Agricultural Water Management最新文献

{"title":"Advancing irrigation uniformity monitoring through remote sensing: A deep-learning framework for identifying the source of non-uniformity","authors":"Ígor Boninsenha ,&nbsp;Daran R. Rudnick ,&nbsp;Everardo C. Mantovani ,&nbsp;Higor de Q. Ribeiro","doi":"10.1016/j.agwat.2025.109376","DOIUrl":"10.1016/j.agwat.2025.109376","url":null,"abstract":"<div><div>Efficient agricultural water management ensures crop productivity and sustainability amidst climate change and water scarcity. This study integrates remote sensing and deep learning to advance irrigation uniformity monitoring by identifying sources of non-uniformity. Sentinel-2 satellite imagery from 2021–2023 was processed to generate 159,088 NDVI images from 1382 center pivot irrigation systems in Mato Grosso, Brazil. These images were classified into nine categories: vegetated, not vegetated, emitters, mechanical problems, low pressure, management zones, operational, partial crop, and clouds. Artificial images mimicking these patterns pre-trained a DenseNet121 convolutional neural network (CNN), addressing the challenge of limited labeled training data. Fine-tuning with six subsets of satellite data (2000–20,000 images) enhanced performance, achieving a Hamming accuracy of 99 % and an Exact Match accuracy of 91 %. Class-specific metrics demonstrated high precision, recall, and F1 scores for most patterns, though underrepresented classes, like mechanical issues, showed lower performance. The methodology was applied to 80 pivots in Mato Grosso (January–October 2024) using 2752 images, integrating classification results with the Satellite-Derived Christiansen Uniformity Coefficient (SDCUC). Among the pivots, 45 showed high uniformity (&gt;90 % SDCUC), with 10 exhibiting irrigation-related issues, and 28 facing non-irrigation challenges. Another 32 pivots had acceptable uniformity (80–90 %), with 9 linked to irrigation problems and 25 to non-irrigation issues. Finally, 3 pivots had low uniformity (&lt;80 %), with all issues related to non-irrigation factors like partial crop coverage. This scalable approach offers actionable insights for addressing non-uniformity, improving irrigation efficiency, and supporting precision agriculture, large-scale water management, and policymaking.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"310 ","pages":"Article 109376"},"PeriodicalIF":5.9,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143436710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Farmer driven water conservation policy on the Ogallala aquifer reduces the environmental footprints of crop production","authors":"José P. Castaño-Sánchez ,&nbsp;C. Alan Rotz ,&nbsp;Jean L. Steiner ,&nbsp;Bill Golden ,&nbsp;Sheri A. Spiegal","doi":"10.1016/j.agwat.2025.109370","DOIUrl":"10.1016/j.agwat.2025.109370","url":null,"abstract":"<div><div>The Ogallala Aquifer underlies 45 million hectares, supporting the robust agricultural economy of the US Great Plains and providing water for about 1.9 million people. The aquifer's long-term viability is threatened though due to severe depletion. Pumping reductions of 25–30 % are required to stabilize water levels on a decadal scale. Legislation has been passed in Kansas to reduce groundwater extraction while supporting productivity and economic viability. One outcome is the Local Enhanced Management Area (LEMA) program, where farmers set water-conservation targets in a region. Our objective was to study the environmental benefits of implementing water-conserving cropping systems in the Sheridan-6 LEMA (longest running LEMA). The Integrated Farm System Model (IFSM), verified with region-specific data, was used to compare simulated cropping systems within the LEMA to those in the surrounding region using conventional crop irrigation management. We found that LEMA management, which includes reduced water use and altered cropping, has provided environmental benefits with a slight to moderate reduction in crop yields (1.2–15 %). Totaled over the LEMA, crop life cycle reductions were found for blue water use (28 %), reactive N losses (1.4 %), fossil energy use (22 %) and GHG emissions (20 %). Considering the environmental intensities expressed per unit of grain produced, LEMA policies decreased blue water (24 %), energy (18 %), and C (15 %) footprints. The exception was the N footprint which increased slightly due to reduced crop yields with similar N loss. The main driver of the reduced impact was decreased water use in crop irrigation, followed by changes in cropping strategies where more water-demanding crops (corn and soybean) were replaced by less water-demanding crops (sorghum and wheat). Replicating LEMA-type policies more widely across the region can be a viable solution (environmental and economic) to stabilize the Ogallala Aquifer water levels for the next few decades, as demonstrated by this and previous research.