Agronomy

21 pages, 16946 KB

Open AccessArticle

Optimizing Soybean Seeding Rate for Yield Across Early to Late Sowing Dates in a Humid Subtropical Environment

by José Salvador Simoneti Foloni, Renan Falcioni, Luis Guilherme Teixeira Crusiol, Marcos Rafael Nanni, Larissa Fernandes Dias Pinto, Claudemir Zucareli and José Renato Bouças Farias

Agronomy 2026, 16(14), 1396; https://doi.org/10.3390/agronomy16141396 - 22 Jul 2026

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Abstract

Soybean grain yield across extended planting calendars depends on sowing date, cultivar maturity group, and plant population. We evaluated BRS 1061 IPRO (MG 6.1) and DM 66i68 IPRO (MG 6.6) sown from September to January in 2021/2022 and 2022/2023 in Londrina, Brazil, at [...] Read more.

Soybean grain yield across extended planting calendars depends on sowing date, cultivar maturity group, and plant population. We evaluated BRS 1061 IPRO (MG 6.1) and DM 66i68 IPRO (MG 6.6) sown from September to January in 2021/2022 and 2022/2023 in Londrina, Brazil, at 200,000, 280,000, 360,000, and 440,000 viable seeds ha⁻¹ in a split-plot randomised complete block design. Grain yield, final stand, and yield components were analysed using mixed-model ANOVA, mean comparisons, regressions, correlations, principal component analysis, clustering, and descriptive permutation-based predictor ranking. Sowing date produced the largest performance gradient: grain yield ranged from 314 to 5771 kg ha⁻¹, and January sowings were consistently low yielding. Final stands ranged from approximately 1.6 × 10⁵ to 4.2 × 10⁵ plants ha⁻¹. Grain yield was strongly associated with grains m⁻² (r = 0.92), while PC1 and PC2 explained 71.3% of multivariate variation. Higher seeding rates did not provide a uniform advantage; intermediate rates were beneficial only in specific sowing-date × cultivar contexts, whereas 440,000 seeds ha⁻¹ sometimes reduced early-sowing yield. Seeding-rate decisions should, therefore, be cultivar- and date-specific, and January sowing is not recommended in this environment. Full article

(This article belongs to the Topic Advances in Cultivation Techniques for Increasing Crop Yield)

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40 pages, 6884 KB

Open AccessReview

Iron and Selenium Biofortification of Crops: Concepts, Soil Constraints, Strategies, and Perspectives

by Silvia Celletti and Michela Schiavon

Agronomy 2026, 16(14), 1395; https://doi.org/10.3390/agronomy16141395 - 22 Jul 2026

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Abstract

Iron (Fe) and selenium (Se) deficiencies are global health concerns associated with adverse health outcomes. Plants constitute a dietary source of these elements, particularly for individuals following plant-based diets. However, plant Fe availability is limited by soil processes that reduce Fe mobility and [...] Read more.

Iron (Fe) and selenium (Se) deficiencies are global health concerns associated with adverse health outcomes. Plants constitute a dietary source of these elements, particularly for individuals following plant-based diets. However, plant Fe availability is limited by soil processes that reduce Fe mobility and uptake, whereas Se accumulation is constrained by the low abundance of Se in soils. Increasing Fe and Se concentrations in edible plant parts through biofortification represents a sustainable strategy to alleviate micronutrient deficiency. This review examines the mechanisms governing Fe and Se uptake, translocation, metabolism, and genetic regulation, and discusses current biofortification strategies, including agronomic practices, natural and microbial-based approaches, conventional breeding and marker-assisted selection, transgenic technologies, and nanoparticles. While cereals remain the principal targets of large-scale biofortification programs, recent advances in horticultural crops are also highlighted because of their growing nutritional and commercial importance. Current evidence indicates that integrated agronomic and genetic approaches are more effective than single interventions, although simultaneous Fe and Se biofortification remains largely underexplored. Successful biofortification is also strongly influenced by soil properties, nutrient interactions, and crop genotype. Emerging tools, including plant–microbe interactions and synthetic biology, offer promising opportunities to enhance micronutrient accumulation and bioavailability. Further research should optimize integrated Fe–Se biofortification strategies while addressing agronomic and socioeconomic constraints to support their large-scale adoption and contribute to sustainable food systems. Full article

(This article belongs to the Special Issue Improving Nutritional and Functional Quality of Horticultural Crops Through Biofortification Approaches)

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27 pages, 5977 KB

Open AccessArticle

A Simplified Evaluation Model for Soybean Seedling Salt Tolerance Based on Core Biomass Traits Under Saline Pond Conditions

by Yixin Tian, Jinying Zhu, Fangjing Hua, Pengpeng Cao, Chunyan Li, Chunyu Wang, Guanxiong Zhu, Qi Gao and Fengju Gao

Agronomy 2026, 16(14), 1394; https://doi.org/10.3390/agronomy16141394 - 22 Jul 2026

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Abstract

Salt stress severely restricts soybean seedling growth and yield formation, and the redundant indicators and low efficiency of conventional salt tolerance evaluation methods limit the large-scale screening and breeding of salt-tolerant soybean germplasms. In this study, we aimed to establish a simplified and [...] Read more.

Salt stress severely restricts soybean seedling growth and yield formation, and the redundant indicators and low efficiency of conventional salt tolerance evaluation methods limit the large-scale screening and breeding of salt-tolerant soybean germplasms. In this study, we aimed to establish a simplified and efficient salt tolerance evaluation system for soybean seedlings under saline pond conditions. We determined 16 phenotypic traits of 100 soybean germplasm resources under soil salt stress (0.3% soil salt content, EC 5.0 dS/m), calculated the salt tolerance coefficient (STC) of each trait, and comprehensively analyzed phenotypic variation, correlation, germplasm classification, and core evaluation indices via principal component analysis (PCA), K-means clustering, random forest model, SHAP interpretation, 10-fold nested cross-validation, and correlation network analysis. Biomass-related traits exhibited abundant phenotypic variation, with coefficients of variation ranging from 42.6% to 48.4%. Five principal components explained 82.90% of the total phenotypic variation and divided the accessions into four salt tolerance categories. Total fresh weight (TFW), stem fresh weight (SFW), and leaf fresh weight (LFW) were identified as the core indices, together accounting for over 93% of the total feature importance in the random forest model, whereas the remaining 13 traits each contributed less than 1.2%. The simplified three-index model showed strong consistency with the full 16-trait model (Pearson r > 0.970, AUC = 0.970) and achieved a screening accuracy of 90.0% under 10-fold nested cross-validation. Under the experimental conditions examined, fresh biomass accumulation emerged as the dominant phenotypic characteristic associated with seedling salt tolerance. This simplified evaluation framework may facilitate rapid preliminary screening of salt-tolerant soybean germplasms at the seedling stage, pending further validation across diverse environments and genetic backgrounds. Full article

(This article belongs to the Special Issue Remote Sensing and Machine Learning for Crop Phenotyping and Structural Analysis)

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23 pages, 3429 KB

Open AccessArticle

Metagenomic Insights into Corn Stalk Biochar-Mediated Carbon Cycling and Microbial Community Shifts in Black Soil Soybean Rhizosphere

by Jianqin Zhu, Kezhen Zhao, Yimeng Li, Ruiming Xing, Yang Jiao and Jihua Wang

Agronomy 2026, 16(14), 1393; https://doi.org/10.3390/agronomy16141393 - 22 Jul 2026

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Abstract

Despite extensive research on biochar’s effects on soil properties, the molecular mechanisms linking carbon-cycling functional genes to soil organic carbon dynamics under biochar application remain poorly understood. This study evaluated the effects of corn stalk biochar applied at different rates (0, 300, 600, [...] Read more.

Despite extensive research on biochar’s effects on soil properties, the molecular mechanisms linking carbon-cycling functional genes to soil organic carbon dynamics under biochar application remain poorly understood. This study evaluated the effects of corn stalk biochar applied at different rates (0, 300, 600, and 900 kg/hm²) on soil physicochemical properties, microbial community structure, carbon cycling genes, and soybean (HeiNong551) growth in Northeast China’s black soil region. Metagenomic analysis and metabolic pathway analysis were also conducted. Biochar application significantly improved soil fertility by increasing pH, moisture content, and various SOC fractions, while modulating the activities of key soil enzymes, including β-glucosidase, alkaline phosphatase, cellulase, and polyphenol oxidase. Metagenomic analysis revealed that biochar substantially enhanced soil microbial richness and diversity, with significant enrichment of beneficial bacterial genera, including Nocardioides and Sphingomicrobium. Functional gene analysis demonstrated that biochar promoted soil carbon cycling by increasing the abundance of Glycosyltransferases, Glycoside Hydrolases, and Auxiliary Activities, while decreasing the abundance of Carbohydrate-Binding Modules, Carbohydrate Esterases, and Polysaccharide Lyases. Analysis of 22 key carbon cycling pathway genes indicated that biochar enhanced carbon fixation via the reductive tricarboxylic acid cycle (korA gene) and promoted the degradation of easily mineralizable SOC components, while suppressing stable carbon degradation pathways. Full article

(This article belongs to the Special Issue Enhancing Soil Nutrient Cycling and Microbial Function for Sustainable Agriculture)

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24 pages, 9173 KB

Open AccessArticle

Hydroclimatic Gradients Shape Differential Responses of Vegetation Photosynthesis in Croplands and Typical Natural Vegetation to Atmospheric Evaporative Demand and Soil Moisture

by Zuyu Liu, Leyi Zhang, Junhua Xue, Xia Li, Guozhuang Zhang, Xiaoning Han, Shuen Liao, Yunfei Chen, Rui Chen, Yi He and Xiuhua Liu

Agronomy 2026, 16(14), 1392; https://doi.org/10.3390/agronomy16141392 - 22 Jul 2026

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Abstract

Vegetation photosynthesis is jointly regulated by precipitation supply, atmospheric water demand, and vertically stratified soil moisture, but their relative roles across vegetation types and hydroclimatic backgrounds remain unclear. Using monthly satellite solar-induced chlorophyll fluorescence (SIF), ERA5-Land hydroclimatic variables, and vegetation-type data across China [...] Read more.

