In this study，3 irrigation amount treatments ( 1．0，1．5 and 2．0 L) were set，the soil column method was used to investigate the change processes and characteristic of surface soil CO2 flux after irrigation at different irrigation level，and the effects of temperature and moisture content on soil CO2 emission were further analyzed． The results showed that the change process of surface soil CO2 flux presented the tendency of decreasing first，then increasing and then decreasing again in 48 hours after irrigation，which was in accordance with the soil temperature changes; the effect of soil temperature on surface soil CO2 flux was significant with exponential relationship，while the effect of soil moisture content on soil CO2 flux decreased with the increase of drip irrigation water and was not significant; the Path Analysis showed that the interaction of soil temperature and soil moisture content affected the surface soil CO2 flux，and soil temperature was the most important factor for surface soil CO2 flux．

Aiming at the problems of imperfect fertilization system design and water ＆ fertilization management scheme for Chinese wolfberry in arid areas of Ningxia，the wetting front migration regulation under drip irrigation is studied to provide reference base for the field fertigation system design． The indoors soil box experiment is conducted to simulate the field point-source drip irrigation． In the experiment，the emitter flow and nitrogen concentration is taken as variable，the planned moisture layer is taken as controlled variable，and the completely random combination design is adopted． The results show that: under the same nitrogen concentration，the larger the drop flow，the shorter the time for the water to reach the wet layer，the larger the volume of the wetting body，and the greater the distance that the wetting front will continue to move after the irrigation; under the same drip flow，the larger the fertilizer concentration，the better the water migration in the vertical direction，the shorter the time for the water to reach the planned moisture layer，the smaller the wetting body，and the smaller the distance the water distribution after the irrigation; there exists a power function relationship between migration distance and time of horizontal wetting front and vertical wetting front，there is no significant change for power exponent b with the change of flow q and fertilizer concentration c， and the coefficient a increases with the increase of drop head flow，and decreases with the increase of fertilizer concentration; both drip flow and fertilizer concentration can affect the soil moisture distribution，but the drip flow plays a major role． The soil moisture migration depth can be predicted through function relation formula．

In order to investigate the effect of different alternating cycles and different pressure head on the growth and development of alpine pepper，the experiment set six different treatments，including treatment A with 1 m pressure head and 4 days alternating irrigation，treatment B with 1．5 m pressure head and 4 days alternating irrigation，treatment C with 1 m pressure head and 8 days alternating irrigation，treatment D with 1．5 m pressure head and 8 days alternating irrigation，treatment E with five tube full irrigation and treatment F with ordinary irrigation． The pepper Plant growth status and pepper yield were analyzed． The results showed that the irrigation water productivity under micro-irrigation was higher than that under ordinary irrigation under the condition of outdoor planting． The treatment with 1．5 m pressure head and 8 days alternating had the highest irrigation water productivity.

In order to explore the appropriate location of moisture sensors and the influence of decision threshold on the physiological growth and yield of cotton under drip irrigation, three full treatment trials of three irrigation thresholds and decision sensors were set up respectively. The results showed that there were significant differences in the photosynthetic characteristics (Pn, Tr, Gs, Ci, WUE), cotton (P<0.05). The results showed that there were significant differences in the photosynthetic characteristics (Pn, Tr, Gs, Ci, WUE) of cotton leaves, (P <0.05). The threshold of irrigation did not reach the significant level above the cotton (P> 0.05). The location of water sensor and the threshold of irrigation had significant effect on the physiological growth of cotton and the yield reached a significant level (P <0.05). The maximum values of Pn, Tr, Gs and Ci and WUE in cotton leaves were all in T5 and the maximum in Ls was in CK. Cotton net photosynthetic rate is closely related to transpiration rate and stomatal conductance. Cotton yield has a good correlation with net photosynthetic rate and leaf area of cotton, and net photosynthesis rate and leaf area can reflect cotton yield to a certain extent. According to the test results, it is preliminarily determined that the position of the moisture sensor is 40cm under the surface and the medium irrigation threshold (T5) is an appropriate solution, which can provide a theoretical basis for automatic control irrigation in Xinjiang.