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"310 ","pages":"Article 109370"},"PeriodicalIF":5.9,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143436711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying the influence of 3,4-dimethylpyrazole phosphate on soil nitrous oxide production in multi-year reclaimed water-irrigated soil","authors":"Yanbing Chi ,&nbsp;Chenchen Wei ,&nbsp;Peiling Yang ,&nbsp;Le Yang ,&nbsp;Linlin Fan ,&nbsp;Miaomiao Shi","doi":"10.1016/j.agwat.2025.109375","DOIUrl":"10.1016/j.agwat.2025.109375","url":null,"abstract":"<div><div>3,4-Dimethyl pyrazole phosphate (DMPP) is commonly used to regulate soil nitrogen transformation and mitigate nitrous oxide (N₂O) emissions, while reclaimed water (RW) irrigation alleviates freshwater shortages but may alter soil properties, affecting N₂O emissions. However, the interaction between DMPP and RW irrigation on N₂O emission pathways remains underexplored. This study conducted a field experiment with two water quality regimes (RW and groundwater (GW)) and two nitrogen fertilizer conditions (with and without DMPP) to assess soil N₂O, nitric oxide (NO), and ammonia (NH₃) emissions. Using the ¹ ⁵N tracing technique, we investigated microbial mechanisms underlying N₂O and NO production under multi-year RW irrigation. The findings indicate that although DMPP effectively reduced soil N₂O and NO concentrations within the 0–30 cm depth, thereby lowering their emissions under RW irrigation, its application also led to an increase in soil NH₃ volatilization. Consequently, cumulative N₂O emissions shifted from 2020 to 2021, with reductions of 15.11 %–38.46 % under RW irrigation and 36.88 %–48.29 % under GW irrigation. However, the inhibitory effect of DMPP was weaker under RW irrigation compared to GW irrigation. This reduction was influenced by RW irrigation, which enhanced the abundance of nitrifying microbial communities and increased the contribution of heterotrophic nitrification to soil N₂O emissions, thereby mitigating the inhibitory effect of DMPP on autotrophic nitrification. Overall, it emphasized the need for optimized nitrogen management strategies under RW irrigation to maximize emission reductions while minimizing trade-offs in NH₃ volatilization and microbial-driven nitrogen transformations.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"310 ","pages":"Article 109375"},"PeriodicalIF":5.9,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A modified model for simulating subsurface drainage with synthetic envelope considering impacts of entrance resistance and its application","authors":"Yingzhi Qian ,&nbsp;Xudong Han ,&nbsp;Yan Zhu ,&nbsp;Wei Yang ,&nbsp;Jiesheng Huang","doi":"10.1016/j.agwat.2025.109371","DOIUrl":"10.1016/j.agwat.2025.109371","url":null,"abstract":"<div><div>Subsurface drainage is an important means to prevent and control salinization and waterlogging. Accurate simulation of water and salt discharge is crucial for determining the design parameters of subsurface pipes. Existing models for simulating subsurface drainage discharge neglect the additional entrance resistances of drains induced by the low permeability of synthetic envelopes, which will overestimate the drainage discharge. This study aimed to develop a numerical model considering the entrance resistance of various envelopes and provided guidance for subsurface drainage design. The proposed modified model is based on the previous developed subsurface drainage package (SDR), in which a correction coefficient (<em>C</em>_<em>sdr</em>) reflecting entrance resistance was proposed and used to calculate the drainage discharge. The modified SDR package was verified by a synthetic case and series of practical examples with different entrance resistances caused by envelope materials. The model was then utilized to figure out the impact of pipe depths, spacings and entrance resistances