Vegetation photosynthesis is jointly regulated by precipitation supply, atmospheric water demand, and vertically stratified soil moisture, but their relative roles across vegetation types and hydroclimatic backgrounds remain unclear. Using monthly satellite solar-induced chlorophyll fluorescence (SIF), ERA5-Land hydroclimatic variables, and vegetation-type data across China from 2000 to 2024, this study combined monthly anomaly analysis, lagged partial correlation, and XGBoost–SHAP to quantify moisture-response patterns in cropland, forest, grassland, and shrubland along an arid–humid gradient. Vegetation SIF increased overall from 2000 to 2024, with a clear northwest–southeast gradient and higher multiyear mean SIF in forests and shrublands than in croplands and grasslands. XGBoost–SHAP results showed that vapor pressure deficit (VPD) was the largest single contributor to SIF anomalies at the national scale, accounting for 31.8% of total moisture-factor contribution, followed by precipitation, shallow soil moisture, and middle- plus deep-layer soil moisture. The VPD contribution differed among vegetation types, reaching 43.3% in grassland, 32.5% in cropland, 30.4% in shrubland, and 27.5% in forest. Lagged responses also varied with soil depth and hydroclimatic background. Precipitation and shallow soil moisture mainly produced concurrent or 1-month lagged responses, whereas middle- and deep-layer soil moisture generated 2–3-month delayed effects in some arid and semi-arid cropland and woody vegetation. Across the arid–humid gradient, dominant moisture constraints shifted from deeper soil-water regulation in arid regions toward VPD control in transitional zones and precipitation or shallow-soil-moisture control in humid ecosystems. These findings demonstrate that vegetation SIF anomalies are shaped by coupled atmospheric demand, precipitation input, and soil-water storage, with vegetation traits and hydroclimatic background jointly determining the dominant moisture-response pathway. Full article

(This article belongs to the Section Water Use and Irrigation)

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13 pages, 18152 KB

Open AccessArticle

Developing Elite Rice ZH381 and ZLY381 by Pyramiding badh2, Pi2, and Wx^b

by Naihui Guo, Jun Jiang, Ruihu An, Yuanyuan Li, Zongliang Ren, Bonian Cai, Xinzhu Huang, Shikai Hu, Gaoneng Shao, Guiai Jiao, Lihong Xie, Ling Wang, Fengli Zhao, Yujun Zhu, Shaoqing Tang, Zhonghua Sheng and Peisong Hu

Agronomy 2026, 16(14), 1391; https://doi.org/10.3390/agronomy16141391 - 22 Jul 2026

Viewed by 339

Abstract

The enhancement of rice yield, quality, and disease resistance plays a crucial role in determining food security. However, there is often a negative correlation among these traits. This study developed elite restorer line Zhonghui381 (ZH381) and two-line hybrid rice Zhongliangyou381 (ZLY381). ZH381 is [...] Read more.

The enhancement of rice yield, quality, and disease resistance plays a crucial role in determining food security. However, there is often a negative correlation among these traits. This study developed elite restorer line Zhonghui381 (ZH381) and two-line hybrid rice Zhongliangyou381 (ZLY381). ZH381 is a restorer line selected from F₇ obtained by crossbreeding Yuenongsimiao (YNSM) and Jiuxiangzhan (JXZ). ZLY381 is a two-line hybrid rice obtained by crossbreeding Z767S and ZH381. The Kompetitive Allele Specific PCR (KASP) shows ZH381 contains badh2, Pi2, and Wx^b. ZLY381 exhibits excellent traits of high yield, high quality, and resistance to rice blast disease in some areas. This study has developed variety has higher yield and high disease resistance, which helps address food security. Full article

(This article belongs to the Section Crop Breeding and Genetics)

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20 pages, 12303 KB

Open AccessArticle

Get It Vigorous! Supplemental Tree Growth Regulators and Mineral Nutrients Can Improve Sweet Orange HLB Tolerance

by Camilo Lázaro Medina, Paulo Roberto de Camargo e Castro, Ricardo Silverio Machado, Nárcya Trindade de Souza and João Paulo Rodrigues Marques

Agronomy 2026, 16(14), 1390; https://doi.org/10.3390/agronomy16141390 - 22 Jul 2026

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Abstract

Huanglongbing (HLB) is the main disease affecting citrus crops, and in the absence of resistant commercial cultivars, alternative management strategies are required. This study aimed to evaluate the effect of early application of tree regulators associated with foliar nutrition on tree development, fruit [...] Read more.

Huanglongbing (HLB) is the main disease affecting citrus crops, and in the absence of resistant commercial cultivars, alternative management strategies are required. This study aimed to evaluate the effect of early application of tree regulators associated with foliar nutrition on tree development, fruit quality, tolerance to HLB in sweet orange trees and vascular tissue organizations. The experiment was conducted in a commercial Citrus sinensis “Lima Verde” orchard, with asymptomatic (PCR−) and symptomatic (PCR+) tree, distributed in a completely randomized design with eight replications per treatment. The following six treatments were evaluated: negative control (asymptomatic trees, PCR−); positive control (symptomatic trees, PCR+); foliar application of gibberellic acid; foliar application of 2,4-D; foliar spraying of nutrients solution; and a combination of nutrients solution with gibberellic acid and 2,4-D. The evaluations included disease severity, canopy growth, analysis of mineral nutrients by fruit, dry mass, fruit quality, and histopathological analysis of the phloem and xylem. The integrated treatment (foliar nutrition + growth regulators) significantly reduced HLB symptom severity, promoted canopy growth comparable to healthy trees, and decreased fruit drop by 62.7% relative to the untreated HLB control. Fruit yield increased from 9.89 to 22.50 kg tree⁻¹, representing a 127% increase, while harvested fruit number increased from 71.0 to 139.8 fruits tree⁻¹. The combined treatment also restored fruit diameter to values similar to healthy trees, increased total fruit dry matter from 14.5 to 24.2 g, and maintained soluble solids (9.56 °Brix) close to the healthy control (10.33 °Brix). Fruit zinc concentration increased by 48% compared with untreated HLB-infected trees. Histological analyses demonstrated enhanced cambial activity, larger phloem and xylem areas, reduced starch accumulation, and improved vascular integrity in treated trees. These findings highlight the potential of integrated tree regulators and nutritional approaches as a valuable alternative for improving tree performance and tolerance under HLB prevalent conditions. Full article

(This article belongs to the Special Issue Current Status and Future Prospects of Citrus Disease Management and Resilience)

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17 pages, 1245 KB

Open AccessArticle

Genotype- and Environment-Dependent Effects of Biostimulant Protocols on Flowering, Maturity, and Stability in White Lupin (Lupinus albus L.)

by Mona A. L. Al-Malki, Ayman E. Badran, Amal A. M. Al-Ghamdi, Manal El-Zohri, Sherine S. S. Fayad, Amr R. Hassan, Amal A. Mostafa, Noha S. El-Khouly and Ahmed M. Hassan

Agronomy 2026, 16(14), 1389; https://doi.org/10.3390/agronomy16141389 - 22 Jul 2026

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Abstract

The decline in cultivating crops like lupin in the Arab region and globally is due to climate change, old local varieties with low yield, and the long cultivation season that delays subsequent crops. This study tested a treatment protocol using zinc sulfate, salicylic [...] Read more.

