In this study，the effects of two irrigation methods，namely drip irrigation and flood irrigation，on the active organic carbon pool and goji berry growth in the dryland soil were analyzed through a three－year field experiment． The results showed that the effect of drip irrigation on the total organic carbon content of soil showed an overall improvement． The carbon pool management index( CPMI) was higher than that of flood irrigation． Especially，in the 0 ～ 10 and 10 ～ 20 cm soil layers of the topsoil，the permanganate－oxidizable organic carbon ( POXC) content were increased by 12．99% and 18．67%，respectively，and the content in the 120 ～ 140 cm soil layer was also significantly higher than that in the same layer of soil compared to flood irrigation conditions，with an increase of 38．17%． The difference between the total yield of goji berry in the two irrigation modes was not obvious． However，the water productivity in drip irrigation mode was increased by 112．12% than that of flood irrigation，and the fruit grade rate was improved． Therefore，in view of the current situation of production management in the research area，the drip irrigation mode is conducive to the improvement of soil organic carbon quality，the soil fertilization of orchard and can meet the demand of plants growth，which will provide a scientific basis for achieving long－term sustainable production．

In order to study the influence of water at heading stage of winter wheat on the physiological conditions of flag leaf under drip irrigation，with Xindong22 and Xindong43 wheat varieties as experimental material，single factor randomized block experiment design was adopted and a field experiment was conducted． Five water processing，including 225 mm ( W1) ，375 mm ( W2) ，525 mm ( W3) ，675 mm ( W4) and 825 mm ( W5) ，were set up． The change of soil water potential was monitored before and after irrigation，and the physiological indexes such as chlorophyll，malondialdehyde，soluble sugar and proline in flag leaves of winter wheat were measured，and the compensation coefficients of each physiological index under different irrigation amounts were calculated． The experimental results show that，under the same irrigation amount，the restoration capacity of soil water potential is the best in 0 ～ 20 cm soil layer，followed by 20 ～ 40 cm soil layer，and the weakest in 40 ～ 60 cm soil layer． Under different irrigation conditions，the treatment with irrigation amount more than W3 could recover well， while the treatment of W1 and W2 with irrigation amount less than W3 showed excessive water consumption． Different physiological indicators have different sensitivity to water，and the order is soluble malonate ＞ sugar ＞ proline ＞ chlorophyll． Under different soil moisture conditions， soluble sugar，proline and other physiological indicators all have the largest compensation effect under W3 treatment，among which proline has a certain lag． Therefore，it is recommended to maintain the soil water potential at －85．5 ～ －68．0 kPa before water potential irrigation in the soil layer 20 ～ 60 cm away from the drip irrigation zone at the heading stage of winter wheat．

The anti－negative pressure clogging performance of single－wing labyrinth drip irrigation belt，inner－mounted drip irrigation belt and internal cylindrical drip irrigation pipe in clay loam，loam and sandy loam soil were studied by indoor soil box test． The research method is that the drip irrigation system is repeatedly opened and closed，and the degree of negative pressure clogging is reflected through the dripper flow changes． The results show that the single－wing labyrinth drip irrigation belt has poor resistance to negative pressure clogging，the flow rate in the loam is reduced by 34%，and blockage occurs; the flow rate in the sandy loam decreases by 12%，and if the test is continued，the blockage may be large; the inner －mounted drip irrigation belt has better resistance to negative pressure clogging; there was no obvious blockage in the three types soil; the flow rate of the columnar drip irrigation pipe in the clay soil and loam is 12%，and there is a tendency of blockage; compared with the other two drip irrigation belts，the drip irrigation pipe has the largest flow rate except for the flow path of the dripper，indicating that the increase of the flow rate does not significantly reduce the negative pressure blockage． 

In order to accurately predict the winter soil temperature of apple orchard，this paper established a BP neural network soil temperature prediction model ( BP－WSPI－T) ，a BP neural network soil temperature prediction model optimized by genetic algorithm ( GA－ WSPI－T) and a BP neural network soil temperature prediction model optimized by incremental back propagation algorithm ( IBP－WSPI－T) under the condition of water storage pit irrigation． The average temperature in the pit，the surface temperature，the distance from the center of the adjacent two water storage pits to the pit wall，and the lowest temperatures of the layered soil 5 cm away from the pit wall were taken as input． The models were used to predict the lowest temperatures of layered soil at 15，25 and 35 cm from the pit wall，and the prediction effects were determined through the statistical analysis with the field measured data． The results show that the mean absolute percentage errors of BP－WSPI－T model，GA－WSPI－T model and IBP－WSPI－T model are 8．19%，4．41% and 7．57%，respectively; the GA－WSPI－T model has the best prediction effect compared with BP －WSPI－T，and the prediction accuracy has been greatly improved． Thus，GA－WSPI－T model is suggested to predict the winter soil temperature of apple orchard under water storage pit irrigation．

