A field experiment is conducted to systematically study the effects of the practical drip irrigation mode according to tensiometer on tomato growth and yield，water and nutrients use efficiencies，and soil environment，with the traditional drip irrigation mode as contrast treatment． The results show that the practical drip irrigation mode，in which when the measuring value of tensiometer buried 15 cm depth is greater than 35 kPa，the fertigation is conducted with the irrigation amount of 5 mm，the nitrogen concentration of 120 mg /L，and the ratio among nitrogen，phosphorus and potassium of 1 ∶ 0．3 ∶ 1．5，can maintain the normal growth of tomato plants，and water amount is saved by 40．4%，fertilizer input is saved by 45．6%，yield is increased by 8．6%，irrigation water use efficiency is increased by 82．1%，and partial productivity of fertilizer is promoted by 99． 5%． In addition，this mode can significantly reduce contents of alkali hydrolyzable nitrogen， available phosphorus，available potassium and total salt in 0 ～ 20 cm soil layer，avoids surface nutrients and salt accumulation，and can significantly decrease soil water content in 20～ 40 cm soil layer and avoids downward migration of soil water．

The field of potato drip irrigation experiment was carried out to analysis effects about water consumption of potato，photosynthetic characteristics，yield and water use efficiency under different supplemental irrigation treatment，obtaining the suitable scheme. The results show that the water consumption in the whole period growth with the increase of irrigation quota increases；changes of photosynthetic rate showed a convex bimodal parabolic type，in the tuber enlargement stage，supplemental irrigation is conducive to the improvement of potato leaf photosynthetic rate; transpiration rate and photosynthetic rate have the similar changes，supplemental irrigation in the tuber expansion period has significant effect on transpiration rate；the highest yield is treatment of F5，for a range of 32790kg/hectares，Irrigation quota can improve the yield，when irrigation quota exceeds 675m3/ hectares，yield and irrigation quantity not positively correlated；irrigation water use efficiency and water production efficiency of F5 are the largest，48.58kg/m3 and 19.0kg/m3 respectively；the average water use efficiency of F8 is the largest，is 1.55 μmolCO2/mmolH2O，followed by the treatment of F5，is 1.25 μmolCO2/mmolH2O. In summary，the treatment of F5 is the best irrigation scheme.

Taking soil in Loess Plateau region as the research object，the soil water characteristic curve and soil basic physical and chemical parameters are tested and the measured data samples of Van-Genuchten model parameters are obtained． The relationship between the basic physical and chemical parameters of soil and the parameters of Van-Genuchten model is established． A nonlinear transfer function prediction model with soil clay content，silt content，bulk density，organic matter content，total salt content as input variable，and Van-Genuchten model parameter as output variable is established． The research result shows that taking soil clay content，silt content，bulk density，organic matter content and total salt as input variables is feasible to carry out nonlinear prediction of Van -Genuchten model parameters; the established nonlinear prediction model has higher accuracy，the average relative error between the measured and predicted values of the Van -Genuchten model parameter α in the prediction sample is 9．66%，the average relative error between the measured and predicted values of parameter n is 6． 83%，the average value of the relative error between the measured and predicted values of the sample parameter α is 7．34%，and the average relative error between the measured and predicted values of the parameter n is 5．45%． The research result provides a convenient way to obtain soil water characteristic curve for the Loess area．

Based on the measured data of winter soil temperature，the BP-WSPI-T model with the topological relation of 11-13-8 is established． In this model，the stratified soil minimum temperature of the layer 5 cm away from the radial wall of the pit，the average temperature in the pit，the surface temperature and the radial distance along the pit wall are selected as input parameters，the minimum temperature distribution of the soil layer 15，25 and 35 cm away from the pit wall is selected as output parameter． The model is used to quantitatively predict the minimum temperature distribution of winter soil，and the field measured data is used to rate and verify the model． The results show that the average relative error is 8．7%，9．4% and 7．3%，respectively，when the BP-WSPI-T model is used to predict the minimum temperature of the layer 15cm，25cm and 35cm away from the pit wall． The average relative error of soil temperature overall forecast is 8．5%．

According to the field measured data of soil moisture and nutrients of winter wheat in the growth period in Linfen city，the optimal irrigation and fertilization scheme under limited irrigation condition is studied through using the crops growth model as the basis of the growth process simulation of winter wheat． The study results show that under the same hydrologic year condition，with the increase of irrigation water，both the fertilizing quantity and yield are increased，while the benefit increases first and then decreases，so there exists an optimal scheme; under the same irrigation water quantity condition，with more serious drought，the fertilizing quantity shows a tendency of increasing first and then decreasing，which indicates that the insufficient water supply has effects on the nutrition absorption of wheat，and the yield also shows a decreasing tendency．

