Ming Li , Jingming Hou , Lei Wang , Shengwei Zong , Guiwen Wang , Xurong Chai
{"title":"Regional variations and climatic drivers of flash droughts during the growing season in China (2000–2020)","authors":"Ming Li , Jingming Hou , Lei Wang , Shengwei Zong , Guiwen Wang , Xurong Chai","doi":"10.1016/j.agwat.2025.109685","DOIUrl":"10.1016/j.agwat.2025.109685","url":null,"abstract":"<div><div>Flash droughts, characterized by rapid onset and severe impacts, have emerged as a critical climate-induced hazard, particularly during the growing season when agricultural systems are most vulnerable. Despite growing global attention, comprehensive assessments of flash drought dynamics across climatically diverse regions remain limited. Here, we systematically investigated the spatiotemporal patterns and drivers of flash droughts in China during the growing seasons from 2000 to 2020. Using high-resolution, pentad-scale soil moisture data, we identified flash droughts based on a percentile-based threshold method, and attributed their drivers using standardized precipitation index and anomalies in potential evapotranspiration, vapor pressure deficit, and surface solar radiation downwards. To assess drought dynamics, we evaluated trends in four key flash drought metrics, namely onset speed, frequency, duration, and severity, across nine major agricultural regions using Kendall’s τ correlation coefficient. Our key findings reveal that: (1) Southern China experienced the highest flash drought frequency, particularly in the Yunnan-Guizhou Plateau (6.39 ± 0.07 events per decade), the Middle-Lower Yangtze Plain (6.26 ± 0.09), and South China (5.89 ± 0.27); (2) The Huang-Huai-Hai Plain, a vital grain-producing region, showed significant increases across all drought metrics (Kendall’s τ > 0.3, p < 0.05), contrasting with slight declines in parts of southern China; and (3) Atmospheric evaporative demand-related anomalies, namely potential evapotranspiration, vapor pressure deficit, and surface solar radiation, contributed more prominently to flash drought development than precipitation anomalies. These findings highlight the urgent need to integrate atmospheric evaporative demand factors into drought monitoring frameworks, while offering a transferable approach for flash drought assessment in other monsoon-affected regions globally.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"318 ","pages":"Article 109685"},"PeriodicalIF":5.9,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nurcan Yavuz , Musa Seymen , Duran Yavuz , Ünal Kal , Ertan Sait Kurtar , Songül Kal , Ayşegül Gür
{"title":"Functional roles of plant growth-promoting rhizobacteria in ungrafted and grafted watermelons under various deficit irrigation strategies","authors":"Nurcan Yavuz , Musa Seymen , Duran Yavuz , Ünal Kal , Ertan Sait Kurtar , Songül Kal , Ayşegül Gür","doi":"10.1016/j.agwat.2025.109687","DOIUrl":"10.1016/j.agwat.2025.109687","url":null,"abstract":"<div><div>Drought is the central abiotic stressor limiting agricultural sustainability in arid and semi-arid regions. Plant growth-promoting rhizobacteria (PGPR) can play a key role in drought resistance in many vegetables including watermelon. This study examined the effects of two distinct PGPRs (<em>Pseudarthrobacter polychromogenes</em> and <em>Paenarthrobacter aurescens</em>) secreting 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase on yield, yield traits, fruit quality, and crop water stress index (CWSI) in watermelons of ungrafted and grafted (onto wild watermelon rootstock) under various deficit irrigation methods over the course of 2-year field trials in 2023 and 2024. This study results showed that increased water stress caused significant fruit yield loss. In both grafted and ungrafted plants, continuous severe water stress (CSWS) conditions led to yield loss of approximately 40 % by comparison to non-water stress (NWS). PGPRs produced varied results in grafted and ungrafted plants. Under CSWS, the wild watermelon rootstock interacted with rhizobacteria, particularly <em>P. aurescens</em>, increasing yield by up to 20 % compared to plants without PGPR. In grafted plants, <em>P. aurescens</em> increased irrigation