Hasil untuk "Irrigation engineering. Reclamation of wasteland. Drainage"

PEI Xiangli, XU Zhenghe, LIU Miao et al.

【Background and Objective】Soil salinization is a major constraint to sustainable agricultural production, and amending such soils with salt-tolerant microorganisms has been found to be effective in improving soil quality and enhancing crop tolerance to water and salinity stress. This paper analyzes international research in this area.【Method】Bibliometric analysis was conducted using VOSviewer and CiteSpace to systematically examine publications from 2004 to 2024 on saline-alkali soil microbiology retrieved from the China National Knowledge Infrastructure (CNKI, 652 articles) and the Web of Science Core Collection (WOS, 982 articles).【Result】Annual publications in saline–alkali soil microbiology showed a substantial increase during this period, with publications in English journals consistently and markedly overshadowing those in Chinese journals. China led the world, publishing 1 103 papers and collaborating with 26 countries, including Canada and the United Kingdom. Keyword clustering analysis showed that research hotspots in this field were: ①microbial community structure and its environmental drivers; ②mechanisms underlying plant-microbe interactions and their ecological functions; and ③ screening of salt-tolerant and growth-promoting microorganisms, as well as the mechanisms underlying biological remediation of saline-alkali soils. From 2004 to 2024, research on microbiology in saline-alkali soil can be divided into three stages: an early stage (2004—2015) emphasizing species identification and soil improvement; a middle stage (2016—2020) focusing on microbial community ecology and functional characterization; and the most recent stage (2021—2024) characterized by increased attention to the regulation of the microbe-soil-plant system.【Conclusion】Future research in saline-alkali soil microbiology will depend on international collaboration and interdisciplinary cooperation. Advances in multi-omics approaches, big data and artificial intelligence will enable systematic elucidation of microbial community assembly and functional regulation mechanisms, which will promote precision microbial management, functional strain development, and microbiome restoration. These advances will provide environmentally friendly solutions for remediating saline-alkali soils and sustaining agricultural production to meet the growing demand for food.

A. Mandal, S. Arora, P. C. Sharma et al.

ZHANG Yan, HE Jia, ZHANG Xiaofei et al.

【Background and Objective】Topsoil water content is a critical factor influencing crop growth and yield, yet traditional measurement methods are often limited in efficiency and scalability. UAV-based remote sensing provides a promising alternative for rapid, high-resolution in situ measurements. This paper evaluates the factors that affect the accuracy of UAV-based soil water content inversion and identifies the optimal combinations of data types, features, and modelling approaches for improving the accuracy of the UAV-based method.【Method】The experiment was conducted in a maize field during its early growth stage, characterized by substantial variation in canopy coverage. UAV imageries and ground-truth measurements were collected simultaneously. A threshold method was applied to remove the influence of soil background information and calculate vegetation coverage. Spectral and texture features were extracted, and vegetation coverage was integrated into different data combination patterns. Three regression methods: random forest regression, ridge regression and partial least squares regression, were used to construct the inversion model for estimating topsoil water content; comparison of their performance was analyzed under different scenarios.【Result】① The effect of background information removal on model accuracy varied with regression method and the data extracted from sensors. In particular, inversion accuracy improved after soil background information removal for RGB sensors but decreased for TIR sensors. ② The combination of visible and thermal infrared data significantly improved model accuracy, providing richer information and improving robustness. ③ Incorporating vegetation coverage improved accuracy of the predicted topsoil water content both with and without background information removal. For datasets without background information removal, the R2 of the methods using the RGB+TIR+FVC pattern increased by 0.01 compared to that of using the RGB+TIR pattern. After background information removal, their R2 increased by 0.11.【Conclusion】Our results show that different data combinations and inclusion of vegetation coverage had varying effects on the accuracy of UAV-based method for topsoil water content estimation. We screened optimal combinations and methods to increase the accuracy of the method for estimating topsoil water content in the early maize growing stage.

Sanjaya K Dash, K. Rayaguru, US Pal

Application of engineering in agriculture is known as agricultural engineering, and thus agricultural engineering aims at performing the agricultural work more easily and effectively with the engineering and technological inputs. Development, fabrication and operation of agricultural machines and equipment, efficient utilization of energy in different field operations, soil conservation, irrigation and drainage and efficient conservation and utilization of water, reclamation of degraded lands, processing of agricultural produce, preservation of food, renewable energy are some of the major subjects covered under agricultural engineering. With the increase in population leading to proportionate decrease in the land availability for farming, with less labour availability for farming operations, the scope and usefulness of agricultural engineering is increasing day by day.

Меліорація І Водне Господарство, ©. Vlasova, O. V. Vlasova et al.