The decline in cultivating crops like lupin in the Arab region and globally is due to climate change, old local varieties with low yield, and the long cultivation season that delays subsequent crops. This study tested a treatment protocol using zinc sulfate, salicylic acid (SA), and aloe vera extract on three Egyptian varieties: Giza 1, Giza 2, and Giza 3. A multi-environment trial was conducted over two seasons across two contrasting locations. Advanced linear mixed-effects modeling revealed that genotype was the dominant source of phenotypic variance, accounting for 5.8% and 4.9% of the variation in days to blooming (DTB) and days to maturity (DTM), respectively. SA was the most effective, significantly reducing DTB by 10.7% (7.9 days) and DTM by 5.9% (9.8 days) compared to the control. A significant genotype × treatment interaction (p < 0.001) identified Giza 2 as the most responsive cultivar, achieving the shortest DTB (60.0 days) under SA. Variance component and AMMI stability analyses confirmed strong environmental modulation, with treatment efficacy amplified at the site with greater abiotic stress potential. However, Giza 3 with zinc sulfate offers stable performance under high-fertility conditions. Such results suggest that the careful management of genotypes and diverse stimuli under continuous environmental changes can significantly accelerate growth and enhance adaptability, thereby achieving stability and increasing productivity. Full article

(This article belongs to the Section Agroecology Innovation: Achieving System Resilience)

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34 pages, 32175 KB

Open AccessArticle

Effects of Herbaceous–Shrub Vegetation Systems on Soil Shear Characteristics and Their Influencing Mechanisms in Eroded Red Soil Regions of Southern China

by Qiaoqiao Yang, Fang Ha, Yuanyuan Zhan, Ying Meng, Yiyang Zhou, Xiang Zhang, Yue Zhang, Jinshi Lin, Yanhe Huang and Fangshi Jiang

Agronomy 2026, 16(14), 1388; https://doi.org/10.3390/agronomy16141388 - 21 Jul 2026

Viewed by 554

Abstract

The shear characteristics of soil–root systems are dynamic indicators for assessing soil erosion resistance. Vegetation type influences shear characteristics by altering soil properties and root traits. However, the mechanisms by which mixed vegetation roots affect shear characteristics remain unclear. We selected naturally restored [...] Read more.

The shear characteristics of soil–root systems are dynamic indicators for assessing soil erosion resistance. Vegetation type influences shear characteristics by altering soil properties and root traits. However, the mechanisms by which mixed vegetation roots affect shear characteristics remain unclear. We selected naturally restored forestland (with Dicranopteris dichotoma, Baeckea frutescens, and their combinations) and artificially managed orchard systems (with Paspalum wettsteinii, Gardenia jasminoides, and their combinations) in the erosion-prone red soil region of southern China. In situ shear tests were conducted to explore the shear characteristics of soil–root systems under different vegetation types, identify the main influencing factors, and clarify the underlying mechanisms. Shear fracture energy (SFE), peak shear stress (PSS), and peak shear stress displacement (DPS) decreased with increasing soil depth across all sites. The average SFE and PSS in the forestland were 2.44 and 3.11 times higher, respectively, than those in the orchards. The main factors influencing shear characteristics in forestland included root volume density, tensile strength, bulk density, and mean weight diameter of aggregates (MWD), whereas those at the orchard sites included root length density, tensile strength, and organic matter content. Root factors had a stronger impact on shear fracture energy than soil properties. Shear fracture energy equations were constructed for forestland and orchard sites, showing high R² and Nash–Sutcliffe efficiency values, indicating adequate predictive performance. These findings contribute to our understanding of the mechanical mechanisms of soils under vegetation restoration, provide scientific evidence for soil and water conservation evaluations, and help optimize vegetation restoration strategies in the Southern Red Soil Region. Full article

(This article belongs to the Special Issue Comprehensive Impacts of Agrobiodiversity in Agricultural Ecosystems)

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24 pages, 18034 KB

Open AccessArticle

Effects of Nitrogen, Phosphorus and Potassium Fertilization on Cotton Yield and Fertilizer Use Efficiency in Xinjiang, China

by Jinbo Gong, Songrui Ning, Jian Huang, Mingyao Tang, Keke Jia and Jingao Dong

Agronomy 2026, 16(14), 1387; https://doi.org/10.3390/agronomy16141387 - 21 Jul 2026

Viewed by 362

Abstract

Nitrogen (N), phosphorus (P), and potassium (K) are important nutrients limiting cotton yield. Although N, P, and K fertilization is an important practice for improving cotton productivity, their fertilizer use efficiencies remain insufficiently evaluated in Xinjiang, China. In this study, field experiments were [...] Read more.

Nitrogen (N), phosphorus (P), and potassium (K) are important nutrients limiting cotton yield. Although N, P, and K fertilization is an important practice for improving cotton productivity, their fertilizer use efficiencies remain insufficiently evaluated in Xinjiang, China. In this study, field experiments were conducted at 57 sites across the major cotton-growing areas of Xinjiang during 2021–2022. Four fertilization treatments, PK, NK, NP, and NPK, were established to evaluate cotton yield response, nutrient accumulation, and fertilizer use efficiencies of N, P, and K under different soil fertility conditions. The results indicated that the cotton yield in both southern and northern Xinjiang significantly increased under NPK treatment, with mean yields of 6300 and 7361 kg ha⁻¹, respectively. The use efficiencies of N, P, and K were 39.8%, 19.5%, and 51.4% in southern Xinjiang, and 40.3%, 20.2%, and 66.1% in northern Xinjiang, respectively. For every 100 kg of seed cotton produced, nutrient uptake was 4.64 kg N, 1.43 kg P₂O₅, and 3.67 kg K₂O in southern Xinjiang, and 4.74 kg N, 1.48 kg P₂O₅, and 4.58 kg K₂O in northern Xinjiang, indicating relatively high N and K requirements but lower P demand in cotton production. Cotton yield in southern Xinjiang was significantly and positively correlated with soil alkali-hydrolyzable N. In northern Xinjiang, cotton yield was significantly and positively correlated with soil organic matter, alkali-hydrolyzable N, and available K, but negatively correlated with available P. Overall, cotton yield was mainly positively affected by soil organic matter, alkali-hydrolyzable N, and available K, whereas K use efficiency was significantly and negatively correlated with N and K rates. The suitable N, P, and K rates for cotton were 285, 120, and 106 kg ha⁻¹ in southern Xinjiang, and 243, 101, and 91 kg ha⁻¹ in northern Xinjiang, respectively. Based on soil fertility classification of cotton fields, the recommended N, P, and K rates were 256–313, 96–117, and 125–153 kg ha⁻¹ in southern Xinjiang, and 219–267, 97–119, and 136–166 kg ha⁻¹ in northern Xinjiang, respectively. Accordingly, reducing N and P inputs in southern Xinjiang, maintaining N and P at appropriate levels in northern Xinjiang, and moderately increasing K are recommended to achieve coordinated improvements in yield stability and N, P, and K use efficiencies. Full article

(This article belongs to the Special Issue Effects of Arable Farming Measures on Soil Quality—2nd Edition)

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15 pages, 746 KB

Open AccessArticle

Grain Yield and Nitrogen Use Efficiency Responses of Indica-Japonica Hybrid Rice to Reduced Nitrogen Application and Increased Planting Density

by Chengyong Li, Qiqiao Yu, Yun Li, Chongyang Ye, Rongyi Zhu, Zhenghao Tang, Honghang Wang and Xiaomin Wang

Agronomy 2026, 16(14), 1386; https://doi.org/10.3390/agronomy16141386 - 21 Jul 2026

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Abstract

Balancing high grain yield with improved nitrogen use efficiency is a critical challenge in intensive rice production systems. Although both nitrogen application rate and planting density are recognized as major determinants of yield, their synergistic physiological mechanisms, particularly in large-panicle Indica–Japonica [...] Read more.

Balancing high grain yield with improved nitrogen use efficiency is a critical challenge in intensive rice production systems. Although both nitrogen application rate and planting density are recognized as major determinants of yield, their synergistic physiological mechanisms, particularly in large-panicle Indica–Japonica hybrid rice, remain insufficiently understood. A two-year (2023–2024) split-plot field experiment was conducted using the high-yield cultivar Yongyou 7860. Treatments included five nitrogen application rates (N0: 0; N12: 180; N14: 224; N16: 240; N20: 300 kg ha⁻¹) and three planting densities (D1: 220,000; D2: 190,000; D3: 160,000 plants ha⁻¹). Grain yield, yield components, canopy chlorophyll status (SPAD value), dry matter accumulation, partial factor productivity of nitrogen, and activities of glutamine synthetase (GS) and glutamate synthase (GOGAT) at critical growth stages were determined. Nitrogen rate and planting density exhibited significant interactive effects on grain yield and nitrogen use efficiency. Grain yield increased with nitrogen application rate but showed a quadratic response to planting density, with an optimum at the medium density. The N16D2 treatment consistently achieved 11.3–11.8 t/ha over two years, exceeding conventional practices by 1.7–9.7%, primarily attributed to a 6.3–11.5% increase in the number of effective panicles. Physiologically, N16D2 sustained higher SPAD values and dry matter accumulation comparable to excessive nitrogen input, while enhancing the partial factor productivity of nitrogen by 33.0% relative to N20D3. Enhanced activities of GS and GOGAT under N16D2 indicated improved nitrogen assimilation capacity. In summary, reduced nitrogen application coordinated with increased planting density optimizes canopy structure, promotes efficient nitrogen metabolism, and sustains high grain yield in Indica–Japonica hybrid rice. This study provides a scientifically grounded and practically applicable strategy for achieving high productivity with improved nitrogen use efficiency in intensive rice systems. Full article

(This article belongs to the Section Soil and Plant Nutrition)

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16 pages, 3191 KB

Open AccessArticle

Effects of Photovoltaic-Associated Microsite Heterogeneity on Soil Bacterial Community Structure in a Grassland

by Yiran Zhao, Liping Gong, Lin Chen, Zhenjian Bai, Haixian Li, Shanmin Qu and Mingjun Wang

Agronomy 2026, 16(14), 1385; https://doi.org/10.3390/agronomy16141385 - 21 Jul 2026

Viewed by 359

Abstract

As solar photovoltaic (PV) infrastructure expands across open landscapes, understanding its belowground effects in grassland ecosystems is important for sustainable solar development. PV panels can create spatially heterogeneous microsites by altering light availability, precipitation redistribution, and soil environmental conditions, but their effects on [...] Read more.