water use efficiency (IWUE) by approximately 21 % under CSWS irrigation strategy. PGPRs were more effective under severe water stress than mild and moderate water stress, and they significantly protected watermelon from the damaging effects of water stress. PGPRs did not significantly affect the physical properties of watermelon fruits, including weight, width, length, rind thickness, and flesh color. However, they increased the soluble solids content in ungrafted plants and total phenolic compounds in grafted plants. Conversely, <em>P. aurescens</em> reduced the sucrose content in the fruit, resulting in a drop in the total sugar content of fruits produced in the presence of this bacterial species. The mean CWSI values of watermelon varied considerably under different deficit irrigation strategies, and increasing water stress caused CWSI values to rise. CWSI threshold were found higher in grafted plants (0.20) than in ungrafted plants (0). This study provides a theoretical basis for rootstock-PGPR synergistic regulation for efficient water-saving in cultivation of watermelon in water stressed environments.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"318 ","pages":"Article 109687"},"PeriodicalIF":5.9,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qi Liu , Xiaolong Hu , Yiqiang Zhang , Liangsheng Shi , Liping Wang , Yixuan Yang , Jiawen Shen , Jiong Zhu , Dongliang Zhang , Zhongyi Qu
{"title":"Assimilating UAV observations and crop model simulations for dynamic estimation of crop water stress","authors":"Qi Liu , Xiaolong Hu , Yiqiang Zhang , Liangsheng Shi , Liping Wang , Yixuan Yang , Jiawen Shen , Jiong Zhu , Dongliang Zhang , Zhongyi Qu","doi":"10.1016/j.agwat.2025.109688","DOIUrl":"10.1016/j.agwat.2025.109688","url":null,"abstract":"<div><div>Crop water stress (CWS) monitoring using UAV remote sensing has traditionally been limited to empirical models and specific growth stages, restricting dynamic, season-long assessment. This study proposes an integrated framework combining multispectral UAV observations with the SAFYE crop model via Ensemble Kalman Filter -based data assimilation (DA) to improve maize growth simulation and enable continuous CWS monitoring. Based on three years of field experiments, accurate inversion models for leaf area index (LAI; R<sup>2</sup>= 0.837, RMSE = 0.397) and aboveground biomass (AGB; R<sup>2</sup> = 0.862, RMSE = 224 g m<sup>−2</sup>) were developed using a random forest algorithm. Model parameters were calibrated using particle swarm optimization, and UAV-derived data were assimilated to optimize simulations of crop growth and actual evapotranspiration (ET<sub>c act</sub>). Results show that DA significantly enhanced model performance: LAI simulation RMSE decreased from 0.29–0.61–0.11–0.36 (NRMSE: 3.57–11.56 %), AGB simulation RMSE from 148.2–255.7–49.3–136.8 g m<sup>−2</sup> (NRMSE: 5.39–14.27 %), and agreement index (d) exceeded 0.92. ET<sub>c act</sub> simulations accurately reflected responses to irrigation and rainfall, with only 4.97 % relative error under full irrigation (W4). The developed crop water stress index (CWSI) effectively quantified water stress under different irrigation treatments. A significant negative correlation was observed between CWSI reduction and irrigation amount, while the severity of water deficit was positively correlated with the peak value of CWSI differences in terms of both timing and magnitude. This study establishes a robust UAV–crop model DA framework for dynamic, season-long CWS diagnosis and assessment.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"318 ","pages":"Article 109688"},"PeriodicalIF":5.9,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuan Tao , Jing Liu , QiuYang Su , Xiaoyan Guan , Xiaomin Chang , Haorui Chen
