Fruit yield, yield components, fruit mineral content, total phenolic content, antioxidant activity and irrigation water use efifciency (IWUE) of summer squash responses to different irrigation quantities were evalua...Fruit yield, yield components, fruit mineral content, total phenolic content, antioxidant activity and irrigation water use efifciency (IWUE) of summer squash responses to different irrigation quantities were evaluated with a ifeld study. Irrigations were done when the total evaporated water from a Class A pan was about 30 mm. Different irrigation quantities were adjusted using three different plant-pan coefifcients (Kcp, 100% (Kcp1), 85% (Kcp2) and 70% (Kcp3)). Results indicated that lower irrigation quantities provided statistically lower yield and yield components. The highest seasonal fruit yield (80.0 t ha-1) was determined in the Kcp1 treatment, which applied the highest volume of irrigation water (452.9 mm). The highest early fruit yield, average fruit weight and fruit diameter, length and number per plant were also determined in the Kcp1 treatment, with values of 7.25 t ha-1, 264.1 g, 5.49 cm, 19.95 cm and 10.92, respectively. Although the IWUE value was the highest in the Kcp1 treatment (176.6 kg ha-1 mm-1), it was statistically similar to the value for Kcp3 treatment (157.1 kg ha-1 mm-1). Total phenolic content and antioxidant activity of fruits was higher in the Kcp1 (44.27 μg gallic acid equivalents (GAE) mg-1 fresh sample) and in the Kcp2 (84.75%) treatments, respectively. Major (Na, N, P, K, Ca, Mg and S) and trace (Fe, Cu, Mn, Zn and B) mineral contents of squash fruits were the highest in the Kcp2 treatment, with the exception of P, Ca and Cu. Mineral contents and total phenolic content were signiifcantly affected by irrigation quantities, but antioxidant activity was not affected. It can be concluded that the Kcp1 treatment was the most suitable for achieving higher yield and IWUE. However, the Kcp2 treatment will be the most suitable due to the high fruit quality and relatively high yield in water shortage conditions.展开更多
The relation between soil water content and the growth of cotton root was studied for the scheme of field water and cotton yield under mulched drip irrigation. Based on the field experiments, three treatments of soil ...The relation between soil water content and the growth of cotton root was studied for the scheme of field water and cotton yield under mulched drip irrigation. Based on the field experiments, three treatments of soil water content were conducted with 90%, 75%θf, and 60%θf (θfis field water capacity). Cotton roots and root-shoot ratio were studied with digging method, and the soil moisture was observed with TDR (time domain reflector), and cotton yield was measured. The results indicated that the growth of cotton root accorded with Logistic growth curve in the three treatments, the cotton root grew quickly and its weight was very high under 75%θf because of the suitable soil water condition, while grew slowly and its weight was lower under 90%θf due to water moisture beyond the suitable condition, and the root weight was in between under 60%θf For the three water treatments, the cotton root weight decreased with soil depth, and decreased more significantly in deeper soil layer with the soil moisture increasing. And the ratio of cotton root weight in 0-30 cm soil layer to the total root weight was the highest under 75%θf. The cotton root system was distributed mainly in the soil of narrow row and wide row mulched with plastic film, and little in the soil outside plastic film. The weight of cotton root was the highest in the soil of narrow row or wide row mulched with plastic film under 75%θf. Root-shoot ratio decreased with the soil moisture increasing. The soil water content affected cotton yields, and cotton yield was the highest under 75%θf. The higher soil moisture level is unfavorable to the growth of cotton root system and yield of cotton under mulched drip irrigation.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
In order to explore the use of groundwater resources,field experiments were conducted for three consecutive years during 2012-2014 in the Shiyang River basin of Northwest China.Irrigation was conducted using four diff...In order to explore the use of groundwater resources,field experiments were conducted for three consecutive years during 2012-2014 in the Shiyang River basin of Northwest China.Irrigation was conducted using four different water salinity levels that were arranged in a split plot design.These four water salinity levels were s0,s3,s6 and s9(0.71,3,6 and 9 g/L,respectively).The soil salt content,soil bulk density,soil porosity,saturated hydraulic conductivity,plant height,leaf area index and yield of maize for seed production were measured for studying the effects of saline water irrigation on soil salt content distribution,soil physical properties and water use efficiency.It was observed that higher salinity level of irrigation water and long duration of saline water irrigation resulted in more salt accumulation.Compared to initial values,the soil salt accumulation in 0-100 cm soil layer after three years of experiments for s0,s3,s6 and s9 was 0.189 mg/cm3,0.654 mg/cm3,0.717 mg/cm3 and 1.135 mg/cm3,respectively.Both greater salt levels in the irrigation water and frequent saline water irrigation led to greater soil bulk density,but poorer soil porosity and less saturated hydraulic conductivity.The saturated hydraulic conductivity decreased with increase in soil bulk density,but increased with improvement in soil porosity.It was noted that the maize height,leaf area index and maize yield gradually decreased with increase in water salinity.The maize yield decreased over 25%and the water use efficiency also gradually declined when irrigated with water containing 6 g/L and 9 g/L salinity levels.However,maize yield following saline water irrigation with 3 g/L decreased less than 20%and the decline in water use efficiency was not significant during the three-year experiment period.The results demonstrate that irrigation with saline water at the level of 6 g/L and 9 g/L in the study area is not suitable,while saline water irrigation with 3 g/L would be acceptable for a short duration together with salt leaching through spring irrigation before sowing.展开更多