As solar photovoltaic (PV) infrastructure expands across open landscapes, understanding its belowground effects in grassland ecosystems is important for sustainable solar development. PV panels can create spatially heterogeneous microsites by altering light availability, precipitation redistribution, and soil environmental conditions, but their effects on soil bacterial community structure remain insufficiently understood. Here, we investigated soil physicochemical properties and bacterial communities across four PV-associated microsites: undisturbed grassland outside the PV array (Control), the front edge of the panel (FE), beneath the center of the panel (BP), and the uncovered interspace between adjacent panel rows (IS). Soil bacterial communities were characterized using 16S rRNA gene sequencing. Most measured soil physicochemical properties did not differ significantly among microsites. Available potassium was the only variable showing an overall microsite effect and was significantly lower in FE and BP than in the Control. Shannon index and Chao1 richness did not differ significantly among microsites. In contrast, Bray–Curtis-based principal coordinate analysis (PCoA) showed that FE samples occupied a relatively distinct ordination position, whereas Control, BP, and IS samples partially overlapped; permutational multivariate analysis of variance (PERMANOVA) indicated a significant overall difference in bacterial community composition among microsites. At the phylum level, no dominant bacterial phylum differed significantly among microsites after false discovery rate (FDR) correction. Redundancy analysis (RDA) indicated that alkali-hydrolyzable nitrogen and available potassium were the measured soil variables most closely associated with bacterial community composition at the operational taxonomic unit level in the final model. Together, these results indicate that differences among PV-associated microsites were detected in overall bacterial community composition but not in Shannon index or Chao1 richness. Alpha-diversity and community-composition analyses therefore provide complementary information for evaluating belowground bacterial responses to PV development in grasslands. Full article

(This article belongs to the Section Grassland and Pasture Science)

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19 pages, 1764 KB

Open AccessArticle

Plant Growth and Development, Yield and Reproductive Quality of Seeds in Fagopyrum tataricum (L.) Gaertn. Differ Depending on Foliar Silicon Addition in a Three-Year Experiment

by Jacek Kwiatkowski and Mateja Germ

Agronomy 2026, 16(14), 1384; https://doi.org/10.3390/agronomy16141384 - 21 Jul 2026

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Abstract

Tartary buckwheat is the second most economically important species of the genus Fagopyrum for human nutrition. It has higher nutritional and nutraceutical value than common buckwheat. Tartary buckwheat is considered a species that is well adapted to adverse conditions such as drought, cold [...] Read more.

Tartary buckwheat is the second most economically important species of the genus Fagopyrum for human nutrition. It has higher nutritional and nutraceutical value than common buckwheat. Tartary buckwheat is considered a species that is well adapted to adverse conditions such as drought, cold and aluminum toxicity. Despite its high stress tolerance, the yield of Tartary buckwheat varies considerably from year to year. The present study was conducted to assess the effect of silicon application on the growth, development, yield, and seed reproductive quality of Tartary buckwheat cultivated in northeastern Poland from 2022 to 2024. The experiment included three genotypes of Tartary buckwheat (of Chinese, Slovenian, and Polish weedy origin). The silicon biostimulant was applied as three foliar sprays at 250 g ha⁻¹ each, at 21-day intervals starting from the three-leaf-unfolded stage (BBCH 13). The use of silicon resulted in a 29% increase in the air-dry mass per plant, an increase in the number of inflorescences and seeds per plant, an increase in the bulk density of achenes, and a reduction in the mean germination time (MGT) of a single seed. The biostimulant did not affect the average yield of achenes or their germination. The main factors that strongly differentiated the plant characteristics and yield of Tartary buckwheat were weather conditions across years of the study and Tartary buckwheat genotypes. Full article

(This article belongs to the Section Soil and Plant Nutrition)

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24 pages, 3977 KB

Open AccessArticle

Organic Almond Cultivation Under Deficit Irrigation: Ecophysio-Logical Response and Cultivar-Driven Performance

by Abel Calderón-Pavón, Juan Francisco Herencia-Galán, Belén Cárceles Rodríguez, Víctor Hugo Durán-Zuazo, Alfredo E. Rubio-Casal, Juan Carlos Castro-García and Iván Francisco García-Tejero

Agronomy 2026, 16(14), 1383; https://doi.org/10.3390/agronomy16141383 - 21 Jul 2026

Viewed by 626

Abstract

Organic production systems (OPSs) for almond crops are rapidly expanding in Mediterranean regions due to the crops’ high adaptation to water-limited conditions and the environmental and economic benefits associated with these farming strategies. However, the response of almond trees to regulated deficit irrigation [...] Read more.

Organic production systems (OPSs) for almond crops are rapidly expanding in Mediterranean regions due to the crops’ high adaptation to water-limited conditions and the environmental and economic benefits associated with these farming strategies. However, the response of almond trees to regulated deficit irrigation (RDI) under OPS remains insufficiently understood. Unlike conventional orchards, organic farming operates under stricter limitations regarding nutrient management and the control of pests and diseases, factors that may modify crop resilience and alter the physiological and productive responses to water deficit. Consequently, it remains unclear how ecophysiological adjustments under organic management translate into yield performance and water productivity, and which cultivars are best adapted to these production conditions. This study evaluated the combined effects of irrigation regime (full irrigation (FI) and RDI), soil management (mulching cover (MC) and incorporated cover (IC)), and cultivar (Guara, Marta, Lauranne, and Marcona) on almond physiology and productivity over two consecutive growing seasons (2024–2025) in a Mediterranean environment. Net photosynthesis (A_n), stomatal conductance (g_sw), transpiration (E), intercellular CO₂ concentration (C_i), and stem water potential (Ψ_stem) were monitored throughout key phenological stages, together with yield components. According to our findings, the phenological stage was the main driver of physiological variability, followed by irrigation doses, whereas cover crop management had negligible effects. The RDI significantly affected Ψ_stem and E, but not A_n, indicating that the imposed water deficit did not severely constrain the photosynthetic machinery. As a consequence, yield response was largely insensitive to the imposed treatments, the cultivar being the dominant factor in terms of production, with cvs. Marta and Lauranne showing, on average, the highest and most stable kernel yields (1092 and 1164 kg ha⁻¹, respectively) in comparison to Guara (600 kg ha⁻¹) and Marcona (442 kg ha⁻¹). Overall, the results indicate a partial decoupling between physiological responses and yield performance, suggesting that almond productivity under RDI in OPS is primarily governed by genotype rather than by short-term physiological adjustments, supporting the viability of RDI strategies in with water savings of up to 45% without substantial yield penalties under Mediterranean conditions. Full article

(This article belongs to the Special Issue Optimizing Crop Water Use: Advances and Applications in Deficit Irrigation Strategies—2nd Edition)

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12 pages, 3905 KB

Open AccessArticle

Ovule Longevity Determines the Fruit Set and Effective Pollination Period in Sweet Cherry Cultivars Under Mediterranean Climate Conditions

by Mira Radunić, Anamarija Jazbec and Smiljana Goreta Ban

Agronomy 2026, 16(14), 1382; https://doi.org/10.3390/agronomy16141382 - 21 Jul 2026

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Abstract

The effective pollination period (EPP) is a key factor determining fruit set in sweet cherry, as it depends on the overlap between pollen tube growth and ovule longevity. This study investigated the duration and components of the EPP in three autochthonous cultivars (‘Stonska’, [...] Read more.

The effective pollination period (EPP) is a key factor determining fruit set in sweet cherry, as it depends on the overlap between pollen tube growth and ovule longevity. This study investigated the duration and components of the EPP in three autochthonous cultivars (‘Stonska’, ‘Gomilička’, and ‘Tugarka’) grown in the Mediterranean region of Croatia over two consecutive flowering seasons. The EPP was determined under field conditions using sequential hand pollinations, while stigma receptivity, pollen tube growth, and ovule viability were assessed by fluorescence microscopy. Significant genotypic and seasonal variation in EPP and fruit set was observed. ‘Stonska’ and ‘Gomilička’ exhibited extended EPPs (9 and 11 days) and moderate to high fruit set. In contrast, ‘Tugarka’ showed a considerably shorter EPP (4–5 days) and consistently low fruit set (<10%). Stigma receptivity and pollen tube growth were not limiting factors for fertilization. However, rapid ovule degeneration in ‘Tugarka’, particularly under elevated temperatures during flowering, reduced the overlap between pollen tube arrival and ovule viability. These results indicated that ovule longevity plays a major role in determining fruit set and EPP under Mediterranean conditions. The study highlights genotypic differences in temperature sensitivity and provides insight into the potential impact of rising spring temperatures on sweet cherry production. Full article

(This article belongs to the Special Issue Impact of Climate Variability on Horticultural Plant Growth and the Development of Agriculture)

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20 pages, 33978 KB

Open AccessArticle

Germination Differences Between Clodinafop-Propargyl-Resistant and -Susceptible Alopecurus japonicus Steud. Populations Under Multiple Abiotic Stresses

by Rui Cheng, Xiaoshen Song, Lilei Zhang, Weitang Liu, Zhiwen Wu and Yaling Bi

Agronomy 2026, 16(14), 1381; https://doi.org/10.3390/agronomy16141381 - 21 Jul 2026

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Abstract

Clodinafop-propargyl-resistant Alopecurus japonicus Steud. has severely threatened wheat production, while its fitness and stress adaptability have not been systematically clarified. This study compared seed germination and seedling emergence of resistant AHHN-6 and susceptible HNLH-1 under multiple abiotic stress treatments including temperature, pH, water [...] Read more.