{"title":"Field and numerical evaluation of discontinuous improved subsurface drainage for waterlogging control","authors":"Yuan Tao , Jing Liu , QiuYang Su , Xiaoyan Guan , Xiaomin Chang , Haorui Chen","doi":"10.1016/j.agwat.2025.109680","DOIUrl":"10.1016/j.agwat.2025.109680","url":null,"abstract":"<div><div>Due to the shortage of farmland, subsurface drainage systems are progressively replacing the lowest-level open ditches, representing an emerging trend in water management practices in China. While subsurface drainage systems are engineered to remove waterlogging, their efficacy in resolving surface ponding is fundamentally constrained by soil permeability. To address this issue, a discontinuous improved subsurface drainage (DISD) has been proposed, featuring discontinuous filter extending from the pipe to the soil surface. Field and numerical experiments have been conducted to evaluate the performance of this proposed system on waterlogging removal and groundwater control. Based on a calibrated and validated HYDRUS-3D model, the simulations involved variations in filter heights, filter widths, filter spacings, and drain spacings have been conducted. The results indicated that DISD exhibited superior performance under conditions of surface ponding and short-duration heavy rainfall, enhanced efficiency in lowering the groundwater table compared to CSD (conventional subsurface drainage) for shallow groundwater table situation. Field experiments revealed that the cumulative discharge of DISD was approximately 2–2.3 times higher than CSD for short-term drainage and 1.37 times higher for long-term drainage. Numerical simulations showed that with a sand-gravel filter length ranging from 0.2 m to 4 m and a filter width of 1.2 m, the drainage discharge of the DISD was 1.91–5.40 times of CSD when surface ponding occurred. DISD is outperformed than ISD (improved subsurface drainage) in removing surface waterlogging when the filter volume of DISD is more than 6 % of ISD. DISD also does better in subsurface waterlogging control than ISD. These research findings provide a scientific basis for designing DISD and lay a solid foundation for their broader application in China.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"318 ","pages":"Article 109680"},"PeriodicalIF":5.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aili Wang , Yuanxiao Xing , Shunsheng Wang , Donglin Wang , Cundong Xu
{"title":"Spatial and temporal evolution trends of groundwater drought and its correlation with meteorological drought in Guizhou province","authors":"Aili Wang , Yuanxiao Xing , Shunsheng Wang , Donglin Wang , Cundong Xu","doi":"10.1016/j.agwat.2025.109682","DOIUrl":"10.1016/j.agwat.2025.109682","url":null,"abstract":"<div><div>Groundwater constitutes a vital water resource in karst regions, where conventional surface-based drought indicators frequently fail to accurately capture groundwater deficits. However, the applicability of GRACE satellite data for monitoring groundwater drought in these complex environments remains uncertain. To address this limitation, this study developed a Groundwater Drought Index (GDI) utilizing GRACE gravity satellite data and applied it to Guizhou Province in Southwest China, a representative karst region. Sen’s slope estimator, the Mann-Kendall test, and Pearson correlation analysis were employed to assess the spatiotemporal trends of groundwater drought and its relationship with meteorological drought. The results indicate that: (1) GRACE-derived total water storage anomalies (TWSA) are significantly correlated with GLDAS data and exhibit consistent seasonal fluctuations; (2) groundwater storage anomalies (GWSA) demonstrate a significant increasing trend of 0.55 cm/year from 2003 to 2022, with the most pronounced seasonal declines occurring in winter and spring; (3) the GDI identified 12 groundwater drought events, primarily concentrated between 2003 and 2011, characterized by longer duration and greater intensity in the northern region; and (4) groundwater drought responds to meteorological drought with lags mainly ranging from 10 to 24 months. These findings confirm the effectiveness of GRACE data for groundwater drought monitoring in karst regions and provide a valuable reference for water resource management and early warning systems.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"318 ","pages":"Article 109682"},"PeriodicalIF":5.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gopal R. Mahajan , Elia Scudiero , Amninder Singh , Aliasghar Montazar , Dennis L. Corwin