[Objectives]This study was conducted to investigate the effects of different irrigation quotas and irrigation times on soil physical and chemical properties and water content in the planting areas of Gentiana macrophy...[Objectives]This study was conducted to investigate the effects of different irrigation quotas and irrigation times on soil physical and chemical properties and water content in the planting areas of Gentiana macrophylla in dry farming areas of southern Ningxia.[Methods]G.macrophylla planted for three years was selected as the experimental material,and the water content,nutrients,bulk density and total porosity of the soil at different depths(0-20 and 20-40 cm)were measured under different irrigation quotas and irrigation times.[Results]Compared with the CK,different irrigation quotas and irrigation times could significantly improve the water contents of the 0-20 and 20-40 cm layers in the planting areas of G.macrophylla.The change trend of water content at the 0-20 cm soil depth was 3 times of irrigation>2 times of irrigation>1 time of irrigation>CK,and that at the 20-40 cm soil depth was 2 times of irrigation>3 times of irrigation>1 time of irrigation>CK.With the increase of irrigation times,soil urease in the 0-20 cm soil showed a trend of decreasing at first and then increasing,reaching a maximum value of 0.415 mg/g·24 h with 1 time of irrigation,which increased by 84.44%compared with the CK,and the value with two times of irrigation was basically the same as that of the CK,but 3 times of irrigation resulted in a value 57.33%higher than the CK.However,the changes of 20-40 cm were the opposite.The change trends of alkali-hydrolyzable nitrogen in the 0-20 and 20-40 cm soil layers with irrigation times was smaller,and the contents of soil organic carbon,available phosphorus and available potassium increased first and then decreased with the increase of irrigation times,and were generally higher than those in the CK.[Conclusions]This study provides a theoretical and technical basis for the artificial cultivation of G.macrophylla in dry farming areas of Ningxia.展开更多
Furrow irrigation when combined with plastic mulch on ridge is one of the current uppermost wa- ter-saving irrigation technologies for arid regions. The present paper studies the dynamics of soil water-salt trans- por...Furrow irrigation when combined with plastic mulch on ridge is one of the current uppermost wa- ter-saving irrigation technologies for arid regions. The present paper studies the dynamics of soil water-salt trans- portation and its spatial distribution characteristics under irrigation with saline water in a maize field experiment. The mathematical relationships for soil salinity, irrigation amount and water salinity are also established to evaluate the contribution of the irrigation amount and the salinity of saline water to soil salt accumulation. The result showed that irrigation with water of high salinity could effectively increase soil water content, but the increment is limited com- paring with the influence from irrigation amount. The soil water content in furrows was higher than that in ridges at the same soil layers, with increments of 12.87% and 13.70% for MMF9 (the treatment with the highest water salinity and the largest amount of irrigation water) and MMF1 (the treatment with the lowest water salinity and the least amount of irrigation water) on 27 June, respectively. The increment for MMF9 was gradually reduced while that for MMF1 increased along with growth stages, the values for 17 August being 2.40% and 19.92%, respectively. Soil water content in the ridge for MMF9 reduced gradually from the surface layer to deeper layers while the surface soil water content for MMF1 was smaller than the contents below 20 cm at the early growing stage. Soil salinities for the treatments with the same amount of irrigation water but different water salinity increased with the water salinity. When water salinity was 6.04 dS/m, the less water resulted in more salt accumulation in topsoil and less in deep layers. When water salinity was 2.89 dS/m, however, the less water resulted in less salt accumulation in topsoil and salinity remained basically stable in deep layers. The salt accumulation in the ridge surface was much smaller than that in the furrow bottom under this technology, which was quite different from traditional furrow irrigation. The soil salinities for MMF7, MMF8 and MMF9 in the ridge surface were 0.191, 0.355 and 0.427 dS/m, respectively, whereas those in the furrow bottom were 0.316, 0.521 and 0.631 dS/m, respectively. The result of correlation analysis indicated that compared with irrigation amount, the irrigation water salinity was still the main factor influ- encing soil salinity in furrow irrigation with plastic mulch on ridge.展开更多
The dynamics of water and salt in soil were monitored in the 2010 and 2011 growing seasons of cotton to evaluate the salinity risk of soil under drip irrigation in arid environments for different management practices ...The dynamics of water and salt in soil were monitored in the 2010 and 2011 growing seasons of cotton to evaluate the salinity risk of soil under drip irrigation in arid environments for different management practices of drip system uniformity and irrigation amount. In the experiments, three Christiansen uniformity coefficients (CU) of approximately 65, 80, and 95% (referred to as low, medium, and high uniformity, respectively) and three irrigation amounts of 50, 75, and 100% of full irrigation were used. The distribution of the soil water content and bulk electrical conductivity (ECb) was monitored continuously with approximately equally spaced frequency domain reflectometry (FDR) sensors located along a dripline. Gravimetric samples of soil were collected regularly to determine the distribution of soil salinity. A great fluctuation in CU of water content and ECb at 60 cm depth was observed for the low uniformity treatment during the irrigation season, while a relatively stable variation pattern was observed for the high uniformity treatment. The ECb CU was substantially lower than the water content CU and its value was greatly related to the water content CU and the initial ECb CU. The spatial variation of seasonal mean soil water content and seasonal mean soil bulk electrical conductivity showed a high dependence on the variation pattern of emitter discharge rate along a dripline for the low and medium uniformity treatments. A greater irrigation amount produced a significantly lower soil salinity at the end of the irrigation season, while the influence of the system uniformity on the soil salinity was insignificant at a probability level of 0.1. In arid regions, the determination of the target drip irrigation system uniformity should consider the potential salinity risk of soil caused by nonuniform water application as the influence of the system uniformity on the distribution of the soil salinity was progressively strengthened during the growing season of crop.展开更多