Clodinafop-propargyl-resistant Alopecurus japonicus Steud. has severely threatened wheat production, while its fitness and stress adaptability have not been systematically clarified. This study compared seed germination and seedling emergence of resistant AHHN-6 and susceptible HNLH-1 under multiple abiotic stress treatments including temperature, pH, water potential, soil moisture, salt and burial depth. Both biotypes exhibited >95% germination under optimal temperature and moisture conditions, indicating the highly resistant biotype AHHN-6 bears no germination-related fitness cost; however, fitness costs were detected in several other resistant populations across the sampling regions. The resistant population displayed markedly higher tolerance to adverse conditions: its 50% inhibitory water potential and salt concentration were −0.43 MPa and 124.22 mmol·L⁻¹ versus −0.35 MPa and 56.25 mmol·L⁻¹ for the susceptible population, and it could emerge normally from deeper soil layers. Collectively, resistance to clodinafop-propargyl does not reduce performance under benign environments but confers enhanced abiotic stress resistance, promoting the long-term survival and spread of resistant A. japonicus in farmlands. Full article

(This article belongs to the Section Weed Science and Weed Management)

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20 pages, 8473 KB

Open AccessArticle

Site-Specific Efficacy of Microbial Inoculants on Sunflower Development and Soil Metabolic Activity in Open-Field Trials

by Andrea Tímea Gergelyné Tóth, Lívia László and Katalin Posta

Agronomy 2026, 16(14), 1380; https://doi.org/10.3390/agronomy16141380 - 20 Jul 2026

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Abstract

Modern agriculture faces critical challenges, including climate change, soil degradation, and reliance on synthetic inputs, necessitating sustainable alternatives. A promising approach is applying microbial solutions. This study investigated the effects of a commercially available powder-formulated seed coating product containing Rhizoglomus irregularis and Azospirillum [...] Read more.

Modern agriculture faces critical challenges, including climate change, soil degradation, and reliance on synthetic inputs, necessitating sustainable alternatives. A promising approach is applying microbial solutions. This study investigated the effects of a commercially available powder-formulated seed coating product containing Rhizoglomus irregularis and Azospirillum spp. on high-linoleic sunflower (Helianthus annuus L.) under field conditions at three Hungarian sites with contrasting soil properties. Plant growth parameters, yield, and the rhizosphere’s microbial carbon-source utilisation potential were assessed to evaluate treatment effects. Seed-applied inoculation increased plant height, stem diameter, and biomass, although responses varied with site conditions and sampling time. The agronomic response was highly site-dependent: the strongest effect was observed at a low-pH, phosphorus-limited site, where seed inoculation achieved a significant yield increase of 18–21%, while effects at sites with higher pH and sufficient phosphorus resulted only in minor, statistically non-significant numerical trends. Distinct shifts in culture-dependent carbon-source utilisation potential were detected by Biolog EcoPlate™ analysis, showing temporal and site-specific variability. These results indicate that seed-applied formulations offer a logistically feasible, targeted delivery method for plant-beneficial microbes, with their agronomic efficacy fundamentally governed by site-specific soil chemical profiles and baseline nutrient availability. Overall, the agronomic benefits of inoculation appear to be context-dependent and more pronounced under nutrient-limited conditions, highlighting the critical importance of site-specific application strategies and the need for further long-term studies. Full article

(This article belongs to the Section Horticultural and Floricultural Crops)

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22 pages, 18514 KB

Open AccessArticle

Dissecting the “Black Box” of Agricultural Green Total Factor Productivity: An Analysis Using a Network SBM Model Based on Eight Consecutive Years of Soil Data

by Anlong Jiang, Mengchun Zhang, Yunze Gong, Wenchao Li, Aijun Zhang and Hong J. Di

Agronomy 2026, 16(14), 1379; https://doi.org/10.3390/agronomy16141379 - 20 Jul 2026

Viewed by 554

Abstract

Agricultural green total factor productivity (AGTFP) is a key indicator for evaluating the level of green development in agriculture. However, conventional approaches to AGTFP measurement often treat intermediate agricultural production processes as a “black box”, overlooking internal system mechanisms and thus leading to [...] Read more.

Agricultural green total factor productivity (AGTFP) is a key indicator for evaluating the level of green development in agriculture. However, conventional approaches to AGTFP measurement often treat intermediate agricultural production processes as a “black box”, overlooking internal system mechanisms and thus leading to biased identification of efficiency bottlenecks. To address this limitation, this study introduces an analysis using a network slack-based measure (NSBM) model to move beyond the traditional single “input–output” transmission framework. By integrating soil sample data from 2017 to 2024, the agricultural production process is decomposed into three sequential stages—material inputs, nutrient transformation, and crop production—to evaluate AGTFP in Baoding, China. The results reveal that AGTFP in Baoding remains at a relatively low level overall, although a steady upward trend is observed over time. Specifically, overall efficiency increased by 18.18%, while the efficiency of converting agricultural inputs into soil nutrients (the input subsystem) improved by 36.13%. The input subsystem serves as the primary driver of AGTFP improvement, with a marginal contribution coefficient of 0.61% to overall efficiency (p < 0.01). Although the efficiency of transforming soil nutrients into agricultural output (the output subsystem) remains relatively high, its growth potential is constrained by biological limits. It is highly sensitive to external factors such as topography and natural disasters. At present, the key bottleneck to enhancing regional AGTFP is the low efficiency with which external inputs are converted into soil nutrients. These findings suggest that policy priorities should shift from simple input reduction to process-oriented management, with an emphasis on improving the conversion efficiency of external inputs into effective soil nutrients, thereby facilitating agricultural green transformation while mitigating non-point source pollution. Based on existing research frameworks, this study supplements and refines the original analytical framework by incorporating soil data from the agricultural production process, providing new empirical evidence for uncovering the “black box” of agricultural production. Full article

(This article belongs to the Section Soil and Plant Nutrition)

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20 pages, 6727 KB

Open AccessArticle

Optimized Sowing Date and Seeding Rate for Simultaneous Improvement of Yield and Quality of Late-Sown Winter Wheat in the Southern North China Plain

by Shuxian Li, Juan Han and Shiju Liu

Agronomy 2026, 16(14), 1378; https://doi.org/10.3390/agronomy16141378 - 20 Jul 2026

Viewed by 407

Abstract

Sowing date and seeding rate are key agronomic measures for regulating yield formation and quality accumulation in winter wheat, especially in the context of global warming, which has led to delayed sowing becoming the norm. Clearly identifying optimal combinations of sowing date and [...] Read more.

Sowing date and seeding rate are key agronomic measures for regulating yield formation and quality accumulation in winter wheat, especially in the context of global warming, which has led to delayed sowing becoming the norm. Clearly identifying optimal combinations of sowing date and seeding rate under late-sowing conditions is crucial for achieving coordinated improvement in both high yield and quality. Therefore, this study used the strong-gluten wheat cultivar ‘Shaannong 33’ and conducted a two-factor split-plot field experiment in the southern North China Plain (Nanyang, Henan) during 2019–2021. Three sowing dates (early sowing: 27 October; intermediate sowing: 31 October–2 November; late sowing: 6–8 November) and four seeding rates (180 × 10⁴, 240 × 10⁴, 300 × 10⁴, and 360 × 10⁴ plants ha⁻¹) were tested to systematically analyze the effects of sowing date and seeding rate on wheat yield and its components, grain processing quality, and starch physicochemical properties. The results showed that sowing from late October to early November (approximately 25 October to 2 November in 2019–2020 and 25 October to 31 October in 2020–2021) combined with a seeding rate of 240–300 × 10⁴ plants ha⁻¹ maintained yield at a comparably high level across both growing seasons while improving processing quality indicators such as protein content, wet gluten content, and dough stability time for the strong-gluten cultivar ‘Shaannong 33’. However, the optimal sowing window varied between years: in 2019–2020, both D1 (27 October) and D2 (2 November) produced comparable yields, whereas in 2020–2021, D2 (31 October) was superior for both yield and quality. This inter-annual variability highlights the influence of climatic conditions on the optimal sowing window. Further delaying the sowing date to after 6 November led to decreases in yield and quality parameters; however, increasing the seeding rate to 360 × 10⁴ plants ha⁻¹ partially compensated for yield loss. In addition, late sowing significantly increased amylopectin content, swelling power, and pasting indicators such as peak viscosity and final viscosity while decreasing amylose content and pasting temperature, which is beneficial for improving cooking and eating quality. Correlation analysis indicated that the amylose/amylopectin ratio was the core factor determining starch pasting properties, while protein content showed a significant negative correlation with starch pasting indicators, reflecting the resource competition effect between grain protein and starch. Yield differences between the two years were mainly driven by changes in spike number per unit area, while inter-annual climate fluctuations (especially precipitation and temperature) significantly affected spike formation capacity. Overall, sowing date and seeding rate have a synergistic regulatory effect on yield and quality of late-sown wheat for the strong-gluten cultivar ‘Shaannong 33’. It is recommended to adopt a sowing date of 25–31 October with the seeding rate controlled at 240–300 × 10⁴ plants ha⁻¹ to achieve synergistic improvement of yield and quality under late-sowing conditions in the southern North China Plain for this cultivar. Full article

