In order to evaluate the applicability of RZWQM2 model in the simulation of naked oat crop growth in a typical north agro-pastoral ecotone and optimize the parameters of the complete crop model for the study of naked oat growth process. In this study， the naked oat growth simulation parameters in the RZWQM2 (Root Zone Water Quality Model2) model were through the field experiments in Bashang area of Hebei Province， a typical northern agro-pastoral， in the two whole growth periods of 2018 and 2019. The results indicated that the optimized model parameters could make the determination coefficient (R ²) value of simulated and measured soil moisture values in different soil depths (0~80 cm) ranged from 0.70 to 0.95， and the root mean square error and mean relative error were 1.73%~1.96% and 21.20%~25.00%， respectively. The R ² values of the leaf area index simulation values were 0.98 and 0.76， respectively. In addition， the R ² values of simulated and measured values of biomass and plant height were all greater than 0.80. The simulation parameters of naked oat crop growth developed in this study showed a good general applicability in Bashang area of Hebei Province. The calibrated RZWQM2 model can be applied to the field water management and crop growth of bare oat in similar areas of the agro-pastoral ecotone in northern China.

In order to clarify the response of soybean with different genotypes to semi-arid region， a 3-year repeated field experiment was conducted with different soybean varieties as research subjects under field conditions to explore the effects of Fuxin located semi-arid region in Liaoning Province and Shenyang located sub-humid region on physiological characteristics and yield of soybean with different genotypes. The results showed that from 2015 to 2017， the aboveground biomass of the plants gradually accumulated with the growth of the plants， namely， the aboveground biomass of the plants in each period of the same treatment showed as follows： R6 > R4 > R2 > V4. The effects of different locations on root and aboveground biomass were as follows： the value of Shenyang semi-humid area was higher than that of Fuxin semi-arid area； the root and aboveground biomass of Liaodou 14 and Liaodou 21 were higher than that of Liaodou 32 at the same site. The variation of soybean root-shoot ratio ranged from 0.08 to 0.35. Generally speaking， the root-shoot ratio of soybean plants at different stages showed as V4>R2＞R4＞R6. From 2015 to 2017， the effects of different locations on SPAD value， plant height and leaf number per plant of the same variety sampled in the same period were generally shown as follows： S14 > F14， S21 > F21， S32 > F32. The yield of the same variety of soybean in Shenyang was higher than that in Fuxin in semi-arid area. In the same location， the yield of Liaodou 14 and Liaodou 32 was higher than that of Liaodou 21. In 2014 and 2015， the yield of Liaodou 14 and Liaodou 32 in Fuxin semi-arid region， was higher than that of Liaodou 21 in Shenyang semi-humid region， indicating that these two varieties are more suitable for planting in semi-arid regions. This study enriches the knowledge of soybean yield and physiological traits in response to drought stress and has important theoretical value and practical significance for soybean drought-resistant production.

In view of the sub-high temperature phenomenon which often appears in the production of greenhouse horticulture in southern China， tomato seedlings were used as test material to study 3 treatment modes， including 80% ET (treatment 1)， 100% ET (treatment 2) and 120% ET (treatment 3) ， on seedling photosynthesis and seedling quality under sub-high temperature.The results showed that the physiological indexes of net photosynthetic rate (Pn) and the maximum photochemical efficiency of PSⅡ (Fm/Fv)， and the growth indexes of dry matter accumulation， strong seedling index and growth function of seedlings， in treatment 3 were the highest under sub-high temperature， and the differences between treatment 1 and treatment 3 were significant. Compared with treatment 3， the Pn of leaves in treatment 1 and 2 decreased， accompanied by the increase of stomatal limit value (Ls). According to the comprehensive analysis， 120% ET irrigation amount can maintain the higher photosynthesis of tomato seedlings under sub-high temperature， relieve the sub-high temperature stress， and improve the seedling quality.

