Field irrigation experiments were conducted in the Hetao Irrigation District of Inner Mongolia,China,to study the effects of irrigation regimes on salt leaching in the soil profile.The data were used to calibrate and ...Field irrigation experiments were conducted in the Hetao Irrigation District of Inner Mongolia,China,to study the effects of irrigation regimes on salt leaching in the soil profile.The data were used to calibrate and validate the HYDRUS-1D model.The results demonstrated that the model can accurately simulate the water and salt dynamics in the soil profile.The HYDRUS-1D model was then used to simulate 15 distinct irrigation scenarios.The results of the simulation indicated that irrigation amount did not have a significant effect on soil water storage but that increases in irrigation amount could accelerate salt leaching.However,when the irrigation amount was larger than 20 cm,the acceleration was not obvious.Compared with irrigating only once,intermittent irrigation had a better effect on increasing soil water storage and salt leaching,but excessive irrigation times and intervals did not improve salt leaching.In addition,we found that the irrigation regime of 20 cm,irrigated twice at 1-d intervals,might significantly increase salt leaching in the plough layer and decrease the risks of deep seepage and groundwater contamination.展开更多
The shortage of groundwater resources is a considerable challenge for winter wheat production on the North China Plain.Water-saving technologies and procedures are thus urgently required.To determine the water-saving ...The shortage of groundwater resources is a considerable challenge for winter wheat production on the North China Plain.Water-saving technologies and procedures are thus urgently required.To determine the water-saving potential of using micro-sprinkling irrigation(MSI)for winter wheat production,field experiments were conducted from 2012 to 2015.Compared to traditional flooding irrigation(TFI),micro-sprinkling thrice with 90 mm water(MSI1)and micro-sprinkling four times with 120 mm water(MSI2)increased the water use efficiency by 22.5 and 16.2%,respectively,while reducing evapotranspiration by 17.6 and 10.8%.Regardless of the rainfall pattern,MSI(i.e.,MSI1 or MSI2)either stabilized or significantly increased the grain yield,while reducing irrigation water volumes by 20–40%,compared to TFI.Applying the same volumes of irrigation water,MSI(i.e.,MSI3,micro-sprinkling five times with 150 mm water)increased the grain yield and water use efficiency of winter wheat by 4.6 and 11.7%,respectively,compared to TFI.Because MSI could supply irrigation water more frequently in smaller amounts each time,it reduced soil layer compaction,and may have also resulted in a soil water deficit that promoted the spread of roots into the deep soil layer,which is beneficial to photosynthetic production in the critical period.In conclusion,MSI1 or MSI2 either stabilized or significantly increased grain yield while reducing irrigation water volumes by 20–40%compared to TFI,and should provide water-saving technological support in winter wheat production for smallholders on the North China Plain.展开更多
Water shortages within the western USA are resulting in the adoption of water-saving agricultural practices within this region. Among the many possible methods for saving water in agriculture, the adoption of subsurfa...Water shortages within the western USA are resulting in the adoption of water-saving agricultural practices within this region. Among the many possible methods for saving water in agriculture, the adoption of subsurface drip irrigation (SDI) provides a potential solution to the problem of low water use efficiency. Other advantages of SDI include reduced NO3 leaching compared to surface irrigation, higher yields, a dry soil surface for improved weed control, better crop health, and harvest flexibility for many specialty crops. The use of SDI also allows the virtual elimination of crop water stress, the ability to apply water and nutrients to the most active part of the root zone, protection of drip lines from damage due to cultivation and tillage, and the ability to irrigate with wastewater while preventing human contact. Yet, SDI is used only on a minority of cropland in the arid western USA. Reasons for the limited adoption of SDI include the high initial capital investment required, the need for intensive management, and the urbanization that is rapidly consuming farmland in parts of the western USA. The contributions of SDI to increasing yield, quality, and water use efficiency have been demonstrated. The two major barriers to SDI sustainability in arid regions are economics (i.e., paying for the SDI system), including the high cost of installation; and salt accumulation, which requires periodic leaching, specialized tillage methods, or transplanting of seedlings rather than direct-seeding. We will review advances in irrigation management with SDI.展开更多
On the basis of analyzing water resources,crop planning structure,and irrigation mode in Lixin County,potentials and benefits of developing efficient water-saving irrigation in the county were explored to provide refe...On the basis of analyzing water resources,crop planning structure,and irrigation mode in Lixin County,potentials and benefits of developing efficient water-saving irrigation in the county were explored to provide references for its future water-saving irrigation.展开更多
The primary purpose of this research was to give suitable irrigation program according to the growth period and water requirement.A cotton field experiment with mulched drip irrigation was conducted at the National Fi...The primary purpose of this research was to give suitable irrigation program according to the growth period and water requirement.A cotton field experiment with mulched drip irrigation was conducted at the National Field Observation and Research Station for Oasis Farmland Ecosystem in Aksu of Xinjiang in 2008.Water balance method was adopted to study the water requirement and water consumption law of cotton under mulched drip irrigation in Tarim Irrigated Area.Statistical analysis of experimental data of irrigation indicates that the relationship between yield of cotton and irrigation presents a quadratic parabola.We fit the model of cotton water production on the basis of field experimental data of cotton.And the analysis on water saving benefit of cotton under mulched drip irrigation was done.Results indicate that water requirements for the irrigated cotton are 543 mm in Tarim Irrigated Area.The water requirements of seedling stage is 252 mm,budding stage is 186 mm,bolling stage is 316 mm and wadding stage is 139 mm.the irrigation amount determines the spatial distribution of soil moisture and water consumption during cotton life cycle.However,water consumption at different growth stages was inconsistent with irrigation.Quantitatively,the water consumed by cotton decreases upon the increase of irrigation amount.From the perspective of water saving,the maximal water use efficiency can reach 3 091 m3/ha.But the highest cotton yield needs 3464 m3/ha irrigation water.In summary,compared to the conventional drip irrigation,a number of benefits in water saving and yield increase were observed when using plastic mulch.At the same amount of irrigation,the cotton yield with plastic mulch was 30.2% higher than conventional approaches,and the efficiency of water utilization increased by30.2%.While at the same yield level,29.3% water was saved by using plastic mulch,and the efficiency increased by 41.5%.展开更多
Two wheat cultivars, strong-gluten Yumai66 and medium-strong-gluten Yumai49, were usedto test the effects of irrigation and nitrogen application regimes on cooking quality ofChinese noodle in 2001-2002. The results sh...Two wheat cultivars, strong-gluten Yumai66 and medium-strong-gluten Yumai49, were usedto test the effects of irrigation and nitrogen application regimes on cooking quality ofChinese noodle in 2001-2002. The results showed that both in Yumai49 and Yumai66, valueof total organic matter (TOM) of noodle and noodle cooking loss rate ranked the firstwhile noodle score (NS) ranked the lowest in treatments without any nitrogen application.As nitrogen application rate increased, TOM value decreased but NS increased. The lowestTOM and the highest NS existed for treatments with 225 and 150 kg N ha-1 in Yumai49 andYumai66, respectively. Increasing irrigation resulted in greater TOM and NS, but lessbroken noodles. However, no significant difference was found in NS among differentirrigation treatments. Significant difference was found in TOM, NS, breaking rate andwater absorption rate of noodle between these two cultivars. Yumai49, with an average TOMvalue of 1.19 g and NS of 88.5, was better than Yumai66, with an average TOM value of1.55 and NS of 85.7. Interaction in TOM value was found between irrigation and nitrogenapplication. Effects of nitrogen fertilization were greater than that of irrigation inYumai49, while in Yumai66 the other way round. It is suggested, therefore, thosedifferent irrigation and nitrogen application regimes be chosen in production practicebased upon cultivar quality traits.展开更多
