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【Objective】 Water storage pit is a technology used in arid regions in northwestern China to collect rainwater for irrigation. In this paper, we studied the three-dimensional distribution of water, heat and oxygen in soil in an orchard under water storage pit irrigation using numerical simulation. 【Method】 Water flow was based on the Richard equation and heat transfer and oxygen diffusion in soil were modelled by convection - diffusion equations. These coupled equations were solved using the COMSOL - a Multiphysics software. The model was verified against data measured from a field, and the validated model was then used to analyze the effect of the water storage pit on distribution of water, heat and oxygen in soils in the proximity of the pit. 【Result】 The three-dimensional coupled model is accurate and can reproduce the measured spatiotemporal changes in soil water, temperature and oxygen, with the RMSE for soil water, temperature and oxygen being 0.036 7, 1.609 9 and 0.013 8, respectively. The water storage pit changed the distribution of water, heat and oxygen in the pit wall greatly. As time elapsed, soil water content in the regions proximal to the pit decreased, while oxygen concentration increased. Temperatures in the pit and soil surface were mainly impacted by atmospheric temperature. Spatial water distribution was ellipsoidal around the pit. Soil water content was the highest in the proximity of the pit bottom, while oxygen concentration and temperature in this region were the lowest. The distribution of water, temperature and oxygen tended to uniformize as time elapsed, despite that temperature and oxygen are less sensitive to irrigation than soil water. Oxygen concentration decreased with the distance from the soil surface and pit wall. 【Conclusion】 Water storage pit irrigation increased the interface between soil and water, thereby affecting transport of water, heat and oxygen in the soil. Numerical simulations indicated that the dynamics of water, heat and oxygen in the soil was affected by evaporation, rainfall, atmospheric temperature, atmospheric oxygen concentration and other environmental factors.

【Objective】 Turgor pressure in crops varies with root water uptake as a response to occurrence of water stress. This paper investigates how turgor pressure in the leaf of celery responds to drip irrigation and the factors which affect the pressure variation. 【Method】 The experiment was conducted in a greenhouse. It consists of sufficient irrigation (FI) and deficit irrigation (NI) treatment. Change in leave turgor pressure, characterized by expansion parameters Pp and Pp*, in each treatment was measured using a probe. We also measured the environmental factors and physiological traits of the plant, and analyzed their relationship with Pp/Pp* using multiple regression, path analysis and time warping methods. 【Result】 ① The parameter Pp* maximized at daytime and minimized at night on typical sunny days, regardless of the irrigation treatments and growing stage. However, Pp* started to increase earlier in NI than in FI treatment, with the peak of Pp* in the former being 39.3%~66.7% higher than that in the latter. ② The diurnal change in Pp* was similar to that in the stomatal conductance (Gs) and transpiration rate (Tr). Pp* was positively correlated to Gs and Tr, but negatively to leaf water potential (Ψ). ③ The change in leaf turgor pressure varied with irrigation. The maximum and minimum Pp increased gradually priori to irrigation and decreased rapidly after irrigation, especially in the NI treatment where the change was more profound. ④ Pp* was positively correlated to atmospheric temperature (TA) and vapour pressure deficit (VPD), but negatively to relative humidity (RH) and wind speed (WS). Path analysis showed that the highest correlation between Pp* and TA, and VPD was an indirect factor affecting Pp*. Stepwise regression indicated that WS impacted Pp* significantly only in NI. We also found that the impact of TA on Pp* was not instant but existed a delay, especially in NI where the delay was more than 10~30 min than that in FI. 【Conclusion】 Variation in leaf turgor pressure in greenhouse celery was closely related to irrigation amount and meteorological factors. Insufficient irrigation increased the maximum turgor-pressure variation parameter but delayed the effect of atmospheric temperature on the turgor pressure.

Precision irrigation relies on accurate perception of plant water statue. Plant-based sensors is a potential method to online monitor change in plant water statues due to its convenience , automaton and being able to measure water in both leaf stomata and other plant organs simultaneously. Among all available sensor, the non-invasive and in-situ leaf patch clamp pressure probe (LPCP) technology is a promising one as it allows continuous monitoring of plant leaf turgor pressure over at predefined interval. The principle of the LPCP is to measure the attenuated pressure of a leaf patch in response to a constant clamp pressure, and it has become a new versatile method to diagnose plant water status with high precision and sensitivity. LPCP has been applied in plant stomatal physiology to measure water status, and it can also help irrigation scheduling and has thus received increased interest over the recent years. We review in this paper its principle for plant water status diagnosis, installation and derivative parameters selection. Combined with leaf turgor measured by it for celery under drip irrigation, we analyzed the relationship between the change in turgor, environmental factors and plant water physiological parameters to explain the application of the device. We also outlined its pitfalls and the ways to improve it. We concluded that further studies on its application to canopy, predicting the impact of multi-environmental factors and evaluation of multi-source continuous indicators were needed. The research focus should be shifted from exploring the mechanism of plant physiological feedback to developing rational irrigation strategies.

