% and 9. 78%-15. 64%,respectively. Compared with CDINH,ADINHdecreased net photosynthesis rate and the stomatal conductance not significantly,other treatments decreased by 9. 16%-19. 22%,14. 49%-32. 91%,and decreased biomass accumulation above ground by 8. 26%-27. 34% except ADINH,and increased irrigation water use efficiency by 16. 46%-60. 95% except CDINMand CDINL. Therefore,alternate drip irrigation under high N level( ADINH) is the best water and nitrogen coupling mode of young Arabica coffee tree for water efficiency.
基金the National Key Research and Development Program of China(2016YFD0300103)the Science and Technology Project of Education Department of Jiangxi Province,China(GJJ190933)+2 种基金the Jiangxi Youth Science Foundation Project,China(20202BABL215003)the Innovation Engineering Plan Project of Jilin Province,China(CXGC2018ZY019)the Chongqing Science and Technology Commission Project,China(cstc2018jxjl80008).
文摘The Northeast Plain is the largest maize production area in China,and drip irrigation has recently been proposed to cope with the effects of frequent droughts and to improve water use efficiency(WUE).In order to develop an efficient and environmentally friendly irrigation system,drip irrigation experiments were conducted in 2016-2018 incorporating different soil water conservation measures as follows:(1)drip irrigation under plastic film mulch(PI),(2)drip irrigation under biodegradable film mulch(BI),(3)drip irrigation incorporating straw returning(SI),and(4)drip irrigation with the tape buried at a shallow soil depth(OI);with furrow irrigation(FI)used as the control.The results showed that PI and Bl gave the highest maize yield,as well as the highest WUE and nitrogen use efficiency(NUE)because of the higher root length density(RLD)and better heat conditions during the vegetative stage.But compared with BI,PI consumed more soil water in the 20-60 and 60-100 cm soil layers,and accelerated the progress of root and leaf senescence due to a larger root system in the top 0-20 cm soil layer and a higher soil temperature during the reproductive stage.SI was effective in improving soil water and nitrate contents,and promoted RLD in deeper soil layers,thereby maintaining higher physiological activity during the reproductive stage.FI resulted in higher nitrate levels in the deep 60-100 cm soil layer,which increased the risk of nitrogen losses by leaching compared with the drip irrigation treatments.RLD in the 0-20 cm soil layer was highly positively correlated with yield,WUE and NUE(P<0.001),but it was negatively correlated with root nitrogen use efficiency(NRE)(P<0.05),and the correlation was weaker in deeper soil layers.We concluded that Bl had advantages in water-nitrogen utilization and yield stability response to drought stress,and thus is recommended for environmentally friendly and sustainable maize production in Northeast China.
文摘Current methods for nasal spray formulations have been elementary evaluating the dripping characteristics of a formulation and have not assessed the behavior of the nasal formulation in the presence of varying types of mucus depending on the indication or diseased state. This research investigated the effects of nasal mucus on the dripping behavior of nasal formulations and focused on developing an improved in vitro analytical test method that is more physiologically relevant in characterizing nasal formulation dripping behavior. Method development was performed using simulated nasal mucus preparations for both healthy and diseased states as coatings for the dripping experiment representing a wide range of viscosity. Factors evaluated during development of this in vitro test method included amount of mucus, application of mucus, drying times, and compatibility of the mucus on a C18 Thin Layer Chromatography(TLC) substrate. The dripping behavior of nasal formulations containing a range of 1%Avicel to 3.5% Avicel was assessed by actuating the nasal spray on a perpendicular TLC plate coated with either healthy or diseased simulated nasal mucus. After actuation of the nasal spray, the dripping of the formulation on the coated TLC plate was measured after the plate was repositioned vertically. The method that was developed generated reproducible results on the dripping behavior of nasal formulations and provided critical information about the compatibility of the formulation with the nasal mucus for different diseased states, aiding in nasal spray formulation development and physical characterization of the nasal spray.
文摘Laboratory tests were conducted at the Irrigation Devices and Equipment’s Test Laboratory, Agricultural Engineering Research Institute, Agriculture Research Center, Giza, Egypt. The experimental design of laboratory experiments was split in randomized complete block design with three replicates. Laboratory tests carried out on three irrigation lateral lines of 40, 60, 80 m under the following three drip irrigation circuit (DIC) designs;1) one manifold for lateral lines or closed circuits with one manifold of drip irrigation system (CM1DIS);2) closed circuits with two manifolds for lateral lines (CM2DIS), and 3) traditional drip irrigation system (TDIS) as a control. The aims of the work were to study the effect of drip irrigation circuits (DIC) and lateral lines lengths (LLL;where): (LLL1 = 40 m, LLL2 = 60 m, and LLL3 = 80 m) on pressure head (PH) and friction loss (FL). Regarding to LLL and according to PH values, DIC designs could be ranked in the following ascending order: TDIS 1DIS 2DIS. The differences in PH among DIC designs were significant at the 1% level. The depressive effects of LLL on PH could be ranked in the following ascending order: LLL1 2 ≤ LLL3. Differences in PH among LLL treatments were significant at the 1% level except that between LLL2 and LLL3. The effects of interactions among: DIC × LLL on PH were significant at the 1% level with some exceptions. The highest value of PH (9.5 m) and the lowest one (6.05 m) were achieved in the interactions of CM2DIS × LLL1 and TDIS × LLL3, respectively. The shapes of the energy gradient lines were affected by DIC and LLL treatments used through their effect on ?H/H ratio. However, they followed similar trends. According to the FL values, DIC and LLL treatments could be ranked in the following descending orders TDIS > CM1DIS > CM2DIS and LLL1 > LLL2 > LLL3. The differences in FL among DIC and LLL were significant and the effects of interactions among DIC × LLL on FL were significant at the 1% level. The maximum and minimum values of FL were obtained in the interactions: TDIS × LLL3 and CM2DIS × LLL1, respectively. Therefore, the CM2DIS system is recommended for use where technically feasible.
