Rice pot seedling machine transplanting effectively combines the characteristics of pot-shaped seedlings and carpet seedlings. It involves the precise transplantation of soil-bearing pot seedlings into the field using specialized machinery, offering advantages such as shortening the slow seedling recovery period and improving yield and stability. This article, based on the practice of rice pot seedling machine transplanting in Anqing, Anhui Province, introduces high-yield and high-efficiency cultivation techniques for rice pot seedling nursery and machine transplanting, covering aspects such as variety selection, seed treatment, seedling management, and pot seedling transplantation. In production, it is advisable to select varieties with suitable maturity and strong disease resistance, such as Haoliangyou 729 and Haoliangyou 985. Seed treatment measures, including sun drying and soaking, are implemented to improve seedling emergence rates. For seedling management, a flat and well-irrigated field is selected as the nursery. Using nursery trays measuring 60 cm in length and 30 cm in width, with 448 holes per tray. The required number of trays is 35 trays per 667 m². After sowing, soil sealing treatment, scientific water management, and fertilization are carried out to cultivate standardized seedlings with a hole formation rate of ≥90%, uniform growth, and free from pests and diseases. During transplantation, the row spacing for pot seedling machine transplanting is set at 33 cm × 14 cm, with a planting density of 14 400 holes per 667 m² and a transplanting depth of 1–2 cm. After machine transplanting, water management follows the principle of “shallow water initially, mid-term drying, and moist conditions later”, shallow water before seedling recovery, field drying when tillers reach 90% of the panicle number, intermittent irrigation during jointing and booting stages, alternating dry and wet conditions during the grain-filling stage, and water supply is cut off 7-10 days before harvest. 5–7 kg /667 m² of urea during the tillering stage to promote tillering, 2–3 kg/667 m² of urea + 3–5 kg/667 m² of potassium chloride during the booting stage to protect panicles, and foliar fertilizers such as potassium dihydrogen phosphate during the grain-filling stage to increase grain weight. Pest, disease, and weed control prioritize prevention, with chemical control applied at specific stages, supplemented by physical and biological control. Pesticide application should avoid high temperatures and the flowering period. Harvesting is conducted timely on sunny days when 95% of the grains turn yellow and 33% of the rice stalks dry out. The grains are dried to a moisture content of 13.5%–14.5% before storage.

To investigate the effects of the plant growth regulator Iron Chlorine e6 on rice growth, an experiment was conducted using the rice variety Ningxiangjing 9. The following treatments were applied: seed dressing with 0.02% Iron Chlorine e6 (A1, 22.5 g/hm²; A2, 45.0 g/hm²; A3, 67.5 g/hm²; A4, 90.0 g/hm²; CK, clear water control); foliar spraying at the jointing stage (B1, 22.5 g/hm²; B2, 45.0 g/hm²; B3, 67.5 g/hm²; B4, 90.0 g/hm²; CK, clear water control); foliar spraying at the booting stage (C1, 22.5 g/hm²; C2, 45.0 g/hm²; C3, 67.5 g/hm²; C4, 90.0 g/hm²; CK, clear water control). The traits, yield, and safety of rice plants under different treatments were determined. The results showed that foliar spraying of 0.02% Iron Chlorine e6 soluble powder increased panicle length and plant height, while seed dressing effectively thickened the basal internodes and enhanced lodging resistance. Both methods, at application rates of 45.0-90.0 g/hm², prevented lodging. Both seed dressing and foliar spraying of Iron Chlorine e6 increased the hundred-grain weight, seed setting rate, and yield of rice, with yield increases ranging from 2.14% to 11.95%. The C4 treatment achieved the highest yield (11 303.55 kg/hm²). All treatments were safe for rice growth. Considering economic benefits, it is recommended to apply 0.02% Iron Chlorine e6 at 67.5 g/hm² during the booting stage to improve rice yield.