Aiming at the problems of subsurface drip irrigation schedule and unclear synergies of water and fertilizer of alfalfa in drought sand savanes of Ningxia，through field experiment，the indexes of alfalfa，including the plant height，soil moisture content，yield and water production efficiency etc．，were analyzed． The results showed that the growth of alfalfa under D11 treatment was good． According to the research，the irrigation schedule of coupling subsurface drip irrigation and fertilization for alfalfa in drought sand savanes of Ningxia is as follows: the irrigation quota is 3 150 m3 / hm2 ，the irrigation times are 12 times，and the fertilizer rates are N 90 kg / hm2 ，P2O5 126 kg / hm2 ， and K2O 108 kg / hm2 ．

Through the control of nitrogen application level，the study of soil water－salt distribution and sunflower yield variation law was carried out，which provided an effective theoretical basis for improving the crop growth environment and increasing yield of saline－alkali crops． In this study，Datong Basin was selected，and two kinds of tillage irrigation methods were adopted，including wide ridge furrow irrigation ( G) and horizontal flood irrigation ( Q) ． Three nitrogen application levels were set，and the nitrogen application rate was 156 kg / hm2 ( N1) ，260 kg / hm2 ( N2) ，364 kg / hm2 ( N3) ，with no nitrogen application ( QN0) as the control group，and the amounts of phosphorus pentoxide and potassium oxide were 45．7 and 54．84 kg / hm2 ，respectively． The irrigation quota was 340 mm． The results showed that under the condition of no nitrogen application，the conductivity of EC1 ∶ 5 of 0 ～ 40 cm on the furrow irrigation ridge was 15% ～ 30% lower than that of horizontal border irrigation，and the 0 ～ 40 cm EC1 ∶ 5 in the ditch was lower than that of the horizontal border irrigation by 40% ～ 50%． For the soil layer below 40 cm，the EC1 ∶ 5 was 20% ～ 40% lower than that of the horizontal border irrigation． Under nitrogen application conditions，there was no significant difference between EC1 ∶ 5 on 0 ～ 40 cm surface layer of furrow irrigation and horizontal border irrigation ( p＜0．05) ． However，with the increase of nitrogen application，EC1 ∶ 5 in both surface layers increased slightly，and the 0 ～ 40 cm EC1 ∶ 5 in furrow irrigation was 40% ～ 60% lower than that in horizontal border irrigation． The EC1 ∶ 5 of furrow irrigation under 40 cm was about 40% lower than that of border irrigation． Under the same irrigation amount，the moisture content of 0 ～ 40 cm surface layer in furrow irrigation ditch was lower than that of the film－covered surface layer on the ridge，and in the whole growth period，except for the influence of rainfall，the moisture content of furrow irrigation with film－covered ditch was 10% ～ 23%，which was not significantly different from that without nitrogen application ( p＜0．05) ． Based on the above analysis，using plastic film mulching furrow irrigation with nitrogen application amount of around 260 kg / hm2 can improve soil water and salt conditions and increase crop yield．

Planting of winter wheat in Henan province People's ShengLiQu irrigation area as the research object, through the analysis of the birth of winter wheat under different irrigation process, shape index and yield components of difference, to determine the water-saving high yield of winter wheat irrigation system which provides the theoretical foundation and the efficient utilization of water resources. The results showed that soil moisture was one of the most important ecological factors affecting the growth and development of winter wheat. Low water treatment (T - 50), leaf area, plant height, dry matter accumulation and yield components traits significantly lower than the optimum water processing, the heavier the drought, the smaller the leaf area, plant height is lower, the smaller amount of dry matter accumulation. The number of effective panicles, length of ears and number of panicles decreased with the decrease of soil moisture, and the treatment of t-50 was the lowest, but the effect of soil water on the number of small panicles was not regular. The grain weight and yield of the suitable water treatment (t-60) are highest.