【Background】Tomato is an important economic crop planted widely in both north and south of China. In addition to its effect in antioxidant and anti-cancer, tomato is also nutritious and rich in VC, lycopene and other nutrients. Water and nutrients are two abiotic factors determining tomato growth. Irrational irrigation and fertilization, especially when they are used excessively, not only waste resources and contaminate groundwater, but could also compromise crop yield and quality. Understanding how water and nutrients combine to modulate tomato growth is hence critical to its sustainable production. 【Objective】The overall objective of this paper is to determine the production functions of water and nitrogen of greenhouse tomato in response to water-nitrogen coupling under mulched drip irrigation. We can therefore find its key water-demand stages and provide guidelines for efficient use of water and nitrogen fertilizer in tomato production. 【Method】The experiment considered four factors and three levels, with all designed using the orthogonal test to study how yield of the tomato responds to change in water and nitrogen coupling. The Jensen model was used to describe the change in tomato yield with water and nitrogen applications. 【Result】The tomato yield calculated by the model was consistent with the measurements, with the squared sum of the model fitting residuals being 0.01 and the determination coefficient being 0.793. The root mean square error, average relative error and average absolute error between the calculated and the measured yield were 2.98 t/hm2, 2.53% and 2.39 t/hm2, respectively. The water sensitive index at each growth stage was ranked in the descending order as flowering stage (λ2=0.200) > seedling stage (λ1=0.096) > ripening stage (λ3=0.059). The water sensitive index calculated from the cumulative curve of the water sensitive index agreed well with the estimate from the Jensen model. The factors that impacted tomato yield was ranked in the following descending order based on their significance: irrigation at flowering stage>irrigation at seedling stage>nitrogen application>irrigation at maturity stage, with the effect of irrigation at flowering stage being significant (P

The study delves into the prevailing focal points and developmental trends within the international sphere of crop root research under drip irrigation. It leverages the Web of Science core database and employs VOSviewer for a systematic review of the literature spanning 2001 to 2022. The analysis encompasses publication counts, publishing journals, contributing authors, research institutions, and keywords. Findings indicate that research on root systems under drip irrigation has become a notable area of interest in the field of irrigation, attracting global scholarly attention. There is a marked upward trend in publication output, with institutions in China and the United States taking on central roles. Journals like Agricultural Water Management and Acta Horticulturae are key publication venues, with Vadose Zone Journal being notable for high-impact articles. The research primarily involves agronomy, water resources, and horticulture, focusing on yield enhancement through drip irrigation, root distribution under various techniques, crop quality in response to partial root-zone drying, and irrigation scheduling model development. Scholars like Jiri Simunek and Yaohu Kang have made substantial contributions. The field's established framework calls for continued international collaboration to drive further innovation. The identified trends and parameters can be a valuable reference for researchers, policymakers, and practitioners, guiding efforts to optimize agricultural productivity and resource use. [ABSTRACT FROM AUTHOR]

The water–zeolite amount–burial depth coupling regulation strategy of high-quality and high-yield tomatoes was explored with drip irrigation under mulch. Greenhouse planting experiments were performed to monitor and analyze the tomato growth, physiology, yield, quality, and water use efficiency (WUE). The suitable amounts of the water–zeolite amount–burial depth for the tomato growth were determined through the analytic hierarchy process (AHP). The results showed that the effects of increasing the water of the intercellular CO2 concentration (Ci), nitrate content (NO), vitamin content (VC), and soluble solids (SS), increasing the WUE, increasing the zeolite amount of the NO, and increasing the zeolite burial depth of the Ci and SS, were inhibited. The effects of increasing the zeolite amount of the plant height (Kh), stem thickness (Kt), total root length (Rl), total root volume (Rv), root average diameter (Rd), net photosynthetic rate (Pn), stomatal conductivity (Gs), organic acid (OA), VC, yield (Ay), and WUE, and of increasing the zeolite burial depth of the Kh, OA, dry matter quality (Ad), and WUE, were promoted first and then inhibited. The other indicators showed a positive response to increasing the water, zeolite amount, and burial depth. The influence of the water (W), zeolite amount (Z), and zeolite depth (H) on the Kt, Tr, Rl, and Rd, was W > H > Z, and that of the Kh, Gs, Pn, Ci, Ra, Rv, OA, VC, NO, SS, Ad, Ay, and WUE was W > Z > H. The order of weight of each index, based on the AHP, is as follows: Ay > WUE > NO > OA > Ad > Kh > Kt > VC > SS > Pn > Rv > Rd > Tr. The highest comprehensive score was W70–90Z6H15, and the most suitable water conditions for the tomato planting under drip irrigation were 70–90% field capacity, 6 t/hm2 zeolite, and 15 cm depth of zeolite. [ABSTRACT FROM AUTHOR]