A field study to evaluate the “growth and yield of sesame (Sesamum indicum L.) under the influence of planting geometry and irrigation regimes” was carried out at Oilseeds Section, Agriculture Research Institute, Ta...A field study to evaluate the “growth and yield of sesame (Sesamum indicum L.) under the influence of planting geometry and irrigation regimes” was carried out at Oilseeds Section, Agriculture Research Institute, Tandojam located at (25°25'60"N, 68°31'60"E) during Kharif 2013. The experiment was laid out in a three replicated randomized complete block design (RCBD) factorial, having net plot size 3 × 3 m (9 m2). The treatments comprised three planting geometry (30 × 20 cm, 45 × 15 cm and 60 × 10 cm) and three irrigation regimes (2 irrigations at 20 and 40 DAS, 3 irrigations at 20, 40 and 60 DAS and 4 irrigations at 20, 40, 60 and 80 DAS). The analysis of variance showed that all the planting geometry and irrigation regimes significantly (P -1 (15.67), capsules plant-1 (38.00), seeds capsule-1 (51.44), seed weight plant-1 (31.89 g), seed index (2.83 g), biological yield (2301.23 kg·ha-1), seed yield (742.33 kg·ha-1) and harvest index (30.44%), followed by planting geometry of 60 × 10 cm in all the parameters. However, minimum growth and yield traits of sesame were recorded under planting geometry of 30 × 20 cm. Moreover, plant height was maximum (99.89 cm) under planting geometry of 30 × 20 cm. Among irrigation regimes, four irrigations (20, 40, 60 and 80 DAS) recorded maximum plant height (103.33 cm), branches plant-1 (16.44), capsules plant-1 (41.22), seeds capsule-1 (54.56), seed weight plant-1 (33.22 g), seed index (2.92 g), biological yield (2321.21 kg·ha-1), seed yield (748.78 kg·ha-1) and harvest index (31.00%), followed by three irrigations (20, 40 and 60 DAS) almost in all the traits. However, minimum growth and yield traits of sesame were recorded when crop was applied two irrigations (20 and 40 DAS). In case of interactive effects, the interaction of planting geometry of 45 × 15 cm × four irrigations (20, 40, 60 and 80 DAS) resulted in maximum attributes, particularly seed yield (765.00 kg·ha-1), whereas minimum traits were noted in the interaction of planting geometry of 30 × 20 cm × two irrigations (20 and 40 DAS). Furthermore, the results of four and three irrigations had non-significant differences with each other means not sharing the same letter differ significantly at 0.05 probability level. Hence, it is concluded that interaction of 45 × 15 cm planting geometry and three irrigations (20, 40 and 60 DAS) is conducive to produce maximum seed yield (kg·ha-1) of sesame.展开更多
<div style="text-align:justify;"> Water is the key factor to ensure plant survival in the process of ecological restoration in the coal base of China northwest deserts. On the premise of meeting the mi...<div style="text-align:justify;"> Water is the key factor to ensure plant survival in the process of ecological restoration in the coal base of China northwest deserts. On the premise of meeting the mine production and living water demands, we should take measures such as dirt wastewater treatment and water-saving irrigation to increase income and reduce expenditure and allocate limited water re-sources rationally, to provide mining area ecological restoration maximum usable water resources. The mining dump has large slope and thin soil layer and it is easy to produce surface runoff. So it is particularly important to study the irrigation technology needed to satisfy vegetation restoration, on the premise of guaranteeing not to produce surface runoff and the slope stability. In this paper, through field plot test, the suitable irrigation method for mine slope, slope surface soil moisture migration characteristics and slope stability analysis were studied. Results show that three slope ir-rigation technologies have their own advantages and disadvantages. On the whole, the effect of drip irrigation is the best, micro spray irrigation is the second, infiltrating irrigation is not ideal. The permeability of mine soil slope is very strong, the infiltration rate of the slope direction is the high-est, inverse slope infiltration rate is lowest. In the process of irrigation, with the increase of soil moisture content, slope safety factor is the decreased obviously, the whole slope surface soil moisture content is 14% for the slope stability safety threshold. </div>展开更多
Water availability is a major constraint on grain production in China, therefore, improving irrigation efficiency is particularly important when agriculture faces extreme weather events. This paper first calculates ir...Water availability is a major constraint on grain production in China, therefore, improving irrigation efficiency is particularly important when agriculture faces extreme weather events. This paper first calculates irrigation efficiency with a translog stochastic frontier production function and then investigates what happens when extreme weather events occur via a Tobit model. The estimated results reveal several important features of irrigation practices: i) irrigation efficiency is lower when extreme weather events occur; ii) large variations in irrigation efficiency occur across irrigation facilities; iii) the farm plots exhibit an extreme distribution across efficiency levels; and iv) water-saving techniques, technology adoption, and the maintenance of farmers’ economic resilience are major determinants of irrigation efficiency. Based on these results we propose the following recommendations: i) farmers should balance crop yield and water use; undertake relevant training programs and adopt water-saving techniques; ii) local governments and researchers should help farmers to find the optimal level of irrigation water use based on their own circumstances and provide better water-saving techniques and training programs rather than simply encouraging farmers to invest in irrigation facilities in the most extreme weather years; and iii) the income level of farm households should be increased so as to improve their resilience to natural disasters.展开更多
With increasing water shortage resources and extravagant nitrogen application, there is an urgent need to optimize irrigation regimes and nitrogen management for winter wheat(Triticum aestivum L.) in the North China...With increasing water shortage resources and extravagant nitrogen application, there is an urgent need to optimize irrigation regimes and nitrogen management for winter wheat(Triticum aestivum L.) in the North China Plain(NCP). A 4-year field experiment was conducted to evaluate the effect of three irrigation levels(W1, irrigation once at jointing stage; W2, irrigation once at jointing and once at heading stage; W3, irrigation once at jointing, once at heading, and once at filling stage; 60 mm each irrigation) and four N fertilizer rates(N0, 0; N1, 100 kg N ha-(-1); N2, 200 kg N ha-(-1); N3, 300 kg N ha-(-1)) on wheat yield, water use efficiency, fertilizer agronomic efficiency, and economic benefits. The results showed that wheat yield under W2 condition was similar to that under W3, and greater than that under W1 at the same nitrogen level. Yield with the N1 treatment was higher than that with the N0 treatment, but not significantly different from that obtained with the N2 and N3 treatments. The W2 N1 treatment resulted in the highest water use and fertilizer agronomic efficiencies. Compared with local traditional practice(W3 N3), the net income and output-input ratio of W2 N1 were greater by 12.3 and 19.5%, respectively. These findings suggest that two irrigation events of 60 mm each coupled with application of 100 kg N ha-(–1) is sufficient to provide a high wheat yield during drought growing seasons in the NCP.展开更多