In order to explore the spatial variation and spatial distribution of salt in continuous subfilm drip irrigation cotton fields.The spatial variation characteristics of soil salinity in submembrane drip irrigation cotton fields were analyzed with ArcGIS10.2 software.The results show that, with the increase of soil depth, the soil salinity rate increases and the variability of the salinity rate increases with the increase of soil depth.The semi-variance function model of soil salinity in the study area is well fitted by using gaussian model. The base station values of each soil layer are all positive, and there is positive base effect caused by sampling error, variation within the minimum distance or random and inherent variation.In conclusion, on the horizontal direction, the salinity of each soil layer is distributed gradually from south to north, with salt mainly accumulated in the 80-100cm and 100-120cm soil layers.In the vertical direction, the soil salinity rate increases with the increase of soil depth.

Deep irrigation of winter wheat is an efficient water－saving irrigation method． In order to simplify the research of winter wheat root system under deep irrigation conditions，this article builds a BP artificial neural network prediction model，which uses soil depth， development time，daily water absorption of soil roots，daily average temperature of soil layer，dry weight of shoots and plant height as the input factors，and uses root density as the output factor． The experiment results show that under the established prediction model，the average relative error between the predicted and measured values of root densities of the training samples is 5．92%，and the average relative error of the test samples is 7．30%． Both the training samples and the test samples have higher precision． So，this model is feasible to predict the distribution of winter wheat roots under deep irrigation conditions． It can provide a new method for root research of winter wheat under deep irrigation conditions．

Crop yield is closely related to the process of dry matter accumulation． Irrigation timing and amount will affect dry matter accumulation and crop yield． Field experiments on Maize irrigation in Minqin Oasis were conducted to study the effects of irrigation amount and time on dry matter accumulation dynamics and yield of Maize in Hexi Oasis． Logistic model of dry matter accumulation was established， and the correlation between maize yield and its components was analyzed． The results showed that the dry matter accumulation of aboveground parts of maize showed a slow－fast－slow growth trend with the advance of growth period，and the big bell－mouth－heading period was a rapid growth period of dry matter，with an average growth rate of 5． 12 ～ 7． 58 g / d． Attention should be paid to the timely irrigation during this period，which can promote the growth of maize; drip irrigation under plastic film significantly increased the growth rate of maize due to the effect of increasing temperature of plastic film． The dry matter accumulation of drip irrigation maize under mulch entered a vigorous period about 65 days after sowing，and the vigorous period lasted about 26 days． The maximum vigorous period was 78 days after sowing． Through correlation analysis，the yield of drip irrigation maize under mulch was significantly positively correlated with ear diameter，grain number per ear and seed yield． The yield of maize could be increased by increasing ear diameter and grain number per ear．

In order to explore the suitable amount of fertilizer for crops under aerated irrigation, three fertilization levels of high nitrogen, middle nitrogen and low nitrogen, and two irrigation methods of aerated and unaerated (as the control) were designed. Two factors and three levels of completely random block design were adopted, with a total of 6 treatments.The effects of different fertilizer levels on plant height, stem diameter, dry matter quality and quality of greenhouse tomato under aerated and unaerated irrigation were studied.The results showed that under aerated irrigation, plant height and stem diameter increased by 6.2% and 11% respectively, dry matter mass increased by 11.7%, yield per plant, vitamin C, soluble sugar, organic acid and saccharic acid increased by 6.7%, 11.6%, 11.3%, 7.5% and 4.1% respectively, compared with that without aeration.Therefore, aerated irrigation can not only promote plant growth and development, but also effectively improve crop yield and quality.At the same time, the test results of different fertilization levels in aerated irrigation showed that under the condition of middle nitrogen, the plant stem diameter, dry matter quality, fruit yield and quality were significantly increased compared with those under high nitrogen and low nitrogen . Moreover, fertilization level and aerated irrigation had significant cross-effect on tomato plant height and yield Therefore, considering the comprehensive influence of each treatment on the growth, development and yield and quality of tomato, the middle nitrogen level in aerated irrigation is a better model of irrigation and fertilization

Based on the basic factors of water resources, including water quantity and quality, the connotations and functions of water resources are further expanded for the multivariate system of water resources carrying capacity and the concept of carrying capacity is proposed from the quantity，quality，space and flow of water resources. According to the subject and object of water resources carrying capacity，a fundamental set of influence factor is structured from water resources，social economy and ecological environment system. The diagnostic system of water resources carrying capacity is composed of the target，the elements，the representations and the index，which is multi-level，multi-element and bi-directional characterization between capacity and load，and the key diagnostic factors are determined from the quantity，quality，space and flow of water resources carrying capacity by the entropy weight method and the DEMATEL.

