The effects of combined salt-drought stress on rice grain quality and starch properties remain poorly understood. A pot experiment was conducted with control, salt, drought, and combined salt-drought stress. Compared with the control, rice grain yield decreased by 24.8% to 65.9% under salt, 12.4% under drought, and 25.1% to 69.5% under combined salt-drought stress. Milling, appearance, and eating quality deteriorated under stress, especially under combined stress, with a 33.0% decrease in taste value and 51.1% increase in amylose content. The amylopectin content declined, while the protein content increased, further impairing palatability. Microscopic and structural analyses revealed cracks, pores, fractured granules, and a smaller average granule size under stress, resulting in lower crystallinity and disrupted molecular order, especially under combined stress. By reducing rapidly digestible starch and increasing resistant starch, stress may help moderate postprandial glucose responses. Overall, combined salt-drought stress synergistically compromises rice yield and quality, providing insights for breeding stress-resilient, high-quality rice.

Context and Objective: Controlled-release urea (CRU) blended with urea as a single basal application can improve nitrogen (N) use efficiency by optimizing N supply and reduce greenhouse gas emissions in paddy fields. Nevertheless, existing studies have mainly focused on the differential responses of rice yield and N use efficiency to different blending ratios. Few systematic studies have addressed the regulation of paddy greenhouse gas emissions by these ratios. Methods: A two-year field experiment was conducted, including a conventional fertilization control (CN) and four treatments with distinct CRU blending ratios, to systematically examine the effects of these ratios on soil N supply, greenhouse gas emissions, and rice yield formation. Results: Results revealed that the maximum nutrient release rate of CRU in paddy fields occurred at 49.13 days after transplanting, which precisely coincided with the second peak of rice nutrient demand. Compared with CN, soil microbial biomass N under controlled-release blended bulk fertilizer (CRBBF) treatments exhibited smaller fluctuations, with a more stable and persistent N supply in the late growth stage. With increasing CRU blending ratio, the abundance of soil pmoA genes and the pmoA/mcrA ratio gradually increased, thereby significantly mitigating CH4 emissions. Relative to CN, CRBBF significantly decreased global warming potential and greenhouse gas emission intensity, and the reduction magnitude increased with rising CRU blending ratio. Furthermore, rice yield exhibited a quadratic response to the CRU blending ratio, with the maximum relative yield increase achieved at a 55.88% blending ratio. Conclusion: In summary, CRBBF can mitigate greenhouse gas emissions in paddy fields by maintaining stable soil N supply. Selecting an appropriate CRU blending ratio enables the synergy of high rice economic benefits and substantial environmental benefits, representing an effective strategy for sustainable agricultural development.

Lodging is one of the key and long-term factors restricting rice production, which not only causes a decrease in yield and quality and economic losses, but also hinders the development of mechanization. The factors that affect rice lodging include both internal and external factors. In this review, we discuss the main factors that have been reported to be significantly correlated with rice stem lodging, including stem morphology, chemical composition, and lodging resistance genes, as well as cultivation management, pests and diseases, meteorological conditions, and their mechanisms of influence on lodging. This article also summarizes the evaluation methods of rice lodging resistance and proposes a critical wind speed model considering wind and rain factors in exploring interdisciplinary evaluation methods. Finally, suggestions were put forward for the future development direction and establishment of new evaluation methods to enhance the lodging resistance of rice stems, in order to provide valuable information for improving the potential of rice stem lodging resistance.