On the basis of the microporous concrete seepage-pipe with excellent hydraulic performance，a seepage-irrigation mode，in which the irrigation water delivery and water seepage are conducted synchronously is proposed in this paper． With sand and cement as raw material， a kind of microporous concrete seepage pipe，with the length of 500 mm，the inner diameter of 50 mm and the external diameter of 70 mm， is made through dry pressing method． Then a 20 m seepage pipeline is connected to study the hydraulic performance of the seepage pipe． The results show that: the flow rate per unit length of the microporous concrete tubes increases linearly with the increase of the system water head; the system water head has great impacts on the water head at the front half part of the pipelines，while has little effect on the water head at the latter half part of the pipelines; the water head decreasing rate is fast in the front part of seepage pipelines，becomes slow in the middle part and very slow in the end part． The study results can provide valuable theoretical basis for scientific building and rational use of microporous concrete sub-irrigation system．

A 2 -year field experiment was conducted from 2014 to 2017 to explore the effect of different nitrogen application rates and irrigation treatments on shoot biomass accumulation，yield，and water and nitrogen use efficiency of winter wheat． In the experiment，the nitrogen application rates were 80 kg /hm2 ( N1) ，160 kg /hm2 ( N2) ，and 240 kg /hm2 ( N3) ; the irrigation treatments were supplement with 30 mm irrigation at jointing and heading stage ( W1) ，and no irrigation ( W0) ． In addition，critical nitrogen concentration dilution curves under the two irrigation conditions were constructed． The nitrogen nutrition index model based on critical nitrogen concentration dilution curve was used to diagnose nitrogen status of winter wheat． The results showed that N2 treatment had a significantly higher shoot biomass than N1 treatment，but had no significant difference with N3 treatment，under a certain irrigation condition; a proper supplementation of irrigation could increase the biomass accumulation of winter wheat at a same nitrogen application level; the relationship between maximum shoot biomass and critical nitrogen concentration of winter wheat could be described by a negative power function with a high fit degree; took consideration of nitrogen nutrition index and the fitted curve between yield and nitrogen application rate，the suitable nitrogen application rate was 171 and 186 kg /hm2 ，respectively，under the W0 and W1 conditions; in the two winter wheat seasons，the average water use efficiency of W1N2 treatment was increased by 10．57% and 14．01% than W0N2 and W1N3 treatment，respectively; the average nitrogen use efficiency of W1N2 treatment was increased by 10．97% and 55．77% than W0N2 and W1N3 treatment，respectively． In conclusion，the W1N2 was the reasonable irrigation and fertilization treatment among the all treatments． 

In order to study the water requirement law of mountain jujube in the Loess Plateau region，an insufficient irrigation experiment was conducted at the Mizhi Experimental Station in 2009－2013． The results show that the order of water consumption and reference crop evapotranspiration ET0 of the jujube in different growth periods from big to little is fruit enlargement period，flowering and fruit bearing period，fruit maturation period，and sprout leaves period; Jujube average crop coefficient in the four growth stages ( sprout leaves，flowering and fruit bearing，fruit enlargement，fruit maturation) is 0．44，0．81，0．99，and 0．91，respectively． According to the daily meteorological data in 1971－2005 provided by the local Bureau of Meteorology，the effective rainfall，jujube water demand and irrigation water demand in the test area for 35 years are calculated，the water requirement and irrigation water requirement of different hydrological year are analyzed， and the relationship between the jujube water requirement and meteorological factors in the same period are also analyzed． By fitting the water requirement and related weather factors，the empirical formula for the water requirement in each growth stages is obtained． The study results also provide a favorable basis for the development of jujube irrigation system in the Loess Plateau in different hydrological years．

In order to explore the optimal covering and planting patterns for maize in northeast dry land，the effects of three covering modes ( straw mulching，plastic film mulching，conventional tillage) and two planting patterns ( maize monoculture，maize intercropping soybean) on soil moisture and temperature regulation，dry matter accumulation and maize yield are studied by plot experiment． The results show that: under the same planting pattern，straw mulching can significantly increase soil water storage in root zone and plastic film mulching can significantly increase the soil temperature，but soil moisture and temperature is not affected by intercropping under same covering mode; the maize yield is obviously affected by the covering and intercropping patterns; the maize yield of DM treatment is about 19．34% and 11．39% higher than that of JM and CM under monoculture mode; the maize yield of DI is about 19．71% and 13．74% higher than that of JI and CI， respectively under intercropping mode． So the plastic film mulching tillage maize intercropping soybean ( DI) is the optimal covering and planting measures in the rain-fed area of the northeast dry land．

