To obtain a drip irrigation fertilization model for high yield, water-saving, and nitrogen oxide (N₂O) emission reduction in sugarcane, as well as explore how different drip irrigation fertilization models affect the relevant factors of nitrogen oxide emissions in sugarcane field soil. Two drip irrigation water levels were set up in the field experiment: W₁: 60%~70% field water capacity (θ_f ) during the seedling and mature stages, and 70%~80% θ_{f during tillering and elongation stages; W2: 70%~80% θf during seedling and maturity stages, and 80%~90% θf during tillering and elongation stages. And two drip irrigation fertilization levels: D1: N 250 kg/hm², P2O5 150 kg/hm², K2O 200 kg /hm², and D2: N 300 kg/hm², P2O5 180 kg/hm², K2O 240 kg/hm². The soil N2O emission flux, ammonium nitrogen (NH4 ⁺-N), nitrate nitrogen (NO3 ⁺-N) content, urease (URE), nitrate reductase (NR), nitrite reductase (NiR) and hydroxylamine reductase (HyR) activity in sugarcane fields were measured in different treatments of sugarcane yield, water use efficiency, and four different growth stages (seedling stage, tillering stage, elongation stage, maturity stage). The sugarcane yield of the W2D1 treatment was the highest, reaching 97.0 t/hm². The water use efficiency of W1D2 and W2D1 treatments was better, reaching 21.46 kg/m³ and 20.59 kg/m³, respectively. At the tillering stage, the activities of NR, NiR, and HyR in all treatments basically reached the maximum, and the denitrification enzyme activity in the W2D1 treatment was higher. There is a significant positive correlation between N2O emission flux in sugarcane field soil and the activities of URE and NiR, with correlation coefficients of 0.502 and 0.709, respectively. There is a significant negative correlation between N2O emission flux and NO3 ^--N content and NR activity, with correlation coefficients of -0.581 and -0.591, respectively. This indicates that the NO3 ^--N content, URE, NR, and NiR activities in sugarcane field soil significantly affect N2O emission flux. W2D1 treatment (70%~80% θf during seedling and mature stages. 80%~90% θf during tillering and elongation stages. N 250 kg/hm², P2O5 150 kg/hm², and K2O 200 kg/hm²) is the optimal drip irrigation fertilization mode, which can improve sugarcane yield and water use efficiency, and have important significance for N2O emission reduction.}

The field experiments were conducted from 2017 to 2019 was for explore the effects of wide and narrow rows with full film planting mode on soil moisture and yield of maize in Longzhong dry area, clarify the effects of wide and narrow rows canopy differences during the whole growth period on soil water storage and water consumption, and further reveal the yield increase mechanism of wide and narrow rows with full film double ridges sowing mode. The effects of two wide and narrow row planting methods (35 cm+65 cm, 40 cm+60 cm) and equal row spacing planting methods (50 cm+50 cm) on soil water storage, evapotranspiration, yield composition and water use efficiency were studied. The results showed that the water storage capacity of wide-narrow row planted in median water year was higher than that of equal-row planted soil, mainly at 40~80 cm depth, and the water storage capacity of wide-narrow row planted soil was higher at 35 cm+65 cm depth. The water storage capacity of wide-narrow row planted soil fluctuated greatly from the wide-trumpet stage to the maturity stage. The water consumption of wide and narrow rows in each test year was significantly higher than that of the same row spacing from the large trumpet stage to the spinning stage, and the evapotranspiration consumption of 35 cm+65 cm wide and narrow rows was more intense. At the same time, the yield of 40 cm+60 cm and 35 cm+65 cm rows increased by 12.9% and 16.9%, respectively, compared with conventional equal row spacing planting. The WUE of 40 cm+60 cm rows increased by 6.4%~13.2%, and the WUE of 35 cm+65 cm rows increased by 11.1%~21.9%. In general, wide and narrow row planting on whole film double ridges can improve corn yield and water use efficiency in Longzhong dry area, and 35 cm+65 cm wide and narrow row planting has the best performance.