A nitrogen fertilizer slow-release membrane was proposed using polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), epoxy resin, and zeolite as raw materials. The effects of the water-based copolymer (PVA:PVP) solution ratio A (A1–A4) and zeolite amount B (B1–B4) on the water absorption rate (XS), water permeability (TS), fertilizer permeability (TF), tensile strength (KL), elongation at break (DSL), and viscosity (ND) of the membrane were explored using the swelling method, a self-made device, and a universal testing machine. The optimal combination of the water-based copolymer and zeolite amount was determined by the coefficient-of-variation method. The results show that the effects of the decrease in A on KL and the increase in B on KL and DSL are promoted first and then inhibited. DSL and ND showed a negative response to the A decrease, whereas XS, TS, and TF showed a positive response. The effect of increasing B on ND, TS, and TF showed a zigzag fluctuation. In the condition of A1–A3, XS showed a negative response to the B increase, whereas in the condition of A4, XS was promoted first and then inhibited. Adding PVP and zeolite caused the hydroxyl stretching vibration peak of PVA at 3300 cm−1 to widen; the former caused the vibration peak to move to low frequencies, and the latter caused it to move to high frequencies. The XRD pattern shows that the highest peak of zeolite is located at 2θ = 7.18° and the crystallization peak of the composite membrane increases with the rise in the proportion of zeolite. Adding PVP made the surface of the membrane smooth and flat, and adding a small amount of zeolite improved the mechanical properties of the membrane and exhibited good compatibility with water-based copolymers. In the evaluation model of the physicochemical properties of sustained-release membrane materials, the weight of all indicators was in the following order: TF > ND > TS > KL > XL > DSL. The optimal membrane material for comprehensive performance was determined to be A2B3. [ABSTRACT FROM AUTHOR]

As freshwater becomes an increasingly scarce and expensive natural resource, novel water-saving irrigation methods for dwarfing apple orchards are needed in the Loess Plateau. However, studies are lacking on the effects of novel root-zone irrigation technology on leaf-level photosynthesis, which directly determines the yield and survival ability of trees. In this study, the leaf gas characteristics and water status of five-year-old dwarfing apple trees in the Loess Plateau of China were monitored during the 2016–2017 growing seasons under water storage pit irrigation (WSPI) and surface irrigation (SI) treatments. Under WSPI, the leaf water potential (Ψm), net photosynthesis rate (Pn), stomatal conductance (gs), and chlorophyll content (Chl) were significantly higher than those under SI (by 12.21–28.36%), while non-photochemical quenching, superoxide dismutase, and sucrose were lower. Compared with SI, WSPI improved dwarfing apple yield by 25.4% and 26.7% in 2016 and 2017, respectively. WSPI increased the photosystem II (PSII) activity by increasing the chlorophyll fluorescence features (the potential quantum yield of PSII (Fv/Fm), actual quantum yield (ΦII), photochemical quenching (qP), and electron transport rate (ETR)). Principal component analysis showed that Ψm, Chl, the chlorophyll fluorescence features (qP, ΦII, and ETR), Pn, and gs could represent the leaf photosynthetic difference between WSPI and SI treatments. Results indicated that apple under WSPI could improve its yield through enhancing leaf photosynthetic performance, and water storage pit irrigation is an effective root-zone irrigation method for apple orchards on the Loess Plateau. [ABSTRACT FROM AUTHOR]