The article presents the results of studies of spatial and temporal changes in the ecological and land reclamation status of drainless areas based on the use of high and medium spatial resolution satellite data. The authors assessed the geomorphological, hydrogeological, soil and land reclamation conditions of the steppe zone of Ukraine and noted that heterogeneous natural conditions such as relief, geomorphology, groundwater, soils and rocks of the active water exchange zone contributed to the development of processes of harmful effects of water and the nature of their manifestation. A large drainless area, the Petrivskyi depression in the area of the Kakhovka irrigation system, was chosen as the object of study. The processes of land degradation on the territory of the sub were identified by detecting various manifestations of spectral and textural changes in soil and vegetation surfaces under the influence of water and wind erosion, and an unbalanced land use system based on satellite images of various earth surface scanning systems. Changes were identified and studied by vegetation, soil, and water spectral indices, which made it possible to observe the flooding of the territory. Observations were carried out in different years and cover a period of more than 40 years: 1985-2015 - the most active flooding of the territory was observed; 2002, 2003 and 2005 - large-scale winter-spring flooding; 2018-2024 - the absence of a drainage system that is in decline was recorded; 2023, 2024 - the impact of hostilities on the territory of the pad. Based on the results of studies of the spatial differentiation of soil emissions and their temporal dynamics, the authors have developed a complex indicator that is a function of three components - the spectral indices NDVI, NDWI and CM. Verification of the studies of the period 1991-2017 of the averaged values of the spectral indices showed that the closest correlation exists between NDWI and NDVI and is 0,92. The experimental area was analyzed for soil fertility in contrast to the depleted soils of the pudu. It was determined that with the change in humus concentration, the color of the topsoil changes, which in turn causes changes in the spectral characteristics of the satellite image. Through long-term observations, the spatial and temporal changes in the ecological and reclamation state of the drainless area and the probability of loss of the functional resource of the reclamation system as a whole were studied.

V. Shevchenko

The purpose of the research is to identify bottlenecks and identify areas of both scientific research and practical actions for the technological provision of agriculture with integrated land reclamation. The main achievements of scientists and researchers of the Federal Scientific Centre for Hydraulic Engineering and Land Reclamation named after A.N. Kostyakov, carried out over the past 5 years on the base of state assignment, are presented in the paper. The proposed scientific developments are both fundamental and applied in priority. Comprehensive research is aimed at soil fertility restoration and improvement within existing reclaimed lands, as well as unused areas return into cultivation. Prospect agro-reclamation technologies and techniques to provide degraded soils cultivation are proposed for these purposes, such as nature-approach agrotechnical and reclamation techniques to provide sustainable improvement of soil fertility; agro-phytomeliorative techniques to restore degraded pasture ecosystems and estuarine lands; methods to protect crops from droughts and frosts. Combined low-volume irrigation systems and an intelligent automated water management system (IAWMS “Water Use”) have been developed and implemented, Bioengineered structure for drainage flow and waste water purification and mineralization reducing in the rice irrigation system are suggested. New hybrids of corn and soybeans have been created, as well as technologies for their cultivation.