Based on the daily observation data of 24 meteorological stations in the Manasi Ｒiver irrigated area，the daily reference evapotranspiration ( ET0 ) value of each station is calculated with the Penman-Monteith equation，then the spatial-temporal variation patterns of reference crop evapotranspiration is analyzed with the methods of empirical Bayes Kriging interpolation method and Anomaly Method． In the meantime，the dominant factors of the ET0 variations in the Manasi Ｒiver irrigated area are analyzed by partial correlational analysis． The results show that: annual reference crop evapotranspiration of Manasi Ｒiver irrigated area is 972 mm，which reveals that the ET0 values are higher in northeast than that in southwest; the reference crop evapotranspiration in Manasi Ｒiver irrigated area has increased during the last 56 years with the rate of 0．51 mm/a． The first main oscillation cycle shows that the ET0 value will be on the high side after 2014． From the perspective of the ET0 change，wind speed was the dominant factors for the change of ET0 in Manasi Ｒiver irrigated area．

For water-saving of tomato under coconut coir cultivation condition and providing theoretical support for intelligent irrigation，in this experiment，the daily and hourly water consumption of tomato is measured by the weighing method，the environmental factors in greenhouse is recorded，the correlation is analyzed，and the irrigation model is formulated to provide data for reasonable irrigation of tomato under coconut coir cultivation condition． The results show that daily water consumption at the seedling stage，flowering stage，and fruiting stage is 94．1，539．2，746．8 mL/plant，respectively． Hourly water consumption at the seedling stage，flowering stage，and fruiting stage is 17．1，44．4，76．4 mL/plant，respectively． The correlation between water consumption and cumulative radiation is the biggest． The linear model for different growth stages is formulated to provide theoretical support to establish reasonable irrigation system of tomato under coconut coir cultivation condition and lay foundation for the further intelligence irrigation by using environmental factors．

In order to seek the best irrigation volume of the wine vineyard in the Hongsipu area to solve the problem of reasonable irrigation in the vineyard，the four-year-old wine grape“Cabernet Sauvignon”is used as the test material，and the drip irrigation method is used to design six different irrigation gradients to analyze the changes of soil water content，available nitrogen，available phosphorus and available potassium contents in the vineyard under different irrigation rates． The effects of different irrigation rates on soil available nutrients and water in soil migration are also studied． The results show that the spatial migration of soil nutrients in the vineyard is affected by different irrigation rates; the amount of available nutrients in the soil increases with the increase of irrigation amount; when the irrigation amount is 2．85 × 103 m3 /hm2 ，the yield of wine grape is the highest，and the amount of soil nutrients migrated downward is the best．

Based on the monthly precipitation data at 27 meteorological stations of Heilongjiang province from 1959 to 2014，the standardized precipitation index ( SPI) with various time scales was calculated． The characteristics of meteorological drought severity，affected area and spatio-temporal distributions with various time scales were analyzed by combining SPI values and principal component analysis approach． The results showed that the occurrence probability of meteorological drought was almost 30% in Heilongjiang province; drought affected area was increasing before 1980 but after that it was shrinking until 2000，and then the affected area was enlarging to stay a steady condition during 2000 to 2014． There were two mainly situations of drought spatial distribution． One was that the regional drought condition had consistency with most individual stations，and the other one was that the drought in the northwest was opposite with that in the southeast． On the temporal distribution，extreme events occurred mostly after 1980 and the trend of drought was significantly after 2000． The conclusion can provide theoretical guidance for water resources allocation and agricultural development in the study area． 

In order to solve the problem of uncertainty in water resources carrying capacity evaluation，this paper combines fuzzy set pair analysis with set pair exponential potential to establish FSPA-SPEP model by choosing ten indexes to quantitatively evaluate the water resources carrying capacity and its influencing factors of Nanning from 2005 to 2015． The results show that water resources carrying capacity of Nanning decreased significantly from 2005 to 2009，while water resources carrying capacity increased obviously from 2010，which reflected the effort of strengthening the construction of water-saving society in Nanning． The main affecting factors of water resources carrying capacity are environment water use rate and daily urban water consumption quota from 2010 to 2015． It is suggested that Nanning should strengthen the construction of water-saving society and promote the social and economic sustainable development．