(This article belongs to the Section Soil and Plant Nutrition)

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46 pages, 2120 KB

Open AccessArticle

Effects of an Ascophyllum nodosum-Based Biofertilizer Applied Through Different Application Methods on Growth, Yield and Nutritional Quality of Phaseolus vulgaris L. var. Opus Under a Controlled Aeroponic System

by Jessica Alejandra Araujo-Rodríguez, José Alfredo Padilla-Medina, Norma Verónica Ramírez-Pérez, Micael Gerardo Bravo-Sánchez, Juan José Martínez-Nolasco and Alejandro Israel Barranco-Gutiérrez

Agronomy 2026, 16(14), 1377; https://doi.org/10.3390/agronomy16141377 - 20 Jul 2026

Viewed by 863

Abstract

The study evaluated the effect of an Ascophyllum nodosum-based biofertilizer applied under three treatments: foliar (FA, 0.5 g/L every 15 days), root (RA, 0.5 g/L every 30 days), and combined (F&RA, 0.5 g/L, Foliar every 15 days and Root every 30 days) [...] Read more.

The study evaluated the effect of an Ascophyllum nodosum-based biofertilizer applied under three treatments: foliar (FA, 0.5 g/L every 15 days), root (RA, 0.5 g/L every 30 days), and combined (F&RA, 0.5 g/L, Foliar every 15 days and Root every 30 days) compared to a control (C) in aeroponic cultivation of Phaseolus vulgaris L. var. Opus. Environmental conditions were continuously monitored using an IoE-based system, ensuring consistent microclimatic characterization throughout the experimental period. A non-parametric statistical approach was applied due to non-normal data distribution. Most growth and yield variables did not show statistically significant differences; however, significant treatment effects were observed for leaf temperature, root temperature, calcium, iron, and manganese. Significant differences among treatments (α = 0.05) were identified using Kruskal–Wallis test for calcium (p = 0.0002), iron (p = 0.0067), and manganese (p = 0.0439), while other micronutrients showed no statistical differences. Descriptive statistics indicated moderate shifts in central tendency, particularly for calcium and iron, with higher values observed in the combined treatment (F&RA). Effect size analysis using Cliff’s delta (δ) revealed moderate to large differences for calcium, iron, and manganese, although these estimates were interpreted cautiously given the unequal replication among treatments. Spearman correlation analysis showed moderate to strong associations, although none were statistically significant (p > 0.05). Overall, results indicate limited effects of the biofertilizer on growth and yield variables but treatment-associated changes in selected nutritional components, suggesting element-dependent responses to biofertilizer application. Full article

(This article belongs to the Special Issue Intelligent Detection of Crop Growth Phenotyping Toward Sustainability: Sensors, IoT Technologies and Signal Processing)

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16 pages, 6605 KB

Open AccessArticle

Variety-Specific Residue Dynamics and Optimal Dose of Thiamethoxam for Borer Control and Harvest Safety in Sugarcane

by Yawei Luo, Cuifang Yang, Limin Liu, Shuquan Su, Shan Zhou, Yuxin Huang, Jing Liu, Shanyu Lu, Shanhai Lin and Yijing Gao

Agronomy 2026, 16(14), 1376; https://doi.org/10.3390/agronomy16141376 - 20 Jul 2026

Viewed by 387

Abstract

Although thiamethoxam is frequently used in sugarcane production in Guangxi, China as a systemic insecticide and bioactivator, little is known about its field control effectiveness and residue dissipation across commercially significant genotypes grown in the region. In this study, we have addressed this [...] Read more.

Although thiamethoxam is frequently used in sugarcane production in Guangxi, China as a systemic insecticide and bioactivator, little is known about its field control effectiveness and residue dissipation across commercially significant genotypes grown in the region. In this study, we have addressed this gap by assessing the residue dynamics and borer control effectiveness of thiamethoxam in three significant sugarcane types (GT 40, Haizhe 22, and ROC22). Three application doses (Low: 750 mL/hm²; Medium: 1500 mL/hm²; High: 2250 mL/hm²) were sprayed as a soil drench along with urea for field and greenhouse studies. Over the course of 75 days, residues in juice and leaf tissues were measured using LC-MS/MS, and stem borer damage and control effectiveness were recorded. Thiamethoxam residues in juice peaked at 45 days after treatment (DAT), with ROC22 exhibiting the highest concentration (11.07 mg/kg). All treated plots continued to have thiamethoxam residues above the Chinese maximum residue limit (MRL) of 0.3 mg/kg at 75 DAT, suggesting an inadequate pre-harvest interval. Leaf residues remained a long-term reservoir for more than 56 days and were an order of magnitude greater. While the low dose demonstrated increased efficacy over time, the medium and high doses produced statistically equal borer control (50–75% efficacy), exhibiting a saturation effect. There were notable varietal differences: Haizhe 22 achieved steady control with fewer residues, while ROC22 was most vulnerable and needed greater doses. These results demonstrate that a 75-day pre-harvest period is insufficient for consumer safety, requiring additional experiments for longer intervals for susceptible cultivars. The ideal economic threshold is determined to be the middle dose (1500 mL/hm²), which balances environmental load, chemical input, and efficacy. To enable precision application techniques suited to certain sugarcane genotypes, future research should concentrate on clarifying the genetic basis of varietal uptake discrepancies. Full article

(This article belongs to the Section Pest and Disease Management)

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16 pages, 14526 KB

Open AccessArticle

Effects of Strip Grass Cover on Runoff and Erosion Processes of Loess Slopes Under Simulated Erosive Rainfall

by Shuai Wang, Qiufen Zhang, Xizhi Lv, Zeyu Xu, Junqiang Xu, Yongxin Ni, Li Ma, Jianwei Wang and Hengshuo Zhang

Agronomy 2026, 16(14), 1375; https://doi.org/10.3390/agronomy16141375 - 20 Jul 2026

Viewed by 351

Abstract

Vegetation restoration is widely used to combat soil erosion on the Chinese Loess Plateau, where intense rainfall and steep slopes make this region one of the most eroded areas in the world. However, the effectiveness of strip grass cover (Vc) in [...] Read more.

Vegetation restoration is widely used to combat soil erosion on the Chinese Loess Plateau, where intense rainfall and steep slopes make this region one of the most eroded areas in the world. However, the effectiveness of strip grass cover (Vc) in reducing erosion under varying rainfall and topographic conditions remains insufficiently quantified. In this research, based on indoor simulated rainfall experiments in a soil tank, we investigated the erosion characteristics of slopes under six Vc levels (0%, 20%, 30%, 40%, 50%, and 60%), three rainfall intensities (RI) (1.33, 1.67, and 2.0 mm·min⁻¹), and four slope gradients (SG) (10°, 15°, 20°, and 25°), and quantified the effects of Vc on slope erosion processes. Runoff and sediment reduction effects by Vc ranged from 3.5% to 62.6% and from 15.2% to 99.1%, respectively. An exponential decay in erosion rate was observed with increasing Vc, whereas runoff velocity initially decreased and then increased as the Vc increased. By integrating RI, SG, and Vc, the average runoff rate and erosion rate models accurately simulate erosion processes on Vc slopes. These findings provide laboratory-based evidence that Vc substantially reduces slope erosion, and support the development of empirical models for predicting runoff and erosion under the tested conditions. Full article

(This article belongs to the Section Water Use and Irrigation)

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16 pages, 7894 KB

Open AccessArticle

Heterologous Expression of the Bean Chitinase Gene (ch5B) in Lettuce (Lactuca sativa L.) Confers Enhanced Tolerance to Rhizoctonia solani and Demonstrates Agronomic Substantial Equivalence in Field Trials

by Laura M. Radonic, Valeria Beracochea, Carla V. Filippi, Sebastián Moschen, Nilda López, H. Esteban Hopp and Marisa López Bilbao

Agronomy 2026, 16(14), 1374; https://doi.org/10.3390/agronomy16141374 - 20 Jul 2026

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Abstract

Fungal pathogens cause severe yield losses in lettuce production worldwide. We developed transgenic lettuce lines overexpressing the ch5B chitinase gene from Phaseolus vulgaris (bean) under the regulation of the rbcS1 (ribulose-1,5-bisphosphate carboxylase small subunit) promoter. Molecular characterization confirmed stable transgene integration and expression [...] Read more.