Rice grain lipids, though constituting a minor fraction of brown rice weight, exert a pivotal influence on grain quality, encompassing eating and cooking quality, nutritional value, and storage stability. Lipids are unevenly distributed within the caryopsis, predominantly localized in the embryo and aleurone layers, and consist of neutral triacylglycerols and polar glycerolipids with a characteristic fatty acid profile rich in oleic, linoleic, and palmitic acids. The application of advanced lipidomics and imaging techniques, such as liquid chromatography-mass spectrometry, matrix-assisted laser desorption/ionization mass spectrometry imaging, and nuclear magnetic resonance, has enabled detailed profiling and spatial visualization of lipid species, revealing their interactions with starch and proteins. Molecular studies have identified key genes (e.g., OsFAD2, OsLOX, OsPLDα1, OsWRI1), enzymes, and QTLs that govern lipid content, composition, and stability. Grain lipids determine eating quality by forming amylose-lipid complexes that influence texture, digestibility, and aroma, while their oxidative degradation, mediated by lipases and lipoxygenases, is a primary cause of quality deterioration during storage. Genetic strategies, including breeding for high-oleic acid, lipoxygenase-null, or high-lysophospholipid genotypes via genetic engineering, and biotechnological interventions are emerging as powerful tools to tailor lipid profiles for enhanced palatability, extended shelf life, and improved nutritional outcomes. Consequently, integrating lipid-centric approaches with traditional starch- and protein-focused breeding paradigms is essential for the holistic improvement of rice quality in the future.

Rice root exudates are known to suppress nitrification and mitigate nitrogen losses in agricultural soils; however, their specific roles in coastal saline soils remain poorly understood. Here, root exudates were collected at 6 and 10 weeks after transplanting from two genotypes (Oryza sativa L. 'Nanjing 9108' and 'Yangjing 5118') using a hydroponic system, and their effects on nitrification in coastal saline soils were investigated through microcosm experiments integrating metabolomic and metagenomic analyses. Root exudates inhibited net nitrification rate (NNR) and potential nitrification activity (PNA), with the inhibitory effect primarily dependent on genotype. The abundance of nitrification genes was not significantly altered by root exudates and was negatively correlated with PNA, suggesting that root exudates mainly inhibited heterotrophic rather than autotrophic nitrification. Root exudates at 10 weeks after transplanting significantly increased the abundance of nitrate reduction genes. Integrated analyses revealed that differential metabolites dominated by terpenoids and lipids, as well as several exudates (e.g., L-isoleucine, L-valine, and pyridoxine) that generated reducing electrons during metabolism, particularly in treatments with root exudates from Nanjing 9108, showed a negative correlation with PNA and positively correlated with the abundance of nitrate reduction genes. Furthermore, the mechanisms of NNR inhibition varied with genotype. Specifically, root exudates from Nanjing 9108 inhibit NNR synergistically by reducing heterotrophic nitrification and promoting nitrate reduction, whereas those from Yangjing 5118 inhibit NNR mainly by reducing heterotrophic nitrification. Overall, root exudates primarily enhance nitrate reduction and/or reduce PNA by creating microhabitats and generating reducing agents, which inhibit nitrate accumulation in coastal saline soils. These findings provide a scientific basis for the formulation of nitrogen management measures in coastal saline paddy fields.

Context Soil salinization is an increasing constraint on rice production, severely limiting nitrogen utilization and grain yield. Partial substitution of mineral nitrogen with organic amendments is widely proposed to improve soil fertility and crop performance; however, its effectiveness is highly variable and may depend on salinity level. The optimal substitution strategy and the underlying soil–plant mechanisms under saline conditions remain poorly understood. Objective This study aimed to determine the optimal organic nitrogen substitution rate under contrasting salinity conditions and to elucidate the mechanisms governing yield formation, nitrogen dynamics, and methane (CH4) emissions in rice systems. Methods A two-year field experiment was conducted under lightly saline (LS) and heavily saline (HS) soils with five organic substitution rates (10–50%). Grain yield and its components, dry matter accumulation and partitioning, nitrogen accumulation, translocation and use efficiency, soil inorganic nitrogen and enzyme activities, root physiological traits, photosynthetic performance, and CH4 emissions were simultaneously measured. Results The optimal substitution rate was strongly salinity-dependent, peaking at 40% under LS and 20% under HS. Under LS, favorable yield performance was associated with coordinated grain filling, reproductive dry matter allocation, and root physiological function, whereas under HS, yield was primarily constrained by sink establishment, with spikelets per panicle showing the strongest response. Moderate substitution improved the coordination between biomass partitioning and reproductive development, while excessive substitution promoted vegetative growth without increasing yield. Nitrogen translocation contributed negatively to yield under LS but positively under HS, indicating a shift from reliance on current nitrogen uptake to remobilization under stress. Soil nitrate nitrogen availability, root physiological activity, and photosynthetic capacity were optimized at moderate substitution rates, particularly under HS. In contrast, higher substitution rates increased CH4 emissions, consistent with enhanced methanogenic potential, leading to higher greenhouse gas intensity under HS. Conclusions Salinity fundamentally alters the optimal organic nitrogen substitution strategy by shifting the physiological and ecological drivers of yield formation. A substitution rate of 40% is optimal for LS because it best balances yield components and reproductive growth, whereas 20% is more appropriate under HS to maintain sink formation and root function while minimizing yield-scaled CH4 emissions. These findings highlight the necessity of salinity-specific nitrogen management strategies to achieve both high productivity and environmental sustainability in rice systems.