Studying the effects of water and fertilizer coupling on the activities of antioxidant enzymes (SOD, POD, CAT), the content of malondialdehyde (MDA), proline (Pro), soluble sugar (SS), protein (SP), and water use efficiency (WUE) of tomato leaves in the vermiculite-based composite substrate, can provide a theoretical basis for the cultivation of protected tomato on vermiculite-based composite substrate. This study employed Double Win Pioneer tomatoes as the experimental material. The experimental design included four factors: irrigation, nitrogen, phosphorus, and potassium. A half-fractional execution of a four-factor, five-level orthogonal rotated combination design was used. The results showed that the activities of SOD, CAT, and the contents of Pro, SS in tomato leaves increased first and then decreased, while the activities of POD and the contents of MDA, SP increased. Too high or too low an amount of irrigation and fertilization will lead to a rapid increase in MDA content and a decrease of enzyme activity. Under proper irrigation, the content of POD, CAT, and SS was higher with medium-level fertilizer, and the content of SP was higher with high nitrogen fertilizer. Under medium levels of water and fertilizer, water use efficiency increased by 53%, and fertilizer partial productivity increased by 42%. In this experiment, W18 was the best treatment, 78.0% irrigation level, 340 kg/hm² of nitrogen, 185 kg/hm² of phosphorus, 310 kg/hm² of potassium. The maximum yield was 147.69 t/hm², and the highest water use efficiency was 22.74 kg/m³, the highest partial fertilizer productivity was 176.24 kg/kg. This study can provide a theoretical basis for scientific management of water and fertilizer for the full use of vermiculite production and high-efficiency and high-quality tomato cultivation in Xinjiang.

In order to investigate the effects of different irrigation rates on the photosynthetic characteristics of Salix psammophila, a man-made forest in Kubuqi Sandy Land was used as experimental material. The diurnal variation of photosynthesis and light response curve of Salix psammophila were measured by Li-6800 portable photosynthetic apparatus under four irrigation conditions. The results show that: The diurnal variations of net photosynthetic rate (Pn), transpiration rate (Tr), water use efficiency (WUE), and intercellular CO₂ concentration (Ci) were significantly affected by different irrigation amounts. Except for WUE, which decreased with the increase of irrigation amount, the above factors all increased with the increase of irrigation amount. The photosynthetic capacity of Salix psammophila was significantly improved with sufficient irrigation amount. The light saturation point (LSP) of Salix psammophila under different irrigation treatments was greater than 1 200 μmol/(m²?s), and the light compensation point (LCP) was between 35 and 175 μmol/(m²?s). The maximum net photosynthetic rate (Pn _max) under different irrigation conditions was N1>N2>N3>CK. Dark reaction rate (R_d ) N1>N3>CK>N2; Apparent quantum efficiency (AQY) N1>CK>N2>N3. The correlation analysis results showed that the most significant factors affecting the net photosynthetic rate were photosynthetically active radiation and intercellular CO₂ concentration under different irrigation treatments.