The water (W; W50, W75, and W100)–zeolite (Z; Z0, Z3, Z6 and Z9) coupling (W-Z) regulation strategy of high-quality and high-yield tomato was explored with alternate drip irrigation under mulch. Greenhouse planting experiments were used in monitoring and analyzing tomato growth, physiology, yield, quality, and water use efficiency (WUE). Suitable amounts of W and Z for tomato growth were determined through the principal component analysis (PCA) method. Results showed that tomato plant height (Ph), stem thickness (St), root indexes, leaf area index (LAI), photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), organic acid (OA), and yield showed a positive response to W, whereas nitrate (NC), vitamin C (VC), soluble solid (SS), intercellular CO2 concentration (Ci), fruit firmness (Ff), and WUE showed the opposite trend. The responses of Ci and Ff to Z were first negative and then positive, whereas the responses of other indexes to Z showed an opposite trend (except yield under W50). The effects of W, Z, and W-Z on tomato growth, physiological, and quality indexes and yield were as follows: W > Z > W-Z; the effects on WUE were as follows: Z > W > W-Z. The two principal components of growth factor and water usage factor were extracted, and the cumulative variance contribution rate reached 93.831%. Under different treatments for tomato growth, the comprehensive evaluation score F was between −1.529 and 1.295, the highest treated with Z6W100, the lowest treated with Z0W50. The PCA method showed that under the condition of alternate drip irrigation under mulch, the most suitable W for tomato planting was 100% E (E is the water surface evaporation), and the amount of Z was 6 t·ha−1. [ABSTRACT FROM AUTHOR]

To reveal the water and heat transfer characteristics of the orchard soil under water storage pit irrigation and to regulate the distribution of soil water and heat for improving apple quality and increasing yield, a 3D soil water and heat transfer model of orchards under water storage pit irrigation was established. The model not only considered the influences of root water uptake, precipitation, evaporation, and irrigation, but also simulated the infiltration process of the variable water head in the pit according to the principle of mass conservation and introduced the pit coefficient to simulate the difference in radiation in the pit to describe the influence of the pit on the model. Verify and analyze the simulation results. Results showed that the variation trend of simulated soil moisture and heat was consistent with that of measured data. The mean absolute percentage error, root mean square error, and mean absolute deviation were 3.23%, 0.9460, and 0.6984 for soil temperature and 10.05%, 0.0269, and 0.0214 for water content after irrigation, respectively. The simulation results have high accuracy and show that the soil moisture content centers on the pit with an ellipsoid distribution and tends to be uniform over time. The soil temperature was higher in the 4–5 cm area near the soil surface and the wall of pit, and it remarkably changed with time. The intraday variation of soil temperature was mainly affected by atmospheric temperature, but a certain lag was observed compared with the change of atmospheric temperature. With the increase of the irrigation amount, the distribution range of soil moisture content and water high value area increased, while the average and maximum soil temperature decreased. With the increase of irrigation water temperature to 18–24 h after irrigation, the soil temperature in the ellipsoidal area around the pit remarkably increased. The model established in this paper can be used to simulate the hydrothermal status of the soil in the field under water storage pit irrigation. The results prove that the water storage pit irrigation can effectively improve the hydrothermal status of the middle-deep soil and promote the root system of fruit trees to absorb water. [ABSTRACT FROM AUTHOR]

Background: Rhino-orbital cerebral mucormycosis (ROCM) is a rare, invasive, and fatal fungal disease. Due to the lack of specific clinical manifestations and adequate auxiliary examinations, patients are easily misdiagnosed in the early stage. Early diagnosis and timely therapy are essential for successful treatment. Case Report: We report a 68-year-old man with diabetic ketoacidosis, presented with orbital apex syndrome (OAS), fever, and pansinusitis, which progressively worsened to death only 4 days after admission. It was finally confirmed as a fungal Rhizopus arrhizus infection by metagenomics cell-free DNA next-generation sequencing (mNGS) testing. Conclusion: Orbital apex syndrome could be the initial presentation for mucormycosis. Thus, it is necessary to evaluate the presence of mucormycosis in patients with OAS, especially in diabetic or immunosuppressed hosts, and mNGS testing and timely antifungal therapy should be strongly recommended in highly suspected cases. [ABSTRACT FROM AUTHOR]

Agricultural producers in China are presently confronting the challenge of "white pollution" caused by the continuous expansion of plastic film area coverage. The main objective of this research is to address the increasing interest in the effects of film residual on tomato growth, yield, and quality under drip irrigation. To reveal the effects of film residual on tomato physiology, field trials were conducted with five levels of film residual treatment applied in two consecutive cropping seasons from 2019 to 2020. Soil water content, plant height, stem diameter, photosynthetic characteristics, yield, soluble sugar content (SSC), organic acid (OA), vitamin C (VC), and nitrate content (NC) were measured; furthermore, four analysis methods were used to assess the comprehensive tomato quality. The results showed that film residuals significantly affected soil water content in 2019 and 2020 and inhibited tomato plant height and stem diameter. The variations in photosynthetic rate and stomatal conductance showed practically the same trend, increasing with an increase in the film residual at the seedling stage. The maximum yields were observed at 94.02 ton/hm2 and 84.44 ton/hm2 in 2019 and 2020, respectively, and tomato yield exhibited a shape reduction with increasing amounts of film residual in all years. SSC, VC, and NC showed an increasing trend with increasing amounts of film residual. The best tomato comprehensive quality was observed when the amount of film residual was lower than 200 kg/hm2 and declined with an increasing amount of film residual. Overall, the soil water content, tomato growth, and fruit quality changed significantly under the influence of film residual. These results not only deepen our understanding of the harm caused by film residual to tomato growth and fruit quality but also provide reasonable advice to establish a management system for residual pollution on cultivated land. [ABSTRACT FROM AUTHOR]