M. Behdarnejad, H. Piri, M. Delbari

Introduction In sustainable farming systems, the use of organic fertilizers is of particular importance in increasing crop production and maintaining sustainable soil fertility. Nowadays, the consumption of organic foods is introduced to consumers as an alternative. The result of the application of chemical products is the crisis of environmental pollution, soil and water resources, and the health risk to human society. Nowadays, in order to reduce the effects of misuse of chemical inputs, chemical fertilizers can be replaced with organic biological fertilizers, including animal manure, compost, and green manure. In this regard, chicken manure has a positive effect on the physical, chemical, and biological characteristics of the soil, and due to its richness in uric acid, the nitrogen contained in it is used by the plant much faster than the nitrogen of other organic fertilizers. Vermicompost is considered a good source of soil fertility due to its organic materials. Organic matter in the soil improves the permeability and drainage of the soil and also prevents excessive dryness of the soil by maintaining sufficient moisture. Despite the fact that vermicompost can be used as a fertilizer in organic farming, high levels of this fertilizer may cause salinity effects in the plant, which affects the growth and development of the plant and even it can cause the death of cucumber as one of the crops sensitive to soil and water salinity. The cucumber (Cucumis sativus L.) is one of the important vegetables that can be produced in a greenhouse all year round. Fresh consumption of cucumber throughout the year has increased its production. The development of technology and the short growth period of this product has made it possible to grow it in most climate zones. Therefore, in this research, the effects of different levels of water deficit with the simultaneous application of vermicompost and chicken manure on cucumber plants in the Behbahan region have been investigated. Materials and Methods In this study, different levels of irrigation water, vermicompost, and poultry manure on ground cucumber were investigated. The experiment was performed in the form of split plots based on completely randomized design and the form of stacks. Treatments included three levels of poultry manure (2, 4 and 8 ton ha-1), three levels of vermicompost (3, 6 and 9 ton ha-1) and three levels of water stress (100, 75 and 50% of plant water requirement). Both vermicompost and poultry manure were applied to the soil before planting. Harvest was done every three days. Fruit weight, diameter and length, plant length, the protein of the dry matter of the fruit percentage, and leaf chlorophyll in each plot were carefully measured. Also, the yield and water productivity at the end of the season were calculated. Water productivity  Referring to the yield to irrigation water ratio, is obtained by the following relation (Payero et al., 2009): WP=Y/IR                                                                                                                               (1) In this equation, WP represents water productivity (kg/m3), Y denotes the yield (kg/ha), and IR shows the amount of irrigation water (m3/ha). Statistical analysis The analysis of variance for the results obtained from different treatments was conducted using SAS software (SAS 9.1, SAS Institute, Cary, NC, USA). The mean values of the main factors and interactive effects were compared using the Duncan method at the 1% and 5% levels of significance. Results and Discussion The results showed that irrigation, poultry manure and vermicompost had a significant effect on the measured parameters at the level of one and five percent probability. Reduction of water consumption reduced yield and yield components, but in this regard, no significant difference was observed between 100% and 75% of water requirement. The highest yield was obtained in the treatment of 100% of plant water requirement and consumption of 4 ton ha-1 of poultry manure and 6 ton ha-1 of vermicompost, in this regard, no significant difference was observed with the treatment of 75% of water requirement. According to the results obtained from this study, it can be said that there is no significant difference in terms of yield between treatments of 75 and 100% of plant water requirement. Therefore, the amount of water given to the plant can be reduced to 75% of the plant water requirement, and with proper management, less water can be consumed without a significant reduction in crop yield. Examining the effects of irrigation water on the amount of the protein of the dry matter of the fruit showed that the highest amount of the protein of the dry matter of the fruit (56.31%) was obtained in the treatment of 75% of the water requirement and the protein of the dry matter of the fruit was less in other treatments. The interaction effect of vermicompost and poultry manure resulted in the highest percentage of cucumber protein at a treatment of 4 tons ha-1 of poultry manure and 6 tons ha-1 of vermicompost (58.42%). However, when the simultaneous use of 8 tons ha-1 of poultry manure and different levels of vermicompost was employed, the percentage of protein in the fruit's dry matter decreased. The combination of drought stress, poultry manure, and vermicompost, along with their interaction effects, significantly influenced the chlorophyll a and b values at both the 1% and 5% probability levels. As the depth of irrigation water decreased, the amounts of chlorophyll a and b also decreased. The treatment with 100% water requirement of the plant showed the highest amounts of chlorophyll a (0.63 mg/g fresh weight) and chlorophyll b (0.36 mg/g fresh weight). However, no significant difference was observed compared to the 75% treatment. Regarding the interactions between vermicompost and poultry manure, it was found that when using 6 tons ha-1 of vermicompost to reduce yield and its components, the use of poultry manure should be reduced to 4 tons ha-1. On the other hand, when higher levels of vermicompost (9 tons ha-1) are used, the application of poultry manure should be reduced to 2 tons ha-1. Result According to the results obtained from this research, it can be said that there is no significant difference in performance between the treatments of providing 75% and 100% of the water requirement of the plant, therefore, the amount of water given to the plant can be reduced to the amount of 75% of the water requirement of the plant. With proper management, less water can be consumed without significantly reducing the yield of the product.

ZHANG Tonggang, HU Xinglu, LUO Min et al.

【Objective】 Saline water has been used as a supplementary irrigation resource in most countries to sustain agricultural production. The purpose of this paper is to study the influence of ionic composition in saline water on soil properties and growth of corn under mulched drip irrigation. 【Method】 The field experiment was conducted from April to September 2021 in the Hetao Irrigation District (HID) in Inner Mongolia. The saline water was created by adding different chloride salts: NaCl (T1), KCl (T2), CaCl2 (T3) and MgCl2 (T4) to fresh water. Irrigation with fresh underground water served as the control (CK). During each treatment, change in soil structure, transport of water and salt in soil, and crop growth were measured. 【Result】 ① Compared to CK, T1 significantly increased the number of small pores in the top 0~20 cm soil layer. This had a detrimental impact on soil structure but increased its water storage, particularly during the jointing stage. Compared to CK, T3 and T4 reduced the small porosity by 147.73% and 132.01%, respectively, but increased permeability of the soil. ② Compared to CK, all treatments increased the concentrations of Na+, K+, Ca2+ and Mg2+ in the 0~60 cm soil layer. Except T1, other treatments increased the concentrations of K+, Ca2+, and Mg2+, compared to CK. T1 resulted in salt accumulation in the soil surface, while other treatments did not show noticeable impact on ion composition. It was found that T3 and T4 moved the salt out the zone controlled by the mulch in the lateral direction, particularly T4. The electrical conductivity (EC) of the saturated extract from the root zone soil was influenced by the EC of irrigation water and varied in the range of 3~4 dS/m. ③ Na+ and K+ contents were the lowest and highest in the aboveground part, respectively. Na+, K+, and Cl- contents were higher in leaves than in stems, while Ca2+ and Mg2+ contents were higher in stem than in leaves. Increasing irrigation amount enhanced crop yield only in some treatments. Among all treatments, T4 gave the highest corn seed yield, 17.33% more than CK. 【Conclusion】 Irrigation with saline water containing high Na+ increased the small porosity of the topsoil, affecting soil water infiltration. In contrast, increasing K+, Ca2+, and Mg2+ contents reduced small porosity, promoting salt leaching due to the increased soil permeability. Keeping concentration of K+, Ca2+ and Mg2+ at appropriate levels under saline water irrigation is beneficial to increasing dry matter accumulation and the final yield, as it offsets the negative effects of excessive Na+. These findings provide guidance for safe utilization of saline water for irrigation in HID.

