Abstract: In 2016 and 2017, field experiments on Drip Irrigation under mulch corn were carried out in Hetao irrigation area, and the effects of different fertilization rates on the growth and yield of corn in the whole growth period were studied. The test set tensiometer guide irrigation drip irrigation fertilization frequency LF (3 times)、MF (6 times), HF (irrigation water with fertilizer,12 times in 2016,13 times in 2017),and CK(no fertilization),total 4 treatments. The results show that:a small amount of high frequency fertilization under mulch drip irrigation can extend the corn plant height and LAI during the tassel stage and filling stage, and promote the translocation of stalk to corn grain and increase the 100 grain weight to get high yield. There was a significant positive correlation between yield and leaf area, dry matter, grain number and 100 grain weight (p<0.01). This study suggested that the way of corn under mulch drip irrigation in Hetao Irrigated Area should be a small amount of high frequency fertilization management with every irrigation and water fertilization, which can promote corn growth and improve fertilizer utilization.

The bulk density of soil affects the soil void ratio, thus affecting the soil infiltration characteristics. With the aim to explore the effect of bulk density on soil water characteristic curve of clay loam, four soils with different bulk density in HuaiHe river were selected. The soil water characteristic curve was determined by pressure membrane. The saturated hydraulic conductivity was determined by the variable head method. The soil-water characteristic curves were fitted by using van Genuchten modelin RETC software. The results show that the water moisture of clay loam increased with the increase of bulk density under the same suction. There is a negative linear correlation(R2=0.9635) between the saturated hydraulic conductivity and the bulk density of the clay loam. The saturated water content θs, residual water content θr and parameter a of the clay loam were negatively correlated with bulk density. Field water capacity and effective moisture content also increased with the bulk deseity increase. The unsaturated hydraulic conductivitys of clay loam with different bulk density increase with the soil moisture increases. The unsaturated hydraulic conductivity curve is flat when the soil mositure is less than 0.4 cm3/cm3, indicating that the unsaturated hydraulic conductivity does not change much and the unsaturated hydraulic conductivity at this time is very small. When the soil moisture is more than 0.4 cm3 / cm3, the unsaturated hydraulic conductivity curve is steep and straight, and the unsaturated hydraulic conductivity changes greatly. When the unsaturated hydraulic conductivity is the same, the moisture content decreases with the increase of the weight. The conclusions of this research can provide numerical support for clay loam infiltration and evaporation.

A field experiment in rain -fed areas in Hongtong，Shanxi province，was conducted to study the effects of organic -inorganic superabsorbent polymer composites on soil water and enzyme activities in dryland wheat fields． The present study consisted of four treatments， including a control treatment ( no film mulching) ，organic-inorganic superabsorbent polymer composites treatment ( no film mulching) ，and two film mulching methods，either ridge film furrow sowing or flat film dibbling． This paper aimed to provide some theoretical bases for the research and application of organic-inorganic superabsorbent composite． The results showed that organic-inorganic superabsorbent polymer composites could significantly increase soil water in a short time． Compared with the control treatment，it increased by 8．46% in 0 ～ 20 cm soil layer ( p≤0．05) and increased by 6．15% in 20 ～ 40 cm soil layer ( p≤0．05) ． Compared with the control treatment，it could significantly increase soil catalase，sucrase，urease and alkaline phosphatase activity． While the soil enzyme activity in 0 ～ 20 cm soil layer was higher than that in the 20 ～ 40 cm soil layer under different treatment． Soil water was significantly positively related to the soil enzyme activity in 0- 20 cm soil layer ( p≤0．05) and significantly positively related to the soil catalase activity in 20 ～ 40 cm soil layer ( p≤0．05) ，while the correlation between the soil water and sucrase，urease，alkaline phosphatase activity was not significant in Zn treatment． 

A field experiment is conducted to study the effects of different application methods and amount of base fertilizer on soil moisture and crop growth status． In this experiment，two application methods treatments，including fertilization before plow ( A) and fertilization after plow ( B) ，are established，with three fertilization levels of 450，600 and 750 kg /hm2 ，to investigate the soil water content at different growth stages of summer maize，growth components and yield． The results showed that: ① compared with the mode B，the soil profile moisture content of mode A changes larger in different growth period，especially for the 0～ 30 cm soil layer． This shows that the upper soil is obviously affected by rainfall infiltration and evaporation; ② different fertilizer rate has significant effects on soil moisture． Soil water-holding capacity increases with the increase of fertilizer rates; ③ the coupling effects of A and 750 kg /hm2 are the best on ear length，ear weight，ear diameter and 100 kernel weight of summer maize with the increase rate of 4．00%，9．19%，2．58%，and 5．48%，respectively．