Ridge-furrow rainwater harvesting (RFRH) planting pattern can lessen the effect of water deficits throughout all crop growth stages, but water shortage would remain unavoidable during some stages of crop growth in a...Ridge-furrow rainwater harvesting (RFRH) planting pattern can lessen the effect of water deficits throughout all crop growth stages, but water shortage would remain unavoidable during some stages of crop growth in arid and semiarid areas. Supplemental irrigation would still be needed to achieve a higher production. Field experiments were conducted for two growing seasons (2012-2013 and 2013-2014)to determine an appropriate amount of supplemental irrigation to be applied to winter oilseed rape at the stem-elongation stage with RFRH planting pattern. Four treatments, including supplemental irrigation amount of 0 (I1), 60 mm (I2) and 120 mm (I3) with RFRH planting pattern and a control (CK) irrigated with 120 mm with flat planting pattern, were set up to evaluate the effects of supplemental irrigation on aboveground dry matter (ADM), nitrogen nutrition index (NNI), radiation use efficiency (RUE), water use efficiency (WUE), and seed yield and oil content of the oilseed rape. Results showed that supplemental irrigation improved NNI, RUE, seed yield and oil content, and WUE. However, the NNI, RUE, seed yield and oil content, and WUE did not increase significantly or even showed a downward trend with excessive irrigation. Seed yield was the highest in 13 for both growing seasons. Seed yield and WUE in 13 averaged 3235 kg ha^-1 and 8.85 kg ha^-1 mm-1, respectively. The highest WUE was occurred in 12 for both growing seasons. Seed yield and WUE in 12 averaged 3089 kg ha^-1 and 9.63 kg ha^-1 mm^-1, respectively. Compared to 13, 12 used 60 mm less irrigation amount, had an 8.9% higher WUE, but only 4.5 and 0.4% lower seed yield and oil content, respectively. 12 saved water without substantially sacrificing yield or oil content, so it is recommended as an appropriate cultivation and irrigation schedule for winter oilseed rape at the stem-elongation stage.展开更多
To achieve the greatest leaching efficiency,water movement must occur under unsaturated flow conditions.Accordingly,the water application intensity of irrigation must be chosen carefully.The aim of this study was to e...To achieve the greatest leaching efficiency,water movement must occur under unsaturated flow conditions.Accordingly,the water application intensity of irrigation must be chosen carefully.The aim of this study was to evaluate the impact of the water application intensity of micro-sprinkler irrigation on coastal saline soil with different salt contents.To achieve this objective,a laboratory experiment was conducted with three soil salinity treatments(2.26,10.13,and 22.29 dS/m)and three water application intensity treatments(3.05,5.19,and 7.23 mm/h).The results showed that the effect of soil salinity on soil water content,electrical conductivity,and pH was significant,and the effect of the water application intensity was insignificant.High soil water content was present in the 40e60 cm profile in all soil salinity treatments,and the content was higher in the medium and high water application intensity treatments than in the low-intensity treatment.Significant salt leaching occurred in all treatments,and the effect was stronger in the high soil salinity treatment and medium water application intensity treatment.In the medium and high soil salinity treatments,pH exhibited a decreasing trend,with no trend change in the low soil salinity treatment,and the pH value was higher in the medium water application intensity treatment than in the other two treatments.These results indicated that the three intensities evaluated had no statistically different effect on the electrical conductivity of saturated soil-paste extracts(EC)in the upper 20 cm of the soil profile,and it would be better to maintain a lower value of the water application intensity.展开更多
Furrow irrigation is a traditional widely-used irrigation method in the world. Understanding the dynamics of soil water distribution is essential to developing effective furrow irrigation strategies, especially in wat...Furrow irrigation is a traditional widely-used irrigation method in the world. Understanding the dynamics of soil water distribution is essential to developing effective furrow irrigation strategies, especially in water-limited regions. The objectives of this study are to analyze root length density distribution and to explore soil water dynamics by simulating soil water content using a HYDRUS-2D model with consideration of root water uptake for furrow irrigated tomato plants in a solar greenhouse in Northwest China. Soil water contents were also in-situ observed by the ECH_2O sensors from 4 June to 19 June and from 21 June to 4 July, 2012. Results showed that the root length density of tomato plants was concentrated in the 0–50 cm soil layers, and radiated 0–18 cm toward the furrow and 0–30 cm along the bed axis. Soil water content values simulated by the HYDRUS-2D model agreed well with those observed by the ECH_2O sensors, with regression coefficient of 0.988, coefficient of determination of 0.89, and index of agreement of 0.97. The HYDRUS-2D model with the calibrated parameters was then applied to explore the optimal irrigation scheduling. Infrequent irrigation with a large amount of water for each irrigation event could result in 10%–18% of the irrigation water losses. Thus we recommend high irrigation frequency with a low amount of water for each irrigation event in greenhouses for arid region. The maximum high irrigation amount and the suitable irrigation interval required to avoid plant water stress and drainage water were 34 mm and 6 days, respectively, for given daily average transpiration rate of 4.0 mm/d. To sum up, the HYDRUS-2D model with consideration of root water uptake can be used to improve irrigation scheduling for furrow irrigated tomato plants in greenhouses in arid regions.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