Droplet shear stress is considered as an important indicator that reflects soil erosion in sprinkler irrigation more accurately than kinetic energy,and the effect of droplet impact angle on the shear stress cannot be ...Droplet shear stress is considered as an important indicator that reflects soil erosion in sprinkler irrigation more accurately than kinetic energy,and the effect of droplet impact angle on the shear stress cannot be ignored.In this study,radial distribution of droplet impact angles,velocities,and shear stresses were investigated using a two-dimensional video disdrometer with three types of low-pressure sprinkler(Nelson D3000,R3000,and Komet KPT)under two operating pressures(103 and 138 kPa)and three nozzle diameters(3.97,5.95,and 7.94 mm).Furthermore,the relationships among these characteristical parameters of droplet were analyzed,and their influencing factors were comprehensively evaluated.For various types of sprinkler,operating pressures,and nozzle diameters,the smaller impact angles and larger velocities of droplets were found to occur closer to the sprinkler,resulting in relatively low droplet shear stresses.The increase in distance from the sprinkler caused the droplet impact angle to decrease and velocity to increase,which contributed to a significant increase in the shear stress that reached the peak value at the end of the jet.Therefore,the end of the jet was the most prone to soil erosion in the radial direction,and the soil erosion in sprinkler irrigation could not only be attributed to the droplet kinetic energy,but also needed to be combined with the analysis of its shear stress.Through comparing the radial distributions of average droplet shear stresses among the three types of sprinklers,D3000 exhibited the largest value(26.94-3313.51 N/m^(2)),followed by R3000(33.34-2650.80 N/m^(2)),and KPT(16.15-2485.69 N/m^(2)).From the perspective of minimizing the risk of soil erosion,KPT sprinkler was more suitable for low-pressure sprinkler irrigation than D3000 and R3000 sprinklers.In addition to selecting the appropriate sprinkler type to reduce the droplet shear stress,a suitable sprinkler spacing could also provide acceptable results,because the distance from the sprinkler exhibited a highly significant(P<0.01)effect on the shear stress.This study results provide a new reference for the design of low-pressure sprinkler irrigation system.展开更多
Wheat straw burial has great potential to sustain rice production under alternate wetting and drying(AWD)irrigation.A field experiment was conducted with three wheat straw burial treatments,including without straw bur...Wheat straw burial has great potential to sustain rice production under alternate wetting and drying(AWD)irrigation.A field experiment was conducted with three wheat straw burial treatments,including without straw burial(NSB),with light straw burial of 300 kg/hm^(2)(LSB)and dense straw burial of 800 kg/hm^(2)(DSB),as well as three AWD regimes:alternate wetting/moderate drying(AWMD),alternate wetting/severe drying(AWSD)and alternate wetting/critical drying(AWCD).The rice growth and grain quality were higher in LSB and NSB than those in NSB under the same AWD regime.The AWMD×DSB treatment resulted in the highest yield,brown rice rate,milled rice rate,amylose content and protein content.Conversely,the AWCD×NSB treatment led to the lowest yield,brown rice rate,milled rice rate,amylose content and protein content.The active absorption area and nitrate reductase activity of roots were higher in the AWMD×DSB treatment than those in the AWCD×NSB treatment,as the former increased organic carbon and nitrogen contents in the rhizosphere,whereas the latter reduced their availability.Total soluble protein content and glutamine synthetase activity were greater in the AWMD×DSB treatment than those in the AWCD×NSB treatment.The activities of superoxide dismutase and catalase were higher in the AWMD×DSB treatment compared with the AWCD×NSB treatment,leading to the amelioration of oxidative cell injury,as shown by a lower malonaldehyde level.This study suggested that farmers should implement AWMD irrigation after leaving the straw residues in the field,followed by deep tillage to improve soil quality and mitigate the drought stress cycles of AWD.This approach can improve rice growth and grain quality and alleviate the problems of disposal of straw residues and water scarcity for sustainable rice production.展开更多
Xinjiang's agriculture is a typical irrigated agriculture for its agriculture water consumption accounts for 96%of the total water use.As a typical resource-deficient area,the key to Xinjiang's agricultural de...Xinjiang's agriculture is a typical irrigated agriculture for its agriculture water consumption accounts for 96%of the total water use.As a typical resource-deficient area,the key to Xinjiang's agricultural development is saving water.This paper takes the high-efficient water-saving irrigation technology of 41 regions along the Tarim River from 2002 to 2013 as the research object,adopts spatial stochastic frontier model to measure the space efficiency of high-efficient water-saving irrigation technology,and analyzes the effect of water-saving irrigation technology on agricultural development.Results show that the water-saving irrigation technology has a spatial effect,if neglecting it,the error of missing variables will occur,and the average loss will be 6.98 percentage points.The spatial correlation effect promotes the improvement of the efficiency of water-saving irrigation technology.The spatial heterogeneity leads to the spatial imbalance of the efficiency of water-saving irrigation technology.The promotion of agricultural water-saving irrigation technology can increase production and the efficiency of agricultural development.Due to the technical heterogeneity of different types of water-saving irrigation technology,the contribution to the development of agriculture is also different.The study finds that water-saving irrigation technology of drip irrigation in the Tarim River contributes more to agricultural development.展开更多
Rice is one of the major crops in China,and enhancing the rice yield and water use efficiency is critical to ensuring food security in China.Determining how to optimize a scientific and efficient irrigation and draina...Rice is one of the major crops in China,and enhancing the rice yield and water use efficiency is critical to ensuring food security in China.Determining how to optimize a scientific and efficient irrigation and drainage scheme by combining existing technology is currently a hot topic.Crop growth models can be used to assess actual or proposed water management regimes intended to increase water use efficiency and mitigate water shortages.In this study,a CERES-Rice model was calibrated and validated using a two-year field experiment.Four irrigation and drainage treatments were designed for the experiment:alternate wetting and drying(AWD),controlled drainage(CD),controlled irrigation and drainage for a low water level(CID1),and controlled irrigation and drainage for a high water level(CID2).According to the indicators normalized root mean square error(NRMSE)and index of agreement(d),the calibrated CERES-Rice model accurately predicted grain yield(NRMSE=6.67%,d=0.77),,shoot biomass(NRMSE=3.37%,d=0.77),actual evapotranspiration(ETa)(NRMSE=3.83%,d=0.74),irrigation volume(NRMSE=15.56%,d=0.94),and leaf area index(NRMSE=9.69%,d=0.98)over 2 a.The calibrated model was subsequently used to evaluate rice production in response to the four treatments(AWD,CD,CID1,and CID2)under 60 meteorological scenarios which were divided into wet years(22 a),normal years(16 a),and dry years(22 a).Results showed that the yield of AWD was the largest among four treatments in different hydrological years.Relative to that of AWD,the yield of CD,CID1,and CID2 were respectively reduced by 5.7%,2.6%,8.7%in wet years,9.2%,2.3%,8.6% in normal years,and 9.2%,3.8%,3.9% in dry years.However,rainwater use efficiency and irrigation water use efficiency were the greatest for CID2 in different hydrological years.The entropy-weighting TOPSIS model was used to optimize the four water-saving irrigation schemes in terms of water-saving,labor-saving and high-yield,based on the simulation results of the CERES-Rice model in the past 60 a.These results showed that CID1 and AWD were optimal in the wet years,CID1 and CID2 were optimal in the normal and dry years.These results may provide a strong scientific basis for the optimization of water-saving irrigation technology for rice.展开更多