Objective: Admission hyperglycemia is an established risk factor for functional outcome in patients with acute ischemic stroke. However, the association between glycated hemoglobin (HbA1c) and prognosis in patients with acute anterior circulation ischemic stroke (AACIS) remains controversial. This study aimed to explore whether elevated HbA1c levels are associated with functional outcome in AACIS patients. Participants and Methods: We enrolled patients with AACIS hospitalized in the First Hospital Affiliated to Soochow University from March 2018 to January 2021. Patients were categorized into three groups based on baseline HbA1c: HbA1c ≤ 6.5%, 6.5% < HbA1c ≤ 8.0%, and HbA1c > 8.0%. Ninety-day modified Rankin Scale scores of 0–1 and 0–2 were defined as excellent and favorable functional outcome, respectively. Early neurological improvement was regarded as a reduction in the National Institutes of Health Stroke Scale (NIHSS) score ≥ 4 points compared with that on admission, or an NIHSS score of 0–1 at discharge. The association between HbA1c and clinical outcome in acute ischemic patients was assessed by logistic regression and adjusted for confounding factors. Subgroup analyses by TOAST classification were also conducted. Results: The study included 326 patients. The proportion with favorable outcome was significantly lower in the HbA1c > 8.0% group than the HbA1c ≤ 6.5% group (30.4 vs. 55.2%; p < 0.01). Binary logistic regression analysis demonstrated that increasing HbA1c levels (as a continuous variable) were associated with reduced functional independence (adjusted OR = 0.739; 95% CI: 0.605–0.904; p = 0.003). In subgroup analyses, higher HbA1c was also associated with favorable outcome in large-artery atherosclerosis (LAA)-type patients (adjusted OR = 0.776; 95% CI: 0.614–0.981; p = 0.034), but not in LAA group. Conclusions: HbA1c level was an independent predictor of worse functional outcome in patients with AACIS, particularly in those with LAA. For patients with anterior circulation atherosclerosis, strict adherence to a target HbA1c < 6.5% may be required. [ABSTRACT FROM AUTHOR]

Hydrological forecasting in semi-arid and semi-arid areas is always the focus problem for hydrologists, and the watershed hydrological model is an effective tool for simulating and forecasting hydrological processes. The double excess watershed model (DEWM) was proposed by the Chinese hydrologists in Shanxi Province and was widely used in local reservoirs. Practical application of reservoirs for many years shows that there exist certain problems in the structure of model. Therefore, we modify the structure from three aspects: 1.Employ new infiltration formulas, 2.Simplify filling container structure and proposes a curve of the underground infiltration capacity, 3.Modify the evaporation simulation. Floods of Zhangfeng reservoir are used to verify the applicability of the modified model (MDEWM). Use the SCE algorithm to calibrate the model parameters, and compare the flow processes of calibration period and validation period with the measured values respectively. The flood peak pass rate are 83.3% and 91.7% in calibration period, and peak current are 50% and 100% in validation period of MDEWM, which results are better than DEWM or equal to it. The research of this article can provide a certain theoretical significance and practical value for flood forecasting, reservoir scheduling and water management in semi-arid and semi-humid areas. [ABSTRACT FROM AUTHOR]

A new algorithm, parameter adaptive DE mixed algorithm, is presented based on the standard differential evolution algorithm. In the process of adjusting the scaling factor and the crossover factor, the comparison judgment of individual fitness is added into the algorithm to improve the convergence speed of the algorithm. At the same time, after the differential evolution algorithm reaches the iterative number, the optimal solution of the differential evolution algorithm is used as the starting point of the trust region reflection to perform secondary optimization andform a mixed differential evolution algorithm finally. Six standard test functions were adopted to test the performance of the parameter adaptive DE mixed algorithm. The test result shows that the new algorithm can greatly improve the convergence of the algorithm. In order to verify the solution quality of the parameter adaptive DE mixed algorithm, 18 historical floods of Zhangfeng Reservoir were taken as study case in this paper, by using this new algorithm and the commonly used SCE-UA algorithm in hydrological model parameters optimization to calibrate the parameters of hydrological model. The results show that the pass rate of the flood peak is 83.3%, and the pass rate of the peak time is 91.7% during the calibrated period, the pass rate of the flood peak and peak time are 66.7% and 83.3% during the tested period by the new algorithm. Compared with the SCE-UA algorithm, the proposed parameter adaptive DE mixed algorithm can more effectively approximate the measured flow process, it indicatesit is feasible that the algorithm can be applied to the parameters calibration of the hydrological model. [ABSTRACT FROM AUTHOR]