This paper presents a smart irrigation system suitable for use in places where water scarcity is a challenge. In many parts of Africa, even when irrigation is practiced, it is manually operated. Smart irrigation syste...This paper presents a smart irrigation system suitable for use in places where water scarcity is a challenge. In many parts of Africa, even when irrigation is practiced, it is manually operated. Smart irrigation system is thereby believed to be a major solution. The paper therefore presents a smart irrigation system that optimizes the available water in the water reservoir thus providing an efficient and effective water usage solution for the irrigation system. The irrigation system is able to automatically start/stop water pumps on the irrigation site based on the soil moisture content acquired from the moisture content sensor as well as the ultrasonic sensor measuring the water level in the reservoir. The measured sensor values are sent to the Arduino microcontroller for configuring the control algorithm. The system prioritizes irrigation operation by determining the number of pumps to be operated at any instance as well as their locations. In this way, different crops can be watered depending on their varying water requirements. In order to implement the design, a laboratory scale architectural model depicting a farm setting with reservoir, direct current (DC) pumps and the control unit was constructed. Experimental results revealed good performance which makes the developed system a suitable tool for studies on irrigation.展开更多
Based on the experimental data,this study investigated the effect of sand content of muddy water on water and nitrogen transport characteristics of the single-line interference infiltration under film hole irrigation ...Based on the experimental data,this study investigated the effect of sand content of muddy water on water and nitrogen transport characteristics of the single-line interference infiltration under film hole irrigation with muddy water and fertilizer.The relationship between the single-line interference infiltration parameters,the sand content,the wetting front movement distances,and the sand content were all established.The model of the cumulative infiltration volume of per unit film pore area,the vertical and horizontal wetting front movement distance of the free surface,and the wetting front movement distance of the interference center with sand content and infiltration time were proposed.Reveal the law of the change of soil water content and the distribution of NO_(3)^(-)-N content based on different muddy water sand content.The results indicate that at the same infiltration time,as the muddy water sand content increases,the cumulative infiltration volume per unit pore area decreases.The infiltration index of the free infiltration and the single-line interference vary little when the sand content increases,mainly are around 0.64 and 0.58.The relationship between infiltration parameters a,b and the sand content is linear function.At the same location,the more the sand content,the smaller the wetting front movement distance in free surface and the single-line interference surface,the less the NO_(3)^(-)-N content.展开更多
Optimum growth and production of fruit crops is strongly linked to managing irrigation water. Various method of estimating tree water requirements have been utilized such as direct and indirect soil, water, and climat...Optimum growth and production of fruit crops is strongly linked to managing irrigation water. Various method of estimating tree water requirements have been utilized such as direct and indirect soil, water, and climatic measurements. Due to differences in fruit tree anatomical and morphological structures and their adaptation to excess and deficit soil water content, such estimates of irrigation water requirements may be more suitable for herbaceous plants but not as accurate for trees. Studies on temperate and tropical fruit trees, using apple (Malus domestica) and star-fruit (Averrhoa carambola), respectively, showed that tree water potential is highly correlated to soil water status. Irrigation based on climate data (ET) and monitoring of soil water resulted in no significant differences in soil or tree water status of orchard-grown fruit trees under temperate and subtropical climatic conditions. The results indicated the need for better understanding and utilization of tree physiological parameters for management of irrigation water of fruit crops. This will ultimately lead to achieving optimum yield and fruit quality while conserving water resources.展开更多
Climate warming has led to the expansion of arable land at high altitudes,but it has also increased the demand for water use efficiency(WUE).To address this issue,the development of water-saving irrigation technology ...Climate warming has led to the expansion of arable land at high altitudes,but it has also increased the demand for water use efficiency(WUE).To address this issue,the development of water-saving irrigation technology has become crucial in improving water productivity and economic returns.This study aimed to assess the impacts of three irrigation methods on water productivity and economic returns in wolfberry(Lycium barbarum L.)cultivation on the Tibetan Plateau,China during a two-year field trial.Results showed that subsurface irrigation with ceramic emitters(SICE)outperformed surface drip irrigation(DI)and subsurface drip irrigation(SDI)in terms of wolfberry yield.Over the two-year period,the average yield with SICE increased by 8.0%and 2.3%compared with DI and SDI,respectively.This improvement can be attributed to the stable soil moisture and higher temperature accumulation achieved with SICE.Furthermore,SICE exhibited higher WUE,with 14.6%and 4.5%increases compared with DI and SDI,respectively.In addition to the agronomic benefits,SICE also proved advantageous in terms of economic returns.Total average annual input costs of SICE were lower than the other two methods starting from the 8th year.Moreover,the benefit-cost ratio of SICE surpassed the other methods in the 4th year and continued to widen the gap with subsequent year.These findings highlight SICE as an economically viable water-saving irrigation strategy for wolfberry cultivation on the Tibetan Plateau.Thus,this research not only provides an effective water-saving irrigation strategy for wolfberry cultivation but also offers insights into addressing irrigation-related energy challenges in other crop production systems.展开更多
To examine the working principle of vertical tube irrigation, variations in vertical tube emitter discharge and their causes were analyzed in the laboratory experiment. The effects of the pressure head, initial soil w...To examine the working principle of vertical tube irrigation, variations in vertical tube emitter discharge and their causes were analyzed in the laboratory experiment. The effects of the pressure head, initial soil water content, and tube diameter on the emitter discharge of the vertical tube were studied. The results show that quantitative relationship between the time and cumulative infiltration and emitter discharge of the vertical tube is obtained, and R 2 is more than 0.98. Emitter discharge exhibits a positive and negative correlation with the pressure head and soil water content, respectively. Tube dia- meter has a nonsignificant effect on the emitter discharge. Changes of the soil water content around the emitter water outlet are the main causes of emitter discharge variations. In the experiments, the range of vertical tube emitter discharge is 0.056-1.102 L/h. The emitter of vertical tube irrigation automatically adjusts the soil water content and maintains the root zone soil water content within an appropriate range, which achieves continuous irrigation, and further achieves the effect of water-saving.展开更多