Fungal pathogens cause severe yield losses in lettuce production worldwide. We developed transgenic lettuce lines overexpressing the ch5B chitinase gene from Phaseolus vulgaris (bean) under the regulation of the rbcS1 (ribulose-1,5-bisphosphate carboxylase small subunit) promoter. Molecular characterization confirmed stable transgene integration and expression across the selected lines. In vitro assays demonstrated that transgenic leaf extracts significantly inhibited Rhizoctonia solani mycelial growth. Furthermore, inoculation assays in both seedlings and adult plants in the greenhouse showed a significant reduction in lesion areas compared to non-transgenic (NT) controls. Finally, two lines were evaluated in field trials, both showing agronomic substantial equivalence to the NT, satisfying international biosafety frameworks for commercial development. Among them, the ch5B 3-4 line appears to be the most promising candidate for further studies, as it showed slightly higher fresh weight compared to the NT under field conditions.: Full article

(This article belongs to the Section Pest and Disease Management)

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19 pages, 11954 KB

Open AccessArticle

Thickness-Dependent Effects of Fully Biodegradable PBAT Mulch Films on Peanut Growth and Soil Properties

by Ruixue Hu, Meiqi Huang, Aizhen Jiang, Haiying Zong, Jun Liu, Fangli Wang, Xiaoli Huang, Jimin Guo, Ningning Song and Xuexia Wang

Agronomy 2026, 16(14), 1373; https://doi.org/10.3390/agronomy16141373 - 20 Jul 2026

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Abstract

This study investigated the effects of fully biodegradable poly(butylene adipate-co-terephthalate) (PBAT) mulch films with different thicknesses on soil hydrothermal conditions, soil fertility indicators, soil enzyme activities, and peanut growth and yield in a three-year field experiment. Three PBAT thicknesses (0.006, 0.008, and 0.010 [...] Read more.

This study investigated the effects of fully biodegradable poly(butylene adipate-co-terephthalate) (PBAT) mulch films with different thicknesses on soil hydrothermal conditions, soil fertility indicators, soil enzyme activities, and peanut growth and yield in a three-year field experiment. Three PBAT thicknesses (0.006, 0.008, and 0.010 mm) were compared with 0.010 mm polyethylene (PE) mulch and a bare soil control (CK). The effects of PBAT mulch films with different thicknesses on peanut yield, agronomic traits, photosynthetic characteristics, soil fertility indicators, and soil enzyme activities were systematically evaluated. PBAT008 showed the most favorable overall balance among the tested treatments. Compared with PE, PBAT008 significantly increased pod yield by 6.87–13.69% and 100-pod weight by 10.36–18.94%, whereas PE tended to reduce pod yield by 5.55–5.95% relative to CK. PBAT008 also promoted biomass accumulation and increased photosynthetic pigment content. Although PE showed the strongest water-retention capacity, PBAT008 maintained moderate soil moisture and suitable soil temperatures during pod formation. PBAT treatments improved soil organic matter, dissolved organic carbon, available phosphorus, and soil enzyme activities more effectively than PE. Path analysis identified available phosphorus, stem weight, and soil temperature as the strongest positive drivers of pod yield. Overall, PBAT008 enhanced peanut yield by achieving a coordinated improvement in soil hydrothermal conditions, soil fertility, and crop physiological performance, suggesting that an appropriate PBAT mulch thickness may provide an agronomically viable biodegradable alternative to PE mulch in peanut production. Full article

(This article belongs to the Special Issue Innovative Agricultural Inputs and Soil–Plant–Microbe Interactions for Sustainable Agronomy)

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20 pages, 5577 KB

Open AccessArticle

Germination Responses of Proso Millet (Panicum miliaceum L.) to Different 2,4-Epibrassinolide Priming Concentrations Under Drought Stress

by Dandan Qiao, Jiuxin Zhang, Ying Wang and Xueqing He

Agronomy 2026, 16(14), 1372; https://doi.org/10.3390/agronomy16141372 - 20 Jul 2026

Viewed by 391

Abstract

Chemical regulators play an important role in alleviating abiotic stress during seed germination and early seedling establishment, providing a low-cost and effective solution for crop production under stress conditions. The seed germination stage is critical for crop establishment under drought stress. Proso millet [...] Read more.

Chemical regulators play an important role in alleviating abiotic stress during seed germination and early seedling establishment, providing a low-cost and effective solution for crop production under stress conditions. The seed germination stage is critical for crop establishment under drought stress. Proso millet (Panicum miliaceum L.) is relatively drought-tolerant during later growth stages but remains sensitive during seed germination and early seedling establishment. In this study, two P. miliaceum varieties (‘Yumi 2’ and ‘Yumi 5’) were used as materials. Seeds were soaked with 2,4-epibrassinolide (EBR) at concentrations of 0, 0.01, 0.1, 0.5, and 1 μmol·L⁻¹, and then germinated under polyethylene glycol (PEG-6000) solutions at 0%, 15%, and 20% (w/v) to simulate drought stress. Drought stress progressively reduced seed germination potential, germination percentage, germination index, and vigor index, while increasing mean germination time and decreasing germination synchrony. EBR soaking, particularly at 0.01 μmol·L⁻¹, consistently alleviated the above inhibitory effects. Under 20% PEG stress, 0.01 μmol·L⁻¹ EBR increased the germination potential of ‘Yumi 5’ to 82% and significantly improved the germination percentage of both varieties. Compared with the control, low concentrations of EBR (0.01 and 0.1 μmol·L⁻¹) increased the germination synchrony of ‘Yumi 2’ by up to 89.5% and 93.6%. Under 20% PEG stress, the germination synchrony of ‘Yumi 2’ treated with 0.01 μmol·L⁻¹ EBR was 54.7% higher than that of the control. EBR treatment increased α-amylase activity, with the highest activity observed at 0.01 μmol·L⁻¹ under non-stress conditions, and it maintained relatively high activity under drought stress, especially in ‘Yumi 5’. The two varieties exhibited genotype-dependent response differences: ‘Yumi 5’ responded to a wider range of EBR concentrations under drought stress, whereas ‘Yumi 2’ showed a selective response. Soaking seeds with 0.01 μmol·L⁻¹ EBR is a promising pre-sowing treatment strategy for improving seedling establishment of P. miliaceum under drought-prone conditions. In summary, this study provides a low-cost and easily applicable hormone soaking method that can be directly used to enhance the early drought tolerance of cereal crops. Furthermore, this strategy may offer practical guidance for improving seedling techniques in medicinal plants facing similar drought stress during propagation, thereby supporting sustainable agricultural production in water-deficient regions. Full article

(This article belongs to the Section Plant-Crop Biology and Biochemistry)

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15 pages, 2462 KB

Open AccessArticle

Evaluation of Seeding Rate on Ratoon Yield in Drill-Seeded Delayed Flood Rice Cultivation

by Manoch Kongchum, Jacob Fluitt, James Leonards and Dustin Harrell

Agronomy 2026, 16(14), 1371; https://doi.org/10.3390/agronomy16141371 - 20 Jul 2026

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Abstract

Rice ratooning is a widely adopted practice in southwest Louisiana because it allows production of an additional crop from the existing rice stand with relatively low input requirements. Although ratoon-crop yield is generally lower than main crop yield, the additional harvest can improve [...] Read more.

Rice ratooning is a widely adopted practice in southwest Louisiana because it allows production of an additional crop from the existing rice stand with relatively low input requirements. Although ratoon-crop yield is generally lower than main crop yield, the additional harvest can improve overall system productivity and profitability due to reduced establishment and production costs. This study evaluated the effect of seeding rates on ratoon yield using data collected from 2016 to 2021 across nine seeding rates ranging from 13.0 to 104.3 kg ha⁻¹, 18 rice varieties, and 37 trials. Linear mixed-effects models were used with seeding rate and plant density as fixed effects and year and variety as random effects. Ratoon yield increased significantly with seeding rate (R = 0.285, p < 0.001), with an estimated gain of 7.48 kg ha⁻¹ for each 1 kg ha⁻¹ increase in seeding rate. The estimated optimum seeding rate was 72 kg ha⁻¹; however, ratoon yield responses remained relatively broad near the optimum. Therefore, a practical seeding rate range of 50–80 kg ha⁻¹ is recommended to maximize ratoon yield while accounting for environmental and varietal variability. Main crop yield was not correlated with ratoon yield (R = −0.044). Variance component analysis showed that year and variety contributed substantially to overall yield variability. These results indicate that ratoon yield is significantly influenced by seeding rates, with moderate to high seeding rates supporting greater ratoon productivity, while environmental and genetic factors also play important roles. Full article

(This article belongs to the Section Soil and Plant Nutrition)

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17 pages, 2146 KB

Open AccessArticle

Improving Out-of-Distribution Robustness for Wheat Head Detection: A Lightweight Modified YOLOv13 Approach

by Peng Hui, Liyuan Zhang and Qingzhen Zhu

Agronomy 2026, 16(14), 1370; https://doi.org/10.3390/agronomy16141370 - 20 Jul 2026

Viewed by 356

Abstract

Wheat head detection is a critical component in high-throughput phenotyping, holding significant application value for wheat yield estimation and breeding analysis. With the continuous advancement of general object detection models, state-of-the-art detectors achieve high accuracy in same-distribution wheat head detection scenarios. However, when [...] Read more.