In order to explore the effect of different particle sizes of biochar on the nutrient changes of pig manureaerobic composting, pig manure and rice straw were used as composting materials, and biochar with particle sizes of 0.15, 4.00 and 20.00 mm was added for aerobic composting. The physical and chemical properties, nutrient forms and contents of biochar with different particle sizes during composting were determined, and the mechanism was analyzed by scanning electron microscopy and Fourier transform infrared spectroscopy. The results showed that F1, F2 and F3 entered the high temperature period earlier than F4. The F1 treatment group entered the high temperature period 2 days earlier than the F2 and F3 treatment groups, and entered the high temperature period 3 days earlier than the F4 treatment group. The pH content of F1, F2 and F3 treatment groups increased compared with F4 treatment group. F1, F2 and F3 could reduce the risk of composting salinization, and F3 treatment group had the best effect on reducing composting salinization. The moisture content of F1, F2, F3 and F4 decreased by 58.57 %, 52.23 %, 66.18 % and 60.90 %, respectively. The organic matter content decreased by 45.33 %, 42.46 %, 42.97 % and 46.67 %, respectively. F1, F2 and F3 can effectively reduce the volatilization of NH3. At the end of composting, F1, F2, F3 and F4 increased by 46.08 %, 41.21 %, 35.70 % and 26.28 % compared with the initial total nitrogen. The nitrate nitrogen content increased by 6.45 %, 9.37 %, 6.25 % and 3.22 %, and the total potassium content increased by 33.21 %, 33.05 %, 33.67 % and 25.83 %. The total phosphorus content increased by 60.82 %, 66.62 %, 102.6 % and 57.51 %. Comprehensive analysis showed that 0.15 mm biochar and pig manure compost could effectively increase the nitrogen content of the compost. Therefore, 0.15 mm biochar could be used as a high-quality particle size to increase the nitrogen content of compost.

In order to understand the tolerance to drought stress of Flax vulgaris and content changes of secondary metabolites of Flax vulgaris after rehydration. The seedlings C. sativa were cultured in the pot, normal watering flax was taken as control (CK), the changes of physiological characteristics, photosynthesis, and secondary metabolites in control and stress groups at 0, 3, 5, 7, and 9 days after stress and after rehydration were studied. The results showed that water content, photosynthetic index, maximum light energy conversion efficiency, actual light energy conversion efficiency, R _ET and Q _p decreased under drought stress. The contents and relative electrical conductivity of Q _NP, chlorophyll and carotenoid, proline, soluble protein, soluble sugar, and MDA increased, and the activities of four antioxidant enzymes increased. After rehydration, water content, chlorophyll b, photosynthetic indexes, proline content, and SOD activity of leaves were lower than those of the CK group, while other physiological indexes were higher than those of the CK group. After rehydration, the contents of these three secondary metabolites were lower than those of the CK. The CBD content in the first and second pair leaves of flax fire decreased with the increase of stress degree, and was much higher than that in the lower leaves.The CBD content in leaves of the third and fourth pairs was the highest at 7 d of stress treatment, but it was still lower than that of CK and there was no significant difference between them (P<0.05). The content of CBD in leaves of the fifth and sixth pairs reached the peak at 3 d after stress treatment. After rehydration, CBD content in leaves of 3 groups was higher than that of the CK group. The comprehensive study showed that drought stress could improve physiological stress resistance, reduce photosynthesis, and increase the content of secondary metabolites. Stress can reduce the content of CBD; After a certain degree of stress exercise, the damage to plants was reduced and the content of CBD was increased.

In order to identify information about old tableland tea gardens using remote sensing technology, we employed a random forest analysis based on Sentinel-2, GF-2, LANDSAT 5-TM remote sensing image data, along with 30-meter resolution Digital Elevation Model (DEM) and other auxiliary data in the study area. This analysis enabled us to extract the spatial distribution and area of tea gardens that are over 30 years old. The process involved utilizing vegetation indices, spectral features, texture characteristics, and topographic attributes to enhance the accuracy of the results. The results showed that: ① the Kappa coefficient of the extracted results of 1990 tea plantations reached 0.83, the overall precision OA reached 88.5%, the production precision PA of tea plantations was 83.73%, UA was 89.68%; the Kappa coefficient of the extracted results of 2020 tea plantations reached 0.80. The overall precision OA reached 87.13%, the production precision PA of tea gardens was 84.18%, and the user precision UA was 94.10%. ② The precision of the information of tea gardens, which was extracted using random forest classification method and incorporating spectral and textural features, demonstrated elevated precision, perfectly aligning with production requirements. ③ The area of tea gardens on the tablelands in the state was 15260 hm² in 1990, and the area of tea gardens on the tablelands in 2020 was 96986.67 hm². The remote sensing technology can be used to detect the spatial distribution and planting area of the old tableland tea plantations, as well as provide data support and regulation reference for the transformation of low-yield tea plantations.