on the water balance items. The influence on the mean and variance of drainage water is quantified by two indicators, AMAE and AMAV, which measure the expected changes in the mean and variance of the output due to parameter variations. Appropriate pipe depth and spacing under different entrance resistances was investigated. The results demonstrated the accuracy of the modified model in simulating the groundwater depth and drainage flux under different entrance resistances. For the scenarios where subsurface pipes were covered with synthetic envelopes, the errors of original SDR were out of range, while for the modified SDR, the normalized root mean square errors (<em>NRMSE</em>s) are less than 3.18 % and Nash-Sutcliffe efficiency coefficient (<em>NSE</em>) and Kling-Gupta Efficiency coefficient (<em>KGE</em>) greater than 0.9, respectively. Analysis of the water balance showed that an increase in subsurface drainage amount is beneficial to reduce the increase amount of the aquifer storage and the control of the groundwater depth. The drainage discharge amount was most sensitive to <em>C</em>_<em>sdr</em>, with AMAE and AMAV being 0.49 and 0.52. The spacing and <em>C</em>_<em>sdr</em> had an interactive effect on the drainage discharge amount, while the buried depth had no interactive effect with other factors. Narrower pipe spacing was recommended for subsurface drain design with relatively high entrance resistance (smaller <em>C</em>_<em>sdr</em> value). For those subsurface pipes covered with non-woven fabric of which the <em>C</em>_<em>sdr</em> is about 0.03, the pipe spacing should be around 10 m. This study provides a new method and insight for suitable design parameter of subsurface drains.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"310 ","pages":"Article 109371"},"PeriodicalIF":5.9,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143436805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pathways to balancing water and food for agricultural sustainable development in the Beijing-Tianjin-Hebei Region, China","authors":"Jianmei Luo ,&nbsp;Ying Guo ,&nbsp;Yongqing Qi ,&nbsp;Yanjun Shen","doi":"10.1016/j.agwat.2025.109344","DOIUrl":"10.1016/j.agwat.2025.109344","url":null,"abstract":"<div><div>Groundwater has significantly supported the increase in agricultural output in the Beijing-Tianjin-Hebei (BTH) region. However, the region has faced severe groundwater depletion for decades. To address this, water conservation in agriculture is considered a key strategy to groundwater decline. However, it is facing with a dilemma to suppress groundwater usage or to pursue agricultural production for food security when considering the criteria for sustainable groundwater use. In this study, we propose a comprehensive water-saving scheme and a planting structure optimisation approach to evaluate the thresholds for the water-food trade-off under various agricultural water conservation scenarios. We investigated, the gains and losses of three main agricultural measures to balancing the groundwater budget: (i) Reducing the planting scale (Sca), (ii) Optimising the planting structure (Str), and (iii) Promoting water-saving technologies (Tec), as well as combined pathways of these water-saving measures. The results showed that: (1) Achieving water conservation goals is challenging when applying a single measure. For example, the effect of water conservation would be 558 million m³ yr⁻¹ by merely optimising the planting structure without reducing the planting scale, whereas the effect would be 527 million m³ yr⁻¹ by solely reducing the planting scale according to farmland conservation plan/goals. (2) Under current water resource conditions in the BTH region, increasing crop water productivity (WP) by 11.5 % could balance the groundwater budget in agriculture, while a 19.2 % increase could achieve balance across all sectors. (3) By employing combined water-saving strategies, including optimising in planting scale/structure and improvements in water-saving technologies, groundwater conservation goals could be met with a 9 % increase in WP, provided that the planting scale and structure are adjusted to meet minimum grain production goals. (4) Two critical thresholds distinguish water-saving pathways, highlighting the marginal effects of investing in technological improvement versus optimising planting scale/structure. These results provide a basis for quantifying critical thresholds in cropping system optimising and provide useful information for similar regions worldwide.