TAN Junli, WANG Xi’na, MA Xiaofu et al.

【Objective】 Brackish water has been used as a supplementary irrigation resource in some arid and semi-arid regions in northwestern China, but the impact of its long-term application on soil environment and crop growth and quality is not well understood. The objective of this paper is to fill this knowledge gap using watermelon as an example. 【Method】 The experiment was conducted in fields with sand mulch, where brackish water has been used as a supplementary irrigation resource for varying periods ranging from 2 to 14 years. During the experiment, we measured the distribution of soil water and salt in the 0~60 cm soil layer, soil bulk density, as well as the yield and quality of watermelon. An uncultivated piece of land nearby was used as the control. 【Result】 Soil salt content increased with the increase in duration of brackish water irrigation in both tendril elongation and harvest stage. The highest soil salt content was in the 20~40 cm soil layer for the control, and in the 40~60 cm soil layer for the sand-mulched field. The supplementary brackish water irrigation increased the soil moisture content in flowering and fruit-setting stages, but the increase varied in that with the increase in the duration of the brackish water irrigation, the soil water content increased first and then declined. The highest soil moisture content in the sand-mulched field was in the surface layer (0~10 cm), while for the control it was in the 10~20 cm soil layer. Sand mulch increased soil bulk density in the 0~40 cm soil layer and soil compaction in the 0~8 cm soil layer. It was also found that with the increase in length of brackish water irrigation, the yield and soluble solids content in the watermelon decreased, while the fruit quality improved first followed by a decline. 【Conclusion】 Long-term use of brackish water for supplementary irrigation in the sand-mulched fields increased soil bulk density and compaction in the upper soil layers, as well as soil moisture and salt content. As the years of brackish water irrigation increased, the yield of watermelon decreased while the quality of its fruits showed an initial improvement before deteriorating.

Waldemar Treder, Krzysztof Klamkowski, Katarzyna Wójcik et al.

A machine learning model was developed to support irrigation decisions. The field research was conducted on ‘Gala’ apple trees. For each week during the growing seasons (2009–2013), the following parameters were determined: precipitation, evapotranspiration (Penman–Monteith formula), crop (apple) evapotranspiration, climatic water balance, crop (apple) water balance (AWB), cumulative climatic water balance (determined weekly, ΣCWB), cumulative apple water balance (ΣAWB), week number from full bloom, and nominal classification variable: irrigation, no irrigation. Statistical analyses were performed with the use of the WEKA 3.9 application software. The attribute evaluator was performed using Correlation Attribute Eval with the Ranker Search Method. Due to its highest accuracy, the final analyses were performed using the WEKA classifier package with the J48graft algorithm. For each of the analysed growing seasons, different correlations were found between the water balance determined for apple trees and the actual water balance of the soil layer (10–30 cm). The model made correct decisions in 76.7% of the instances when watering was needed and in 87.7% of the instances when watering was not needed. The root of the classification tree was the AWB determined for individual weeks of the growing season. The high places in the tree hierarchy were occupied by the nodes defining the elapsed time of the growing season, the values of ΣCWB and ΣAWB.

Daniil I. Marshall, Olena H. Zhukova

After the explosion of the Kakhovka hydroelectric power station, the problem of restoring damaged areas of reclamation systems and rational use of water resources in the de-occupied territories of southern Ukraine is extremely relevant today. An integral part of solving this problem is the theoretical justification and assessment of filtration losses in damaged areas of open drainage channels with interception of this flow by drainage structures. This study presents a methodology for calculating the filtration losses of water from a main canal that runs in an excavation with a channelside pipe drainage. The calculations take into account the pressure drop on the canal lining. The filtration water losses per linear metre of the main channel of the Ingulets irrigation system were determined, taking into account the filtration resistance of the screen, which is economically feasible to restore from local water-resistant natural materials. In this case, the channel drainage performs two functions. Firstly, it prevents flooding of the territory; secondly, it is possible to use innovative technologies to return part of the filtration effluent for use in various water supply sectors of the region. The research results will allow us to further develop recommendations for effective engineering protection of water resources from pollution and depletion in this region.

Yevheniy O. Yakovlev, O. Rogozhin, D. Stefanyshyn et al.