Winter wheat–summer maize cropping system in the North China Plain often experiences droughtinduced yield reduction in the wheat season and rainwater and nitrogen(N)fertilizer losses in the maize season.This study ai...Winter wheat–summer maize cropping system in the North China Plain often experiences droughtinduced yield reduction in the wheat season and rainwater and nitrogen(N)fertilizer losses in the maize season.This study aimed to identify an optimal interseasonal water-and N-management strategy to alleviate these losses.Four ratios of allocation of 360 kg N ha^(-1)between the wheat and maize seasons under one-time presowing root-zone irrigation(W0)and additional jointing and anthesis irrigation(W2)in wheat and one irrigation after maize sowing were set as follows:N1(120:240),N2(180:180),N3(240:120)and N4(300:60).The results showed that under W0,the N3 treatment produced the highest annual yield,crop water productivity(WPC),and nitrogen partial factor productivity(PFPN).Increased N allocation in wheat under W0 improved wheat yield without affecting maize yield,as surplus nitrate after wheat harvest was retained in the topsoil layers and available for the subsequent maize.Under W2,annual yield was largest in the N2 treatment.The risk of nitrate leaching increased in W2 when N application rate in wheat exceeded that of the N2 treatment,especially in the wet year.Compared to W2N2,the W0N3 maintained 95.2%grain yield over two years.The WPCwas higher in the W0 treatment than in the W2 treatment.Therefore,following limited total N rate,an appropriate fertilizer N transfer from maize to wheat season had the potential of a“triple win”for high annual yield,WPCand PFPN in a water-limited wheat–maize cropping system.展开更多
The present study investigated whether an irrigation system could be established to save water and increase grain yield to enhance water productivity by proper water management at the field level in irrigated lowland ...The present study investigated whether an irrigation system could be established to save water and increase grain yield to enhance water productivity by proper water management at the field level in irrigated lowland rice (Oryza sativa L.). Using two field-grown rice cultivars, two irrigation systems; conventional irrigation and water-saving irrigation, were conducted. In the water-saving irrigation system, limiting values of soil water potential related to specific growth stages were proposed as irrigation indices. Compared with conventional irrigation where drainage was in mid-season and flooded at other times, the water-saving irrigation increased grain yield by 7.4% to 11.3%, reduced irrigation water by 24.5% to 29.2%, and increased water productivity (grain yield per cubic meter of irrigation water) by 43.1% to 50.3%. The water-saving irrigation significantly increased harvest index, improved milling and appearance qualities, elevated zeatin-I-zeaUn riboside concentrations in root bleedings and enhanced activities of sucrose synthase, adenosine diphosphate glucose pyrophosphorylase, starch synthase and starch branching enzyme in grains. Our results indicate that water-saving irrigation by controlling limiting values of soil water potential related to specific growth stages can enhance physiological activities of roots and grains, reduce water input, and increase grain yield.展开更多
To investigate the effect of irrigation regime,soil clay content and their combination on growth,yield,and water productivity of rice,a shelter experiment was conduct using Randomized Complete Block Design(RCBD)with a...To investigate the effect of irrigation regime,soil clay content and their combination on growth,yield,and water productivity of rice,a shelter experiment was conduct using Randomized Complete Block Design(RCBD)with a factorial arrangement of treatments with four replications.Irrigation regime was the main treatment investigated,set in three levels as R(30 mm-100%)(100%of saturation and 30 mm flooded),R(30 mm-90%)(90%of saturation and 30 mm flooded)and R(30 mm-70%)(70%saturation and 30 mm flooded),respectively.The sub-treatment was soil type,set in three levels as 40%,50%and 60%clay content,respectively.Results showed that irrigation regime and soil clay content had significant effects on growth,yield and water productivity of rice.However,their combination showed no significant impact on panicles number,root biomass,harvest index and irrigation water productivity.Higher soil clay content results in increase in growth,yield,and water productivity of rice.The total water consumption during R(30 mm-100%)was higher than that during R(30 mm-90%)and R(30 mm-70%)because the latter two saturation levels led to the cracking of soil and decrease of total number of irrigations.Cracks were consistently getting more serious with the reduction in soil water content and the increase in soil clay content.Cracks in soil will preferentially become the major routes of water losses,thus water percolation during R(30 mm-70%)was higher than that during R(30 mm-90%)and R(30 mm-100%)after each irrigation event.The total water use under R(30 mm-70%)exceeded the water consumption under R(30 mm-90%)due to the great amount of soil cracking as well as the excessive volume of standing water depth.Considering water consumption and grain yield,the following conclusion can be reached:(i)The reduction in water consumption was greater than the reduction in grain yield in the case of drying soil 10%below saturation before reflooding.(ii)The reduction in water consumption was less than the reduction in grain yield in the case of drying soil 30%below saturation before reflooding;(iii)The increase in water use was greater than the increase in grain yield in the case of maintaining soil moisture at 100%of saturation before reflooding.Therefore,the water use efficiency was recorded in the order of R(30 mm-90%)>R(30 mm-100%)>R(30 mm-70%).展开更多
Developing water-saving irrigation regimes has important practical significance not only in alleviating the crucial water shortage,but also in controlling soil salinization for the protected cultivation in eastern Chi...Developing water-saving irrigation regimes has important practical significance not only in alleviating the crucial water shortage,but also in controlling soil salinization for the protected cultivation in eastern China.A field study with six treatments was conducted to evaluate the effects of different irrigation regimes with subdrainage systems on the soil nitrate nitrogen,salinity and moisture,also evaluate the effects on tomato growth,fruit yield and irrigation water use efficiency(IWUE).The treatments were distinguished by three different irrigation amounts of 310 mm,360 mm and 410 mm,and two irrigation frequencies of 7 and 11 times.Results showed that the irrigation amount had significant effects on the soil NO_(3)^(-)-N and electric conductivity(EC).A positive correlation was detected between soil NO_(3)^(-)-N(x)and EC(y)at 0-20 m depth after harvest,with a linear equation of y=0.063x-0.670.Soil volumetric moisture at 0.10 m and 0.20 m depth was increased as the irrigation amount increased.Moreover,a higher amount of irrigation increased the fruit yield but reduced the IWUE of tomato.It was also found that smaller irrigation amounts combined with frequent intervals could increase fruit yield and IWUE.However,the fruit quality of tomato had a significant(p<0.05)negative correlation with irrigation amount.Therefore,the parameters of irrigation regime including the irrigation amount and intervals should be considered comprehensively in order to find a compromise between salinity control and irrigation water use efficiency improvement.展开更多
基金supported by the National"Twelfth Five-Year"Plan for Science & Technology Support Program(2011BAD25B07)the State Natural Science Fund(51279142)the Fundamental Research Fund for the Central Universities of the Ministry of Science and Technology,China.(2012206020206)
文摘Field irrigation experiments were conducted in the Hetao Irrigation District of Inner Mongolia,China,to study the effects of irrigation regimes on salt leaching in the soil profile.The data were used to calibrate and validate the HYDRUS-1D model.The results demonstrated that the model can accurately simulate the water and salt dynamics in the soil profile.The HYDRUS-1D model was then used to simulate 15 distinct irrigation scenarios.The results of the simulation indicated that irrigation amount did not have a significant effect on soil water storage but that increases in irrigation amount could accelerate salt leaching.However,when the irrigation amount was larger than 20 cm,the acceleration was not obvious.Compared with irrigating only once,intermittent irrigation had a better effect on increasing soil water storage and salt leaching,but excessive irrigation times and intervals did not improve salt leaching.In addition,we found that the irrigation regime of 20 cm,irrigated twice at 1-d intervals,might significantly increase salt leaching in the plough layer and decrease the risks of deep seepage and groundwater contamination.