Van-Genuchten model of soil water characteristic curve (hereinafter referred to as VG model) is widely used because of its high fitting accuracy and wide adaptability. However, VG model has many parameters (θ, θr, θs, h, α, n, m), and its parameter fitting is a nonlinear problem. In order to improve the accuracy of parameter fitting, Gaussian chaos variation theory was introduced to improve the Dung Beetle optimization algorithm (DBO), Circle chaos sequence was used to increase population diversity, improve the quality of initial solutions, and form a CDBO optimization algorithm. In this paper, DBO and CDBO algorithms were applied to optimize VG model parameters and calculate simulated water content, and MATLAB R2021a simulation software and SPSS26 software were used for simulation and data analysis. The results show that the error range between the simulated water content and the measured water content of the VG model optimized by CDBO is (0, 0.8), while that of DBO is (0, 3.0). Finally, HYDRUS-2D software was used to simulate soil water migration. SPSS26 software was used to estimate the curve of the simulation results. The root mean square error (RMSE) before and after optimization were 0.051 and 0.039, and the coefficient of determination (R ²) were 0.733 and 0.859, respectively. The results show that the VG model optimized by CDBO algorithm has higher accuracy and applicability in water content simulation and soil water characteristics description.

The quality of meteorological dataset has a considerable impact on the performance of land surface models. Two meteorological datasets, GSWP3 and WFDE5, were used to drive the CLM4.5 to simulate the surface evapotranspiration process across the Yellow River Basin (YRB). The performance was systematically assessed applying various metrics based on multiple space-time scales. The RMSE of multi-year averaged simulated ET for GSWP3 and WFDE5 were 61.5 and 49.5 mm/a, and KGE values were 0.83 and 0.87 against reference ET, respectively. Temporally, both simulated ET and reference ET showed significant increasing trends. Spatially, the best performance of GSWP3 and WFDE5 occurred in the middle reaches of the YRB with the smallest relative errors, while the poorest performance occurred in the source area of the YRB. Seasonally, the GSWP3 is superior to WFDE5 in spring and winter, whereas WFDE5 is superior to GSWP3 in summer and autumn. Overall, the performance of CLM4.5 driven by WFDE5 was better than that of GSWP3. The study can provide motivation and direction for the improvement of the ET module in land surface models.

In order to investigate the effect of salt drainage culvert installation on local water and salt transport in Binhai New Area of Tianjin, China, a typical test area was selected as the study area, and the Hydrus-2D mathematical model was established and verified by using the test data. The RMSE of soil water content ranged from 0.004 2 to 0.006 2 cm³/cm³, R ² from 0.916 7 to 0.977 3, and NSE from 0.760 6 to 0.793 1; Soil salinity RMSE ranged from 0.717 8 to 1.1694 g/kg, R ² from 0.973 2 to 0.986 1, NSE from 0.714 0 to 0.924 0, the established model can accurately simulate the soil water and salt transport under the synergistic effect of leaching and culvert drainage. The simulation results show that when the soil salinity in the 30 cm soil layer is set to 3% and the depth of the concealed pipe is fixed, there is always a concealed pipe layout spacing which corresponds to the maximum water consumption, and the water consumption decreases when the spacing between the layouts increases or decreases. There is also always a concealed pipe layout spacing, which corresponds to the 0~500 cm soil layer desalination rate as the maximum value, when the spacing increases or decreases, the desalination rate also decreases. When the width of the concealed pipe is fixed, the water consumption decreases with the increase of the concealed pipe depth, while the water consumption decreases with the increase of the concealed pipe width, the salt discharge rate increases with the increase of the concealed pipe depth. Considering the water consumption and desalination rate of drenching, a comprehensive parameter selection index α is proposed for concealed pipe laying, and the optimal combination of depth and width of 20 kinds of concealed pipe laying combinations with depth of 120cm and spacing of 200cm is determined using the index. The research results can provide guidance for the application of the technology of controlling and cutting the drainage concealed pipe in coastal dredger fill regions.