In the article, in the aspect of engineering and geological safety of structures and communications, the long-term hydrogeological consequences of the support and drainage effects at coastal areas of destroyed Kakhovsky hydro node reservoir as a leading eco-forming component of a giant natural and man-made geosystem are considered. In particular, it included Zaporizhia NPP, the largest in Europe, and the largest irrigation systems in Ukraine. The consequences of the hydrodynamic disaster due to explosion of Kakhovskaya HPP, the dynamics and current state of drainage of the bed of its reservoir are briefly described, according to the data of GIS analysis of space images. And also – the state of hydrogeological and engineering-geological conditions in the reservoir support zone at the time of disaster and in retrospect. A calculated assessment of changes in hydrogeological conditions for the next 10-15 years has been carried out. Long-term natural and man-made threats that arose as a result of such changes in hydrogeological (geofiltration and geodynamic) conditions are named. The set of socio-economic threats that arose due to the negative consequences of Kakhovsky reservoir existence and draining is described. It is emphasized that the restoration of hydrotechnical and water management parameters of the reservoir in the previous values (according to the conservative version) will lead to secondary geospatial water saturation of subsiding loess-loamy silty-clay floatingable rocks that have already undergone deformations due to a decrease in geotechnical stability during the initial flooding and subsequent drainage. This will start a new stage in the formation of dangerous violations of stress-deformed state of coastal slopes, of Zaporizhzhya NPP responsible structures foundation and in nearby cities and towns. A socially and ecologically favorable option for the rehabilitation of affected region is possible only on the modern European ideological and technological basis of taking into account the maximum permissible changes in the hydrological network, i.e. by means of: creating a cascade of low support channel reservoirs with locks and small hydroelectric power stations, reconstruction of riverside ponds and water supply systems, transfer of domestic water supply to underground sources, irrigated lands – for drip irrigation, ecological reclamation and afforestation of drained lands.

Xiaoyan Shi, Wang Haijiang, Jianghui Song et al.

Abstract Understanding the impacts of desalination treatments on salt migration in saline soil during the farmland abandonment-reclamation process has significance for saline soil development and utilization. In this study, the soil salt content of severely salinized land in Xinjiang, China, was monitored over seven consecutive years using electromagnetic induction (EMI) rapid measurement technology. The experiment involved three different soil desalination engineering treatments and one control in the newly reclaimed, highly saline land (T1: salt isolation treatment at root area with conventional planting; T2: underground tube salt drainage with conventional planting; T3: conventional planting; CK: a natural control). A profile salinity prediction model was built based on the EMI to simulate the three-dimensional spatial distribution characteristics of soil salinity in the test area. The effects of the different saline soil improvement treatments on the distribution of salt content in the soil profile and the effect of desalination were analysed. The results demonstrated the following: (1) the soil salt content in the test area showed an obvious trend of surface salt accumulation. The salt content in the 0−100 cm layers under the different treatments showed decreasing, increasing and decreasing trends with the process of cotton planting, abandonment and reclamation, respectively, with a greater decrease in salt content associated with a longer planting period. (2) The soil salt content obviously decreased under the T1 treatment in the 0−40 cm and 80−100 cm soil layers and in the 20−60 cm soil layers under the T2 and T3 treatments. After the implementation of salinized soil improvement measures and tillage abandonment, a trend of increased salt content was evident in the plough layer under the different treatments; however, engineering improvement measures were able to inhibit salt migration to a certain degree. Under engineered drainage and salt isolation at the root area in combination with agricultural cultivation, irrigation could effectively reduce the soil salt content in the plough layer. These results provide a theoretical basis for soil improvement and utilization in arid areas.