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"310 ","pages":"Article 109344"},"PeriodicalIF":5.9,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143436804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cover-management impacts on runoff and sediment dynamics at different slope positions in Northeast China","authors":"Jianhui Zeng,&nbsp;Zhonglu Guo,&nbsp;Dongyao Li,&nbsp;Li Hua,&nbsp;Wei Li","doi":"10.1016/j.agwat.2025.109373","DOIUrl":"10.1016/j.agwat.2025.109373","url":null,"abstract":"<div><div>The C-factor of the Universal Soil Loss Equation (USLE) reflects the impact of vegetation cover and management practices, playing a crucial role in predicting soil erosion. Slope position on rolling hills significantly affects soil properties and crop growth due to spatial variations in erosion intensity, potentially influencing soil erosion. However, few studies have quantified the effects of corn growth on runoff and sediment processes across different slope positions on long gentle slopes. The simulated rainfall experiments were conducted to investigate the temporal dynamics of runoff and sediment via rescaled range and wavelet analyses and determine the C-factor across slope positions during corn growth under three management practices: bare soil (CK), corn planting (CR), and corn planting with straw mulching (CRST). Results showed that runoff peak occurred at the maturing stage, with increases of 47.90 %, 127.61 %, and 259.53 % under CK, CR and CRST, respectively. The highest runoff rates were observed at the lower slope as it approached the late growth stage. Straw mulching mitigated frequency-domain variations in sediment and runoff, extended the primary cycle of sediment and runoff variations; therefore, delayed the response of runoff and sediment processes to rainfall. Management practices effectively postponed the peak sediment yield. The sediment yield on the middle slope (MS) was 71.46 % higher than that on the lower slope (LS) and 162.08 % higher than that on the upper slope (US). At the MS, the C-factor increased by an average of 106.69 % and 214.32 % individually under CR and CRST compared to other slope positions. Corn planting primarily reduced sediment by decreasing runoff, when runoff surpassed 600 mL·m⁻²min⁻¹ , straw mulching altered the runoff-sediment relationship to further reduce sediment loads thus reducing sediment. This study provides a theoretical support for studying the erosion processes in farmlands, and emphasizes the variation of the C-factor at different slope positions.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"310 ","pages":"Article 109373"},"PeriodicalIF":5.9,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimized parameters for SCS-CN model in runoff prediction in ridge-furrow rainwater harvesting in semiarid regions of China","authors":"Qi Wang ,&nbsp;Xiaole Zhao ,&nbsp;Fuchun Li ,&nbsp;Wucheng Zhao ,&nbsp;Ibrahim Awuku ,&nbsp;Wen Ma ,&nbsp;Qinglin Liu ,&nbsp;Bing Liu ,&nbsp;Tao Cai ,&nbsp;Yanping Liu ,&nbsp;Xuchun Li","doi":"10.1016/j.agwat.2025.109363","DOIUrl":"10.1016/j.agwat.2025.109363","url":null,"abstract":"<div><div>Soil erosion and water loss are the major drivers of land degradation, ecosystem malfunction, and low crop production in water-scarce regions. The Loess Plateau in China, one of the most erosion-prone areas globally, has implemented ridge-furrow rainwater harvesting technology to address water loss and soil erosion. Numerous hydrological models have been applied for runoff and sediment prediction in small watersheds. However, the application of the SCS-CN model to runoff and sediment prediction in small-scale fields has remained uncertain. Predictive models for runoff and sediment yield in ridge-furrow rainwater harvesting remained limited. This study utilized regression analysis of precipitation and runoff data from 2015 to 2018 to determine initial abstraction. The statistical parameters, including root mean square deviation (RMSE) and Nash-Sutcliffe efficiency (NSE), were employed to optimize initial abstraction ratios and potential maximum retention values of the SCS-CN model based on rainfall-runoff data from 2015 to 2018. Validation of the SCS-CN model with optimized parameters was performed using rainfall-runoff data from 2019 