Saline fields hold great promise for boosting rice production in China. Salinity-tolerant/susceptible rice cultivars respond differently to salinity, yet limited research has focused on how salinity modulates their agro-physiological traits and grain yield of rice under saline field conditions. This research aimed to explore how salinity affects rice yield formation and identify key agro-physiological characteristics underlying differential tolerance responses. Field experiments were conducted with salinity-tolerant rice (Yannongjing 3426 and Nanjingyan 1) and salinity-susceptible rice (Wuyunjing 30 and Huajing 5) under low salinity (LS) and high salinity (HS) over 2 years. Rice grain yield was reduced by 34.2%-54.9% at HS across 2 years, compared with LS. The increased salinity stress led to lower shoot biomass and stem non-structural carbohydrate (NSC) content, accompanied by higher harvest index and NSC reserve remobilization. Meanwhile, the increased salinity stress brought higher leaf (sodium) Na+ concentration and Na+/(potassium) K+ ratio, accompanied by reductions in post-heading leaf SPAD value and photosynthetic rate, and total accumulation of nitrogen (N), phosphorus (P), and K. Salinity-tolerant rice yielded 10.1% (LS) and 27.1% (HS) more than salinity-susceptible rice. Salinity-tolerant rice at HS maintained lower leaf Na+ concentration and Na+/K+ ratio, but higher shoot biomass and harvest index, post-heading leaf SPAD value and photosynthetic rate, stem NSC content and remobilization, K+ concentration in leaf, and total N, P, and K accumulation than salt-susceptible rice. The present study indicated that salinity stress reduced rice grain yield by 34.2%-54.9%. The superior yield of salinity-tolerant rice over salinity-susceptible rice under HS was attributed to larger sink size and higher sink-filling efficiency, driven by the favourable agro-physiological traits.

Context: Rice yield relies on the efficient allocation of carbon assimilates from source to sink organs. The regulation of carbon flow direction through phloem transport and carbon metabolism is a key factor in determining yield. Identifying factors that determine the allocation of carbon assimilates is crucial for balancing biomass and yield in rice. Objectives: This study investigated the effects of stem-grain carbohydrate allocation on yield and elucidated the underlying physiological mechanisms in different rice varieties. Methods: A 2-year field experiment was performed to investigate differences in structural and non-structural carbohydrate (NSC) allocation, physiological and molecular mechanisms related to NSC translocation and vascular bundle characteristics in stems between two chromosome single-fragment substitution lines with striking differences in biomass allocation and yield. Results: The two rice lines contained the same amount of biomass; however, the high-yielding line had more biomass allocated to grains. High NSC accumulation in stems, activities of starch-sucrose transformation enzymes in stems (e.g. alpha-amylase, beta-amylase and sucrose phosphate synthase), activities of starch biosynthesis enzymes (e.g. sucrose synthase and adenosine diphosphate glucose pyrophosphorylase) in grains, expression of sucrose translocation genes in stems (e.g. OsSUT1, OsSUT2 and OsSWEET13) and grains (e.g. OsSUT1, OsSUT2, OsSWEET11 and OsCIN1), a high proportion of vascular bundles and large phloem area contributed to the enhanced remobilisation of stem NSCs to grains, resulting in increased grain filling percentage and yield in the high-yielding rice line. Conversely, the high expression of cellulose synthesis genes (e.g. OsCES4 and OsCES9) in the low-yield line indicated that the plant utilised photosynthates preferentially for the synthesis of structural carbohydrates, resulting in a high biomass content in stems and low carbohydrate allocation to grains. Conclusion: Vascular transport, enzymes involved in carbon metabolism and genes involved in sucrose translocation promoted biomass allocation to rice grains and explained differences in biomass allocation and yield between the two rice lines. These findings highlight the importance of source-sink coordination in optimizing carbon partitioning for yield improvement in rice.