An experiment was conducted to explore the effects of rice straw returning and tillage methods on wheat growth, the wheat variety Yangmai 30 was used as the material. 5 treatments were designed: full amount of rice straw returned to the field followed by deep tillage + shallow rotary tillage (T1), full amount of straw returned to the field followed by shallow rotary tillage (T2), no-tillage with full amount of straw returned to the field (T3), all rice straw baled and removed from the field followed by deep tillage + shallow rotary tillage (T4), and all straw baled and removed from the field followed by shallow rotary tillage (T5). The emergence of wheat seedlings, occurrence of weeds in wheat fields, the entire growth period of wheat, and yield factors under various treatments were determined. The results showed that the emergence rates of the treatments, in descending order, were T4 > T5 > T1 > T2 > T3. The total weed occurrence, in descending order, was T2 > T5 > T4 > T1 > T3. The growth progress was generally consistent, with a full growth period of 199 days for all treatments. In terms of yield, the yields of the treatments ranged from 6 108.8 to 6 603.3 kg/hm², in descending order: T4 > T1 > T2 > T5 > T3. The economic benefits, in descending order, were T3 > T2 > T5 > T4 > T1. Overall, T3 and T2 were associated with higher economic benefits, while T4 achieved the highest wheat yield. Different regions can select suitable straw management methods based on local conditions to enhance wheat yield while improving economic benefits. This article provides a reference for efficient planting of rice stubble and wheat.

To investigate the effects of side-deep fertilization of slow-release blended fertilizer on the growth and yield of machine-transplanted rice, a field experiment was conducted using rice cultivar Jingliangyou 1125. 5 treatments were designed: CK (conventional manual fertilization + machine transplanting), T1 (side-deep fertilization + conventional amount), T2 (side-deep fertilization with 10% reduction), T3 (side-deep fertilization with 20% reduction), and T4 (side-deep fertilization with 30% reduction). The growth period, agronomic traits (such as plant height and effective panicle number), and yield were observed and measured. The results showed that side-deep fertilization had no significant effect on the growth period of rice. There were no significant differences in plant height, grain number per panicle, or 1 000-grain weight among the treatments. The number of effective panicles in the side-deep fertilization treatments was 1.1–3.5 panicles/cluster higher than that in CK. The average yield increased by 2.8%–24.9% compared to CK. Among them, treatment 2 had the highest number of effective panicles and yield, which were 14.1 panicles/cluster and 11 089 kg/hm², respectively.In conclusion, side-deep fertilization can promote rice tillering, increase effective panicle number, and thereby improve rice yield.Moreover, under reduced fertilizer application conditions, the yield is higher, achieving the goal of cost reduction and efficiency improvement.

The genetic characteristics and types of rice dwarfism were systematically analyzed, the role of plant hormones was examined in this process, the ideal plant architecture for dwarf breeding was discussed, and prospects for future research directions were provided. Rice plant height determined jointly by the number and length of internodes, was identified as a key trait affecting lodging resistance and yield. Dwarfing mutants in rice types were diverse and could be classified inter-node shortening mode into categories such as d6-type and dm-type. Currently, plant height was categorized into tall, semi-dwarf, and dwarf based on height, though the distinction between semi-dwarf and dwarf remained to be clarified, reflecting the complexity of the underlying genetic mechanisms. Dwarfism was primarily associated with deficiencies in the metabolism or signal transduction of 3 types of hormones: gibberellin (GA), brassinosteroid (BR), and strigolactone (SL). Among these, GA and BR were directly involved in regulating internode elongation, and mutations in their related genes led to dwarfism. In contrast, SL synthetic gene mutations resulted in dwarfism along with increased tillering. A total of 36 major dwarf genes (sd1, d18, and etc.) had been cloned, providing important genetic resources for lodging-resistant breeding. The development of rice varieties with high lodging resistance, yield potential, and suitability for mechanized production had become a major objective in modern breeding. Progress in rice dwarf breeding was expected to be effectively advanced through in-depth research on the gene function, genetic diversity, and key gene networks of rice dwarfing mutants, combined with modern technologies such as gene editing and phenomics. This review provides a reference for the selection and improvement of rice varieties.