Study on the change law of ground temperature and its influencing factors in drip irrigation under automatic film，field tests were carried out in Hutubi County, Changji, Xinjiang，three irrigation caps were set up in the test, the effects of ground temperature and meteorological factors, plant coverage, soil moisture content, rainfall and irrigation were studied. The results show ：In time, the ground temperature increases first and then decreases in the irrigation period, and there is a certain fluctuation in the local temperature. The correlation between solar radiation, atmospheric pressure, relative humidity and air temperature is significantly correlated with the ground temperature. The established least squares regression equation can better simulate the daily average temperature change. In space, the depth of soil layer is deeper and the amplitude is smaller with a certain lag. The increase of soil moisture content and coverage can inhibit the change of soil temperature in the cotton field. Rainfall and irrigation have little influence on the change of ground temperature, and the soil temperature is changed mainly by increasing the soil water content. Research shows that：through the establishment of sine function of meteorological factors and average daily temperature of regression equation and the temperature of different soil layers with time can be simulated by soil temperature, combined with real-time field coverage, soil moisture and rainfall, water and heat environment suitable structural root zone, provide reference for optimizing irrigation system.

?In order to reveal during the freeze-thaw effect of different soil surface mulching Method on soil water,This paper sets up three treatment of soil surface,including the bare land,plastic film mulching and straw mulching,The dynamic changes of soil water in three treatment of soil surface compared and analyzed.The results showed that soil water present a tendency of increase after the first reduce with during freezing-thawing period,Shallow soil moisture content by the external environment, the variations higher than deep soil moisture.Soil surface mulching changed soil external environment and blocked the soil water and energy exchange of external environment. moisture content range of performance for three processing: bare land > straw mulching > plastic film mulching.The shallow layer soil moisture content variation coefficient higher than deep shallow. shallow layer soil moisture variability moderate variability,deep soil moisture content variability moderate variability or weak variability.

In view of the two resource and environmental problems of water shortage and alkali-saline soil in north Yinchuan irrigation area of Ningxia，the drip irrigation，ridging and plastic mulching are combined，and economic crops such as tomatoes are planted，to achieve the goal of water saving and alkali-saline soil utilization． Field experiments are conducted to study the water and salt transport law in alkali-saline soil． The results show that in the shallow groundwater area，the groundwater depth can be controlled effectively and the soil salt content in the tillage layer can be kept at a relatively low level through ridging，plastic mulching and drip irrigation; the soil water content in 0 ～ 40 cm soil layer changes greatly，and the law of average water content in the 1m depth soil layer is that the ridge is larger than the furrow，high ridges is larger than low ridges，and high ridge furrows is less than low ridges; the change of soil total salt decreases with the increase of soil depth， and the soil total salt content in 0 ～ 20 cm soil layer changes greatly，and the law of average total salt content in the 1 m depth soil layer is that the furrow is larger than the ridge，the high ridges is less than the low ridges，and the high ridge furrows is larger than the low ridges．

For the complexity and randomness of rainfall sequence, based on markov chain principle, clustering analysis was used to classify the rainfall sequence, and the degree of membership was used to measure the state vector of samples. The rainfall prediction model of clustering-fuzzy-markov chain model was established and the results are improved. A total of 48 years of rainfall data from 16 sites across the country were calculated as predicted samples. The results showed that the mean error of the 48 predicted samples was 12.4%. The year with the error less than 10% accounts for 56.25% of the total year, and the accuracy is higher. It is reasonable to apply the model to rainfall prediction. It can provide basis for rational planning and utilization of water resources.

Insufficient water resources availability will lead to river drought out or ecological damage． The availability of water resources plays a crucial role in regional economic development． The use of water resources is constrained by the construction of water supply projects and the size of water supply capacity． This article analyzes the concept of surface water resources availability and the calculation method，and uses the positive algorithm to calculate the water resources availability in the current conditions and future horizontal years in Ｒongchang District． The results show that the amount of surface water resources that can be used in Ｒongchang District for many years will not cause damage to the ecological environment，but it is necessary to consider the use of passenger water and water transfer measures to meet future water demand．