Based on tracking test data in wintering period of greenhouse group in Xinyi Town，Lishi District，Shanxi Province，the change characteristics were analyzed． The wintering period was divided into warming up period and not warming up period and the minimum permissible irrigation temperature was determined in warming up period． The warming up time for irrigation water in different part of wintering period was calculated． The results showed that: ① The period that the irrigation water from river surface could be directly used for irrigation without warming up was the whole month of November，the period that river water must be warmed up before using for irrigation was midDecember to mid-March of the following year，the river water could be directly used for irrigation in part time of the whole day in the rest period of wintering period． ② During the period when the irrigation water needed to be warmed，the minimum irrigable temperature was between 7．5 ℃ and 10．8 ℃，the largest value of minimum irrigable temperature appeared in early and middle of January and the lowest value of minimum irrigable temperature appeared in early and middle of March． ③ During the period that river water must be warming up before using for irrigation，different warming time was needed during different period and time for warming was between 5 and 51 hours． The results could provide practical technical support for the management of irrigation water temperature in the greenhouse in the wintering period of the seasonal frozen soil． It had certain scientific value for the enriching the irrigation theory and technology.

In order to investigate the soil water transportation under alternative micro-irrigation，through indoor soil tank experiments with clay loam soil as an example，1 m pressure head，10 cm moistube pipe depth，8 d alternate cycle，and 3 different groups of tube spacing ( 10，20 and 30 cm) ，the soil water transportation in different treatments under alternative micro-irrigation is observed． And the experiment is repeated for three times． The results show that: when the tube spacing is 30 cm，soil moisture content in the midline soil box remains at the initial moisture content of about 1．38%，the soil wetting bodies formed by two moistubes are cylindrical and do not intersect with each other; when the spacing is 20 cm，after changing the irrigation channel，the soil water content in the midline of soil box begins to rise and reaches 11．01% at the end of the test，and the soil wetting bodies formed by two moistube are intersecting and cylindrical，and have little influence on each other; when the spacing is 10 cm，from the beginning of the experiment，the soil water content in the midline of soil box begins to rise and reaches 13．88% at the end of the test，and the soil wetting body is approximately elliptical．

In order to explore the effects of different water and fertilizer combinations on grape quality in greenhouse，and to get the best combination of water and fertilizer，the five －year －old “6－ 12”grape was used as experimental object． The results showed that the drip fertigation could significantly increase the soluble solid content，solid－acid ratio and sugar－to－acid ratio of grape fruits compared with CK， and did not significantly reduce the other quality of grap fruits． And compared with the control，W1F1 treatment can reduce water consumption by 36% and fertilizer by 16%． Under the condition of drip fertigation，besides the Vc content of fruit，the interaction of water and fertilizers have a very significant impact on the rest of the quality indicators; under W1 and W2 irrigation levels，with the increasing of fertilizer amount，the longitudinal and single grain weight of the fruit increased firstly and then decreased; under the same irrigation level，the fruit shape index and the color index of red grape fruit( CIＲG) firstly increased and then decreased with the increase of fertilizer amount． With the increasing of irrigation quantity，the fruit diameter as a whole showed the trend firstly increased and then decreased，reaching the maximum at W2F3 treatment． At the same irrigation level，soluble solid，soluble sugar，ratio of solid to acid，ratio of sugar to acid and titratable acid all showed completely opposite changes with the increasing of the fertilizer amount． The influence on Vc content of grape fruit was not significant with the change of irrigation quantity，fertilizer amount and interaction between water and fertilizer． Through the principal component analysis of the fruit quality of different treatments，concluding that the optimum comprehensive quality of grape can be obtained when drip irrigation treatment W2F3，irrigation quantity 3 045 m3 / hm2 ，fertilization amount 750 kg / hm2 ．

In order to study the effect of desulfurization gypsum ( DG) on saline-alkali land in Gansu province，based on the same condition of a unified leaching rate of 3 200 m3 / hm2 ，organic fertilizer 40 t / hm2 and yellow sand of 225 m3 / hm2 ，through 2 years field contrast test， the effects of different desulfurization gypsum contents，including 0 ( T0) ，18 ( T1) ，22 ( T2) ，26 ( T3) ，30 t / hm2 ( T4) ，on the pH， alkalization，electrical conductivity，salt ions content，Chinese wolfberry growth and yield are studied． The results show that with the increase of the application of desulphurization gypsum，the soil pH and alkalization decrease and the soil electrical conductivity first decreases and then increases; drip irrigation is helpful for the reduction of soil electrical conductivity; under the T3 treatment，the yield of wolfberry in the second year is 1．85 t / hm2 ，which indicates that the appropriate amount of desulfurized gypsum combined with drip irrigation can improve the soil physicochemical properties and facilitate the growth of wolfberry．