【Objective】To meet the increasing food demand driven by population growth and environmental changes, it is necessary to continuously cultivate varieties with high yield, good quality, and multiple resistances. Efficiently create new germplasm with rich genetic backgrounds and genetic diversity to provide a reference for breeding new varieties that balance multiple excellent traits. 【Method】The Sanming dominant genic male sterile material was used to simplify the hybridization procedure. It was hybridized with multiple parents with distant geographical relationships to aggregate multiple excellent traits. Aiming at problems such as a narrow genetic basis and the difficulty of applying molecular markers, S221 was successively and continuously hybridized with materials such as 09598, Ezhong 5, Yuanfengzhan, Yunxiangruan, etc. Fertile plants were selected from the offspring of the last hybridization. The new variety was cultivated by combining the pedigree method with heat-tolerance analysis, rice quality analysis, and resistance screening. The DNA of 60 selected single plants from the F₁₀ series of lines and 4 parents was extracted. Primers for the target sites were designed. The target DNA fragments were captured by PCR and sequenced. Finally, the genotyping analysis of the target sites was carried out. The SLYm1R high-density rice whole-genome SNP chip was used for the analysis of functional genes. 【Result】Genotype analysis is carried out to analyze the degree of genetic relationship or similarity based on the magnitude of the base substitution rate. The parental materials Ezhong 5 and Yunxiangruan have a relatively distant relationship with other parental materials, while 09598 has a relatively close relationship with Yuanfengzhan. The base substitution rates among the three newly obtained lines are as follows: 0.0099545 (170531-170532), 0.0338213 (170531-170533), and0.0371913 (170532-170533). Within each line, the base substitution rate is 0, indicating that there are differences among the three lines, but there is no genetic difference within each line. Through successive generations and expansion propagation, new germplasms were formed, which were named ZY531, ZY532, and ZY533 respectively. The results of functional gene analysis show that the functional genes of the ZY532 series of germplasms are respectively derived from 4 parents, aggregating excellent genes from multiple parents. For example, the Os-MOT1;1 gene is derived from Yunxiangruan, which can reduce abiotic stresses such as molybdenum accumulation; the Bph3 gene is derived from 09598 and Ezhong 5, which can enhance the resistance to brown planthoppers; the OsGSK2 gene is derived from 09598, Yuanfengzhan, and Yunxiangruan, which can increase the length of the mesocotyl and is suitable for direct seeding; the Badh2 gene is derived from Yunxiangruan, making the rice fragrant; multiple blast resistance genes are derived from different parents and can also be aggregated into the innovative resources, enabling it to obtain good blast resistance. ZY532 has excellent rice quality, good blast resistance, and strong heat resistance. ZY532 also has good heat resistance, and the heat resistance of the hybrid combination prepared reaches level 3. 【Conclusion】When using dominant genic male sterility to cultivate new varieties, due to the complex genetic background, the breeding cycle is often long. Combining high-throughput SNP marker detection can quickly screen out stable lines and more types, which not only broadens the genetic basis but also improves the breeding efficiency. It is an efficient breeding method.

The necessity of producing ratoon rice in Huizhou District, Huangshan City, Anhui Province was summarized. Based on the current status of ratoon rice production in the study area, aspects that required further improvement were identified, and corresponding countermeasures were proposed. The promotion of ratoon rice production was considered beneficial for increasing total yield, raising farmers’ income, improving rice quality, and effectively reducing agricultural losses caused by flood disasters. Although the planting area of ratoon rice in the study area had increased year by year, aspects such as the scale of cultivation, mechanization level, industrial system, and policy support still need enhancement. To promote the sustainable development of this industry, a series of countermeasures were proposed: training and publicity were strengthened to improve farmers’ understanding of ratoon rice cultivation techniques; full-process mechanized production was advanced by introducing machinery suitable for ratoon rice harvesting to enhance the yield of the ratoon season; characteristic brands were developed to boost the market competitiveness and added value of ratoon rice products through brand building and the integration of agriculture and tourism; support for the ratoon rice industry was intensified by establishing special subsidies, giving full play to the role of agricultural industrialization consortia, and adopting order-based production models to improve production efficiency. This paper provided a reference for promoting the development of the ratoon rice industry in relevant regions and advancing the process of agricultural modernization.