B. Sadeghi, B. Farhadi Bansouleh, A. Bafkar et al.

IntroductionThe rapid growth of the world's population, followed by an increase in the need for water, has put great pressure on water resources, so it is necessary to plan for the optimal use and increase of efficiency of this vital resource. Sunflower is one of the most important oilseed crops that is mainly cultivated in Kermanshah province. Therefore, determining the appropriate sowing time of this crop for maximum production and water use efficiency is of particular importance. Because field experiments are costly and time-consuming, researchers use crop growth simulation models to determine the optimal planting time for each crop in a specific environment and climate. The use of simulation models minimizes the limitations of field experiments and allows the analysis of plant responses to environmental stresses and management scenarios. The objective of this study was to determine the optimal planting date of the Farrokh sunflower cultivar in four regions of Kermanshah province (Kermanshah, Islam Abad, Sarpol Zahab, and Kangavar) in order to maximize yield and water use efficiency using the AquaCrop model.Materials and MethodsA field experiment was conducted at the Research Farm of Razi University, Kermanshah, Iran in order to calibrate and validate the crop parameters in the AquaCrop model. The experiment was performed in a randomized complete block design with eight irrigation treatments in three replications. The irrigation treatments were the application of 60, 80, 100, and 120% of irrigation requirement (T1, T2, T3, and T4), 20 and 40% deficit irrigation in vegetative phase (T5 and T6), and 20 and 40% deficit irrigation in reproductive phase (T7 and T8). The crop water requirement was calculated based on the daily weather data collected from an automated meteorological station at the Research Farm using the FAO Penman-Monteith equation. During the growing season, canopy cover, biomass, and soil moisture were measured weekly. The crop parameters were calibrated based on the measured data in treatments T1, T3, T6, and T7 and validated with four treatments T2, T4, T6, and T8. In the calibration and validation stages, the statistical indices including compatibility index (d) and root mean square error (RMSE) were used to evaluate the model outputs. The calibrated model was used to simulate crop growth based on daily weather data for 30 years (1988-2017) in four synoptic stations in Kermanshah province (Kermanshah, Islam Abad, Sarpol Zahab, and Kangavar) and for several different planting dates. The crop water productivity was calculated based on simulated grain yield and seasonal crop evapotranspiration. Finally, the model outputs under different planting dates were analyzed to determine the most appropriate planting time from the perspective of maximum production and maximum water use efficiency.Results and Discussion Statistical indicators show that the model has simulated the parameters of biomass, crop canopy, and soil moisture in the calibration stage with good accuracy. T1 and T6 treatments in biomass simulation, T7, T6, and T3 treatments in crop canopy simulation, and T3 and T7 treatments in soil moisture simulation had the highest accuracy. The accuracy of the model outputs in the validation stage for biomass and canopy cover was as accurate as in the calibration stage, while the accuracy of the simulated soil moisture in the validation stage was not high except in T4 treatment. Based on the model results, grain yield, seasonal evapotranspiration and water productivity were determined. According to the results, it can be said that in the study period (1988 -2017), grain yield has generally increased with a slight slope. The results showed that the planting date, which maximizes grain yield and water productivity, varies in the studied regions.  According to the model results, planting in the second decade of May and the second decade of June will lead to the highest grain yield and water productivity in Kermanshah, respectively. Planting in the third decade of May showed the highest grain yield and crop water productivity in Islam Abad. In Sarpol Zahab, which has the highest temperature among the studied stations, planting in the last decade of March and the first decade of April has the highest grain yield and water productivity, respectively. In Kangavar, which is located in the east of Kermanshah province and has the coldest climate, by cultivating sunflower in the last decade of May and the first decade of June, respectively, the highest grain yield and water productivity can be achieved.ConclusionDue to the fact that some crop parameters of crop growth simulation models are variety specific, in this study, the crop parameters of the AquaCrop model for Farrokh sunflower cultivar were calibrated and validated. The accuracy of the calibrated model for estimating biomass and canopy cover was higher than soil moisture. The simulation results showed that the values of the studied parameters (grain yield and seasonal evapotranspiration) have changes according to the planting time in each region. The highest crop yield can be obtained in Sarpol Zahab, Islam Abad, Kermanshah, and Kangavar regions (west to east of the province) by cultivation in the last decade of March, last decade of April, the second decade of May, and last decade of May, respectively. In all study areas except Islamabad, planting date that resulted in maximum water productivity was different from the planting date that had maximum grain yield station and delayed planting had the highest water productivity.

محمد جلینی, محمد کریمی, جواد باغانی

باتوجه ‏به کمبود آب در کشور، بهبود مدیریت آبیاری مزارع سیب‌زمینی می‌تواند کاهش مصرف آب و افزایش بهره‏ وری آب این محصول مهم را به همراه داشته باشد. به این منظور، لازم است اطلاع کافی و دقیقی از وضعیت میزان آب کاربردی و بهره‌وری آب در شرایط مدیریت زارعین وجود داشته باشد. ازاین‏‌رو میزان آب کاربردی، عملکرد و بهره‌وری آب در شرایط مدیریت زارعین در دو منطقه عمده تولید سیب‌زمینی در استان خراسان رضوی بررسی شد. دو منطقه فریمان و تربت حیدریه با بیشترین سطح زیرکشت و تولید محصول سیب ‏زمینی به‏ عنوان شهرستان‏‌های پایلوت انتخاب شدند. روش آبیاری تمام مزارع، روش قطره‏‌ای (تیپ) بود. در مزارع آزمایشی، خصوصیات آبی و زراعی، مشخصات منبع آب و شبکه آبیاری، داده‌های هواشناسی مورد نیاز، حجم آب کاربردی، عملکرد سیب‌زمینی و بهره‌وری آب در سال زراعی 1398 اندازه‌گیری شد. همچنین حجم آب کاربردی توسط کشاورزان با نیازآبیاری برآورد شده براساس داده‌های هواشناسی سال 98 و ده ساله اخیر محاسبه شده به روش پنمن- مانتیث مقایسه شد. مقدار آب کاربردی بر اساس داده‌های هواشناسی سال 98 حدود 26 درصد و نسبت به آمار 10 ساله حدود 15 درصد بیشتر بود. نتایج همچنین نشان داد، حجم آب کاربردی سیب‌زمینی در مزارع مورد مطالعه از 9888 تا 14573 مترمکعب در هکتار متغیر و میانگین آن 11885 مترمکعب در هکتار بود. عملکرد سیب‌زمینی در مزارع منتخب از 28600 تا 60000 کیلوگرم ‌بر هکتار متغیر و میانگین آن 40399 کیلوگرم ‌بر هکتار بود. بهره‌‏وری آب از 2/22 تا 5/25 متغیر و میانگین 3/42 کیلوگرم ‌بر مترمکعب بود.