Soil salinity is a major constraint to wheat production worldwide. Efficient screening of salt-tolerant cultivars is essential for breeding programs, yet a rapid and reliable evaluation system based on full-life-cycle salt stress treatment is lacking. To address this, we conducted a hydroponic experiment encompassing the entire growth cycle of 37 wheat cultivars under control and salt stress (85.5 mM NaCl). Using principal component and stepwise regression analyses on 15 agronomic and yield-related traits, we identified five key indicators-total dry weight, root dry weight, plant height, thousand-grain weight, and number of grains per spike-that effectively represent overall salt tolerance. Based on a comprehensive evaluation value (D-value), the cultivars were classified into five distinct categories: highly salt-tolerant, salt-tolerant, moderately salt-tolerant, weakly salt-tolerant, and salt-sensitive. Notably, the highly salt-tolerant cultivar 'Yangfumai 8 ' and the salt-sensitive cultivar 'Yangmai 22' were selected as representative extremes. A subsequent pot experiment confirmed significant physiological differences between them in antioxidant enzyme activities (SOD, POD, CAT) and proline accumulation under salt stress. This study establishes a practical and efficient screening framework, providing breeders with a simplified index set for high-throughput evaluation and offering ideal contrasting materials for in-depth physiological research on salt tolerance mechanisms in wheat.

Wheat (Triticum aestivum L.) is one of the most important cereal crops globally, and its productivity and processing quality are often constrained by saline-alkaline soils, which impair nitrogen (N) uptake and grain quality development. Optimizing nitrogen management is therefore essential for improving wheat yield and quality in such marginal environments. However, limited studies have comprehensively evaluated how different nitrogen management strategies influence both grain composition and end-use performance under saline-alkaline conditions. A two-year field experiment (2023-2025) was conducted in Yancheng, Jiangsu, China, to assess six nitrogen management strategies under an equal nitrogen rate (270 kg hm-2), including conventional split urea, blended fertilizer, and controlled-release fertilizer with different application timings. Nitrogen management significantly affected grain yield, compositional traits, rheological properties, and end-use quality. Across both growing seasons, the split application of controlled-release fertilizer (N5) consistently achieved the highest grain yield, with increases of 11.4%-11.7% compared with conventional split urea (N1). N5 also enhanced protein content, gluten strength, and glutenin accumulation, while promoting amylopectin enrichment and improved starch pasting characteristics. These compositional changes were associated with improved dough stability and resistance, reduced noodle break rate, and increased mantou specific volume. In conclusion, optimized split application of controlled-release fertilizer improves both yield and processing quality under saline-alkaline conditions, suggesting that nitrogen timing plays a key role in wheat quality development. These findings highlight the importance of nitrogen timing rather than nitrogen rate in stress-prone agroecosystems.