To clarify the influence of different agronomic traits on rice yield, a grey relational analysis was conducted to investigate the correlation between agronomic traits and yield using 11 hybrid rice varieties, including Quanliangyou 985 and Quanyou 1001. Variance analysis was also performed on the plot yield of each rice variety. The results showed that the relational degree between 10 agronomic traits and yield, in descending order, was as follows: growth period (0.859 8) > plant height (0.825 7) > seed-setting rate (0.763 1) > 1000-grain weight (0.740 6) > panicle length (0.734 2) > number of effective ears per plant (0.675 3) > total grain number (0.634 7) > filled grains per panicle (0.623 9) > number of filled grains (0.622 0) > total grains per panicle (0.562 1). According to the principle of grey relational analysis, the growth period was identified as the primary factor affecting the yield of the tested rice varieties. The variance analysis results indicated that the plot yield of Quanliangyou 985 was significantly different from other varieties at both the 0.05 and 0.01 levels. Except for Quanliangyou Jingsimiao, the plot yields of the other nine varieties were significantly higher than that of Fengliangyou No.4 (CK). Overall, nine varieties, including Quanliangyou 985, Quanyou 1001, and Quankeyou 211, demonstrated promising prospects for widespread cultivation.

To clarify the application of 48% controlled release fertilizer in mid-season rice production, the rice variety Pingliangyouyazhan was used as the material. 5 fertilizer treatments were established in Chongyi County, Ganzhou, Jiangxi Province (T1, nitrogen free zone, calcium, magnesium, phosphorus+potassium chloride; T2, phosphorus free zone, urea+potassium chloride; T3, potassium free zone, urea+calcium, magnesium, and phosphorus; T4, nitrogen phosphorus potassium zone, 48% controlled release fertilizer; T5, blank area). The effects of these treatments on rice growth period, main agronomic traits, yield, and fertilizer use efficiency were investigated. The results showed that the total growth period of rice under different treatments ranged from 129 to 133 days. The application of controlled-release fertilizer was found to accelerate seedling recovery and prolong the tillering and heading stages. In terms of main agronomic traits, plant height varied from 101.9 to 121.2 cm, and the seed setting rate ranged from 66.90% to 74.22%. The use of controlled release fertilizer increased the effective panicle number and seed-setting rate of mid-season rice. Both grain yield and straw yield were the highest in the T4 treatment, reaching 560.28 and 509.81 kg/667 m², respectively. The nitrogen, phosphorus, and potassium use efficiencies were 37.33%, 26.17%, and 52.56%, respectively, with potassium use efficiency being the highest. In conclusion, 48% controlled release fertilizer was beneficial for increasing mid-season rice yield. This study provides a reference for the promotion and application of controlled release fertilizer in agricultural production.

To screen safe and effective herbicides for direct-seeded rice fields, 4 agents including 40% bensulfuron-methyl·pretilachlor WP were tested, with a blank control as the reference. The treatments included: treatment 1 (40% bensulfuron-methyl·pretilachlor WP + 25% cyhalofop-butyl EW), treatment 2 (40% bensulfuron-methyl·pretilachlor WP + 15% pyrazosulfuron-ethyl·bispyribac-sodium OD), treatment 3 (33% bensulfuron-methyl·pretilachlor OD + 25% cyhalofop-butyl EW), treatment 4 (33% bensulfuron-methyl·pretilachlor OD + 15% pyrazosulfuron-ethyl·bispyribac-sodium OD), treatment 5 (25% cyhalofop-butyl EW), and treatment 6 (15% pyrazosulfuron-ethyl·bispyribac-sodium OD). The safety to rice and weed control efficacy in the field were evaluated. The results showed that all tested herbicides were relatively safe for rice growth when applied at appropriate doses and methods. The dominant weeds in the direct-seeded rice fields were Leptochloa chinensis and Echinochloa crus-galli, with fewer Cyperaceae and Broadleaf weeds. The plant control efficacy at 7, 14, and 21 days after treatment across all treatments ranked from highest to lowest as: treatment 1 > treatment 3 > treatment 2 > treatment 4 > treatment 5 > treatment 6. similarly, the fresh weight control efficacy at 21 days followed the same descending order: treatment 1 > treatment 3 > treatment 2 > treatment 4 > treatment 5 > treatment 6. Treatments 1–4 achieved over 97% control efficacy (by plant number) for total weeds at 7 and 14 days after treatment, and over 96% control efficacy (by plant number and fresh weight) at 21 days after treatment (36 days after rice sowing). In conclusion, applying bensulfuron-methyl·pretilachlor for soil sealing, supplemented with cyhalofop-butyl or pyrazosulfuron-ethyl·bispyribac-sodium for post-emergence treatment, effectively controls weeds in direct-seeded rice fields and is suitable for widespread adoption in production.