S. Yehorova

The purpose of the article is to establish the scientific achievements of scientists of branch research institutions and institutions of higher education in the improvement of water reclamation for different soil and climatic conditions of Ukraine in the 1990s. The research methodology is based on the use of general scientific methods: analysis, synthesis, systematization and classification of archival materials and printed sources. In the course of the research special historical methods were used: problem-chronological, comparative-historical, retrospective, which helped to determine the priority areas of activity of prominent agricultural scientists, their scientific achievements in improving water reclamation of Ukraine: irrigation and drainage. Results. It is established that in the 1990s an important role for the development of scientific support for the regulation of water reclamation in Ukraine was played by highly effective measures developed by agricultural scientists for optimal irrigation and drainage of land. It is determined that scientists have developed technological equipment for sowing crops and applying mineral fertilizers with irrigation water. The efficiency of creation of irrigation systems and technical means of irrigation of new generation, ecologically reliable reclamation systems and technologies is found out. Improvement of mechanized technologies of production and application of local organic fertilizers – sapropel and silt is established. It was found that scientists have attached great importance to the development of a comprehensive system for improving water reclamation: rational structure of sown areas and crop rotations, tillage and fertilization, agronomic and reclamation measures to prevent degradation of irrigated and drained lands. Conclusions. It can be concluded that in the 1990s, high-performance technologies for the conservation and efficient use of water and land resources played an important role in improving Ukraine's water reclamation. They were based on the scientific achievements of scientists from the Institute of Hydraulic Engineering and Land Reclamation of the Ukrainian Academy of Agrarian Sciences, as well as their co-performers who performed research in different soil and climatic conditions of Ukraine.

GUAN Guanghua, LI Huiying, SU Haiwang et al.

【Background】 Open channels have been widely used to transfer water in many projects. Automatically controlling them is a prerequisite in realizing intelligent management, optimizing water distribution, and achieving flexible water supply in emergency. Traditional automatic control systems normally use water level, flow rate, or storage pool as objective to control the channel operation based on some logic analysis. Existing control operation modes include keeping the upstream and downstream water levels constant, equal-volume method and control-volume method, with the control-volume method being most flexible and able to quickly respond to any changes. The disadvantage of the control-volume method is that it only uses the volume of a single channel section as its control objective. Therefore, its storage capacity is limited, and it cannot complement adjacent channels. 【Objective】 The objective of this paper is to resolve the inferiorities of the control-volume method, including limited storage capacity, inability to adjust the changes in the storage capacity between adjacent channels when using the storage capacity of a single section as the control objective. 【Method】 The proposed method was based on the balanced operation mode of multi-channel pool storage capacity with equal downstream water depth. We established a robust and easy-to-implement model to calculate the gate target flow based on the change in storage capacity, which not only keeps the total storage capacity of the channel unchanged, but also makes the downstream target water depth in each channel pool consistent. As a validation and verification, we applied the model to Jiping main canal on the east route of the south-north water transfer project. 【Result】 In the multi-canal pool storage balance mode, multiplying the storage difference by a weight coefficient can effectively reduce the gate flow overshoot and shorten the time it takes the system to stabilize. Under normal operating conditions, the regulation pressure on the head reservoir in the canal calculated by the proposed method was lower than that calculated by the conventional downstream constant water level control mode. Overall, the proposed method improved all dimensionless performance indexes, with the system stabilization time reduced by up to 10 hours. Considering that the difference in pool lengths in a canal could be more than 10 times, it is found that when there are large flow changes, adding a control gate to reduce the length of a single pool can further reduce the overall stabilization time and improve all dimensionless performance indexes. 【Conclusion】 Multi-channel pool storage control works better than the single channel pool storage control system, and the method we proposed lays a foundation for its further study and improvement.

LIU Jialing, WAN Jixiang, LI Hao et al.

【Objective】 The distribution of water droplet diameter of the sprinkler nozzle is an important parameter in designing sprinkler irrigation. The purpose of this paper is to study how non-circular nozzles affect this distribution. 【Method】 We studied two non-circular nozzles: an rhombic nozzle and an elliptical nozzle. By keeping the spraying rate the same, we compared the distribution of water droplet diameters of each nozzle using the PY15 rocker arm by keeping the working water pressures in the range of 100 to 300 kPa. For each test, we measured the distribution of the droplet diameters using a video raindrop spectrometer, with that measured from round circular nozzle taken as the control. 【Result】 The diameter of coverage of all nozzles was ranked in the order of round > rhombic > elliptical. Shape coefficient of the non-circular nozzle decreased as the outlet diameter of the nozzle increased while increased as the length-diameter ratio increased. The diameters of water droplets of the rhombus nozzle increased most quickly in the radial direction, compared to the other two nozzles. When working water pressure was the same, the diameter of the end-water droplet decreased as the shape coefficient of the nozzle increased; the diameter of the coverage increased with the diameter of the nozzle outlet. Increasing the outlet diameter can speed up the droplet velocity, while increasing the diameter-length ratio reduces the maximum distance that the droplets can reach due to the increased droplet diameter and velocity. The increase in droplet velocity of the elliptical nozzle with droplet diameters was the least. The kinetic energy and the increase in amplitude of unit volume of the droplets at the same location both decreased as the working water pressure increased. The diameter and kinetic energy of the droplets increased with the radial distance exponentially and linearly, respectively, while the relationship between velocity and diameter of the droplets was logarithmic. 【Conclusion】 Geometrical shape of the sprinkler nozzle has a significant impact on the diameters of the water droplets and their spatial distributions.