Dunhuang basin is located in arid Northwest China and has the disadvantages of the harsh climate and fragile ecological environment，especially the water shortages． The evaluation of sustainable utilization of water resources is becoming a hotspot in the field of water resources management． However，the researches on water resources sustainable utilization in arid area are still few and not so mature． Based on the unique ecological features of the arid Northwest China，this paper establishes a basic orientation index framework to evaluate the sustainable development condition of water resources subsystem，ecological subsystem，economic subsystem，social subsystem and population subsystem． The results show that overall Dunhuang holds the weak sustainability with the restrictions of the lack of water resources and the fragile ecologic environment． Furthermore，based on the analysis of orientation indexes，the composite system is extremely sensitive to coexistence class indexes，and relatively sensitive to safety，energy and adaptation indexes，while the influence of survival and freedom indexes to the composite system are little．

Three screening methods，including conventional method，DEHP method，and pyridine method，are used to screen the best biofloccullant． The results show that the screening success rate of conventional method is higher than other methods． Bioflocculant-production strain，which is identified as Enterobacterludwigii by 16S rDNA sequence，is isolated from sediment by the traditional screening method． The COD removal character is studied by varying conditions of pH，temperature，biofloccullant dose，and calcium chloride etc． The optimum conditions for COD removal occurrs at a temperature of 30℃，a pH of 3，an bioflocculant dosage of 0．25 g and a calcium chloride dosage of 0．8 ml． Under this condition，the highest COD removal efficiency is 72．2%． It is further proved that biofllocculant is a prospect flocculant．

Based on the 2015 monitoring data of six sections in Yellow Ｒiver，this study selected the Dissolved Oxygen ( DO) ，Permanganate Index ( CODMn) and Ammonia-Nitrogen ( NH3-N) as evaluation indexes，used the improved Nemerow Pollution Index method to evaluate the water quality and compared the evaluation results with Grey Clustering method and Single Factor method． The results show that the six monitoring sections water quality of Yellow Ｒiver are within Ⅲ standard，and the main stream water quality is relatively good． But only the improved Nemerow Pollution Index method can show that order from good to bad of the water quality of the six monitoring sections is: Jinan Yukou，Lanzhou Xinchengqiao，Baotou Painter Yingzi，Jiyuan Xiaolangdi，Shizuishan Ephedra，Zhangzhou Wanjiazhai Ｒeservoir． The study results indicate that: the results of the improved Nemerow Pollution Index method and Grey Clustering method evaluation are almost the same; they are more reasonable and comprehensive to reflect the comprehensive water quality than Single Factor method，and can get the water quality status by comparing the pollution index when the water quality is at the same level．

The development of the water resources supporting capacity and urbanization system in Guangxi Beibu Gulf Economic Zone has a bearing on the successful implementation of the overall strategy for regional development and the open strategy of mutual benefit and win-win progress． Based on the understanding of the natural and social attributes of the administrative water resources in the economic zone，through the quantitative analysis of the support capacity of the water resources for the regional socio -economic development and the rational construction of the urbanization system index system，a coupling model is used to study the coordinated development of water resources support capacity and urbanization system in Guangxi Beibu Gulf Economic Zone． The results show that: between 2010 and 2016，the water resources supporting capacity of the Guangxi Beibu Gulf Economic Zone and the development of the urbanization system are not in synch with each other; the support ability of water resources is highly volatile，while the development of the urbanization system shows a trend of steady increase． Although the two systems have been at the limit of development，the marginal nature of water is more obvious． Based on the study results a proposal is made to stabilize the pace of urbanization in the Guangxi Beibu Gulf Economic Zone，improve the quality of urbanization，and tap water-saving potentials to increase the efficiency of the use of water resources．

Through constructing the irrigation water efficiency evaluation index system in irrigation district，according to the linear weighting idea，the subjective and objective weights obtained from PSO-AHP and rough set theory are combined to obtain combination weight，the fuzzy comprehensive evaluation is adopted to evaluate irrigation water efficiency evaluation in irrigation district． The Spearman rank correlation coefficient is used to test the evaluation results of the fuzzy comprehensive evaluation method and the irrigation water effective utilization coefficient，the correlation coefficient reaches 0．833 and the ranking of irrigation water efficiency obtained by the two methods was less than 2． This proves that the rationality of adopting PSO -AHP and rough set theory to combine weighting for evaluation index，and fuzzy comprehensive evaluation to evaluate irrigation water efficiency． By comparing the extreme value and variation coefficient of the two methods， this paper finds that the 1．051 and 0．170 of the fuzzy comprehensive evaluation method are much larger than 0．048 and 0．035 of the effective utilization coefficient of irrigated water，which is more conducive to the division of rating． This shows that the evaluation method adopted in this paper has obvious superiority than irrigated water effective utilization coefficient method in the field of irrigation water efficiency evaluation．