基金the National Key Research and Development Program of China(2017YFD0300203 and 2016YFD0300105)。
文摘The shortage of groundwater resources is a considerable challenge for winter wheat production on the North China Plain.Water-saving technologies and procedures are thus urgently required.To determine the water-saving potential of using micro-sprinkling irrigation(MSI)for winter wheat production,field experiments were conducted from 2012 to 2015.Compared to traditional flooding irrigation(TFI),micro-sprinkling thrice with 90 mm water(MSI1)and micro-sprinkling four times with 120 mm water(MSI2)increased the water use efficiency by 22.5 and 16.2%,respectively,while reducing evapotranspiration by 17.6 and 10.8%.Regardless of the rainfall pattern,MSI(i.e.,MSI1 or MSI2)either stabilized or significantly increased the grain yield,while reducing irrigation water volumes by 20–40%,compared to TFI.Applying the same volumes of irrigation water,MSI(i.e.,MSI3,micro-sprinkling five times with 150 mm water)increased the grain yield and water use efficiency of winter wheat by 4.6 and 11.7%,respectively,compared to TFI.Because MSI could supply irrigation water more frequently in smaller amounts each time,it reduced soil layer compaction,and may have also resulted in a soil water deficit that promoted the spread of roots into the deep soil layer,which is beneficial to photosynthetic production in the critical period.In conclusion,MSI1 or MSI2 either stabilized or significantly increased grain yield while reducing irrigation water volumes by 20–40%compared to TFI,and should provide water-saving technological support in winter wheat production for smallholders on the North China Plain.
基金funded by 948 Program of Ministry of Agriculture, China (2006-G52)
文摘Water shortages within the western USA are resulting in the adoption of water-saving agricultural practices within this region. Among the many possible methods for saving water in agriculture, the adoption of subsurface drip irrigation (SDI) provides a potential solution to the problem of low water use efficiency. Other advantages of SDI include reduced NO3 leaching compared to surface irrigation, higher yields, a dry soil surface for improved weed control, better crop health, and harvest flexibility for many specialty crops. The use of SDI also allows the virtual elimination of crop water stress, the ability to apply water and nutrients to the most active part of the root zone, protection of drip lines from damage due to cultivation and tillage, and the ability to irrigate with wastewater while preventing human contact. Yet, SDI is used only on a minority of cropland in the arid western USA. Reasons for the limited adoption of SDI include the high initial capital investment required, the need for intensive management, and the urbanization that is rapidly consuming farmland in parts of the western USA. The contributions of SDI to increasing yield, quality, and water use efficiency have been demonstrated. The two major barriers to SDI sustainability in arid regions are economics (i.e., paying for the SDI system), including the high cost of installation; and salt accumulation, which requires periodic leaching, specialized tillage methods, or transplanting of seedlings rather than direct-seeding. We will review advances in irrigation management with SDI.
文摘On the basis of analyzing water resources,crop planning structure,and irrigation mode in Lixin County,potentials and benefits of developing efficient water-saving irrigation in the county were explored to provide references for its future water-saving irrigation.
基金Supported by 973 Project(2009CB421302)Innovation Project of Chinese Academy of Sciences(KZCX2-YW-127)Youth Science Foundation of China(41401025)
文摘The primary purpose of this research was to give suitable irrigation program according to the growth period and water requirement.A cotton field experiment with mulched drip irrigation was conducted at the National Field Observation and Research Station for Oasis Farmland Ecosystem in Aksu of Xinjiang in 2008.Water balance method was adopted to study the water requirement and water consumption law of cotton under mulched drip irrigation in Tarim Irrigated Area.Statistical analysis of experimental data of irrigation indicates that the relationship between yield of cotton and irrigation presents a quadratic parabola.We fit the model of cotton water production on the basis of field experimental data of cotton.And the analysis on water saving benefit of cotton under mulched drip irrigation was done.Results indicate that water requirements for the irrigated cotton are 543 mm in Tarim Irrigated Area.The water requirements of seedling stage is 252 mm,budding stage is 186 mm,bolling stage is 316 mm and wadding stage is 139 mm.the irrigation amount determines the spatial distribution of soil moisture and water consumption during cotton life cycle.However,water consumption at different growth stages was inconsistent with irrigation.Quantitatively,the water consumed by cotton decreases upon the increase of irrigation amount.From the perspective of water saving,the maximal water use efficiency can reach 3 091 m3/ha.But the highest cotton yield needs 3464 m3/ha irrigation water.In summary,compared to the conventional drip irrigation,a number of benefits in water saving and yield increase were observed when using plastic mulch.At the same amount of irrigation,the cotton yield with plastic mulch was 30.2% higher than conventional approaches,and the efficiency of water utilization increased by30.2%.While at the same yield level,29.3% water was saved by using plastic mulch,and the efficiency increased by 41.5%.
文摘Two wheat cultivars, strong-gluten Yumai66 and medium-strong-gluten Yumai49, were usedto test the effects of irrigation and nitrogen application regimes on cooking quality ofChinese noodle in 2001-2002. The results showed that both in Yumai49 and Yumai66, valueof total organic matter (TOM) of noodle and noodle cooking loss rate ranked the firstwhile noodle score (NS) ranked the lowest in treatments without any nitrogen application.As nitrogen application rate increased, TOM value decreased but NS increased. The lowestTOM and the highest NS existed for treatments with 225 and 150 kg N ha-1 in Yumai49 andYumai66, respectively. Increasing irrigation resulted in greater TOM and NS, but lessbroken noodles. However, no significant difference was found in NS among differentirrigation treatments. Significant difference was found in TOM, NS, breaking rate andwater absorption rate of noodle between these two cultivars. Yumai49, with an average TOMvalue of 1.19 g and NS of 88.5, was better than Yumai66, with an average TOM value of1.55 and NS of 85.7. Interaction in TOM value was found between irrigation and nitrogenapplication. Effects of nitrogen fertilization were greater than that of irrigation inYumai49, while in Yumai66 the other way round. It is suggested, therefore, thosedifferent irrigation and nitrogen application regimes be chosen in production practicebased upon cultivar quality traits.