Haloxylon ammodendron is an important desert plant in maintaining ecological balance in desert regions. In the area where salt water is abundant but fresh water is insufficient, it is of great significance to study the distribution and accumulation of salt in soil profile by using salt water to irrigate ammodendron. This study adopted the method of combining outdoor soil column simulation experiment with indoor analysis, and adopted the water irrigation treatment with five salinity levels of fresh water (CK), 20 g/L、30 g/L、40 g/L、50 g/L. The experimental results showed that: ① High salinity water drip irrigation has a significant impact on soil salt content and ion composition. In general, the degree of soil salt accumulation increases with the increase of salinity of irrigation water. In the vertical direction, the salt content of the surface salt crust soil is much higher than that of the subsoil, and the salt content of the subsoil on the whole increases with the deepening of the soil layer, while the soil pH value, on the contrary, tends to decrease with the deepening of the soil layer, and the soil gradually changes from non-saline soil to mildly saline soil. ② Soil salinity is mainly composed of Cl^- and Na⁺, and contains more SO₄ ^2- ions. The content of Cl^-, Na⁺, Ca²⁺, K⁺, Mg²⁺ and SO₄ ^2- six ions from topsoil to bottom experienced a sudden drop. Then, as the soil layer deepened, the content of ions increased to different degrees, presenting surface accumulation and deep accumulation characteristics. CO₃ ^2- and HCO₃ ^- presented surface accumulation characteristics. ③ When the salinity of irrigation water is between 20~30 g/L, ammodendron can still grow well, but more than 30 g/L, although ammodendron can survive, its growth is obviously inhibited. This study has theoretical significance and application value for rational exploitation and utilization of high salinity groundwater in arid areas and construction of shelterbelt in desert areas.

To test the influence of droplet size, droplet evaporation, quartz surface wet degree and quartz capillary inner diameter on contact angle measurement, this paper, based on the measurement of height, employed a contact angle and surface tension testing instrument to investigate the variation patterns of contact angles under the influence of different factors and analyzed the underlying reasons. The results indicate that: with the increase of droplet volume, the average relative error of contact angle measured by alt-measuring method increased gradually. With the continuation of the measurement time, the contact angle generally showed a decreasing trend. With the increase of the wetting degree of hydrophilic solid surface, the average contact angle measured by alt-measuring method decreased gradually. With the increase of the inner diameter of the quartz capillary, the contact angle decreased first and then increased.

To provide a theoretical basis for the optimization of flow channel, an experiment on the influence of channel structure parameters of inner drip emitter on hydraulic performance was carried out in this paper. Taking 6 drip tapes which are commonly used in water-saving irrigation projects as the major researched tape, the author measured the 7 main structural parameters of the emitter channel by UG and Space claim software and then applied the Principal Component Analysis (PCA) method to rank these parameters. The relationship between the flow rate and the structure parameters of the inner drip emitter was studied through a pressure flow rate experiment under the work pressure of 0.02~0.15 MPa and an anti-clogging experiment with sand content of 5 and 15 g/L under the work pressure of 0.1 MPa. The results show that the influence of each structural parameter is: tooth spacing> the flow channel width> the arc length of the teeth> the flow channel depth>teeth height> the flow channel circumference>teeth number, of which the influence of tooth spacing is the first. From the pressure flow rate experiment, the hydraulic performance of NO.2 drip tape is better than others with smaller changes in flow rate and structural parameters. The result of the anti-clogging test sand rate under 5 g/L shows that the relative flow rate is positively correlated with the flow channel area and the teeth arc length, while is negatively correlated with the tooth spacing. In conclusion, the tooth spacing, the arc length of the teeth, and the flow channel area are the three crucial parameters influencing the performance of drip emitters and play a positive role in the designation and production of drip emitters.