Context: Rice-wheat rotation systems (RWS) on saline-alkali soils are vital for food security in South and East Asia. However, these systems face growing challenges from soil salinization, degradation, and climate variability, threatening their productivity and long-term sustainability. Objective: This review aims to synthesize recent advances in sustainable agronomic, tillage, irrigation, and nutrient management strategies to enhance productivity, ecological resilience, and climate adaptability of RWS under saline-alkali conditions. Method: A comprehensive review of recent field studies, meta-analyses, and modeling research was conducted across major saline-alkali regions in China and South Asia. The analysis focused on integrated soil-water-nutrient management practices, crop adaptation strategies, and policy frameworks that contribute to sustainable intensification. Results: Conservation tillage, residue retention, and deep subsoiling improve soil aggregation, enhance infiltration, and stimulate microbial activity. Integrated soil amendments combining gypsum, biochar, and organic matter effectively correct chemical imbalances and support biological recovery. Innovative irrigation techniques such as alternate wetting and drying, controlled drainage, and precision irrigation optimize water-use efficiency and stabilize salt-water dynamics. Integrated nutrient management and salt-tolerant cultivars further enhance crop resilience. Policies promoting straw recycling, organic amendments, and digital agriculture aligned with SDGs 2 and 13 are essential for scaling sustainable practices. Conclusions: The transformation of saline-alkali RWS into resilient agroecosystems requires system-level integration of agronomic, hydrological, and ecological management with participatory governance and technological innovation. Long-term and cross-regional studies are urgently required to elucidate the coupled dynamics of soil, water, and salt processes in relation to socioeconomic drivers, thereby supporting the development of adaptive policy and management frameworks for sustainable agriculture.

Soil types vary considerably and sowing dates are generally delayed for wheat production in the Yangtze–Huaihe River Basin. To identify the differential yield responses to increased basic seedling density in late-sown wheat under different soil types, this study investigated the interactive effects of soil type (sandy loam vs. clay soil) and basic seedling density (2.8 × 106 and 4.5 × 106 grains hm−2) on yield formation, canopy photosynthesis, root morphology, and nitrogen utilization enzymes in late-sown wheat (cv. Yangmai 25). Increasing seedling density enhanced effective spike number, grain number per spike, tiller dynamics, leaf area index, aboveground dry matter accumulation, root activity, and grain yield; however, these increases were statistically significant only under sandy soil conditions. At the same density, sandy soil exhibited higher SPAD values, net photosynthetic rate, photosynthetic potential, and root morphological traits than clay soil. Although clay soil increased nitrogen utilization enzyme activities (NR, NiR, GS, and GOGAT) at heading and mid-filling stages, this advantage could not offset the yield disadvantages caused by restricted photosynthetic capacity and root development. Overall, soil type-dependent responses were detected for yield components, tiller traits, physiological characteristics and root morphological, indicating that soil conditions may influence the mechanisms through which density affects late-sown wheat.

Saline–alkali soils severely constrain rice productivity and nitrogen-use efficiency by limiting nutrient availability, suppressing microbial activity, and impairing plant physiological functions, while simultaneously altering methane and nitrous oxide emissions from paddy fields. Integrating controlled-release and organic nitrogen fertilizers has been proposed to improve crop performance in salt-affected systems. However, how nitrogen source composition regulates the trade-off between productivity and greenhouse gas emissions under saline–alkali conditions remains unclear. Here, a two-year field experiment was conducted in lower-salinity and higher-salinity saline–alkali zones using two rice genotypes differing in salt tolerance, Nanjing 9108 (weakly salt-tolerant) and Nanjing yan1 (moderately salt-tolerant), to investigate how nitrogen source composition regulates soil nitrogen dynamics, enzyme activity, rhizosphere functioning, methane and nitrous oxide emissions, and rice performance. Four nitrogen treatments were compared at an equal nitrogen rate: split application of urea, controlled-release fertilizer–urea blended fertilization, organic fertilizer substitution, and an integrated controlled-release fertilizer–urea plus organic nitrogen treatment. The integrated treatment consistently achieved the highest grain yield, although the yield response varied with salinity level and genotype. Under the integrated treatment, Nanjing yan1 achieved a higher grain yield than Nanjing 9108 in the higher-salinity zone, whereas Nanjing 9108 achieved a higher grain yield in the lower-salinity zone. Although organic inputs increased cumulative methane emissions, the integrated controlled-release fertilizer–urea plus organic nitrogen treatment exhibited higher methane emissions than the controlled-release fertilizer–urea blend treatment, but its lower nitrous oxide emissions and higher grain yield generally resulted in the lowest greenhouse gas intensity, demonstrating a clear productivity–greenhouse gas trade-off. The moderately salt-tolerant genotype Nanjing yan1 maintained stronger nitrogen assimilation and rhizosphere functioning in the higher-salinity saline–alkali zone, whereas the weakly salt-tolerant Nanjing 9108 performed better in the lower-salinity saline–alkali zone. Overall, these findings demonstrate that nitrogen management in saline rice systems should be tailored to both salinity level and management objectives, balancing productivity gains and greenhouse gas mitigation. Specifically, controlled-release fertilizer–urea blended fertilization is preferable when the primary goal is to reduce absolute greenhouse gas emissions, whereas integrated fertilization is recommended for improving yield stability and nitrogen use efficiency while maintaining low greenhouse gas intensity in the higher-salinity zone.