Ways of understanding and quantifying the effectiveness of new irrigation methods are required in order to more precisely evaluate them, including the effect of root growth on water storage pit irrigation (WSPI). In this study, the effective root growth zone (ERGZ) of 5-year-old apple trees under WSPI and traditional surface irrigation (CK) treatment was estimated using stable isotope technology during two seasons 2015 and 2016. The stable isotopes of water in stems and different soil depths were analyzed using four analysis methods (namely direct inference, the Romero-Saltos model, the IsoSource model and the coupled model). Results showed that the ERGZ depth under surface irrigation ranged from 10 cm to 60 cm, with the main contribution at 0–40 cm during the growth stage. Under water storage pit irrigation, the ERGZ depth for the apple tree was deeper and ranged from 20 cm to 100 cm, with the main contribution of ERGZ deepened to 20–100 cm after the earlier of shoot rapid-growing stage. The use of a water storage pit irrigation system on apple demonstrated improved root growth in the middle-depth soils, as compared to traditional surface irrigation. [ABSTRACT FROM AUTHOR]

The traditional qualitative analysis of the individual factors on the kinetic and thermodynamic parameters cannot sufficiently reveal the mechanism underlying ammonia volatilization in soil. This study aimed to determine the effects of temperature, moisture content, and their interaction on the kinetic and thermodynamic parameters, which revealed the key control mechanism underlying ammonia volatilization, modified the traditional Arrhenius model, and established a quantitative prediction model of cumulative NH3-N loss (CNL). Laboratory culture experiments were conducted under different temperatures (T) (15°C, 20°C, 25°C and 35°C) and moisture contents (θ) (60%, 80%, and 100% field capacities). Soil ammonia volatilization was also measured every 2 d. Results showed that the effects of individual factors and their interaction on the values of reaction rate (KN), Activation free energy (ΔG), and activation entropy (ΔS) followed the descending order of T>θ>T·θ, whereas those of activation enthalpy (ΔH) and activation degree (lgN) followed the descending order of θ>T>T·θ. The interaction showed significant effect on KN value and insignificant effect on all the thermodynamic parameters. The effects of water and temperature were mainly observed during the preparatory stage and the most critical transition state stage of the chemical reaction, respectively. Given that ΔH > 0, ΔG > 0, and ΔS > 0, ammonia volatilization is found to be an endothermic reaction controlled by enthalpy. The new KN(T)-2 model with the determination coefficient (R²) of 0.999 was more accurate than the traditional Arrhenius model with the R² of 0.936. The new NH3(T, θ) model with the mean absolute percentage error (MAPE) of 4.17% was more accurate than the traditional NH3(T) model with the MAPE of 7.11%. These results supplemented the control mechanism underlying ammonia volatilization in soil fertilized with urea and improved the prediction accuracy of CNL. [ABSTRACT FROM AUTHOR]

It is of great significance to explore the strategy of regulated deficit irrigation (RDI) under mulched drip irrigation to stabilize tomato yield and improve quality and efficiency. This experimental study was conducted on a drip-irrigated greenhouse in two consecutive years (2020 and 2021). Three deficit levels were set for the flowering and fruit development stage (Stage I), and three were set for the fruit-ripening stage (Stage II). As a combination evaluation method, the fuzzy Borda model was used to optimize the RDI strategy of greenhouse tomato. The results showed that the net photosynthetic rate, stomatal conductance, transpiration rate, and total shoot biomass of tomato decreased with an increase in the water deficit, while the intercellular CO2 concentration had an opposite trend. The mild and moderate water deficit at Stage I reduced tomato yield by 16–24% and 30–40% compared to full irrigation. The water deficit at Stage II was able to improve various quality parameters and the water-use efficiency of tomato; the irrigation water-use efficiency (32.8–33.9 kg/m3) and leaf water-use efficiency (3.2–3.6 μmol/mmol) were the highest when the soil water content was 70–90% θf (field capacity) at Stage I and 40–60% θf at Stage II (T3). Based on the fuzzy Borda combination evaluation model, T3 was determined as the treatment with stable yield, high quality, and efficient irrigation under the experimental conditions. The irrigation regime was as follows: irrigating 20–25 mm in the transplanting stage, no irrigation in the seedling stage, irrigating 193.2–220.8 mm at Stage I, and then irrigating 27.6 mm at Stage II. [ABSTRACT FROM AUTHOR]