Wanyou 66 was a mid-late maturing three-line hybrid rice variety using the indica-type three-line sterile line Wan 8A as the female parent and the high quality, blast-resistant restorer line Wanhui 66 as the male parent. The characteristics and high yield cultivation techniques of this variety were introduced in the Wuyishan region of Fujian Province. From 2022 to 2024, multi-location demonstration and trial experiments of this variety were conducted in Wuyishan City. It was characterized by a suitable growth period, strong tillering ability, and uniform panicle structure in field cultivation. The yield ranged from 8 349.4 to 9 596.0 kg/hm⊃2;. The variety exhibited resistance to rice blast and good lodging resistance, as well as a high head rice rate, good grain appearance, and desirable palatability. Its high yield cultivation techniques included selecting an appropriate sowing date (late April to early May) and adjusting the seeding rate according to different transplanting methods; cultivating strong seedlings through treatments such as chemical seed soaking, paclobutrazol application, and “farewell fertilizer and farewell pesticide” before transplanting; achieving reasonable planting density to establish an efficient population; implementing a fertilization strategy of “heavy base fertilizer, early topdressing, and supplemental panicle and grain fertilizer” combined with a water management model of “shallow water, sun-drying, and alternating wet and dry conditions” to promote tillering, panicle formation, and lodging resistance; applying pesticides such as 16% emamectin benzoate·indoxacarb at 150 g/hm⊃2; to control pests like the rice stem borer; and harvesting under sunny conditions when 90% of the panicles were mature. This study provides a reference for the promotion and cultivation of this variety in relevant regions.

This study aimed to mitigate or prevent the adverse effects of heat damage on yield of single-season rice in Xuancheng, ensuring stable rice production in the region. Using meteorological data from seven meteorological stations (1961-2023) and rice yield data (2000-2023) in Xuancheng, the spatiotemporal distribution, variation patterns, and yield impacts of heat damage during the critical growth stages of single-season rice (booting to heading-flowering stages) were analyzed through yield modeling and wavelet analysis. The findings revealed that: (1) total heat damage events increased after the 1990s. After 2000, mild, severe, and extreme heat damage showed rising trends, while moderate damage declined gradually. Mild events were most frequent, followed by severe and moderate, with extreme events being the least common. (2) The spatial extent of heat damage followed the order: mild > severe > moderate > extreme. (3) Heat damage was more prevalent in the southwest and less frequent in the northeast. Ningguo experienced the highest frequency, while Guangde had the relatively lower frequency, with an overall increasing trend. (4) A 4-5 year inverse-phase resonance cycle existed between rice yields and heat damage in Xuancheng, becoming more pronounced after 2007. There was a significant positive correlation between the intensity of high temperature heat damage and the yield reduction of single-season rice. Recommendations include: promoting high-temperature-tolerant indica rice varieties paired with emergency measures like “deep-water irrigation + foliar salicylic acid application” in southern high-risk zones; optimizing sowing dates in northeastern low-risk zones to avoid critical flowering stages from late July to early September. The research results, combined with the above targeted measures, can provide scientific basis and technical support for the stable and high yield of local rice and the enhancement of climate resilience.

In the context of global climate warming and evolving agricultural practices, cases of premature sowing and cultivation in rice production have increased. This study focuses on Keqiao District, Shaoxing City, utilizing 43 years of observational data from the Keqiao National First-Class Agrometeorological Observation Station, combined with field surveys of current agricultural sowing practices. Five phased sowing schemes for machine-transplanted and direct-seeded early rice were developed. Analyze the probabilities of agrometeorological disasters occurring at different developmental stages for machine-transplanted and direct-seeded early rice under various sowing dates, and determine the suitable sowing periods for both machine-transplanted and direct-seeded early rice based on the principle of seeking advantages and avoiding disadvantages. The results showed that the suitable sowing period for machine-transplanted early rice in Keqiao, Shaoxing City is from late March to early April, and the suitable sowing date for direct-seeded early rice is from early April to early mid-April. This provides a scientific basis for farmers to reasonably arrange the production and planting of machine-transplanted and direct-seeded early rice, as well as to seek advantages and avoid disadvantages under climate change.