In order to obtain the suitable parameters of moistube irrigation technology in the production of protected cucumber， the experiment considering the moistube buried depth was carried out from 2018 to 2019. Three test levels (15 cm， 25 cm and 35 cm) were set to study the effects of moistube buried depth on soil water and fertilizer distribution， growth and yield of cucumber in greenhouse by comparing with the furrow irrigation which was widely used in local greenhouse vegetables. The results showed that compared with furrow irrigation， moistube irrigation could effectively save water and fertilizer， and was more conducive to cucumber growth， yield and water and nitrogen use efficiency improvement. Besides， moistube irrigation could effectively reduce the leakage， and had a tendency to reduce the accumulation of nitrate nitrogen and available phosphorus in deep soil. The moistube irrigation had the best effect when the moistube buried depth was 25 and 35 cm.

The radar signal is an important basis for reflecting the information of the medium. In order to explore the response characteristics of the radar signal to the water and salt in the cotton field soil under long-term drip irrigation， in this experiment， the pulse EKKO PRO ground penetrating radar with a center frequency of 250 MHz was adopted with the wasteland without drip irrigation as a control， the two plots with a drip irrigation period of 11 years and 21 years were detected. The measured profile was compared with the stratified results of GPR spectral images， and the response characteristics of electromagnetic wave signals to soil water and salt were analyzed by combining the methods of electromagnetic wave time domain and frequency domain. The results show that： ①The combination of the reflection layer on the GPR image and the actual excavation profile can quickly identify the upper and lower boundaries of different soil layers in the 0~140 cm range of drip irrigation cotton fields under the film. At the same time， when combined with sampled data， it can effectively identify a wide range of soil structure information. However， when the water and salt content is high， GPR will not be able to effectively identify the reflective layer of the soil， making it difficult to distinguish the soil hierarchy. ②The long-term drip irrigation of saline soil in the cotton field under film has a significant effect on electromagnetic waves. Moisture content and salt content are the main factors that cause electromagnetic wave attenuation. The amplitude energy value is a sign parameter of the radar signal response to water and salt， and the water salt content is inversely proportional to the amplitude energy value. ③For antennas with a center frequency of 250 MHz， the main frequency shifted in plots with different drip irrigation years. The drip irrigation cotton field appeared around 160 GHz， and the wasteland appeared around 190 GHz. The multi-peak phenomenon occurs in the wasteland， with the sub-primary frequencies at 371 MHz and 688 MHz， respectively. And the amplitude energy value of the wasteland is less than that of drip irrigation cotton field. Using the advantages of rapid and non-destructive ground penetrating radar， large-area acquisition of soil water and salt change information of drip irrigation in cotton fields under a large area is conducive to the timely treatment of saline-alkali soils.

In order to explore the effect of different ridge width on maize water and nutrient use efficiency under ridge-furrow rainfall harvesting planting mode， during 2019-2020， the effects of furrow and ridge ratio on leaf area index (LAI)， aboveground biomass， water use efficiency (WUE)， nutrient use efficiency (NUE) and yield of maize were studied with traditional plain cropping (ridge width 60 cm) mode as control. The results showed that the furrow and ridge ratio of 60 cm to 60 cm had the maximum leaf area index (LAI) of 2.9， which was 42.16% higher than that of the control； the highest yield was 13.13 t/hm²， which was 26.37% higher than that of the control； the water use efficiency (WUE) was the highest， which was 27.15 kg/（hm²·mm）， increased by 42.37% compared with the control； the nutrient use efficiency was the highest， which was N of 7.55 kg/kg， P of 48.49 kg/kg， and K of 4.66 kg/kg， and 177.57 %， 142.69 %， 59.58 % higher than the control， respectively. Therefore， In North China， the ratio of ridge and furrow for rainfall harvesting planting mode of 60 cm to 60 cm can promote maize yield increase and efficient utilization of water and fertilizer.

Water， fertilizer and their interaction play a vital role for determining growth and development of crops， and both of them are closely related and influenced by each other. With the global warming and the social and economic development， the available of freshwater source is decline. Moreover， unscientific or overuse of nitrogen fertilizer induces series of environmental issues， including groundwater pollution， greenhouse gas emission and soil acidification. In this regard， how to use the combined regulation measures of water and fertilizer to achieve the synergistic improvement of water and fertilizer utilization efficiency for crop have received widely attention from home and abroad. Maize is one kind of the typical crops， its growth requires a lot of water and nitrogen fertilizer. Therefore， in this review， the research process of the coupling effects of water and nitrogen on leaf area index (LAI)， dry matter accumulation， root growth， photosynthetic characteristics， yield and water and nitrogen utilization efficiency of maize were summarized. Moreover， the issues in the interaction effects of water and nitrogen were analyzed and discussed， and the direction to be further studied was figured out.