文摘A field study to evaluate the “growth and yield of sesame (Sesamum indicum L.) under the influence of planting geometry and irrigation regimes” was carried out at Oilseeds Section, Agriculture Research Institute, Tandojam located at (25°25'60"N, 68°31'60"E) during Kharif 2013. The experiment was laid out in a three replicated randomized complete block design (RCBD) factorial, having net plot size 3 × 3 m (9 m2). The treatments comprised three planting geometry (30 × 20 cm, 45 × 15 cm and 60 × 10 cm) and three irrigation regimes (2 irrigations at 20 and 40 DAS, 3 irrigations at 20, 40 and 60 DAS and 4 irrigations at 20, 40, 60 and 80 DAS). The analysis of variance showed that all the planting geometry and irrigation regimes significantly (P -1 (15.67), capsules plant-1 (38.00), seeds capsule-1 (51.44), seed weight plant-1 (31.89 g), seed index (2.83 g), biological yield (2301.23 kg·ha-1), seed yield (742.33 kg·ha-1) and harvest index (30.44%), followed by planting geometry of 60 × 10 cm in all the parameters. However, minimum growth and yield traits of sesame were recorded under planting geometry of 30 × 20 cm. Moreover, plant height was maximum (99.89 cm) under planting geometry of 30 × 20 cm. Among irrigation regimes, four irrigations (20, 40, 60 and 80 DAS) recorded maximum plant height (103.33 cm), branches plant-1 (16.44), capsules plant-1 (41.22), seeds capsule-1 (54.56), seed weight plant-1 (33.22 g), seed index (2.92 g), biological yield (2321.21 kg·ha-1), seed yield (748.78 kg·ha-1) and harvest index (31.00%), followed by three irrigations (20, 40 and 60 DAS) almost in all the traits. However, minimum growth and yield traits of sesame were recorded when crop was applied two irrigations (20 and 40 DAS). In case of interactive effects, the interaction of planting geometry of 45 × 15 cm × four irrigations (20, 40, 60 and 80 DAS) resulted in maximum attributes, particularly seed yield (765.00 kg·ha-1), whereas minimum traits were noted in the interaction of planting geometry of 30 × 20 cm × two irrigations (20 and 40 DAS). Furthermore, the results of four and three irrigations had non-significant differences with each other means not sharing the same letter differ significantly at 0.05 probability level. Hence, it is concluded that interaction of 45 × 15 cm planting geometry and three irrigations (20, 40 and 60 DAS) is conducive to produce maximum seed yield (kg·ha-1) of sesame.
文摘<div style="text-align:justify;"> Water is the key factor to ensure plant survival in the process of ecological restoration in the coal base of China northwest deserts. On the premise of meeting the mine production and living water demands, we should take measures such as dirt wastewater treatment and water-saving irrigation to increase income and reduce expenditure and allocate limited water re-sources rationally, to provide mining area ecological restoration maximum usable water resources. The mining dump has large slope and thin soil layer and it is easy to produce surface runoff. So it is particularly important to study the irrigation technology needed to satisfy vegetation restoration, on the premise of guaranteeing not to produce surface runoff and the slope stability. In this paper, through field plot test, the suitable irrigation method for mine slope, slope surface soil moisture migration characteristics and slope stability analysis were studied. Results show that three slope ir-rigation technologies have their own advantages and disadvantages. On the whole, the effect of drip irrigation is the best, micro spray irrigation is the second, infiltrating irrigation is not ideal. The permeability of mine soil slope is very strong, the infiltration rate of the slope direction is the high-est, inverse slope infiltration rate is lowest. In the process of irrigation, with the increase of soil moisture content, slope safety factor is the decreased obviously, the whole slope surface soil moisture content is 14% for the slope stability safety threshold. </div>
基金supported by the State Social Science Funds of China (14BGL093)the Specialized Research Fund for the Jointed Doctoral Program of Higher Education of China (20124105110006)the International Development Research Center (107093-001)
文摘Water availability is a major constraint on grain production in China, therefore, improving irrigation efficiency is particularly important when agriculture faces extreme weather events. This paper first calculates irrigation efficiency with a translog stochastic frontier production function and then investigates what happens when extreme weather events occur via a Tobit model. The estimated results reveal several important features of irrigation practices: i) irrigation efficiency is lower when extreme weather events occur; ii) large variations in irrigation efficiency occur across irrigation facilities; iii) the farm plots exhibit an extreme distribution across efficiency levels; and iv) water-saving techniques, technology adoption, and the maintenance of farmers’ economic resilience are major determinants of irrigation efficiency. Based on these results we propose the following recommendations: i) farmers should balance crop yield and water use; undertake relevant training programs and adopt water-saving techniques; ii) local governments and researchers should help farmers to find the optimal level of irrigation water use based on their own circumstances and provide better water-saving techniques and training programs rather than simply encouraging farmers to invest in irrigation facilities in the most extreme weather years; and iii) the income level of farm households should be increased so as to improve their resilience to natural disasters.
基金supported by the National Key Research and Development Program of China (2016YFD0300808)the National Key Technologies R&D Program of China during the 12th Five-Year Plan period (2013BAD05B02)+2 种基金the National Natural Science Foundation of China (31571612 and 31100191)the Science and Technology Service Network Initiative of Chinese Academy of Sciences (KFJ-STSZDTP-001)the Hebei Key Research and Development Program, China (15226407D and 17227006D)
文摘With increasing water shortage resources and extravagant nitrogen application, there is an urgent need to optimize irrigation regimes and nitrogen management for winter wheat(Triticum aestivum L.) in the North China Plain(NCP). A 4-year field experiment was conducted to evaluate the effect of three irrigation levels(W1, irrigation once at jointing stage; W2, irrigation once at jointing and once at heading stage; W3, irrigation once at jointing, once at heading, and once at filling stage; 60 mm each irrigation) and four N fertilizer rates(N0, 0; N1, 100 kg N ha-(-1); N2, 200 kg N ha-(-1); N3, 300 kg N ha-(-1)) on wheat yield, water use efficiency, fertilizer agronomic efficiency, and economic benefits. The results showed that wheat yield under W2 condition was similar to that under W3, and greater than that under W1 at the same nitrogen level. Yield with the N1 treatment was higher than that with the N0 treatment, but not significantly different from that obtained with the N2 and N3 treatments. The W2 N1 treatment resulted in the highest water use and fertilizer agronomic efficiencies. Compared with local traditional practice(W3 N3), the net income and output-input ratio of W2 N1 were greater by 12.3 and 19.5%, respectively. These findings suggest that two irrigation events of 60 mm each coupled with application of 100 kg N ha-(–1) is sufficient to provide a high wheat yield during drought growing seasons in the NCP.
基金the National Natural Science Foundation of China(51939005)the Key Research and Development Program of Hebei Province,China(21327002D)+2 种基金the Hebei Forage Industry Innovation Team of Modern Agro-industry Technology Research System of China(HBCT2018160202)the Regional Collaborative Innovation Project of Xinjiang Uygur Autonomous Region of China(2021E02056)the China Agriculture Research System of Ministry of Finance and Ministry of Agriculture and Rural Affairs(CARS-34).