In this study，in order to study the effect of mulching drip irrigation and water-nitrogen coupling on water and fertilizer use of fluecured tobacco and nutrient content of tobacco-cultivated soil，different irrigation water amounts ( 300，400，500 and 300 mm) and N application rates ( 4，5，and 6 g /plant) are designed，the flue-cured tobacco irrigation water use efficiency，nitrogen harvest index，soil available nutrient content and other indexes under different treatments are observed and analyzed． The results show that the irrigation water amount is significantly negative correlation ( P＜0．01) with flue-cured tobacco irrigation water use efficiency and nitrogen harvest index; N application amount is significantly positively correlated with nitrogen accumulation amount of flue-cured tobacco ( P＜0．01) ，and significantly negatively correlated with nitrogen partial productivity ( P＜0．01) ; within the irrigation and nitrogen fertilizer scope of this study，the increase of irrigation amount is conductive to improve soil available nutrient elements ( N，P，K) content，while the increase of the applied amount of N fertilizer is conductive to improve soil alkali-hydrolysable nitrogen content; the T5 treatment has the optimum comprehensive benefit on water and fertilizer saving，its irrigation water use efficiency，nitrogen harvest index，nitrogen for tobacco leaf production efficiency，tobacco cultivated soil alkali-hydrolysable nitrogen are 0．68 kg /m3 ，0．764，33．50 kg /kg and 137．28 mg /kg，respectively．

The study is based on optimization phosphorus content the influence on the intercropping wheat /corn soil water and salt and yield， and the relationship between them under different nitrogen level ( such as N0，N1，N2 and N3 ) through field experiment on salinization irrigation area． Ｒesults show that under optimization phosphorus content，intercropping wheat /corn soil moisture content and salt firstly reduces and then increases with the increase of N application，during N2P2 processing soil moisture content and salt is the lowest; intercropping wheat /corn yield increases and later decreases with the increase of N application，during N2P2 processing wheat maize yield is the largest，these shows that reasonable nitrogen and phosphorus ( N2P2 ) can improve the utilization of water and nutrients by crops，increase crop yield． Between N application rate and soil moisture content was significantly negative correlation ( P＜0．05) ，and the correlation of soil salt is a very significant negative correlation ( P＜ 0．01) ，and there were very significant positive correlation between yield ( P＜ 0．01) ． To set the rational fertilization scheme，control soil water and salt content，to achieve high and stable yield crop，reducing environmental pollution and the sustainable development of agriculture has a certain guiding role．

The wetland water environment has been deteriorating． Some studies have shown that aquatic plants can effectively absorb organic matter，nitrogen and other nutrients in water． This paper analyzes the effects of aquatic plants on the changes of organic matter and nitrogen in sediments，and provides the basis for improving wetland water environment． In this paper，Shifu Temple wetland is divided into five research areas ( Ｒeed area，lotus area，Pucao area，mixed area of submerged macrophytes and chlorophyll plant，blank control area) ，and the sediment of the 5 sampling points are sampled for 1 year ( excluding 1，2 months) ． Then，the contents of organic matter ( OM) and nitrogen ( TN) are measured． The effects of aquatic plants on OM and TN contents in sediment are analyzed from the changes of OM and TN contents． Temperature，rainfall，microbial，flow direction and other factors also have impact on OM，TN content changes in the sediment． The results show that the changes of OM and TN contents are mostly affected by the growth and consumption of aquatic plants and microbial decomposition of plant dead bodies． Among the five study areas，the organic matter and nitrogen content in the reed area and lotus area are the highest，followed by Pucao area，mixed area，the blank area in sequence． Different aquatic plants have different effects on organic matter and nitrogen content．

In order to determine the spatial scope of water resources of Wuchang County water resources and clear the ownership of water rights，rights and obligations，this paper discusses the application of AHP in the allocation of initial water rights in Wuchang City of Heilongjiang Province． the index system of allocation of water rights is constructed，the relative weight of each layer element is calculated，the priority order of the evaluation index is determined，and finally，the weight coefficient of each evaluation index is determined through the judgment matrix method by hierarchy chart to allocate the domestic water，agriculture water，non-agricultural production water and the ecological water．

The farmers’ adoption of water-saving irrigation technology is of great significance to the development of agriculture in arid and water deficient areas. Based on survey data of 544 farmers’ situation about adopting water-saving irrigation technology in zhangye city, this paper respectively make empirical analysis to farmers’ behavior of adopting water-saving irrigation technology or not and adoption rate by using the Probit model and Tobit model,the results show that the significant factors influencing farmers’ two kinds of adoption behavior are different:age, level of education, the distance to the nearest market, the scale of land management only significantly influence farmers’ behavior adopting water-saving irrigation technology or not, health status, family income, cost-income only significantly affect farmers’ adoption rate behavior; the proportion of agricultural income accounted for total household income, effect level ,government promotion and government subsidies are common factors that significantly affect farmers' two kinds of adoption behavior,among them,government promotion and government subsidies have a greater impact on farmers’ behavior adopting water-saving irrigation technology.Based on this, the paper puts forward several measures: to promote effectively, to develop the large-scale land operation, to increase the agricultural income of farmers, to improve the performance of water-saving irrigation technology, and to strengthen government support.