文摘Fruit yield, yield components, fruit mineral content, total phenolic content, antioxidant activity and irrigation water use efifciency (IWUE) of summer squash responses to different irrigation quantities were evaluated with a ifeld study. Irrigations were done when the total evaporated water from a Class A pan was about 30 mm. Different irrigation quantities were adjusted using three different plant-pan coefifcients (Kcp, 100% (Kcp1), 85% (Kcp2) and 70% (Kcp3)). Results indicated that lower irrigation quantities provided statistically lower yield and yield components. The highest seasonal fruit yield (80.0 t ha-1) was determined in the Kcp1 treatment, which applied the highest volume of irrigation water (452.9 mm). The highest early fruit yield, average fruit weight and fruit diameter, length and number per plant were also determined in the Kcp1 treatment, with values of 7.25 t ha-1, 264.1 g, 5.49 cm, 19.95 cm and 10.92, respectively. Although the IWUE value was the highest in the Kcp1 treatment (176.6 kg ha-1 mm-1), it was statistically similar to the value for Kcp3 treatment (157.1 kg ha-1 mm-1). Total phenolic content and antioxidant activity of fruits was higher in the Kcp1 (44.27 μg gallic acid equivalents (GAE) mg-1 fresh sample) and in the Kcp2 (84.75%) treatments, respectively. Major (Na, N, P, K, Ca, Mg and S) and trace (Fe, Cu, Mn, Zn and B) mineral contents of squash fruits were the highest in the Kcp2 treatment, with the exception of P, Ca and Cu. Mineral contents and total phenolic content were signiifcantly affected by irrigation quantities, but antioxidant activity was not affected. It can be concluded that the Kcp1 treatment was the most suitable for achieving higher yield and IWUE. However, the Kcp2 treatment will be the most suitable due to the high fruit quality and relatively high yield in water shortage conditions.
基金supported by the National Natural Science Foundation of China (50569004)
文摘The relation between soil water content and the growth of cotton root was studied for the scheme of field water and cotton yield under mulched drip irrigation. Based on the field experiments, three treatments of soil water content were conducted with 90%, 75%θf, and 60%θf (θfis field water capacity). Cotton roots and root-shoot ratio were studied with digging method, and the soil moisture was observed with TDR (time domain reflector), and cotton yield was measured. The results indicated that the growth of cotton root accorded with Logistic growth curve in the three treatments, the cotton root grew quickly and its weight was very high under 75%θf because of the suitable soil water condition, while grew slowly and its weight was lower under 90%θf due to water moisture beyond the suitable condition, and the root weight was in between under 60%θf For the three water treatments, the cotton root weight decreased with soil depth, and decreased more significantly in deeper soil layer with the soil moisture increasing. And the ratio of cotton root weight in 0-30 cm soil layer to the total root weight was the highest under 75%θf. The cotton root system was distributed mainly in the soil of narrow row and wide row mulched with plastic film, and little in the soil outside plastic film. The weight of cotton root was the highest in the soil of narrow row or wide row mulched with plastic film under 75%θf. Root-shoot ratio decreased with the soil moisture increasing. The soil water content affected cotton yields, and cotton yield was the highest under 75%θf. The higher soil moisture level is unfavorable to the growth of cotton root system and yield of cotton under mulched drip irrigation.
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 research was financially supported by National Natural Science Foundation of China(51179166)Specialized Research Fund for the Doctoral Program of Higher Education of China(20123250110004)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘In order to explore the use of groundwater resources,field experiments were conducted for three consecutive years during 2012-2014 in the Shiyang River basin of Northwest China.Irrigation was conducted using four different water salinity levels that were arranged in a split plot design.These four water salinity levels were s0,s3,s6 and s9(0.71,3,6 and 9 g/L,respectively).The soil salt content,soil bulk density,soil porosity,saturated hydraulic conductivity,plant height,leaf area index and yield of maize for seed production were measured for studying the effects of saline water irrigation on soil salt content distribution,soil physical properties and water use efficiency.It was observed that higher salinity level of irrigation water and long duration of saline water irrigation resulted in more salt accumulation.Compared to initial values,the soil salt accumulation in 0-100 cm soil layer after three years of experiments for s0,s3,s6 and s9 was 0.189 mg/cm3,0.654 mg/cm3,0.717 mg/cm3 and 1.135 mg/cm3,respectively.Both greater salt levels in the irrigation water and frequent saline water irrigation led to greater soil bulk density,but poorer soil porosity and less saturated hydraulic conductivity.The saturated hydraulic conductivity decreased with increase in soil bulk density,but increased with improvement in soil porosity.It was noted that the maize height,leaf area index and maize yield gradually decreased with increase in water salinity.The maize yield decreased over 25%and the water use efficiency also gradually declined when irrigated with water containing 6 g/L and 9 g/L salinity levels.However,maize yield following saline water irrigation with 3 g/L decreased less than 20%and the decline in water use efficiency was not significant during the three-year experiment period.The results demonstrate that irrigation with saline water at the level of 6 g/L and 9 g/L in the study area is not suitable,while saline water irrigation with 3 g/L would be acceptable for a short duration together with salt leaching through spring irrigation before sowing.