The timely acquisition of soil moisture is of great significance to guide precision irrigation． Winter wheat at heading stage is studied in this paper． The spectral information of winter wheat canopy is collected by an unmanned aerial vehicle ( UAV) equipped with a multispectral camera of six bands aiming at getting the difference( DＲ) between the spectral reflectance of reference point and that of each plot． Then，the difference ( DSM) between the soil moisture content of reference point and that of each plot is calculated in the similar way． Through analyzing the relationship between DＲ and DSM，the single linear models and multivariate linear regression models are established and validated． The results show that the model of 40 cm is better than that of 60 cm in the single models and the model of 40 cm in wide spacing is the best with Ｒ2 ( determination coefficient ) up to 0．9 and the prediction of ＲMSE ( Ｒoot Mean Square Error) only 0．016 in the multivariate models． The study can quickly obtain soil moisture content in field to provide some theoretical basis for precision irrigation．

In this paper，the water-saving and emission-reduction effect of rice in cold region of North China is systematically studied with water and fertilizer management ( including combination of 4 kinds of water-saving irrigation modes and 5 kinds of fertilizer modes) as the control index，the field experiments as foundation，and the theoretical analysis and numerical calculation method as measure． The results show that: the comprehensive water-saving effect of the controlled irrigation-drainage mode is the best，the water use efficiency of the shallow -wet irrigation mode is the lowest，and the water-saving index of the controlled irrigation-drainage mode is increased by 9．40%，15．67%，35． 58%，respectively，than that of the wet irrigation mode，intermittent irrigation mode，and shallow-wet irrigation mode． Moreover，the nonpoint source pollution load of the controlled irrigation-drainage mode is the minimum under the condition of the same fertilizer amount，while the non-point source pollution load of the low fertilizer mode is the minimum under the condition of the same irrigation mode． The variance analysis results show that the influences of irrigation and fertilization on non-point source pollutant emission are significantly． Additionally， the yield is higher under the condition of controlled irrigation-drainage mode than other water-saving technologies in the test fertilizer range． From lower mode to low mode，if the fertilizer amount is increased 45．00 kg / hm2 hectare，the yield is obviously increased by about 132．90 kg / hm2 hectare． In summary，the mode of Controlled Irrigation-drainage with Ｒain Storage with Low Fertilizer is the most conducive to water -saving，emission-reduction and high yield．

This research takes Harbin and other seasonal frozen soil areas as the research reference area. In the process of researching the frozen soil water and soil properties, selected a low freezing point liquid that it is suitable for the determination of the basic parameters of the soil, measured permeability coefficient of frozen soil which moisture content is 20%, researched the hydro logical properties of frozen soil. Simultaneously, measured permeability coefficient of non-frozen soil which moisture content is 20%, exploring the differences of water quality between frozen soil and non-frozen soil. The main content of this research is the low temperature in cold area, it is an innovative point to seek a low-freezing liquid for testing the parameters of the frozen soil.

In this paper，the rice drought risk assessment model is established by precipitation anomaly percentage and the rice drought risk in transplanting-tillering stage，jointing-booting stage，heading-maturity stage and whole growth stage in Guizhou province is assessed based on the prediction data of daily precipitation data of CMIP5 global climate model． The results show that: under ＲCP2．6 ＲCP4．5 and ＲCP8．5 condition，the order of rice drought risk in Guizhou province in each growth stage from large to small is jointing-booting stage，headingmaturity stage and transplanting-tillering stage; the rice drought risk in 2081 to 2100 is higher than that in 2016－2035; there are great spatial differences among each growth stage and whole growth stage for rice drought risk in 2016 to 2035; the rice drought risk in 2046 to 2065 and 2081 to 2100 in north and east parts was higher than that in south and west parts．

The objective is to Present a reasonable mathematical analysis method to determine the precise soil water potential threshold for starting irrigating in the fruiting stage of “Kyoho”grapevine． After using the methods of real -time monitoring soil water potential，non - destructive measurement of fruit size and collecting the data that formed the discrete curve of the relationship between the berry enlargement rate and soil water potential，the figures are given a scatter plot curve smoothing processing via the cubic spline interpolation method based on Matlab software，and then they are inspected through the changes of derivative curve slope． Finally，the significant differences between the growth of shoots indicators are conducted by comprehensive analysis． The critical values to distinguish the different stages of the period of berry set，berry first rapid growth period and veraison are determined，as well as the soil water potential thresholds to start irrigating at the corresponding stages of“Kyoho”grapevine． The development of berries during the fruiting stage in“Kyoho”grapevine are divided into four phases，including high speed growth phase，rapid growth phase，slow growth phase and shrinking phase． In addition to this，the soil water potential thresholds to start irrigating during the period of berry set，berry first rapid growth period and veraison are determined as －11．64，－14．86 and 21．00 kPa respectively，which can be used to guide the water management in the cultivation of fruit and provide key parameters and theoretical basis for the research in precision irrigation technology upon soil water potential threshold．