By constructing an agricultural water evaluation index system，including water-saving technology inputs，the information entropy method is used to determine the weights of the evaluation indexes，and the raw data is processed in combination with the fuzzy matter-element method． On this basis，Euclidean closeness is introduced to obtain comprehensive evaluation and ranking of the efficiency of agricultural water use in each year． The evaluation results of Jiangsu＇s agricultural water use efficiency over the years show that the fuzzy matter-element method based on entropy weight can determine the weight more objectively，and its evaluation result has certain rationality． The results of the study and relevant suggestions will help Jiangsu Province to transform from a“large water user”to a“large water-saving province”．

Abstract: Selected the time series from 1970 to 2013 of rainfall, crop water demand and irrigation water in Luhun irrigation district, then co-integrated test without considering the structural mutation or not was conducted, respectively. Co-integration test results show that there is cointegration relationship between water supply and demand in the Luhun irrigation district at 1% significance level. Furthermore, with the unit root test it was detected that the crop water requirement varied from 1986 to 1991, and the structural break occurred in 1989. After the introduction of structural mutation point, the statistics of vector error correction model have been improved and the model has a higher ability to fitting sample than the model without structural mutation. The cointegration relationship that has the drift of constant term, trend term and co-integration vector is more correspond with the changes mechanism of water supply and demand in Luhun irrigation district.

A Smart Irrigation Decision Support ( SIDS) system based on fuzzy inference decision algorithm for irrigation time is proposed in this paper． SIDS aims to measure the agricultural parameters，including the soil temperature and soil moisture，by using the sensor nodes． The rate of soil moisture reduction is calculated from the current soil moisture data and the previous one． The soil temperate data and the rate of soil moisture reduction are employed as input parameters for fuzzy logic controller to decide the amount of irrigation time as output parameter． The experimental results show that by using the SIDS system，the amount of irrigation time is precisely calculated based on the measured agricultural parameters．

To ascertain the probability of land salinization in the arid desert area affected by the groundwater level, Gansu Province Jingtaichuan Power Station irrigation irrigation area was selected as the research area, and TM image data and annual average groundwater depth data were used for 1994, 2001, and 2015. At the end of the data, the ArcGIS supervised error classification method was used to extract and classify the remote sensing images in different levels of saline-alkaline soil, and the measured groundwater level was spatially converted by Kriging space interpolation. On this basis, the classification results and interpolation results were passed through the reclassification elimination amount. The outlines were combined with equal weights, and the equalization results were divided into five equal intervals to indicate the probability of land salinization formation due to groundwater level. The results showed that the saline-alkali land in the irrigation area showed an expansion trend from 1994 to 2015, with a growth rate of 61.87% and an average annual growth rate of 2.95%. The groundwater interpolation results showed that the overall groundwater level in the area was uplifted, with an average annual lift of 0.125m, and the northeast groundwater level. The most dramatic changes occurred; from the southwest to the northeast, the formation probability of salinization increased gradually, the land grade change was more obvious, Grade 1 and Grade 2 lands increased significantly, and the elevation of water level had a significant impact on increasing salinization levels. The study can provide a theoretical basis for groundwater utilization in the arid desert area.