Accurate evaluation of groundwater quality is an important guarantee for the safety of drinking water for residents in the region． Aiming at the ambiguity and randomness in groundwater quality assessment，considering the importance of weights in the evaluation process， a water quality evaluation system based on game theory of AHP－CＲITIC combination weighting is established，and a comparative analysis is carried out in a certain area of Xichang City． The results show that the evaluation system is practical． At the same time，for the problems found in the evaluation process that the single super－standard pollutant is affected by the minima of other indicators and resulting in distortion of the results，it is proposed to add the measured data values of various indicators in the process of selecting cloud characteristic parameters to subjectively eliminate the evaluation results error．

On the basis of summarizing the previous studies on the evaluation of water resources allocation schemes, a new method for optimizing the allocation of water resources was established. From the perspectives of resource efficiency, social benefit, ecological benefit and economic benefit, 15 typical indicators such as per capita water consumption, canal water utilization coefficient and water resources development and utilization rate were selected for research. The weights are determined by the improved entropy method, and the TOPSIS method and the gray correlation method are improved respectively, and then the improved algorithms are combined to solve the relative progress of different schemes. The results of the improved TOPSIS-grey correlation method are consistent with the actual situation, and the validity and feasibility of the method are verified.

Based on the traditional floating island technology，a combined floating island system supplemented by microbial immobilization technology and aeration oxygen technology is designed． Static test and field observation are combined to investigate the treatment effect of combined floating island and traditional floating island on polluted water at low temperature． The static test results show that the combined floating island has a better treatment effect on NH+ 4 －N and CODCr，with the removal rate of NH+ 4 －N being 99．70% and the removal rate of CODCr being 65．78%． Due to the high dissolved oxygen in the small test of combined floating island，TN removal efficiency is lower than that of traditional floating island． The field observation results show that during solstice on October 30 and November 10，the average removal rates of CODCr，NH+ 4 －N and TN in test reach with combined floating islands are 21．49%，18．51% and 13．44% respectively，while the control reach with traditional floating islands is 0%，1．21% and －1．03% respectively． The results of static test and field observation all show that the ecological floating island has a good effect on the restoration of eutrophication water after the introduction of microbial carrier and aeration device．

By constructing a reasonable evaluation index system，this paper evaluates the comprehensive benefit of the integrated technology system of cotton water and fertilizer integration，and finds out the area with the best adaptability of the technology． This study establishes the three areas of core experiment demonstration base，collects related data through experiment and questionnaire survey． Considering the four aspects，including economic benefit，ecological benefit，social benefit and technological progress benefit，this paper selects scientific and reasonable evaluation indexes，and constructs AHP model for efficiency evaluation of cotton water － fertilizer integrated cost － saving and efficiencies－enhancing technology system，and compares and evaluates the adaptability of this technology in different regions． Due to the different conditions in different areas，the comprehensive benefits of cotton water－fertilizer integrated cost－saving and efficiency technology is also different． Among them，Bole city＇s comprehensive benefit score is the highest，it is suggested to carry out a wider range of promotion in places with similar conditions in this area． While Yuli county，Jinghe county and other places have relatively poor effect with potential for further improvement．

In order to improve the accuracy of the solution of the Van Genuchten equation of soil moisture measurement，a parallel competitive PSO algorithm is proposed． Firstly，based on the PSO algorithm，when the maximum radius value of the particle swarm is less than a certain threshold，the competition is triggered，and the worst particle is reset． Then，the particle swarm is divided into several subgroups，and the difference between the average fitness of the subgroup and the average fitness of the original particle swarm can not be less than the set threshold． Different sharing factors are introduced to dynamically adjust the information sharing between the subgroups and the subgroups and between the particles and the subgroups． Finally，the particle fitness function is composed by the parameters of Van Genuchten equation，and the algorithm flow is given． Experimental simulation shows that the algorithm in this paper has the characteristics of fast convergence speed and high solution accuracy in solving the test function，and the maximum relative error of the measured data of dehumidification of powdery loam is 5%，and the maximum relative error of the moisture absorption data is 4%，which is smaller than other algorithms．