The ridge–furrow mulching system with plastic film (RFMS) has been widely used in semi-arid areas in order to improve soil water and heat conditions, crop yields and water use efficiency. It is of practical significance to study the effect of mulching and ridge types on soil water and heat in order to optimize mulching measures and improve the effectiveness of the ridge and furrow system. To clarify the combined effect of soil water and heat beneath the system and the influence of ridge morphology on it, field experiments were conducted with three treatments, including conventional planting in bare land (CK), a ridge–furrow (wide ridge with 70 cm width and 10 cm height, narrow ridge with 40 cm width and 15 cm height) mulching system with complete plastic film (RFWN) and a ridge–furrow (equal ridge with 55 cm width and 15 cm height) mulching system with complete plastic film (RFE). An insufficient irrigation system was adopted and the two-dimensional numerical software HYDRUS-2D was used to simulate the soil water and heat flow under the experimental conditions. The model was calibrated and verified according to test data for the period of 2018 to 2019, which showed good agreement between the simulated and measured values. The simulation results revealed that the ground temperatures of RFWN and RFE were much higher than that of CK, and the average value of 0–25 cm during the growth period could increase by 2.29–4.61%. Compared with CK, RFWN and RFE reduced soil evaporation (84.71–93.73%) and field evapotranspiration (12.02–21.75%), while they increased root water uptake (25.87–40.98%) and T/ET (48.85–80.15%). Plastic film mulching and ridge morphologies affected the infiltration range and the direction of soil water movement, increased soil moisture when there was no rainfall or irrigation and reduced soil water and heat fluctuations, which was more conducive to crop growth, especially under the RFWN system. The simulation method proposed in this paper is an effective technique for calculating the soil water and heat dynamics under different ridge and furrow sections under the condition of film mulching, and it can be used for the optimal management of soil water and heat in this area. [ABSTRACT FROM AUTHOR]

Water storage pit irrigation (WSPI) has been proven effective in improving the water use efficiency of fruit trees in Loess Plateau, but so far there are still no matching efficient fertilization management methods. A two-year experiment was conducted to explore the management strategy of fertilization under the consideration of apple production and environmental sustainability. N isotope tracer technique was used to study the distribution of labelled nitrogen in soil, leaf, root and fruit. Moreover, the yield in different fertilizer managements were observed to evaluate the apple production. The results showed that increasing the amount of fertilizer could increase the accumulation of fertilizer nitrogen in soil, but also increased the risk of nitrogen leaching. Under the same amount of fertilizer, split fertilization can effectively increase of fertilizer nitrogen in soil by a mean of 4.7 times. Further, N300 application with split fertilization effectively increased apple yield. The yield of N300II treatment was higher than other treatment by maximum 68.5%. In addition, the root system mainly absorbed the fertilizer nitrogen applied in the current year, and the fruit mainly absorbed the fertilizer nitrogen applied in the previous year, but there was no significant difference in the leaves. [ABSTRACT FROM AUTHOR]

As an important step for formulating a water-saving agricultural strategy, it is essential to make quantitative calculations for orchard soil evaporation and confirm its inner mechanism, so as to reduce ineffective water consumption and improve the utilization efficiency of water resources. To reveal the effect of water storage pits under water storage pit irrigation conditions in orchard soil evaporation, micro-lysimeters were used to measure the soil evaporation in two different forms (soil surface evaporation and pit wall evaporation) under diverse irrigation systems using water storage pit irrigation in the apple growth period of 2018. To calculate the orchard soil evaporation of water storage pit irrigation, the pit irrigation coefficient was introduced and a model was constructed. To illustrate the inner mechanism of orchard soil evaporation, the soil surface resistance under water storage pit irrigation conditions was analyzed and calculated quantitatively. The results show that: (1) introducing the pit irrigation coefficient can boost the calculation precision of the orchard soil evaporation under water storage pit irrigation conditions; (2) when applying the soil evaporation of the water storage pit irrigation model for calculation of the orchard soil evaporation, R 2 can reach 0.92; and (3) the mechanisms of the two orchard soil evaporation forms under water storage pit irrigation are very different. When soil surface evaporation and pit wall evaporation were calculated by the soil surface resistance of water storage pit irrigation model, R 2 values were 0.95 and 0.96, respectively. [ABSTRACT FROM AUTHOR]