Wheat head detection is a critical component in high-throughput phenotyping, holding significant application value for wheat yield estimation and breeding analysis. With the continuous advancement of general object detection models, state-of-the-art detectors achieve high accuracy in same-distribution wheat head detection scenarios. However, when applied to cross-distribution environments, their performance often degrades significantly. To investigate this issue, this paper adopts the official division of the GWHD2021 public dataset as the cross-distribution evaluation setting. Using the recently state-of-the-art object detection model YOLOv13 as the baseline, we systematically explore effective approaches to enhance cross-distribution generalization performance in wheat head detection. Specifically, we propose two lightweight modifications to YOLOv13’s Full-PAD architecture and HyperACE’s core modules, analyzing their potential mechanisms: (1) Replacing scalar gating in Full-PAD with channel-level gating enables finer-grained branch injection control. Concurrently, channel-level gating introduces equivalent stronger weight penalties during training, generating additional regularization effects. Through exploratory controlled experiments aligning weight-penalty strengths, we find that this gain depends on both channel decoupling and the accompanying implicit regularization rather than on decoupling alone. (2) Removing Batch Normalization from HyperACE’s core C3AH modules and adopting normalization strategies independent of batch statistics—such as Identity, Group Normalization, or Instance Normalization. Preliminary experiments show that while this results in a small, directionally positive change, the change remains within run-to-run variance; we therefore do not claim BN removal as a reliable standalone improvement. Furthermore, combining channel gating with BN removal does not yield further additive improvements compared to channel gating alone, indicating an interaction effect. To address this, we analyze relevant statistics between channel gating and HyperACE branches, providing an exploratory explanation for this non-additive phenomenon. In summary, this paper delivers empirical evidence and preliminary insights for enhancing generalization performance in the cross-distribution wheat head detection task of the advanced general-purpose detection model YOLOv13. Full article

(This article belongs to the Collection AI, Sensors and Robotics for Smart Agriculture)

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25 pages, 10209 KB

Open AccessArticle

Light-FCCNet: A Compact Multi-Scale Framework for Accurate Field Crop Counting

by Yuxiang Liu, Rongyue Wei and Fuquan Zhang

Agronomy 2026, 16(14), 1369; https://doi.org/10.3390/agronomy16141369 - 19 Jul 2026

Viewed by 328

Abstract

Accurate field crop counting supports phenotyping, crop monitoring, and yield-related analysis, but real field images often contain scale variation, target overlap, cluttered vegetation, shadows, and visually similar backgrounds. These factors make density-map regression difficult because weak target responses and accumulated false responses in [...] Read more.

Accurate field crop counting supports phenotyping, crop monitoring, and yield-related analysis, but real field images often contain scale variation, target overlap, cluttered vegetation, shadows, and visually similar backgrounds. These factors make density-map regression difficult because weak target responses and accumulated false responses in non-target regions can both bias the final count. This study proposes Light-FCCNet, a compact multi-scale framework for accurate field crop counting under a limited parameter budget. The framework integrates three coordinated components: a lightweight feature pyramid aggregation module for compact scale-aware representation, a multi-attention fusion module for refining fused features and suppressing background-induced responses, and an FCC loss that combines pixel-level density regression, count consistency, and structural similarity. Light-FCCNet is evaluated on three public field crop counting datasets, namely GWHD, MTC, and URC. In the canonical ablation trajectory consisting of baseline, baseline_p1, baseline_p1_p2, and full configurations, the full model achieves the lowest errors, with MAE values of 13.28 on GWHD, 18.10 on MTC, and 61.23 on URC, corresponding to reductions of 18.0%, 25.3%, and 35.2% relative to the baseline. Compared with representative general counting baselines and our implementation of TasselNetV2++ under the same experimental protocol, Light-FCCNet obtains the lowest MAE on all three datasets while using only 0.92 M parameters. These results indicate that its advantage comes from the coordinated design of compact pyramid aggregation, attention-guided feature refinement, and counting-oriented supervision, rather than from any isolated module alone. Full article

(This article belongs to the Collection AI, Sensors and Robotics for Smart Agriculture)

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23 pages, 5340 KB

Open AccessArticle

Multi-Omics Characterization of Temporal Microbial and Metabolic Dynamics During Solid-State Fermentation of Mulberry Branch Residue

by Feng Qian, Delong Guan, Qiuxia Lao, Xiao-Yan Zhang, Fuzhi Lu and Jing Song

Agronomy 2026, 16(14), 1368; https://doi.org/10.3390/agronomy16141368 - 19 Jul 2026

Viewed by 411

Abstract

The microbial fermentation of mulberry branch residues offers a potential strategy for sustainable lignocellulosic biomass valorization. This study integrated 16S rRNA gene sequencing and untargeted LC–MS metabolomics to characterize temporal microbial and metabolic changes during a 12-day solid-state fermentation at 35 °C using [...] Read more.

The microbial fermentation of mulberry branch residues offers a potential strategy for sustainable lignocellulosic biomass valorization. This study integrated 16S rRNA gene sequencing and untargeted LC–MS metabolomics to characterize temporal microbial and metabolic changes during a 12-day solid-state fermentation at 35 °C using a defined consortium of lactic acid bacteria, Bacillus subtilis, and Saccharomyces cerevisiae. Microbial community analysis revealed distinct temporal succession, with Bacillus accounting for 19.5% of the bacterial community during early fermentation, followed by increasingly diverse assemblages. Exploratory machine learning analysis ranked Azotobacter and Kyrpidia among the genera contributing most strongly to temporal differentiation. FAPROTAX-based predictions indicated that chemoheterotrophy-related functions remained prevalent across fermentation stages, although these predictions do not represent direct functional activity. Untargeted metabolomics detected 2782 putatively annotated features, dominated by lipids (15.1%), organic acids (13.8%), and phenylpropanoids (13.2%). Correlation analysis identified temporal associations between bacterial genera and metabolite classes, including associations of Geobacillus with alkaloids and glycerophospholipids. Exploratory OPLS-DA further highlighted pseudouridine and 3-methylxanthine as discriminatory features across fermentation stages. These findings provide a descriptive multi-omics overview of microbial succession and metabolic variation during mulberry branch residue fermentation. Full article

(This article belongs to the Special Issue Agricultural Biomass Waste Conversion into Value-Added Products—2nd Edition)

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21 pages, 2058 KB

Open AccessArticle

Proline Raises Maize Yield Under Low Temperature by Regulating Photosynthesis, Leaf Senescence and Nitrogen Metabolism

by Shiyu Zuo, Xiaofeng Hu, Xin Zhou, Lei Sun, Bianbin Qi, Yuetao Zuo, Zirui He and Jing Li

Agronomy 2026, 16(14), 1367; https://doi.org/10.3390/agronomy16141367 - 18 Jul 2026

Viewed by 392

Abstract

Maize (Zea mays L.) is a global staple crop for food, feed and industrial use in China. As a thermophilic crop, its seedlings suffer from cold stress. Heilongjiang, China’s major maize producer, faces worsening early cold that impedes germination and seedling growth, [...] Read more.

Maize (Zea mays L.) is a global staple crop for food, feed and industrial use in China. As a thermophilic crop, its seedlings suffer from cold stress. Heilongjiang, China’s major maize producer, faces worsening early cold that impedes germination and seedling growth, causing heavy yield losses. Improving germination cold tolerance stabilizes yields. Ubiquitous proline (Pro) works as a key osmoprotectant and core stress-resistance regulator in plants. In this field experiment, the maize cultivar Damin 3307 was used to explore the effects and regulatory mechanisms of Pro seed soaking on low-temperature-stressed maize. We analyzed seedling emergence, plant growth, photosynthetic performance, nitrogen metabolism, dry matter accumulation, ear traits and grain yield of treated maize under low temperature. The results showed that seed soaking with 15 mmol·L⁻¹ Pro effectively improved the seedling emergence rate of early-sown maize under low temperature and compensated for cold-induced population decline. It significantly increased plant height at the seedling and jointing stages, which enhanced vegetative growth. Exogenous Pro regulated the activities of key nitrogen metabolism enzymes, including NR, GS, GOGAT, GDH, GOT and GPT, alleviating low-temperature-induced nitrogen metabolism inhibition and accelerating ammonia assimilation as well as protein and amino acid synthesis to promote maize growth. Additionally, Pro soaking mitigated the cold-induced suppression of leaf photosynthetic indices (Pn, Gs, Tr, Ci) and key photosynthetic enzymes (RuBPCase, PEPCase). It maintained higher leaf chlorophyll content and green leaf area, delayed leaf senescence, and sustained stable carbon and energy supply for nitrogen metabolism. These improvements strengthened maize cold resistance, promoted dry matter accumulation, optimized ear and kernel traits by increasing ear number and kernels per ear and reducing empty kernels, and ultimately improved the grain yield of early-sown maize under low-temperature stress. Full article

(This article belongs to the Special Issue Harnessing Exogenous Applications for Crop Stress Tolerance and Enhanced Productivity)

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Agronomy, Volume 16, Issue 14 (July-2 2026) – 95 articles

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