{"title":"Assessing onion salt tolerance using soil apparent electrical conductivity directed soil sampling, planet scope derived yield maps, and boundary analysis","authors":"Gopal R. Mahajan , Elia Scudiero , Amninder Singh , Aliasghar Montazar , Dennis L. Corwin","doi":"10.1016/j.agwat.2025.109679","DOIUrl":"10.1016/j.agwat.2025.109679","url":null,"abstract":"<div><div>Plant-salt tolerance parameters support decision making directed at conserving water in salt-affected farmland. Traditional methods for determining crop salt tolerance are labor-intensive and often do not accurately represent on-farm growing conditions. This research on dehydrated processing onion evaluates a novel approach utilizing boundary line analysis (BLA) for plant salt tolerance determination. We used soil and plant near-ground and remote sensing to generate extensive datasets (over 3900 yield-salinity data pairs) with limited ground-truth data (20 or fewer samples per field over four onion fields). First, root-zone soil salinity was mapped (R<sup>2</sup>=0.82) using apparent electrical conductivity through ensemble modeling with field-specific and multi-field regressions. Second, onion yield was mapped (R<sup>2</sup>=0.82) using a novel time-series analysis of daily PlanetScope surface reflectance. Third, a novel resampling procedure was applied to fit a BLA-based Maas and Hoffman salt tolerance curve to the upper boundary of the salinity × yield data point cloud. The examined onion variety was classified as moderately salt-tolerant, with a soil salinity threshold of 3.05 dS m<sup>−1</sup> and a relative yield decrement slope of 2.27 % at higher salinity levels. This proof-of-concept research demonstrated the feasibility of BLA-based crop salt tolerance determination using geospatial soil and plant sensing with limited ground sampling. Crop breeding programs may use the proposed methodology to determine salt tolerance in new crops in realistic environmental and management conditions and potentially reduce the labor required for traditional salt tolerance curve determination.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"318 ","pages":"Article 109679"},"PeriodicalIF":5.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yingnan Wei , Ziya Zhang , Miaolei Hou , La Zhuo , Ning Yao , LinChao Li , Jiangfeng Xiangli , Tehseen Javed , Jianqiang He , Qiang Yu
{"title":"Strategies for mitigating winter wheat yield reduction in the Yellow River basin: Simulations and insights from CMIP6 data and the improved DSSAT-CERES-wheat model","authors":"Yingnan Wei , Ziya Zhang , Miaolei Hou , La Zhuo , Ning Yao , LinChao Li , Jiangfeng Xiangli , Tehseen Javed , Jianqiang He , Qiang Yu","doi":"10.1016/j.agwat.2025.109678","DOIUrl":"10.1016/j.agwat.2025.109678","url":null,"abstract":"<div><div>Winter wheat is a vital staple crop in northern China, and climate change is expected to increase the frequency of droughts, leading to reduced yields. Therefore, it is crucial to study the impact of climate change on winter wheat yield and develop strategies to mitigate these effects. This study used CMIP6 data and an improved DSSAT-CERES-Wheat model to simulate winter wheat's phenological stages, yield, and water stress factors in the Middle and upper reaches of Yellow River basin from 2022 to 2050 and proposed measures to counteract yield reduction. The results revealed that optimal sowing dates and irrigation strategies remained stable under both the Shared Socioeconomic Pathway 2–4.5 (SSP2–4.5) and Shared Socioeconomic Pathway 5–8.5 (SSP5–8.5) scenarios across the middle and upper reaches of the Yellow River Basin. Early sowing combined with targeted irrigation during the jointing and grain-filling stages enhanced winter wheat yields but led to delayed phenological development. Moreover, variations in water productivity (WPc) and yield exhibited consistent spatial patterns across the three subregions of the study area. In region 1, the optimal sowing date is 10 days earlier, with a sowing window of 7–13 days earlier. During normal and dry years, irrigation requirements at the jointing and filling stages are 70 mm and 90 mm, respectively. In regions 2 and 3, the optimal sowing date is 15 days earlier, with a sowing window of 12–18 days earlier. Under the SSP2–4.5 and SSP5–8.5 scenarios, the overall growth rates of winter wheat yield in the Middle and upper reaches of Yellow River basin were 20.62 % and 16.32 %, respectively, with irrigation levels of 60 mm and 80 mm at the jointing and filling stages during normal and dry years. This study provides valuable insights and references for developing strategies to mitigate winter wheat yield reduction in the Middle and upper reaches of Yellow River basin under future climate scenarios.