to 2023, leveraging NSE and coefficients of determination (R²) as evaluation criteria. The optimized initial abstraction ratios for flat planting, open-ridging, and tied-ridging were 0.09–0.14, 0.06–0.07, and 0.04–0.05, respectively. Corresponding potential maximum retention values were 58.3–93.9, 129.5–154.2, and 188.9–237.7 mm, respectively, while the curve numbers (CN) were 73.0–81.3, 62.2–66.2, and 51.7–57.3, respectively. For slope gradients of 5° and 10°, the optimized initial abstraction ratios were 0.05 and 0.07, respectively, with potential maximum retention values of 181.4 and 127.0 mm, respectively. The CN values for these slopes were 58.3 and 66.7, respectively. Significantly, increased slope gradients resulted in higher optimized initial abstraction ratios and CN values, along with reduced potential maximum retention values. The study concluded that ridge-furrow rainwater harvesting technology, particularly tied-ridging, demonstrated lower optimized initial abstraction ratios and CN values, coupled with higher potential maximum retention values, compared to flat planting. The SCS-CN model, incorporating optimized parameters, is a robust tool for accurately predicting runoff in ridge-furrow rainwater harvesting systems in the Loess Plateau of China.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"310 ","pages":"Article 109363"},"PeriodicalIF":5.9,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An agent-based model of farmer decision making: Application to shared water resources in Arid and semi-arid regions","authors":"Imane El Fartassi ,&nbsp;Alice E. Milne ,&nbsp;Helen Metcalfe ,&nbsp;Rafiq El Alami ,&nbsp;Alhousseine Diarra ,&nbsp;Vasthi Alonso-Chavez ,&nbsp;Joanna Zawadzka ,&nbsp;Toby W. Waine ,&nbsp;Ron Corstanje","doi":"10.1016/j.agwat.2025.109357","DOIUrl":"10.1016/j.agwat.2025.109357","url":null,"abstract":"<div><div>The study presents an agent-based modelling framework that integrates behavioural and biophysical models to investigate shared irrigation water management in an arid region. The behavioural model simulates farmers' decisions about their water irrigation sources (dam or groundwater) and whether to continue cultivating in the face of drought. This model was parameterised using survey data. The biophysical model component quantifies the impact of water availability and irrigation sources on soil salinity accumulation and its effects on crop productivity. Applied to the Al Haouz Basin, in Morocco, the integrated model reveals several key findings: (1) Increased groundwater access through water abstraction authorization can initially boost productivity but leads to widespread salinisation and farm abandonment, particularly under climate change scenarios. (2) Scenarios with reduced dam water availability demonstrate that mixed irrigation strategies mitigate short-term productivity losses but fail to prevent long-term soil salinity issues. (3) Land abandonment is significantly influenced by the level of water abstraction authorizations, with higher abstraction leading to more severe environmental degradation and social impacts. (4) Policy scenarios reveal that there is a theoretical optimal level of groundwater abstraction that maximises productivity while minimising land abandonment and salinity build-up. These results highlight the complex trade-offs between short-term gains and long-term sustainability, emphasising the need for holistic water governance policies that balance individual and collective interests.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"310 ","pages":"Article 109357"},"PeriodicalIF":5.9,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal water, nitrogen, and density management increased wheat yield by improving population uniformity","authors":"Yanmei Gao ,&nbsp;Qi Wang ,&nbsp;Yang Liu ,&nbsp;Jie He ,&nbsp;Weiwei Chen ,&nbsp;Jun Xing ,&nbsp;Min Sun ,&nbsp;Zhiqiang Gao ,&nbsp;Zhimin Wang ,&nbsp;Meng Zhang ,&nbsp;Yinghua Zhang","doi":"10.1016/j.agwat.2025.109362","DOIUrl":"10.1016/j.agwat.2025.109362","url":null,"abstract":"<div><div>The ideal population type is the basis of high-yield and high-efficiency cultivation of wheat. Population uniformity is an important index to evaluate the population ideotype. Therefore, it is necessary to analyze the yield difference of winter wheat at different spike layers between different populations because spike layer affects the production