IntroductionRice cultivation in coastal saline soils is critical for global food security. However, optimizing nitrogen (N) fertilizer strategies in these environments to enhance yield and reduce greenhouse gas emissions, particularly methane (CH4), remains a challenge. This study investigates the effects of controlled-release fertilizers (CRF) on rice yield and CH4 emissions in coastal saline soils.MethodsA two-year (2023–2024) field study was conducted using two rice cultivars, Nanjing 5718 and Yongyou 4953, under four different nitrogen treatments: N0 (zero N), N1 (conventional split urea), N2 (50% 80-day CRF + 50% basal urea), and N3 (50% 120-day CRF at seedling + 50% basal urea). Grain yield and CH4 emissions were measured, and root morphological traits were also assessed.ResultsThe N3 treatment significantly increased grain yield by 10.2 to 12.9% compared to N1, while N2 reduced yield by 11.9 to 13.0%. CH4 emissions were highest under N1 and decreased under N2 and N3 treatments. Specifically, N2 reduced peak CH4 flux by 18.9% and total emissions by 20.4%, while N3 reduced peak flux by 6.8% and total emissions by 7.7%. Root development was enhanced under N3, with significant increases in root length, surface area, and oxidation activity.DiscussionThe application of CRF, especially with a 120-day release period at the seedling stage, improved rice grain yield and mitigated CH4 emissions. These results suggest that CRF provides a promising strategy for sustainable rice cultivation in coastal saline soils, with the added benefit of reducing environmental impact.

In recent decades, substantial reclamation efforts have successfully transformed the coastal tidal flats of eastern China, expanding agricultural land and increasing crop yields. Timely monitoring of spatiotemporal variations in soil organic carbon content (SOCC) through remote sensing has become crucial for assessing the effectiveness of saline soil improvement measures in reclaimed areas and gaining insights into the carbon sequestration dynamics in agricultural fields. Despite the significance of the issue, there is a notable lack of research in humid coastal regions. This study focused on three zones in the coastal tidal flats of Jiangsu Province, eastern China, distinguished by varying reclamation ages and diverse crop planting histories. The research involved comprehensive soil sampling and the acquisition of Sentinel-1 and 2 images. A total of 206 existing remote sensing indices were compiled, and an additional 10 new indices were proposed. Through variable selection and the application of various machine learning models, the Random Forest Regression (RFR) model demonstrated proficiency in accurately estimating SOCC in the study area. The RFR model exhibited excellent estimation performance in the training set (R2 = 0.933, RMSE = 0.054 %, RPD = 3.887) and very good performance in the testing set (R2 = 0.758, RMSE = 0.083 %, RPD = 2.080). Notably, the optimal model displayed high accuracy across samples with varying SOCC values and soil salinity levels, and it mapped the SOCC spatial distribution in reclaimed areas with varying reclamation ages and crop planting histories, providing a satellite-based approach for uncovering spatiotemporal SOCC variations in different reclaimed areas of coastal tidal flats in Jiangsu. Furthermore, by comparing five scenarios, this study underscores the indispensability of newly proposed remote sensing indices, the integration of non-texture features with texture features, and the fusion of optical and Synthetic Aperture Radar (SAR) data for accurate SOCC estimation. This research marks a pioneering use of texture information in SOCC remote sensing estimation, providing valuable insights for future studies in similar coastal environments.