A self-adaptive fuzzy PID controller has been developed to tackle the challenges posed by nonlinearity, time variability, time delays, and precision issues within the context of the nutrient solution preparation system in the integrated water-fertilizer equipment. This study established a control system model based on the principle of nutrient solution preparation and engineering application conditions. Based on this model, the Nutrient Solution Preparation System Platform is constructed under adaptive fuzzy PID control technology. The comparison experiment with traditional PID control showed that compared to traditional PID control, adaptive fuzzy PID control reduced overshoot by 53% and response time by 270 s, which effectively solved the problems of nonlinearity, time variability, time delays, and precision issues in nutrient solution preparation systems. To verify the superiority of the application effect, the CK group (Artificial planting), PID group (Traditional PID control), and FPID group (Adaptive Fuzzy PID control) were set up for comparative planting experiments，the CK group serves as the benchmark reference group (with 0% water and fertilizer conservation rates). The results showed that the water saving rate of FPID group is 22.62%, and the fertilizer saving rate is 15.01%, and the water saving rate of PID group is 17.53%, and the fertilizer saving rate is 11.69%; Verification and control effect of net photosynthesis efficiency detection: the adaptive fuzzy PID control > the PID control > the manual cultivation, which proved that the control method in this paper has good application superiority.

Radar flow measurement technology has been gradually popularized for monitoring and managing the water resources in irrigated areas, and investigating its flow measurement accuracy becomes a hot topic. In this study, taking a typical radar measurement section in Dujiangyan irrigation district (located at the Heishi river outlet near the junction between Chongzhou and Xinjin county) as an example, the accuracy and reliability of rotating radar flow measurement technology were analyzed based on comparing with the benchmark water depth-discharge data measured by ADCP. It was found that the overall correlation between rotating radar measured data and the benchmark water depth-discharge by ADCP is good. However, there are also abundant measurement points with large deviations, which leads to large systematic flow measurement deviation (15%, with a quite high uncertainty of 103%). Given that large measurement deviations mainly occur at low water level and discharge conditions, it is suggested to perform flow measurements at high water level and discharge conditions to obtain high accuracy and reliability results.

To investigate the rationality of winter irrigation for different crops in the Ningxia Yellow River Diversion Irrigation Area and further optimize the irrigation system, this study takes the Pingluo County Improved Seed Breeding Plant in Huinong Canal Irrigation Region of Ningxia as the experimental site, establishing winter irrigation monitoring zones, non-winter irrigation monitoring zones, and pre-sowing irrigation monitoring zones.Through a comprehensive monitoring of soil properties before crop planting, post-planting growth conditions, and post-harvest yields, the physicochemical properties of soil and the growth characteristics of crops under different irrigation patterns are analyzed.The results show that: ①Winter irrigation plays an important role in replenishing water, preserving soil moisture, leaching salt, reducing salt accumulation, and maintaining soil temperature in the farmland of the Yellow River irrigation area in Ningxia. The moisture content at the depths of 0-30 cm in the winter irrigation area before spring sowing is 29.2% higher than that in the non-winter irrigation zones, but the soil moisture preservation and desalination effects are short-term. ②Winter irrigation plays a crucial role in ensuring the emergence, growth, and yield of early-maturing wheat in the Ningxia Yellow River Irrigation Area, but its effect on the growth and yield of late maturing corn is not significant. For non-winter irrigated wheat, the initial emergence rate is only 30.2%. The pre-sowing irrigation reduces yield by 52.3% compared to winter irrigation. ③Winter irrigation is necessary for wheat farmland in the Ningxia Yellow River Diversion Irrigation Area, and both winter and spring irrigation can be used for corn farmland. The results of this study can provide important references for the optimization of irrigation systems, water-salt regulation, and agricultural water-saving development in Ningxia Yellow River Diversion Irrigation Area.