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"318 ","pages":"Article 109678"},"PeriodicalIF":5.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Samuel Massart , Mariette Vreugdenhil , Rafael Rogério Borguete , Carina Villegas-Lituma , Pavan Muguda Sanjeevamurthy , Sebastian Hahn , Wolfgang Wagner
{"title":"High-resolution drought monitoring with Sentinel-1 and ASCAT: A case-study over Mozambique","authors":"Samuel Massart , Mariette Vreugdenhil , Rafael Rogério Borguete , Carina Villegas-Lituma , Pavan Muguda Sanjeevamurthy , Sebastian Hahn , Wolfgang Wagner","doi":"10.1016/j.agwat.2025.109638","DOIUrl":"10.1016/j.agwat.2025.109638","url":null,"abstract":"<div><div>This study investigates the potential of active microwave remote sensing to develop high-resolution drought indicators based on surface soil moisture (SSM) in Mozambique. A 500-meter resolution SSM product is derived from Sentinel-1 C-band radar backscatter using a change detection model (SSM<sub>s1</sub>) and validated with state-of-the-art products including ASCAT, ERA5-Land, and SMAP. Results show that SSM<sub>s1</sub> provides consistent moisture information with greater spatial resolution compared to existing datasets. Two drought indicators are derived from SSM<sub>s1</sub>: the soil water deficiency index (SWDI<sub>s1</sub>) using SSM<sub>s1</sub> with auxiliary soil properties from Soilgrids, and the Z-score<sub>s1</sub>, combining ASCAT long-term climatology with Sentinel-1 spatial resolution to develop an anomaly-based indicator. Both SWDI<sub>s1</sub> and Z-score<sub>s1</sub> are compared against precipitation and vegetation anomalies in six regions of Mozambique. Precipitation anomalies show low regional variability and often fail to capture drought dynamics during the dry season, yet correlate with Surface Soil Moisture (SSM) anomalies during the rainy season. The vegetation indicator detects drought with a temporal delay compared to both SWDI and Z-score<sub>s1</sub>, suggesting that SSM provide information on earlier drought development, prior to observable vegetation anomalies. The results highlight the complementary strengths of these datasets and suggest their combined use in early warning systems. Combining information from precipitation, vegetation, and SSM<sub>s1</sub> enables complete monitoring of drought development. This research contributes to the development of strategies to monitor droughts and the improvement of early warning systems to improve the resilience of smallholder farmers as communities in Mozambique often rely on rain-fed agriculture.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"318 ","pages":"Article 109638"},"PeriodicalIF":5.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yilin Li , Jiancha Li , Binyan Zhang , Xuewen Yue , Kun Li , Daming Chen , Yujiao Yang , Xiaogang Liu , Haidong Fang
{"title":"Dry matter accumulation, translocation, and bulb yield of short-day onion as affected by cultivars and drip irrigation regimes in the dry-hot regions of southwest China","authors":"Yilin Li , Jiancha Li , Binyan Zhang , Xuewen Yue , Kun Li , Daming Chen , Yujiao Yang , Xiaogang Liu , Haidong Fang","doi":"10.1016/j.agwat.2025.109677","DOIUrl":"10.1016/j.agwat.2025.109677","url":null,"abstract":"<div><div>Seasonal water scarcity and improper cultivar selection have severely restricted the production potential of short-day onions in the dry-hot regions of southwest China. However, the appropriate irrigation regime and cultivar are still unclear. Therefore, field experiments were conducted during the two onion growing seasons (2022–2023 and 2023–2024) to evaluate the effects of irrigation levels [full irrigation (W1: 