This study evaluated the effects of one-time application of controlled-release fertilizer (CRF) on rice (Oryza sativa L.) grain yield, grain quality, and agronomic nitrogen use efficiency (ANUE, ANUE (kg/kg) = (Grain yield with N application − grain yield without N application)/N application amount) in coastal saline soils. A two-year field experiment (2023–2024) was conducted using two rice varieties (Nanjing 5718 and Yongyou 4953) under four nitrogen treatments: N0 (no nitrogen fertilization), N1 (270 kg·hm−2, with a ratio of 5:1:2:2 at 1-day before transplanting, 7-day after transplanting, panicle initiation, and penultimate-leaf appearance stage, respectively), N2 (270 kg·hm−2, one-time application at 1-day before transplanting as 50% CRF with 80-day release period + 50% urea), and N3 (270 kg·hm−2, 50% one-time application of CRF with 120-day release period at the seedling stage + 50% urea at 1-day before transplanting). Compared with N1, the N3 treatment significantly increased grain yield by 10.2% to 12.9% and improved ANUE by 18.5% to 51.6%. It also improved processing quality (higher brown rice, milled rice, and head rice rates), appearance quality (reduced chalkiness degree and chalky rice percentage), and taste value (by 19.3% to 31.2%). These improvements were associated with lower amylose, protein, and soluble sugar contents and favorable changes in starch composition and pasting properties. While N2 slightly improved some quality traits, it significantly reduced yield and ANUE. Correlation analysis revealed that starch and protein composition, as well as pasting properties, were significantly associated with taste value and related attributes such as appearance, stickiness, balance degree, and hardness. Overall, one-time application of CRF with a 120-day release period at the seedling stage, combined with basal urea, offers an effective strategy to boost yield, quality, and ANUE in coastal saline rice systems.

Remote sensing of soil salinity is essential for selecting suitable salt-tolerant crops and improving soil management. Previous research focused mainly on arid regions. Synthetic aperture radar (SAR) data are crucial for wet coasts due to frequent cloudiness, but significant changes in soil moisture and vegetation impede the soil salinity assessment accuracy. This study demonstrated the feasibility of mapping soil salinity on China's wet east coast through combining machine learning and multi-date SAR data. Two field surveys were carried out on June 17 and July 21, 2017. Using recursive feature elimination, this study generated and screened SAR variables derived from Sentinel-1A SAR imagery acquired on 15 individual dates, and developed support vector regression (SVR) based- and random forest regression (RFR) based-soil salinity models, respectively. The SVR models outperformed the RFR models. The SVR models yielded accurate soil salinity estimations for the 2017-06-17 (R2 = 0.98, RPD = 7.01, RMSE = 0.18 dS/m and RRMSE = 6.28

Hydrogen sulfide (H2S), a well-established gaseous signaling molecule, can effectively enhance plant tolerance to various environmental stresses. However, there is still a lack of suitable methods to release H2S in agricultural production, and the mechanism by which H2S improves stress resistance remains poorly understood. Here, we show the novel role of sodium butyrate (NaB) in producing H2S consistently in rice rhizosphere soil and the epigenetic mechanism of H2S to enhance rice drought tolerance. We found that NaB increased sulfate-reducing bacteria (SRB) abundance in the rhizosphere soil, resulting in higher expression of sulfite reductase (SiR), and consequently increased H2S production. Mechanistic investigation showed that H2S enhanced the level of H4K5ac in promoter regions of drought-tolerant genes, facilitating their expression by repressing the histone deacetylase (HDAC) gene OsHDA710. Loss-of-function mutants of OsHDA710 exhibited enhanced drought tolerance compared to wild-type (WT) plants, while OsHDA710 overexpression plants showed drought hypersensitivity. Moreover, we demonstrated that OsHDA710 could bind directly to promoters of drought-tolerance genes by recognizing the TGACC motif. Our findings illustrate an efficient way to produce H2S and a novel mechanism for H2S in improving the drought resistance of plants.