Aiming at the problem of inaccurate results and low correction rate when calculating the transpiration rate of kiwi fruit leaves with traditional methods， this paper proposed a new parameter correction method to solve the above problems. Based on the dynamic simulation and analysis method of the leaf area transpiration rate of kiwi fruit by hyperspectral sensor， the transpiration model was constructed. The model was used to analyze the influence of various factors on the transpiration rate， and the soil moisture status coefficient was obtained through the function modification method， so as to realize the accurate calculation of the leaf area transpiration rate of kiwi fruit. In order to verify the effectiveness of the proposed method， a comparative experiment was designed. The results showed that humidity and temperature had great effects on the leaf area transpiration rate of kiwi fruit. The leaf area transpiration rate was positively correlated with temperature， but negatively correlated with humidity. The correction rate of transpiration rate and the accuracy of transpiration rate of the method in this paper can both reach 98%， and the experimental results can provide reference for kiwi fruit planting.

Through field experiments， different soil moisture lower limits were set for the four growth periods of pepper to study the effects of subsurface infiltration irrigation on pepper growth， water consumption， yield and water use efficiency. The results showed that T3 treatment [the lower limit of soil moisture in the seedling stage was 65% θ_? ( θ_? was field water holding capacity)] and T9 treatment (the lower limit of soil moisture in the aftermath was 65% θ_? ) had no significant effect on the growth indexes of pepper plant height and stem thickness (P>0.05). The pepper plant height， stem diameter and leaf area index of T1 treatment (the lower limit of soil moisture at seedling stage was 45% θ_? ) were significantly (P<0.05) lower than those of the control by 24.67%， 21.49% and 29.83%， respectively. As the lower limit of soil moisture increases， the water consumption and yield of pepper increase. The water use efficiency of pepper under T2 treatment (the lower limit of soil moisture at seedling stage was 55% θ_? ) was the best， which was 10.83% higher than that of the control treatment， and the yield was not significantly different from that of the control treatment (P>0.05)， which was at the highest level. Therefore， T2 treatment was the optimal irrigation method in this experimental scheme.

In order to realize water saving and yield increasing， this paper took winter wheat and summer maize in Huantai County， Shandong province as an example， and the SWAP model was used to simulate the soil moisture content and crop yield of winter wheat and summer maize under different irrigation scheme combinations， so as to optimize the irrigation program. The results indicated that SWAP model could well simulate the growth process of winter wheat and summer maize in Huantai County， and the simulation effect was ideal. By using the calibrated SWAP model to simulate the relative crop yield and water use efficiency of different rainfall years under the 3 conditions of ET_c， the results indicated that the wheat with 3-times irrigations and maize with twice irrigations could improve the crop yield and significantly improve the water use efficiency. According to the simulation results， the optimal irrigation system was as follows： under 80% ET_c， the irrigation quota of winter wheat in different growth stages in normal and dry flow years respectively should be 87.3 mm and 92.9 mm for jointing stage， 124.7 mm and 132.7 mm for heading stage， 62.4 mm and 66.4 mm for filling stage. Irrigation quota of summer maize in different stages should be 19.8 mm and 40.2 mm for jointing stage， 29.8 mm and 60.6 mm for tasseling stage. The optimized scheme can guarantee the yield of winter wheat and summer maize yield in the study area and increase water use efficiency. The result of the study for water-saving in winter wheat and summer maize provides reference to the production target.