基金Supported by Collection of Gentiana macrophylla Germplasm Resources in Imitated Wild Conditions under Forests in Liupan Mountains and High-yield Cultivation Technology(2020GYKYF011)Sub-project of Scientific and Technological Innovation Demonstration Project for High-quality Agricultural Development and Ecological Protection in Ningxia Hui Autonomous Region(NGSB-2021-16-05)。
文摘[Objectives]This study was conducted to investigate the effects of different irrigation quotas and irrigation times on soil physical and chemical properties and water content in the planting areas of Gentiana macrophylla in dry farming areas of southern Ningxia.[Methods]G.macrophylla planted for three years was selected as the experimental material,and the water content,nutrients,bulk density and total porosity of the soil at different depths(0-20 and 20-40 cm)were measured under different irrigation quotas and irrigation times.[Results]Compared with the CK,different irrigation quotas and irrigation times could significantly improve the water contents of the 0-20 and 20-40 cm layers in the planting areas of G.macrophylla.The change trend of water content at the 0-20 cm soil depth was 3 times of irrigation>2 times of irrigation>1 time of irrigation>CK,and that at the 20-40 cm soil depth was 2 times of irrigation>3 times of irrigation>1 time of irrigation>CK.With the increase of irrigation times,soil urease in the 0-20 cm soil showed a trend of decreasing at first and then increasing,reaching a maximum value of 0.415 mg/g·24 h with 1 time of irrigation,which increased by 84.44%compared with the CK,and the value with two times of irrigation was basically the same as that of the CK,but 3 times of irrigation resulted in a value 57.33%higher than the CK.However,the changes of 20-40 cm were the opposite.The change trends of alkali-hydrolyzable nitrogen in the 0-20 and 20-40 cm soil layers with irrigation times was smaller,and the contents of soil organic carbon,available phosphorus and available potassium increased first and then decreased with the increase of irrigation times,and were generally higher than those in the CK.[Conclusions]This study provides a theoretical and technical basis for the artificial cultivation of G.macrophylla in dry farming areas of Ningxia.
基金supported by the National Natural Science Foundation of China (91025002,30970492)the National Key Technology R & D Program (2012BAC08B05)
文摘Furrow irrigation when combined with plastic mulch on ridge is one of the current uppermost wa- ter-saving irrigation technologies for arid regions. The present paper studies the dynamics of soil water-salt trans- portation and its spatial distribution characteristics under irrigation with saline water in a maize field experiment. The mathematical relationships for soil salinity, irrigation amount and water salinity are also established to evaluate the contribution of the irrigation amount and the salinity of saline water to soil salt accumulation. The result showed that irrigation with water of high salinity could effectively increase soil water content, but the increment is limited com- paring with the influence from irrigation amount. The soil water content in furrows was higher than that in ridges at the same soil layers, with increments of 12.87% and 13.70% for MMF9 (the treatment with the highest water salinity and the largest amount of irrigation water) and MMF1 (the treatment with the lowest water salinity and the least amount of irrigation water) on 27 June, respectively. The increment for MMF9 was gradually reduced while that for MMF1 increased along with growth stages, the values for 17 August being 2.40% and 19.92%, respectively. Soil water content in the ridge for MMF9 reduced gradually from the surface layer to deeper layers while the surface soil water content for MMF1 was smaller than the contents below 20 cm at the early growing stage. Soil salinities for the treatments with the same amount of irrigation water but different water salinity increased with the water salinity. When water salinity was 6.04 dS/m, the less water resulted in more salt accumulation in topsoil and less in deep layers. When water salinity was 2.89 dS/m, however, the less water resulted in less salt accumulation in topsoil and salinity remained basically stable in deep layers. The salt accumulation in the ridge surface was much smaller than that in the furrow bottom under this technology, which was quite different from traditional furrow irrigation. The soil salinities for MMF7, MMF8 and MMF9 in the ridge surface were 0.191, 0.355 and 0.427 dS/m, respectively, whereas those in the furrow bottom were 0.316, 0.521 and 0.631 dS/m, respectively. The result of correlation analysis indicated that compared with irrigation amount, the irrigation water salinity was still the main factor influ- encing soil salinity in furrow irrigation with plastic mulch on ridge.
基金supported by the National Natural Science Foundation of China (50979115)
文摘The dynamics of water and salt in soil were monitored in the 2010 and 2011 growing seasons of cotton to evaluate the salinity risk of soil under drip irrigation in arid environments for different management practices of drip system uniformity and irrigation amount. In the experiments, three Christiansen uniformity coefficients (CU) of approximately 65, 80, and 95% (referred to as low, medium, and high uniformity, respectively) and three irrigation amounts of 50, 75, and 100% of full irrigation were used. The distribution of the soil water content and bulk electrical conductivity (ECb) was monitored continuously with approximately equally spaced frequency domain reflectometry (FDR) sensors located along a dripline. Gravimetric samples of soil were collected regularly to determine the distribution of soil salinity. A great fluctuation in CU of water content and ECb at 60 cm depth was observed for the low uniformity treatment during the irrigation season, while a relatively stable variation pattern was observed for the high uniformity treatment. The ECb CU was substantially lower than the water content CU and its value was greatly related to the water content CU and the initial ECb CU. The spatial variation of seasonal mean soil water content and seasonal mean soil bulk electrical conductivity showed a high dependence on the variation pattern of emitter discharge rate along a dripline for the low and medium uniformity treatments. A greater irrigation amount produced a significantly lower soil salinity at the end of the irrigation season, while the influence of the system uniformity on the soil salinity was insignificant at a probability level of 0.1. In arid regions, the determination of the target drip irrigation system uniformity should consider the potential salinity risk of soil caused by nonuniform water application as the influence of the system uniformity on the distribution of the soil salinity was progressively strengthened during the growing season of crop.