Pan evaporation (Epan) is an important indicator to measure the atmospheric evaporation demand. Studying the pan evaporation in China is beneficial to explore its hydrological cycle and provide guidance for the rational distribution of water resources. This study used daily weather observation data (average temperature, wind speed, relative humidity, and sunshine hours) of 751 stations nationwide from 1961 to 2017 to estimate the evaporation of 20 cm pan evaporation based on the PenPan model. This paper analysed the trend of 57 years of meteorological data and PenPan model calculations in China to explore the dominant factors affecting Epan. The results showed that: during the period from 1961 to 1993, there was a phenomenon of “evaporation paradox” in China, and the dominant factor affecting Epan was wind speed; the phenomenon of “evaporation paradox” disappeared in 1994-2017, and the dominant factor was saturated water vapor pressure. Two-stage comparison: the effect of air temperature on evaporation increased while that of wind speed decreased. Different seasons of spring, summer, autumn and winter, the amount of evaporation varied greatly in space. The summer maximum of radiation component was in northwest China, and the rest of the season was in south China. The maximum value of areodynamic component in winter was in southern China and the rest seasons were in northwest China. As the season went on, the region with the largest total evaporation had shifted from northwest to southern China. The summer maximum of radiation evaporation was in northwestern China and the rest of the season was in southern China. According to the total evaporation, it can be concluded that the northwest region and the southern China need to reasonably allocate water resources according to the seasonal variation of evaporation in the region.

In this paper，wheat，corn，cotton，rice，sugar beet and potato were selected as research objects． Based on calculating the unit virtual water yield of 6 main crops in 14 prefectures and 64 main producing counties of Xinjiang by Penman－Monteith formula，the unit virtual water value of main crops were clarified． Through corresponding analysis with IBM SPSS software，the planting preference and layout of major crops in Xinjiang were studied from the perspective of virtual water value． The results showed that: ① among the six main crops，the value of virtual water was the highest in tubers ( 8．34 yuan/m3 ) ，and the lowest in cotton ( 1．51 yuan/m3 ) ． ② from the perspective of virtual water value，there were significant differences in planting preference and planting scale of crops． At the county level，according to the order of virtual water value of crops from high to low，the top three counties had a high degree of compatibility with the“13th five－year plan” ( planting industry) of the autonomous region． ③ after adjusting the planting industry structure，the total output value of virtual water of crops could increase by 60．125 billion yuan，which could achieve the goal of“adjusting cotton and reducing water”in the 13th five－year plan ( planting industry) ． According to the research，there were significant differences in the value of virtual water per unit of different crops in crop types and regions，and the optimization of water resources allocation could increase the total production value of planting industry． Xinjiang should pay attention to the improvement of conical quality while adjusting the external dominant planting structure，and produce high －quality products with characteristics．

In order to improve irrigation accuracy and water use efficiency of fine planting, a precise irrigation system based on Raspberry was designed. The hardware of the system is designed with Raspberry Pi 3b and related sensors. The relevant program of the system is written in pyhton language, and the database is built. The fuzzy algorithm control program of the two-dimensional fuzzy controller is compiled. The input value is the change value of soil moisture and soil moisture, and the output value is the PWM value of the DC motor. Finally, through the experiment of Cucumber Seedling planting, the anticipated goal of water saving was achieved. It provides theoretical basis and reference basis for the full realization of intelligent irrigation.

In view of the problems of small rural agricultural bases，in combination with the more advanced 4G communication technology， database of cloud and cloud service technology，Internet technology，the mobile web APP technology，GIS technology and other advanced technology，based on the independent research and development of dual－core multi－functional Internet of things acquisition device，through the improvement of the overall framework of the integrated management cloud system，a set of integrated management system with low investment cost，reasonable structure，convenient operation and suitable for the application of small rural agricultural bases is realized． The application practice shows that the system can solve many problems of small rural agricultural base，can be industrialized and applied，and has good value and significance．

In order to solve the water-saving problem in traditional greenhouse irrigation system, this paper proposes a water-saving Fuzzy-PID control system for greenhouse drip-irrigation. Firstly, the real-time soil moisture of greenhouse is measured. Secondly, an adaptive Fuzzy-PID control strategy is presented to adjust the soil moisture according to the nature of plants, which ensures an optimal growing environment and avoids the waste of water resource. Then, simulation results show that compared with traditional Fuzzy control and PID control, the proposed control method can reduce adjustment time by 17s and decrease overshoot by 9.4%. Finally, experimental results show that the proposed system works stably and has a strong robustness. It can save 23% water consumption and meet the requirements of water-saving irrigation, and has a good popularization value.