From 2011 to 2015 in Guizhou karst region 53 daily observation of soil moisture and soil humidity automatic observatory meteorological stations observation data, applying EOF analyses the aim of 0 ~ 100 cm soil moisture spatial distribution characteristics, and relationship with possible evapotranspiration and precipitation, the results showed that: (1) 10~20cm, 30~50cm, 60~100cm spatial distribution is similar, Weining, Yanhe, Zhengan, Yinjiang and Sinan which soil moisture are smaller, Tongren, Anshun, Duyun area are larger. (2) The soil moisture in 10~50cm soil layers was relatively low in middle of July and September, middle of mid-March and mid-May, and high in mid-November and mid-January. The soil moisture in 60~100cm soil layers were not very different, and the soil moisture were 70~89% in mid-January, mid-March, mid-May, mid-July, mid-September and mid-November. (3) The first principal component and the second principal component of soil moisture field converge rapidly in 10~100cm soil layers ,and the cumulative contribution rate of variance is over 98%, the maximum value of the first main component was in northwest and southeast of Guizhou , and the minimum value was mainly in west of Guizhou. (4) The effect of potential evapotranspiration on soil moisture maybe less affected in spring. In summer, the lag time of the effect of evapotranspiration are 10 days on 10~50cm, 60~100cm are low correlation. In autumn, the lag time of the evapotranspiration in the soil moisture of 10~50cm are 10 or 20 days, with a low correlation between 60~100cm. In winter, the potential evapotranspiration may have less effect on 10~50cm soil moisture. (5) In spring, Zhenyuan’s precipitation affect the time lag for two ten-day for 10~60 cm soil humidity, Nayong’s precipitation is not obvious effect on soil moisture, Fenggang’s spring precipitation affect the lag time is when the ten-day or a meadow in 10~30 cm soil moisture; In summer, the precipitation affects the soil humidity of 10~30cm in the Zhenyuan, Nayong and Fenggang; In autumn, the effects of the precipitation on the soil moisture are not obvious. In winter, the precipitation influence lag time are10 days of 10, 20cm soil moisture in Zhenyuan and Fenggang.

At present，more accurate evapotranspiration estimation in small watershed is conducive to the rational and effective allocation of water resources，the reduction of resource disputes，and water conservation． Based on the Landsat 8 remote sensing data set and the ENVI remote sensing image processing software and combined with the meteorological data of average temperature，average wind speed，station air pressure and sunshine hours，the SEBS model is used to estimate the evapotranspiration of April to August from 2013 to 2015 in Hutubi county． And the Penman formula is used to verify the estimation results of SEBS． The results show that: the annual variation of evapotranspiration in Hutubi county increases first and then decreases; the spatial variation of evapotranspiration in Hutubi county shows a trend of increasing from north to south; In June 2013，the daily evapotranspiration of Hutubi county reached the maximum value，and the daily average evapotranspiration was 4． 806mm; In April 2015，the daily evapotranspiration was the smallest，and the daily average evapotranspiration was 2．176mm．The comparing result with the Penman formula shows that the SBES model is reasonable for estimating the evapotranspiration in Hutubi． Through visualization short time series data，the spatial distribution and change trend of Hutubi County can be quickly obtained to provide the basis for the development of water-saving agriculture and precision agriculture and soil ＆ water conservation．

Soil moisture is a key factor for the growth of crop plants，and soil and water conservation measures has a profound impact on soil moisture，which in turn affects vegetation changes． This paper summarizes the study on main soil and water conservation measures in the Loess Plateau region and the soil and water conservation effects，discusses the impact of soil and water conservation measures on soil moisture，and puts forward the existing problems and future research priorities in order to provide a theoretical basis for the rational and efficient use of soil water resources，and a reference for the formulation of soil and water conservation measures，which are compatible with economic benefits and ecological effects．

The farmer＇s water-saving irrigation cooperative is the inevitable result of the specialized social division of labor in agriculture． The farmer water-saving irrigation cooperative is a bridge between water-saving technology and farmers． The differences between the three establish modes，including village collective leading mode，enterprise leading mode，and the farmer＇s self-selection mode，in the establish purpose and the resource endowment of the creator lead to some differences in the operation effect，which will affect the applicability of farmers＇ watersaving irrigation cooperatives in supporting the diffusion of efficient water-saving irrigation technologies． Based on the investigation data，this paper applies the method of Logit multivariate discrete model to view the diffusion of technology． In this paper，the indexes of running cost， saving water resources and scale of farmers are used to carry out empirical research，and the differences and applicability of the three models in supporting the diffusion of high-efficiency water-saving technology are analyzed．

Based on the observed data of soil relative humidity，precipitation，temperature and 80 cm＇s depth temperature from 1980 to 2015 in western Liaoning Province，the variation characteristics of soil relative humidity during spring period is discussed． The major impact factors for soil relative moisture are selected through correlation analysis，and the multiple linear regression models are constructed to predict the soil relative moisture． The results show that: ① the soil relative humidity shows a remarkable desiccation trend，and the agricultural drought is increased． ② There are positive correlations between soil relative humidity at spring period and soil moisture before freezing，precipitation of last autumn，80 cm＇s depth temperature of last winter，precipitation in the same period． The correlation coefficient is the highest between soil relative humidity and soil moisture before freezing． ③ Based on correlation factors，the forecasting model of soil relative humidity during spring period is constructed． The multiple correlation coefficient is 0．78，and the forecasting precision of model is more than 93．3%．