The effective evaluation of the regional water saving irrigation development level is an important precondition for making the regional water-saving irrigation program． Aiming at the problem that the existing evaluation methods has not the function of interactively verifying the accuracy of the results，this paper uses the entropy weight method and the binary correlation method to conduct the subjective － objective-combined empowerment，applies the theory of contradiction principle of variable fuzzy sets ( VFS) to prove evaluation results，and used the fuzzy number to describe uncertain information． Then the evaluation model based on VFS is established． Finally，the water saving irrigation development level in Shaanxi Province is taken as an analysis example． The water saving irrigation development level of all the cities and districts is evaluated and sorted． The evaluation results show that the method is rational and effective． Then the policy suggestions are proposed to improve the efficiency of water saving irrigation in Shaanxi province．

The public financial subsidies policy and its implementation for purchase and use of water-saving irrigation equipment in China was summarized， the related issues are analyzed，and on this basis，the countermeasure for increase the public financial subsidies to purchase and use of water-saving irrigation equipment is proposed.

Sprinkler irrigation is a widely used irrigation technology，and the wind resistance of sprinkler is an important index of sprinkler irrigation technology． In this paper，the differential equation of water droplet running in air is given by studying the law of water droplet movement in windy condition． By comparing and analyzing the distance between the landing point of different size water droplets and the nozzle and the water distribution under windy and no-windy conditions，it can be concluded that adjusting the nozzle pitching angle and water jet can improve the wind resistance of the nozzle and so the working performance of the sprinkler head will not be affected by wind force under the windy condition．

In order to solve the synchronous control problem in the front wheel independent steering system of mobile sprinkler machine，the cross－coupling control method based on fuzzy PD is proposed to reduce contour error，which is estimated on the basis of the following error in single wheel PID control and Ackermann principle． The method can compensate the front wheels in real time according to the contour error． Simulation and experimental results showed that the control algorithm can quickly eliminate the contour error between wheels based on a high precision of angle tracking in front wheels． The system has a fast response speed，a small overshoot and a high synchronization control precision． This study has some practical significance for the steering synchronous control of the independent steering agricultural machinery．

It is necessary to develop different irrigation strategies for different plants and geograph- ical environment. Soil moisture plays a key role in the growth of plants,According to the problems of non-linearity and pure delay of greenhouse irrigation system, the fuzzy PID controller is desig- ned and the greenhouse intelligent irrigation control system is built with simulink. The simulation curve shows that compared with the fuzzy controller Accuracy increased by 2%; compared with t- he PID controller to reduce the amount of overshoot 5%, convergence time reduced by 20seconds. The results show that the fuzzy controller by good robustness, good dynamic performance, can m- eet the requirements of greenhouse plant irrigation.

In view of the present status of common water shortage and greenhouse planting area expanded year by year in northern China.This paper proposes a intelligent greenhouse monitoring and control system，which combined of C/S and B/S model.This system will get sensors, actuators, and the send unit for fusion.Implementation will be equipped in the field of soil moisture sensor, temperature sensor collected data;Real time data such as pump rotation speed, working time to send and receive.Mobile terminal analysis, classification and processing the data, realized farmland data remote transmission and intelligent processing.In the lab for sensors and mobile terminals connections with wireless module , data reception,the remote control test has obtained the ideal effect.

The problem of irrigation uniformity is one of obstructions in the popularization of low-pressure pipe irrigation. The pumping head is usually too large when using the traditional design method, which results in the phenomenon that the discharge of outlets in the front of a branch pipe is much larger than that of outlets at the back. Strategies for the difference of operating head between the outlets of the same branch pipe, the appropriate operating head and suitable size of outlets were proposed. At the same time, the checking method for design results was proposed and applied in the design of low-pressure pipe irrigation project in Zhongde demonstration area of Huanghai State Farm in Jiangsu Province. The results showed that the checking method could enhance the irrigation uniformity of low-pressure pipe irrigation and increase the accuracy and reliability of design results.