The future production of irrigated fruit orchards in the Loess Plateau of China is threatened by a shortage of freshwater. To improve water use efficiency under conditions where irrigation is limited, it is necessary to quantify the root water uptake (RWU) of apple trees. The RWU of apple trees was estimated under surface irrigation using water stable isotope technology and the Hydrus-1D model. Using the Romero-Saltos and IsoSource models, the stable isotopes of water in stems, different soil depths, and different precipitation were analyzed in a 5-year-old dwarfing apple orchard during two seasons 2016 and 2017. Hydrus-1D model was able to simulate the RWU of apple using the maximum coefficient of determination (0.9), providing a root mean square error of 0.019 cm3 cm−3 and a relative error of 2.25%. The results showed that the main depth of RWU ranged from 0–60 cm during the growth season, with the main contribution occurring in the 0–40 cm depth. These findings indicated that reducing the traditional surface irrigation depth will be important for improving the irrigation water use efficiency. [ABSTRACT FROM AUTHOR]

Soil water content (SWC) distribution plays an important role in root water uptake (RWU) and crop yield. Reasonable deep irrigation can increase the yield of winter wheat. The soil water movement model of winter wheat was established by considering the root water uptake and the different soil depths of irrigation and using the source term of the soil water movement equation to simulate irrigation at different soil depths. For model verification, experiments on three treatments of winter wheat growth were conducted at irrigation soil depths of 0% (T1), 40% (T2), and 70% (T3) of the distribution depth of the winter wheat root system. The SWC calculated by the model is in accordance with the dynamic change trend of the measured SWC. The maximum absolute error of the model was 0.022 cm3/cm3. The maximum average relative error was 7.95%. The maximum root mean square error was 0.28 cm3/cm3. Therefore, the model has a high simulation accuracy and can be used to simulate the distribution and dynamic changes of SWC of winter wheat in irrigation at different soil depths. The experimental data showed that irrigation soil depth has a significant effect on the root distribution of winter wheat (p < 0.05), and deep irrigation can reduce the root length density (RLD) in the upper soil layers and increase the RLD in the deeper soil layers. The dynamic simulation of RWU and SWC showed that deep irrigation can increase the SWC and RWU in deep soil and decrease the SWC and RWU in upper soil. Consequently, deep irrigation can increase the transpiration of winter wheat, reduce evaporation and evapotranspiration, and increase the yield of winter wheat. [ABSTRACT FROM AUTHOR]

A field experiment using PVC growth tubes was conducted in the Loess Plateau of China to determine the effective root depth (ERD) of winter wheat and its relationship with root distributions and soil water conditions. The water stable isotopes technique was used to estimate the water uptake contributions of different root depths during the growth stages. On the basis of IsoSource and the Romero-Saltos model, the ERD was 0-40 cm in the majority of the growth stage. However, in the heading and filling stages, the ERD could reach 60%-75% of the maximum root depth. Furthermore, the contributions to water uptake of different root depths were correlated with variations in soil water and root length density (r=0.395 and 0.368, respectively; p<0.05). However, by path analysis, the low decisive coefficient indicated that root distribution and soil water content did not always follow the same trend as water uptake. The conclusions of this study can help with understanding winter wheat water uptake mechanisms in arid and semi-arid regions and increasing water use efficiency. [ABSTRACT FROM AUTHOR]

• The evapotranspiration mechanism of the water storage pit orchard is revealed. • An evapotranspiration model of the water storage pit irrigation trees (SWp) is established. • The mechanism of the simulation error of the SW P model is illustrated. Accurately predicting the evapotranspiration of the orchard is of great significance for improving the water use efficiency of orchard and optimizing the water management of orchard. Based on both the evapotranspiration mechanism of the water storage pit irrigation orchard and the Shuttleworth-Wallace dual-source evapotranspiration model, an evapotranspiration model S W p suitable for water storage pit irrigation trees was established in this study. The evapotranspiration measured by the thermal diffusion sap flow meter and mic-lysimeter methods during 2018 were used to verify the performance of the PM model, the SW model and the S W p model under the water storage pit irrigation conditions. The results show that: (1) an evapotranspiration model of the water storage pit irrigation trees is established, and the Nash efficiency coefficient of the model is 0.93; (2) the diurnal variation of the evapotranspiration obtained by the three models of P M , S W , and S W p are the same as the measured value. The simulated value of P M model is 11.45% lower than the measured value, the simulated value of S W model is 24.01% higher than the measured value, and the simulated value of S W p model is 5.55% higher than the measured value; and (3) sensitivity analysis is performed on the six resistance variables in the S W p model, which reveals the mechanism of the simulation error of the S W p. model. Thus the S W p model significantly improved the accuracy against the PM and SW models and can be used to estimate the evapotranspiration under the water storage pit irrigation conditions. [ABSTRACT FROM AUTHOR]