文摘Droplet shear stress is considered as an important indicator that reflects soil erosion in sprinkler irrigation more accurately than kinetic energy,and the effect of droplet impact angle on the shear stress cannot be ignored.In this study,radial distribution of droplet impact angles,velocities,and shear stresses were investigated using a two-dimensional video disdrometer with three types of low-pressure sprinkler(Nelson D3000,R3000,and Komet KPT)under two operating pressures(103 and 138 kPa)and three nozzle diameters(3.97,5.95,and 7.94 mm).Furthermore,the relationships among these characteristical parameters of droplet were analyzed,and their influencing factors were comprehensively evaluated.For various types of sprinkler,operating pressures,and nozzle diameters,the smaller impact angles and larger velocities of droplets were found to occur closer to the sprinkler,resulting in relatively low droplet shear stresses.The increase in distance from the sprinkler caused the droplet impact angle to decrease and velocity to increase,which contributed to a significant increase in the shear stress that reached the peak value at the end of the jet.Therefore,the end of the jet was the most prone to soil erosion in the radial direction,and the soil erosion in sprinkler irrigation could not only be attributed to the droplet kinetic energy,but also needed to be combined with the analysis of its shear stress.Through comparing the radial distributions of average droplet shear stresses among the three types of sprinklers,D3000 exhibited the largest value(26.94-3313.51 N/m^(2)),followed by R3000(33.34-2650.80 N/m^(2)),and KPT(16.15-2485.69 N/m^(2)).From the perspective of minimizing the risk of soil erosion,KPT sprinkler was more suitable for low-pressure sprinkler irrigation than D3000 and R3000 sprinklers.In addition to selecting the appropriate sprinkler type to reduce the droplet shear stress,a suitable sprinkler spacing could also provide acceptable results,because the distance from the sprinkler exhibited a highly significant(P<0.01)effect on the shear stress.This study results provide a new reference for the design of low-pressure sprinkler irrigation system.
基金supported by the Water Conservancy Science and Technology Project of Jiangsu Province,China(Grant Nos.2020049 and 2021055).
文摘Wheat straw burial has great potential to sustain rice production under alternate wetting and drying(AWD)irrigation.A field experiment was conducted with three wheat straw burial treatments,including without straw burial(NSB),with light straw burial of 300 kg/hm^(2)(LSB)and dense straw burial of 800 kg/hm^(2)(DSB),as well as three AWD regimes:alternate wetting/moderate drying(AWMD),alternate wetting/severe drying(AWSD)and alternate wetting/critical drying(AWCD).The rice growth and grain quality were higher in LSB and NSB than those in NSB under the same AWD regime.The AWMD×DSB treatment resulted in the highest yield,brown rice rate,milled rice rate,amylose content and protein content.Conversely,the AWCD×NSB treatment led to the lowest yield,brown rice rate,milled rice rate,amylose content and protein content.The active absorption area and nitrate reductase activity of roots were higher in the AWMD×DSB treatment than those in the AWCD×NSB treatment,as the former increased organic carbon and nitrogen contents in the rhizosphere,whereas the latter reduced their availability.Total soluble protein content and glutamine synthetase activity were greater in the AWMD×DSB treatment than those in the AWCD×NSB treatment.The activities of superoxide dismutase and catalase were higher in the AWMD×DSB treatment compared with the AWCD×NSB treatment,leading to the amelioration of oxidative cell injury,as shown by a lower malonaldehyde level.This study suggested that farmers should implement AWMD irrigation after leaving the straw residues in the field,followed by deep tillage to improve soil quality and mitigate the drought stress cycles of AWD.This approach can improve rice growth and grain quality and alleviate the problems of disposal of straw residues and water scarcity for sustainable rice production.
基金supported by the National Social Science Fund under Grant No.18BTJ010Fundamental Research Projects of Central Universities Fund under Grant Nos.31512211201,31423211202,31513111217 and 31712211202。
文摘Xinjiang's agriculture is a typical irrigated agriculture for its agriculture water consumption accounts for 96%of the total water use.As a typical resource-deficient area,the key to Xinjiang's agricultural development is saving water.This paper takes the high-efficient water-saving irrigation technology of 41 regions along the Tarim River from 2002 to 2013 as the research object,adopts spatial stochastic frontier model to measure the space efficiency of high-efficient water-saving irrigation technology,and analyzes the effect of water-saving irrigation technology on agricultural development.Results show that the water-saving irrigation technology has a spatial effect,if neglecting it,the error of missing variables will occur,and the average loss will be 6.98 percentage points.The spatial correlation effect promotes the improvement of the efficiency of water-saving irrigation technology.The spatial heterogeneity leads to the spatial imbalance of the efficiency of water-saving irrigation technology.The promotion of agricultural water-saving irrigation technology can increase production and the efficiency of agricultural development.Due to the technical heterogeneity of different types of water-saving irrigation technology,the contribution to the development of agriculture is also different.The study finds that water-saving irrigation technology of drip irrigation in the Tarim River contributes more to agricultural development.
基金financially supported by the Basic Scientific Research Project of Chinese Academy of Agricultural Sciences(Grant No.FIRI2021010601)Key Technologies R&D and Promotion Program of Henan Province(Grant No.212102110031)National Natural Science Foundation of China(Grant No.52179015).
文摘Rice is one of the major crops in China,and enhancing the rice yield and water use efficiency is critical to ensuring food security in China.Determining how to optimize a scientific and efficient irrigation and drainage scheme by combining existing technology is currently a hot topic.Crop growth models can be used to assess actual or proposed water management regimes intended to increase water use efficiency and mitigate water shortages.In this study,a CERES-Rice model was calibrated and validated using a two-year field experiment.Four irrigation and drainage treatments were designed for the experiment:alternate wetting and drying(AWD),controlled drainage(CD),controlled irrigation and drainage for a low water level(CID1),and controlled irrigation and drainage for a high water level(CID2).According to the indicators normalized root mean square error(NRMSE)and index of agreement(d),the calibrated CERES-Rice model accurately predicted grain yield(NRMSE=6.67%,d=0.77),,shoot biomass(NRMSE=3.37%,d=0.77),actual evapotranspiration(ETa)(NRMSE=3.83%,d=0.74),irrigation volume(NRMSE=15.56%,d=0.94),and leaf area index(NRMSE=9.69%,d=0.98)over 2 a.The calibrated model was subsequently used to evaluate rice production in response to the four treatments(AWD,CD,CID1,and CID2)under 60 meteorological scenarios which were divided into wet years(22 a),normal years(16 a),and dry years(22 a).Results showed that the yield of AWD was the largest among four treatments in different hydrological years.Relative to that of AWD,the yield of CD,CID1,and CID2 were respectively reduced by 5.7%,2.6%,8.7%in wet years,9.2%,2.3%,8.6% in normal years,and 9.2%,3.8%,3.9% in dry years.However,rainwater use efficiency and irrigation water use efficiency were the greatest for CID2 in different hydrological years.The entropy-weighting TOPSIS model was used to optimize the four water-saving irrigation schemes in terms of water-saving,labor-saving and high-yield,based on the simulation results of the CERES-Rice model in the past 60 a.These results showed that CID1 and AWD were optimal in the wet years,CID1 and CID2 were optimal in the normal and dry years.These results may provide a strong scientific basis for the optimization of water-saving irrigation technology for rice.