M. Romashchenko, O. O. Dekhtiar, Yu. V. Husyev et al.

Climate change has caused rapid soil dehydration in Ukraine; therefore sustainable agriculture will only be possible applying throughout irrigation or water regulation. Meanwhile, the use of the irrigation and drainage systems potential remains extremely unsatisfactory. In 2019, 532,000 ha were actually irrigated, and water regulation was performed on less than 300,000 ha. The purpose of the research. To analyze the existing state and substantiate the areas of the irrigation and drainage sector development to ensure the sustainable agriculture in the face of a changing climate. Materials and methods of the research. In the work, a set of methods was used: analytical, expert evaluations, surveys, comparisons and analogues, experimental. Observation data from the state meteorological stations network were used to evaluate hydrothermal conditions and the data from the network of hydrological posts of Ukrhydrometcentre were used to evaluate the river condition. To assess the technical condition of the engineering infrastructure, methodological approaches were used in accordance with the requirements of the international and European standards and the normative documents currently in force in Ukraine. To identify the possible ways and mechanisms to restore the irrigation and drainage systems potential, the reasons of the existing state were analyzed and it was determined that the uncompleted land and economic reforms, imperfections in the existing legislation and state support mechanisms, especially in the sector management, caused the long-year underfunding of irrigation and drainage facilities operation and restoration and resulted in the crisis situation in the sector. Conclusions. Based on the study of the world experience and the carried out research, it was established that the restoration and development of irrigation and drainage in Ukraine are possible only along with the implementation of a legal and institutional reform to introduce decentralization, improvement of the existing legislation, modernization of irrigation and drainage systems through the development and implementation of investment projects for restoration and development of irrigation and drainage systems, creation of attractive investment environments, development and introduction of a financing mechanism to cover management, operation and maintenance costs based on a new tariff formation system, introduction of the scientific support and staffing system for the land reclamation sector. The basis for the deployment of irrigation and drainage restoration should be the "Irrigation and Drainage Strategy in Ukraine until 2030", and the appropriate plan of measures, formed on the basis of fundamentally new institutional, scientific, technical and technological, economic, organizational, social and environmental approaches, should become a tool for achieving the goals of the "Strategy ...". Successful implementation of the goals of irrigation and drainage restoration in Ukraine will create the conditions to sustainable and profitable agricultural production in the face of climate change, to restore irrigation on the area of about 1,0 to 1,2 mln. ha and drainage on the area of 1,0 mln. ha and to additionally get up to 10 mln. tons of grain, 8-10 mln. tons of fruit, berries and vegetables annually.

فاطمه عسکری بزایه, رویا محمدزاده, یدالله آذرین فر

منطقه منا  شامل گروه ناهمگنی از کشورها با طیفی از کشورهای صادرکننده نفت با درآمد بالا در خلیج فارس تا کشورهای با درآمد متوسط و متوسط روبه پایین و کشورهای کمتر توسعه یافته می‏‌باشد. این منطقه به‏‌عنوان یکی از بزرگترین واردکنندگان خالص مواد غذایی در جهان می‏‌باشد و با عدم قطعیت‏‌های قابل توجه از جانب عرضه و تقاضا مواجه است. بر اساس گزارش مجمع جهانی اقتصاد، بحران آب مهمترین چالشی است که خاورمیانه و شمال آفریقا دارای کمترین آمادگی برای مواجه با آن است. این مقاله با رویکرد مروری مخاطرات جهانی عمده، وضعیت منابع آب، مصرف و سیاست‏‌های آب کشاورزی، بهره‌‏وری آب مصرفی در تولید کشاورزی، اثرات تغییرات اقلیمی بر تولید و نظام‏‌های کشاورزی در منطقه، آسیب‏‌پذیری کشاورزی دیم، تقسیم‌‏بندی کشور‏های منا براساس چالش‌‏های اصلی مدیریت آب، انواع مداخلات احتمالی با توجه ‏به نظام کشاورزی و وضعیت منابع طبیعی کشورها را بررسی می‏نماید. در نهایت بر اساس نتایج، راهبردهای حفاظت از محیط‌زیست، مدیریت تخصیص آب و مدیریت خدمات آب برای کشورهای منطقه پیشنهاد شده است.