Agricultural water saving is an important guarantee for agricultural sustainable development. In order to understand the current status， hot spot and development tendency of world-wide agricultural water saving research， using the Web of Science core collection database as the data source， this paper conducted an quantitative analysis of the literatures on agricultural water-saving technology published from 1992 to 2019. The results show that：①The research on agricultural water-saving technology is developing rapidly， and the number of papers published in this field is increasing rapidly in the world， especially in China.② Agricultural water-saving technology research is a multidisciplinary field， but the journal distribution is relatively concentrated. ③Spain takes the leading position in the field of agricultural water-saving technology research， and the quantity and quality of the papers are high. China and the United States rank first and second respectively in the number of published papers， but the citation frequency of both papers are low. The Council for Higher Research in Spain (CSIC) is prominent in this field， with the highest number and quality of papers. Four Chinese institutions， namely China Agricultural University， Chinese Academy of Sciences， Northwest Agriculture and Forestry University and Hohai University， are among the world's top 10 in terms of publication volume， but the quality of their publications needs to be further improved. ④Irrigation methods are the research focus in recent years， mainly including drip irrigation， sprinkler irrigation， alternate root separation irrigation and fertilizing irrigation. The research on agricultural water-saving technology to increase production and increase efficiency mechanism is also a hot spot， including the research on carbon and nitrogen metabolism， water and nitrogen interaction， plant hormones and so on. Environmental temperature and greenhouse gas emission are also hot topics. It can be seen that the research on agricultural water saving is a hot research direction both at home and abroad， and China's overall performance in this field is outstanding. However， it needs to further strengthen international cooperation to improve its influence in this field.

In order to investigate the suitable irrigation water quantity of urban green areas in different regions of the country in different seasons and to explore the irrigation water saving potential of green areas, this paper proposed the seasonal irrigation water quantity in different regions of the country and different green area plant types through calculation based on the discussion of determining the irrigation water quantity calculation method and its influencing factors and based on the multi-year seasonal reference crop evapotranspiration and its seasonal precipitation data of 20~30 years in 19 provinces and cities of the country. And the water saving potential of green space in Beijing, a city with serious water shortage, was determined as a case study. The results show that the irrigation water quantity of urban green areas is affected by climate conditions, plant types, soil properties, precipitation intensity, groundwater level and the irrigation technology adopted, among which the main influencing factors are climate conditions, plant types, precipitation intensity and the irrigation technology adopted; Among different regions in China, the irrigation water quantity is the largest in North China and the smallest in South China, and the irrigation water quantity of summer lawn in North China with different precipitation levels was 2.39~3.08 times of that in South China; In 2019, there is a water-saving potential of 190 million m³ of green space water in the whole city of Beijing, among which Haidian, Fengtai, Daxing and Shunyi districts have a greater water-saving potential.

The water transmission and distribution channel system often adopts the form of an inverted siphon when crossing a river valley. The elastic wave propagation speed is orders of magnitude different than the gravity wave speed in an open channel. Therefore， this article attempts to explore the control logic difference and control methods of gate and valve. The Preissmann slot model are used as the calculation methods to unify the pressure flow and open flow control equations. The feedforward logic and feedback algorithm are selected for research and comparison. Due to the faster response speed of the pipeline， the control effect of the valve without feedforward is still ideal， and the control effect of the valve without feedback is very poor. This paper selects the combination of performance indicators such as water level fluctuation， gate adjustment and stabilization time to form a general indicator GI. Compared with PI control， when the valve and gate are only controlled by proportional or integral control， GI has increased by 39%， 17% and 75%， 55%. For the general pipe and channel combination system similar to the calculation example in this paper， the valve can adopt no feedforward control， and feedback control is recommended. The valve can choose different control methods according to pipeline characteristics， and the gate is best controlled by PI. Proportional control only can be used for long pipelines， integral control only can be used for pipelines that avoid flow fluctuations. The main research methods and results of this paper can be used in the design of the controller for the pressureless-pressure system in the water distribution project to realize the safe， efficient and automated operation of the water distribution system.