How to increase crop yield in coastal saline-alkali land has become a focus and hot topic of concern for researchers. Field experiments were conducted to identify whether foliar application of magnesium sulfate (MgSO4·7H2O) can enhance rice salt tolerance and improve rice yield. Treatments with four concentrations of MgSO4·7H2O (10 g L-1, 20 g L-1, 30 g L-1, and 40 g L-1) were applied during the jointing and heading stages of rice in three fields with different salt levels in Yancheng City, Jiangsu Province, China in 2022 and 2023. Results showed that the application of magnesium sulfate, even the lowest concentration of MgSO4, could significantly increase the rice yield and total biomass under all the three salt treatments, while the increase displayed more obvious under higher salt treatment. Magnesium sulfate treatment enhanced the Rubisco enzyme activity and total chlorophyll content in rice flag leaves, delayed leaf tip wilt, and thus improved the photosynthetic capacity of rice. Additionally, magnesium sulfate treatment significantly reduced the accumulation of toxic sodium ions (Na+) in rice compared to the untreated control, accompanied with notable enhancement of Mg/Na, K/Na, P/Na, and Ca/Na. This study found that magnesium sulfate could enhance the salt tolerance of rice in coastal saline-alkali soils, whereas the effects vary significantly among different concentrations. Under 20 g L-¹ of MgSO4 treatment, rice leaves exhibited the highest net photosynthetic rate and total chlorophyll content, while the incidence of leaf tip wilt and the accumulation of toxic sodium ions (Na+) were minimized, resulting in the highest yield and total biomass. Therefore, 20 g L-¹ of MgSO4 is likely to be recommended as the optimal application concentration in saline-alkali areas.

Saline-alkaline soils pose significant challenges for sustainable wheat production due to poor soil structure, osmotic stress, and low nutrient availability, compounded by nitrogen losses and greenhouse gas emissions. To address these constraints, a two-year field experiment (2023-2025) was conducted in coastal saline-alkaline soils of eastern China (EC 4.6-4.9 dS m(-1)) to evaluate six nitrogen management regimes differing in fertilizer type and application timing. The objective was to determine how different nitrogen management strategies affect wheat productivity, nitrogen use efficiency, and N2O emissions under saline-alkaline conditions. Treatments included: (i) a nitrogen-free control (N0); (ii) conventional two-stage urea application (N1); (iii) single and two-time applications of blended fertilizer (N2 and N3); and (iv) single and two-time applications of controlled-release fertilizer (N4 and N5). Among these, N5 and N3 enhanced soil nitrogen synchronization by reducing early-stage nitrate nitrogen (NO3--N) and ammonium nitrogen (NH4+-N) concentrations while maintaining higher levels during reproductive stages. At tillering and regreening, NO3--N and NH4+-N under N5 were significantly lower than N1, but became higher at heading and anthesis, indicating more stable and prolonged nitrogen availability. These changes enhanced nitrate reductase and nitrite reductase activities and significantly reduced nitrous oxide (N2O) emissions. Improved nitrogen coordination under N3 and N5 supported greater shoot and root dry matter accumulation, particularly after regreening. At maturity, N5 increased shoot and root biomass by up to 29.0-40.3 % and 11.6-27.5 % across both years, respectively. Enhanced root morphology and oxidation activity contributed to stronger nutrient uptake. Consistent nitrogen supply also improved photosynthetic efficiency. N3 and N5 treatments increased net photosynthetic rate, stomatal conductance, and transpiration rate while reducing intercellular CO2 concentration, indicating more effective carbon assimilation during grain filling. These physiological improvements resulted in higher grain yields, with N5 producing 11.8-12.5 % more than N1 across both years, primarily due to increased spike number and thousand-grain weight. Nitrogen accumulation in reproductive organs and post-anthesis translocation were also enhanced under N5. Compared with N1, N5 improved agronomic, physiological, and nitrogen uptake efficiency by 19.0-19.1 %, 16.5-18.6 %, and 39.1-59.5 %, respectively. Among all nitrogen strategies tested, two-time application of controlled-release fertilizer proved the most effective for enhancing wheat productivity and nitrogen use efficiency in saline-alkaline soils, while split application of blended fertilizer also offered meaningful improvements.