100 %ET<sub>c</sub>) and three deficit irrigation levels (W2: 80 %ET<sub>c</sub>, W3: 60 %ET<sub>c</sub> and W4: 40 %ET<sub>c</sub>); where ET<sub>c</sub> was crop evapotranspiration] on aboveground dry matter accumulation, partitioning, translocation, bulb yield and irrigation water productivity (WP<sub>I</sub>) of different onion cultivars [a local traditional cultivar (C1: Hongshuai) and two new cultivars (C2: Niu 4 and C3: Shahu)]. The results showed that the logistic growth model could effectively fit the process of dry matter accumulation in onions. C2 and C3 reduced aboveground dry matter accumulation, maximum accumulation rate of dry matter (AR<sub>max</sub>), and average accumulation rate of dry matter (AR<sub>avg</sub>), but increased bulb yield and WP<sub>I</sub> when compared with C1. Notably, C2 had the highest bulb yield and WP<sub>I</sub> in the two growing seasons. Deficit irrigation decreased dry matter accumulation after bulb initiation (DMAI), but increased bulb dry matter proportion and dry matter translocation (DMT). Bulb yield under W1 and W2 had insignificant difference, but W2 enhanced WP<sub>I</sub>. Although W3 and W4 significantly increased WP<sub>I</sub>, bulb yield decreased significantly. Bulb dry matter had significantly positive correlation with DMAI. Comprehensively considering bulb yield and WP<sub>I</sub>, the ‘Niu 4’ cultivar was preferred and an irrigation amount of 80 %ET<sub>c</sub> (onion evapotranspiration) was recommended for onions production in the dry-hot regions of southwest China. By optimizing the irrigation strategy of onions, WP<sub>I</sub> can be improved without significantly reducing bulb yield, which is of great practical significance for dry-hot regions with water scarcity. This study can provide a theoretical basis for optimizing onions irrigation management and cultivar selection in the dry-hot regions.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"318 ","pages":"Article 109677"},"PeriodicalIF":5.9,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"DRAINMOD predicted impact of climate change on hydrology, corn yield, and drainage design in the Western Lake Erie Basin, United States","authors":"Babak Dialameh , Ehsan Ghane , Mohamed Youssef","doi":"10.1016/j.agwat.2025.109641","DOIUrl":"10.1016/j.agwat.2025.109641","url":null,"abstract":"<div><div>Climate change presents challenges to agricultural water management, necessitating a reevaluation of subsurface drainage design for sustainable crop production. The objectives were to (1) investigate the impacts of climate change on hydrology and corn yield in southeast Michigan, United States, and (2) assess the climate change impact on the optimum drain spacings under two drain depths of 75 cm shallow and 125 cm deep. Using DRAINMOD and climate projections (2030–2059) from nine general circulation models under the SSP2–4.5 pathway, the study predicted hydrological responses and economic returns for various drain spacing designs. The optimum drain spacing was determined as the spacing that maximizes economic return using historical (1994–2023) and future scenarios. Future predictions showed an increased annual temperature (9.6°C for historical vs 12.1°C for future), relatively stable annual precipitation (933 mm for historical vs 928 mm for future), increased evapotranspiration (21%), reduced drainage discharge (21%), and deeper water table (7%) compared to the historical. Drought stress was the primary driver of future yield reductions, averaging 25% for both drain depths. The number of dry days during the growing season is expected to increase in the future due to higher evapotranspiration and a deeper water table. Optimum drain spacings were projected to widen from 7 m to 11 m for shallow drains and from 12 m to 19 m for deep drains to mitigate drought stress. In conclusion, future climate conditions showed a yield decline, suggesting a wider drain spacing may be needed to mitigate the drier growing season.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"318 ","pages":"Article 109641"},"PeriodicalIF":5.9,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144672253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}