It is of great significance for the application and promotion of "integrated water and fertilizer" drip irrigation technology to carry out the research on the hydraulic performance of different water and nitrogen gradients on the irrigation uniformity and blockage rate of drip irrigation belt in arid areas. Taking the drip irrigation belt during the growth period of winter wheat and reseeding maize in Aksu area of southern Xinjiang as the research object， a comprehensive measuring platform for hydraulic performance of drip irrigation belt was used to test the drip irrigation belt， and the change rules of irrigation uniformity and blockage rate after long-term use (12 months) of drip irrigation belt under different water and nitrogen treatments was explored. The results showed that the irrigation uniformity decreased with the increase of nitrogen application for the same drip irrigation amount， and the irrigation uniformity of high fertilizer level was the smallest. The application of nitrogen fertilizer was an important factor that caused the drip irrigation belt to block. Through establishing a regression prediction model for irrigation uniformity， it can be seen that the uniformity of irrigation decreases with the increase of the average flow deviation， and the average flow deviation \overline{\mathrm{\Delta }q} has a greater impact on the irrigation uniformity C_u . The irrigation uniformity under the treatment of high-water， low-fertilizer and intermediate-water fertilizers reaches more than 80%， indicating that the drip irrigation belt can meet the water and fertilizer needs of crops under the appropriate ratio of water and fertilizer. This technology can save the use of drip irrigation belt， reduce the investment and provide technical support for the popularization and application of drip irrigation "water and fertilizer integration" technology.

In order to improve the soil characteristics of the soda saline-alkaline soil in western Jilin and improve the irrigation effect of the concealed pipe irrigation system in the soda-alkali area， the irrigation characteristics were studied under different water supply pressures. According to the theory of soil hydrodynamics， with the concealed pipe system as the research object， based on the indoor concealed pipe system irrigation test， according to the conclusion of the previous experiment， 3% rice husk and 5% corn stalk were selected as additives to mix with the soil. The characteristics of soil water and salt transport during irrigation of the concealed pipe system were studied from three aspects， namely the horizontal right， vertical upward， and vertical downward migration distance of the wet front under different water supply pressures， the cumulative infiltration amount and the distribution of soil water and salt. The results shows that the greater the water supply pressure， the farther the wetting front moves in all directions， the shorter the irrigation duration， the greater the cumulative infiltration， and the faster the average infiltration rate. Under the same water supply pressure， the relationship between the moving distance of the wet front in all directions is as follows： vertical upward > horizontal right > vertical downward. The effect of corn stalk is stronger than that of rice husk. The soil profile water content in the vertical upward and horizontal right direction inside the wetted body decreases as the distance from the top of the concealed pipe filter layer increases. Soil salinity moves with water to the vicinity of the wet front， and the salt content of the soil surface and the vicinity of the wet front in the horizontal and right direction are both greater than 0.45%. In summary， choosing a water supply pressure of 100cm and mixing 5% corn stalks with soil can provide sufficient root water absorption for crops， accelerate the speed of water reaching the roots of crops， increase crop yields， which is of certain significance for soil salinization and agricultural sustainable development.

In order to explore the hydrochemical characteristics and water quality of groundwater in Huixian county， based on 56 groundwater samples collected in the wet season in 2016， the hydrochemical characteristics of groundwater were determined by using mathematical statistics， hydrochemistry， correlation analysis， fuzzy comprehensive evaluation and principal component analysis， the groundwater quality was evaluated， and the pollution sources were analyzed. The results show that the groundwater in the study area is weak alkaline， belongs to hard water and low salinity water. The main anions and cations in groundwater are HCO₃ ^-， SO₄ ^2- and Ca²⁺. In terms of mean value， cations are Ca²⁺>Mg²⁺>Na⁺> K⁺ and anions have the order of HCO₃ ^->SO₄ ^2-> Cl^->NO₃ ^-. The main hydrochemical types of groundwater are HCO₃-Ca type and HCO₃-Ca·Mg type water. The comparison results of water quality data in different periods show that hydrochemistry has evolved from simple to complex， and its seasonal and interannual changes are different. Hydrochemistry is mainly controlled by water rock interaction， but also affected by surface water and human factors. The results of water quality evaluation show that the groundwater quality in the study area is basically good and the main chemical components affecting the groundwater quality are TH， TDS and SO₄ ^2-. The results of groundwater pollution source analysis based on principal component analysis show that the water quality in the study area is mainly affected by agricultural production activities， domestic aquaculture wastewater and industrial and mining enterprise activities.