基金supported by the Special Fund for Agro-scientific Research in the Public Interest,China(201503105 and 201503125)the National High-Tech R&D Program of China(863 Program,2011AA100504)
文摘Ridge-furrow rainwater harvesting (RFRH) planting pattern can lessen the effect of water deficits throughout all crop growth stages, but water shortage would remain unavoidable during some stages of crop growth in arid and semiarid areas. Supplemental irrigation would still be needed to achieve a higher production. Field experiments were conducted for two growing seasons (2012-2013 and 2013-2014)to determine an appropriate amount of supplemental irrigation to be applied to winter oilseed rape at the stem-elongation stage with RFRH planting pattern. Four treatments, including supplemental irrigation amount of 0 (I1), 60 mm (I2) and 120 mm (I3) with RFRH planting pattern and a control (CK) irrigated with 120 mm with flat planting pattern, were set up to evaluate the effects of supplemental irrigation on aboveground dry matter (ADM), nitrogen nutrition index (NNI), radiation use efficiency (RUE), water use efficiency (WUE), and seed yield and oil content of the oilseed rape. Results showed that supplemental irrigation improved NNI, RUE, seed yield and oil content, and WUE. However, the NNI, RUE, seed yield and oil content, and WUE did not increase significantly or even showed a downward trend with excessive irrigation. Seed yield was the highest in 13 for both growing seasons. Seed yield and WUE in 13 averaged 3235 kg ha^-1 and 8.85 kg ha^-1 mm-1, respectively. The highest WUE was occurred in 12 for both growing seasons. Seed yield and WUE in 12 averaged 3089 kg ha^-1 and 9.63 kg ha^-1 mm^-1, respectively. Compared to 13, 12 used 60 mm less irrigation amount, had an 8.9% higher WUE, but only 4.5 and 0.4% lower seed yield and oil content, respectively. 12 saved water without substantially sacrificing yield or oil content, so it is recommended as an appropriate cultivation and irrigation schedule for winter oilseed rape at the stem-elongation stage.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2016B14614)the Program of China Scholarship Council(Grant No.201906715015)+1 种基金the National Key Research and Development Program of China(Grant No.2017YFC040320502)a project funded by the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.
文摘To achieve the greatest leaching efficiency,water movement must occur under unsaturated flow conditions.Accordingly,the water application intensity of irrigation must be chosen carefully.The aim of this study was to evaluate the impact of the water application intensity of micro-sprinkler irrigation on coastal saline soil with different salt contents.To achieve this objective,a laboratory experiment was conducted with three soil salinity treatments(2.26,10.13,and 22.29 dS/m)and three water application intensity treatments(3.05,5.19,and 7.23 mm/h).The results showed that the effect of soil salinity on soil water content,electrical conductivity,and pH was significant,and the effect of the water application intensity was insignificant.High soil water content was present in the 40e60 cm profile in all soil salinity treatments,and the content was higher in the medium and high water application intensity treatments than in the low-intensity treatment.Significant salt leaching occurred in all treatments,and the effect was stronger in the high soil salinity treatment and medium water application intensity treatment.In the medium and high soil salinity treatments,pH exhibited a decreasing trend,with no trend change in the low soil salinity treatment,and the pH value was higher in the medium water application intensity treatment than in the other two treatments.These results indicated that the three intensities evaluated had no statistically different effect on the electrical conductivity of saturated soil-paste extracts(EC)in the upper 20 cm of the soil profile,and it would be better to maintain a lower value of the water application intensity.
基金supported by the National Key Research and Development Program of China (2016YFC0400207)the National Natural Science Foundation of China (51222905, 51621061, 51509130)+2 种基金the Natural Science Foundation of Jiangsu Province, China (BK20150908)the Discipline Innovative Engineering Plan (111 Program, B14002)the Jiangsu Key Laboratory of Agricultural Meteorology Foundation (JKLAM1601)
文摘Furrow irrigation is a traditional widely-used irrigation method in the world. Understanding the dynamics of soil water distribution is essential to developing effective furrow irrigation strategies, especially in water-limited regions. The objectives of this study are to analyze root length density distribution and to explore soil water dynamics by simulating soil water content using a HYDRUS-2D model with consideration of root water uptake for furrow irrigated tomato plants in a solar greenhouse in Northwest China. Soil water contents were also in-situ observed by the ECH_2O sensors from 4 June to 19 June and from 21 June to 4 July, 2012. Results showed that the root length density of tomato plants was concentrated in the 0–50 cm soil layers, and radiated 0–18 cm toward the furrow and 0–30 cm along the bed axis. Soil water content values simulated by the HYDRUS-2D model agreed well with those observed by the ECH_2O sensors, with regression coefficient of 0.988, coefficient of determination of 0.89, and index of agreement of 0.97. The HYDRUS-2D model with the calibrated parameters was then applied to explore the optimal irrigation scheduling. Infrequent irrigation with a large amount of water for each irrigation event could result in 10%–18% of the irrigation water losses. Thus we recommend high irrigation frequency with a low amount of water for each irrigation event in greenhouses for arid region. The maximum high irrigation amount and the suitable irrigation interval required to avoid plant water stress and drainage water were 34 mm and 6 days, respectively, for given daily average transpiration rate of 4.0 mm/d. To sum up, the HYDRUS-2D model with consideration of root water uptake can be used to improve irrigation scheduling for furrow irrigated tomato plants in greenhouses in arid regions.