function of population. Here, two 2-year field experiments were conducted to investigate the effects of irrigation times, nitrogen application rate, and planting density on wheat yield, population traits, sugar and dry matter accumulation, and photosynthetic parameters at different spike layers. The results indicated that optimal planting density (SD3), nitrogen (N2) and irrigation (W1 or W2) deceased the ineffective tillers number at flowering stage and improved the spike number at upper and middle spike layers, which leading to lower coefficient of variation (CV) and higher population uniformity. Increasing planting density, nitrogen, and irrigation promoted high grain yield and population-scale biomass accumulation mainly due to the increment of spike number and yield at upper and middle spike layers. But, the single-stem biomass and grain dry weight reduced with increased planting density whereas improved with an increase of nitrogen and irrigation. Increasing planting density, nitrogen, and irrigation improved the leaf area index (LAI) and light interception at the upper and middle canopy, but decreased it at the lower canopy. Furthermore, the chlorophyll content at flag leaf and penultimate leaf was higher than that of top third leaf. Thus, the single-stem and each organ biomass accumulation, and sugar content gradually decreased from the upper to the lower layers, leading to decreased grains number per spike and average grain weight. Increasing planting density decreased spike length, total soluble sugar content and dry matter accumulation of spike at different spike layers but improved these indicators in stem, which leading to decreases in grain number per spike; whereas these indicators improved with increased irrigation. Overall, these findings provided theoretical and practical basis for building ideal crop population, and breeding and cultivation of winter wheat with high yield.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"310 ","pages":"Article 109362"},"PeriodicalIF":5.9,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time-frequency insights: Uncovering the drivers of reference evapotranspiration across China","authors":"Shuting Zhao ,&nbsp;Jinglong Wu ,&nbsp;Rangjian Qiu ,&nbsp;Tao Zhang ,&nbsp;Yufeng Luo ,&nbsp;Wei Hu","doi":"10.1016/j.agwat.2025.109367","DOIUrl":"10.1016/j.agwat.2025.109367","url":null,"abstract":"<div><div>Reference evapotranspiration (ET_o) is an important variable required in many disciplines and is influenced by many factors. However, the bivariate and multivariate relationships between ET_o and affecting factors across multiple time-frequency domains remain unknown. Here, we identified the primary factors affecting ET_o across time-frequency domain in 653 meteorological stations of mainland China based on the combination of wavelet transform coherence (WTC) and multiwavelet coherence (MWC) methods. The results indicated that ET_o and all affecting factors (solar radiation, R_s; vapor pressure deficit, VPD; air temperature, T_a; wind speed, <em>u</em>₂) during 1967–2016 exhibited a frequency ranging from 2 days to 211 months, and had a continuous annual (374 d) periodicity (except <em>u</em>₂) for almost all sites. Results of percentage area of significant coherence (PASC) of WTC indicated that VPD or R_s is the dominant single factor driving variations of ET_o across time-frequency space in majority sites (66.3 % and 32.0 %, respectively), while <em>u</em>₂ is only dominant in limited (11) sites. This quite differs from the daily scale, where daily ET_o was primarily influenced by daily R_s at 361 sites, daily VPD at 286 sites, and daily T_a at 6 sites. Results of MWC showed that the explanation for the time-frequency variations of ET_o can be further improved using two-factors in 40.7 % of all sites as indicated by absolute increased PASC of MWC by 5 %. Overall, we found that the variation of ET_o across time-frequency domain can be well explained by using only one variable (VPD or R_s) in 59.3 % of all sites, while by combinations of VPD-R_s and VPD-<em>u</em>₂ in remaining sites. This study provides novel insights into understanding the variations of ET_o across multiple time-frequency spaces.</div></div>","PeriodicalId":7634,"journal":{"name":"Agricultural Water Management","volume":"310 ","pages":"Article 109367"},"PeriodicalIF":5.9,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}