Phreatic evaporation method and quota area method are common methods for estimating ecological water requirement of vegetation． In current research，often only one method of estimating ecological water requirement of arid area，phreatic evaporation method or quota area method is applied，and the calculation method is single and the rationality of the research results is disputed． So the reasonable ecological water requirement of desert vegetation in arid area should be obtained in order to solve these problems． In this study，the upper mainstream of the Tarim Ｒiver in 2013 is regarded as the research area，the remote sensing technique is used to interpret various desert vegetation area， phreatic evaporation method and quota area are used to estimate the ecological water requirement of desert vegetation，and the percentage of relative difference are obtained，then the results are compared with the former research results． The values are 54．33%，41．39%，52．78%， respectively． It is indicated that using phreatic evaporation method and quota area method to estimate ecological water requirement of desert vegetation is reasonable; the reasonable ecological water requirement of desert vegetation in arid area，which can be obtained by average value，is 2．65×108 m3 ． So the methods can be applied to estimate the reasonable ecological water requirement of desert vegetation in other arid area．

In this study，the grid method is used to sample the convection dispersion test field in testing base of Key Laboratory of Degraded and Unused Land Ｒemediation Engineering，Ministry of Land and Ｒesources，in Fuping City，Shaanxi province． The pH and conductivity in the depth of 0～ 10，10～ 20，20～ 30，30 ～ 50，50 ～ 70，70 ～ 100，100 ～ 150，150 ～ 200 cm are respectively tested． The spatial distribution characteristics of soil pH and conductivity and the correlation between them are studied under the condition of water storage． The results show that under the condition of water storage，soil pH and conductivity increases with the increase of soil depth; both the pH and conductivity of soil have the highest coefficient of variation at the 20 ～ 50 cm depth soil layer． The pH is positively correlated with conductivity． The study results can provide basis for salinization prevention and reasonable use of saline-alkali land in salty soil area

Study on the effect of the water deficit on Yield and its components, aims to explore the different water deficit and rice intensity adaptation mechanism of the environment at the same time, the existing study on water production function to do the analysis, the critical period of water response model validation to find regional crop water requirement, the shortage of water resources play the maximum value. However, the research conclusions are inconsistent because of the differences of soil type, climate condition, irrigation control standard and water stress degree. By summarizing the relevant literatures, it is concluded that should not be subjected to water stress in jointing-booing and heading to flowering stage. otherwise the yield and its components will be significantly reduced,and the tiller and filling stage will be insensitive Period, moderate water shortage on the yield have less effect in this stage.Viewed from rice yield components, the number of effective panicles can significantly decreased at tillering stage, and the grain weight showed a sharp decrease under water stress in grain filling stage,and show a significant correlation trend. The most influential factors were the seed setting rate when the water stress occurred in heading to flowering and milk stage. while the drought degree at the jointing and booting stage was consistent with the decrease of grains per panicle.

The inland climate in southern Xinjiang provides exceptional natural conditions for cotton growth, but cotton planting in this area is extensive, extremely arid, and irrigated area is large. However, irrigation in this area is hard for its broad and droughty. In order to solve the problems of low degree of automation, serious waste of water resources and low energy efficiency in traditional irrigation methods, This paper designs a intelligent set of water-saving irrigation intelligent control system by using frequency conversion speed regulation, wireless communication, sensors and automatic control technology. The system uses High-precision soil temperature and humidity sensors are used to remotely collect soil moisture content. achieving The data of moisture content (drought) automatic prediction, irrigation water intelligent decision-making, remote / automatic control pumps, motors and other irrigation equipment frequency conversion operation would be collected through using high-precision soil temperature and humidity sensors to remotely collect soil moisture content. The system has the best irrigation time, irrigation water and water-saving measures through the intelligent management of IPC platform to monitor the whole irrigation process in real time. So as to obtain irrigation forecast results, scientific and reasonable guidance, timely and appropriate irrigation, to achieve a high degree of automation, water saving, energy saving purposes. Timely and appropriate irrigation will be realized through using this system with its advantages of high degree of automation, water conservation and energy saving.