基金supported by Hebei Province Key Research Project(21327003D-1)Beijing Science and Technology Planning Project(Z221100006422005)+1 种基金China Postdoctoral Science Foundation(2023M743815)China Agriculture Research System(CARS301)。
文摘Winter wheat–summer maize cropping system in the North China Plain often experiences droughtinduced yield reduction in the wheat season and rainwater and nitrogen(N)fertilizer losses in the maize season.This study aimed to identify an optimal interseasonal water-and N-management strategy to alleviate these losses.Four ratios of allocation of 360 kg N ha^(-1)between the wheat and maize seasons under one-time presowing root-zone irrigation(W0)and additional jointing and anthesis irrigation(W2)in wheat and one irrigation after maize sowing were set as follows:N1(120:240),N2(180:180),N3(240:120)and N4(300:60).The results showed that under W0,the N3 treatment produced the highest annual yield,crop water productivity(WPC),and nitrogen partial factor productivity(PFPN).Increased N allocation in wheat under W0 improved wheat yield without affecting maize yield,as surplus nitrate after wheat harvest was retained in the topsoil layers and available for the subsequent maize.Under W2,annual yield was largest in the N2 treatment.The risk of nitrate leaching increased in W2 when N application rate in wheat exceeded that of the N2 treatment,especially in the wet year.Compared to W2N2,the W0N3 maintained 95.2%grain yield over two years.The WPCwas higher in the W0 treatment than in the W2 treatment.Therefore,following limited total N rate,an appropriate fertilizer N transfer from maize to wheat season had the potential of a“triple win”for high annual yield,WPCand PFPN in a water-limited wheat–maize cropping system.
基金Supported by the National Natural Science Foundation of China(30671225)the State Key Project(2004-BA520A12-5)+1 种基金the Natural Science Foundation of Jiangsu Province(BK2006069)Hong Kong Research Grants Council(Project HKBU 2465/05M).
文摘The present study investigated whether an irrigation system could be established to save water and increase grain yield to enhance water productivity by proper water management at the field level in irrigated lowland rice (Oryza sativa L.). Using two field-grown rice cultivars, two irrigation systems; conventional irrigation and water-saving irrigation, were conducted. In the water-saving irrigation system, limiting values of soil water potential related to specific growth stages were proposed as irrigation indices. Compared with conventional irrigation where drainage was in mid-season and flooded at other times, the water-saving irrigation increased grain yield by 7.4% to 11.3%, reduced irrigation water by 24.5% to 29.2%, and increased water productivity (grain yield per cubic meter of irrigation water) by 43.1% to 50.3%. The water-saving irrigation significantly increased harvest index, improved milling and appearance qualities, elevated zeatin-I-zeaUn riboside concentrations in root bleedings and enhanced activities of sucrose synthase, adenosine diphosphate glucose pyrophosphorylase, starch synthase and starch branching enzyme in grains. Our results indicate that water-saving irrigation by controlling limiting values of soil water potential related to specific growth stages can enhance physiological activities of roots and grains, reduce water input, and increase grain yield.
基金This research is supported by the National Natural Science Foundation of China(51079042 and 51309080)Water Conservancy Science and Technology Project of Jiangsu Province.
文摘To investigate the effect of irrigation regime,soil clay content and their combination on growth,yield,and water productivity of rice,a shelter experiment was conduct using Randomized Complete Block Design(RCBD)with a factorial arrangement of treatments with four replications.Irrigation regime was the main treatment investigated,set in three levels as R(30 mm-100%)(100%of saturation and 30 mm flooded),R(30 mm-90%)(90%of saturation and 30 mm flooded)and R(30 mm-70%)(70%saturation and 30 mm flooded),respectively.The sub-treatment was soil type,set in three levels as 40%,50%and 60%clay content,respectively.Results showed that irrigation regime and soil clay content had significant effects on growth,yield and water productivity of rice.However,their combination showed no significant impact on panicles number,root biomass,harvest index and irrigation water productivity.Higher soil clay content results in increase in growth,yield,and water productivity of rice.The total water consumption during R(30 mm-100%)was higher than that during R(30 mm-90%)and R(30 mm-70%)because the latter two saturation levels led to the cracking of soil and decrease of total number of irrigations.Cracks were consistently getting more serious with the reduction in soil water content and the increase in soil clay content.Cracks in soil will preferentially become the major routes of water losses,thus water percolation during R(30 mm-70%)was higher than that during R(30 mm-90%)and R(30 mm-100%)after each irrigation event.The total water use under R(30 mm-70%)exceeded the water consumption under R(30 mm-90%)due to the great amount of soil cracking as well as the excessive volume of standing water depth.Considering water consumption and grain yield,the following conclusion can be reached:(i)The reduction in water consumption was greater than the reduction in grain yield in the case of drying soil 10%below saturation before reflooding.(ii)The reduction in water consumption was less than the reduction in grain yield in the case of drying soil 30%below saturation before reflooding;(iii)The increase in water use was greater than the increase in grain yield in the case of maintaining soil moisture at 100%of saturation before reflooding.Therefore,the water use efficiency was recorded in the order of R(30 mm-90%)>R(30 mm-100%)>R(30 mm-70%).
基金This work was financially supported by the National Natural Science Foundation of China(51509068)the China Postdoctoral Science Foundation(2015M581716)the Fundamental Research Funds for the Central Universities(2018B00314).
文摘Developing water-saving irrigation regimes has important practical significance not only in alleviating the crucial water shortage,but also in controlling soil salinization for the protected cultivation in eastern China.A field study with six treatments was conducted to evaluate the effects of different irrigation regimes with subdrainage systems on the soil nitrate nitrogen,salinity and moisture,also evaluate the effects on tomato growth,fruit yield and irrigation water use efficiency(IWUE).The treatments were distinguished by three different irrigation amounts of 310 mm,360 mm and 410 mm,and two irrigation frequencies of 7 and 11 times.Results showed that the irrigation amount had significant effects on the soil NO_(3)^(-)-N and electric conductivity(EC).A positive correlation was detected between soil NO_(3)^(-)-N(x)and EC(y)at 0-20 m depth after harvest,with a linear equation of y=0.063x-0.670.Soil volumetric moisture at 0.10 m and 0.20 m depth was increased as the irrigation amount increased.Moreover,a higher amount of irrigation increased the fruit yield but reduced the IWUE of tomato.It was also found that smaller irrigation amounts combined with frequent intervals could increase fruit yield and IWUE.However,the fruit quality of tomato had a significant(p<0.05)negative correlation with irrigation amount.Therefore,the parameters of irrigation regime including the irrigation amount and intervals should be considered comprehensively in order to find a compromise between salinity control and irrigation water use efficiency improvement.