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.
文摘This paper presents a smart irrigation system suitable for use in places where water scarcity is a challenge. In many parts of Africa, even when irrigation is practiced, it is manually operated. Smart irrigation system is thereby believed to be a major solution. The paper therefore presents a smart irrigation system that optimizes the available water in the water reservoir thus providing an efficient and effective water usage solution for the irrigation system. The irrigation system is able to automatically start/stop water pumps on the irrigation site based on the soil moisture content acquired from the moisture content sensor as well as the ultrasonic sensor measuring the water level in the reservoir. The measured sensor values are sent to the Arduino microcontroller for configuring the control algorithm. The system prioritizes irrigation operation by determining the number of pumps to be operated at any instance as well as their locations. In this way, different crops can be watered depending on their varying water requirements. In order to implement the design, a laboratory scale architectural model depicting a farm setting with reservoir, direct current (DC) pumps and the control unit was constructed. Experimental results revealed good performance which makes the developed system a suitable tool for studies on irrigation.
基金National Key R&D Program of China(2016YFC0400204)National Natural Science Foundation of China(51479161,51279157,51779205)。
文摘Based on the experimental data,this study investigated the effect of sand content of muddy water on water and nitrogen transport characteristics of the single-line interference infiltration under film hole irrigation with muddy water and fertilizer.The relationship between the single-line interference infiltration parameters,the sand content,the wetting front movement distances,and the sand content were all established.The model of the cumulative infiltration volume of per unit film pore area,the vertical and horizontal wetting front movement distance of the free surface,and the wetting front movement distance of the interference center with sand content and infiltration time were proposed.Reveal the law of the change of soil water content and the distribution of NO_(3)^(-)-N content based on different muddy water sand content.The results indicate that at the same infiltration time,as the muddy water sand content increases,the cumulative infiltration volume per unit pore area decreases.The infiltration index of the free infiltration and the single-line interference vary little when the sand content increases,mainly are around 0.64 and 0.58.The relationship between infiltration parameters a,b and the sand content is linear function.At the same location,the more the sand content,the smaller the wetting front movement distance in free surface and the single-line interference surface,the less the NO_(3)^(-)-N content.
文摘Optimum growth and production of fruit crops is strongly linked to managing irrigation water. Various method of estimating tree water requirements have been utilized such as direct and indirect soil, water, and climatic measurements. Due to differences in fruit tree anatomical and morphological structures and their adaptation to excess and deficit soil water content, such estimates of irrigation water requirements may be more suitable for herbaceous plants but not as accurate for trees. Studies on temperate and tropical fruit trees, using apple (Malus domestica) and star-fruit (Averrhoa carambola), respectively, showed that tree water potential is highly correlated to soil water status. Irrigation based on climate data (ET) and monitoring of soil water resulted in no significant differences in soil or tree water status of orchard-grown fruit trees under temperate and subtropical climatic conditions. The results indicated the need for better understanding and utilization of tree physiological parameters for management of irrigation water of fruit crops. This will ultimately lead to achieving optimum yield and fruit quality while conserving water resources.
基金This research was funded by the National Natural Science Foundation of China(52079131,51779246).
文摘Climate warming has led to the expansion of arable land at high altitudes,but it has also increased the demand for water use efficiency(WUE).To address this issue,the development of water-saving irrigation technology has become crucial in improving water productivity and economic returns.This study aimed to assess the impacts of three irrigation methods on water productivity and economic returns in wolfberry(Lycium barbarum L.)cultivation on the Tibetan Plateau,China during a two-year field trial.Results showed that subsurface irrigation with ceramic emitters(SICE)outperformed surface drip irrigation(DI)and subsurface drip irrigation(SDI)in terms of wolfberry yield.Over the two-year period,the average yield with SICE increased by 8.0%and 2.3%compared with DI and SDI,respectively.This improvement can be attributed to the stable soil moisture and higher temperature accumulation achieved with SICE.Furthermore,SICE exhibited higher WUE,with 14.6%and 4.5%increases compared with DI and SDI,respectively.In addition to the agronomic benefits,SICE also proved advantageous in terms of economic returns.Total average annual input costs of SICE were lower than the other two methods starting from the 8th year.Moreover,the benefit-cost ratio of SICE surpassed the other methods in the 4th year and continued to widen the gap with subsequent year.These findings highlight SICE as an economically viable water-saving irrigation strategy for wolfberry cultivation on the Tibetan Plateau.Thus,this research not only provides an effective water-saving irrigation strategy for wolfberry cultivation but also offers insights into addressing irrigation-related energy challenges in other crop production systems.
基金National Natural Science Foundation of China (41571222)。
文摘To examine the working principle of vertical tube irrigation, variations in vertical tube emitter discharge and their causes were analyzed in the laboratory experiment. The effects of the pressure head, initial soil water content, and tube diameter on the emitter discharge of the vertical tube were studied. The results show that quantitative relationship between the time and cumulative infiltration and emitter discharge of the vertical tube is obtained, and R 2 is more than 0.98. Emitter discharge exhibits a positive and negative correlation with the pressure head and soil water content, respectively. Tube dia- meter has a nonsignificant effect on the emitter discharge. Changes of the soil water content around the emitter water outlet are the main causes of emitter discharge variations. In the experiments, the range of vertical tube emitter discharge is 0.056-1.102 L/h. The emitter of vertical tube irrigation automatically adjusts the soil water content and maintains the root zone soil water content within an appropriate range, which achieves continuous irrigation, and further achieves the effect of water-saving.