To find out the enrichment characteristics of functional elements of selenium, zinc and iron in rice, which have great influence on human health, and promote the development of functional agriculture, the leaf surface application of selenium (A₁, A₂, A₃, A₄ and A₅) was carried out on the leading hybrid high quality rice ‘Yexiang Youbasi’ (B₁) and conventional high quality rice ‘Baixiang 139’ (B₂) by split zone design. The results showed that the experimental treatment significantly increased the selenium content of rice and rice straw. The average selenium content of B₂ rice was significantly higher than that of B₁ by 17.2%. There was no significant difference in the average selenium content of rice straw between B₁ and B₂. B₁ rice had a stronger tolerance to high exogenous selenium stress than B₂, and B₂ rice straw had a stronger tolerance to high exogenous selenium stress than B₁. The interaction effect of A₄×B₂ and A₄×B₁ (applied 1.5 times selenium) on the difference in selenium content between B₁ and B₂ rice was extremely significant. A₁×B₁ and A₁×B₂ (without selenium application) had no significant effect on the difference in selenium content between B₁ and B₂ rice, indicating that exogenous selenium had an impact on the difference in selenium enrichment between rice varieties (combinations). Foliar application of selenium had no significant effect on the zinc and iron content of rice, but increased the difference in zinc enrichment between B₁ and B₂ rice and reduced the difference in iron enrichment between B₁ and B₂ rice. This suggested that exogenous selenium also had an impact on the differences in zinc and iron enrichment between rice varieties (combinations). B₁ rice had significantly stronger zinc enrichment than B₂ rice, while B₁ and B₂ rice had comparable iron enrichment. Exogenous selenium had different effects on the enrichment of selenium, zinc and iron in rice, and also affected the difference in the enrichment ability of selenium, zinc and iron among rice varieties. It was worth paying attention to the evaluation and screening of rice varieties (combinations) rich in selenium, zinc and iron.

As a national commercial grain base, the soil health of green rice planting areas in Jilin Province is crucial for ensuring food security and ecological safety. This study systematically analyzed the spatial distribution characteristics of soil pH and heavy metal (Cd, Hg, As, Pb, Cr) contents, along with their correlations, across 42 green rice planting areas in Jilin Province. The results indicated that the soil pH in the study area ranged from 4.6 to 10, with a mean pH value of 7.23 and significant spatial heterogeneity (standard deviation of 1.21). The analysis of heavy metal content revealed that the mean concentrations of Cd, Hg, As, Pb, and Cr were 0.1094, 0.043, 8.1, 21.79 and 49.23 mg/kg, respectively. Notably, the levels of Cd and Hg approached or exceeded the screening values for soil environmental risks in certain areas. Correlation analysis demonstrated a significant negative relationship between soil pH and heavy metal contents (P<0.01), particularly for Cd (r=-0.387) and Hg (r=-0.627), suggesting that increased pH could effectively reduce the bioavailability of heavy metals. Further spatial analysis revealed a coupling relationship between heavy metals and pH, indicating significant overlap between low pH regions and areas with high heavy metal content. Based on the findings of this study, recommendations for acidic soil amendment (with a suggested lime application rate of 1500-3000 kg/hm²) and the establishment of a comprehensive heavy metal—pH monitoring network are proposed. These measures could serve as a scientific basis for soil pollution prevention and control, as well as for sustainable agricultural development in the green rice growing areas of Jilin Province.

To improve the resistance of rice cultivar ‘Yunjing 37’ to Manaporthe oryzae, the rice cultivar ‘Yunjing 37’ was used as the recurrent parent. By employing a combination of conventional hybridization, backcrossing, selfing, and marker-assisted selection (MAS) strategies, the blast resistance genes Pi57 and Pi69 were pyramided into the japonica cultivar ‘Yunjing 37’. M. oryzae strains virulent to ‘Yunjing 37’ were used to evaluate the blast resistance of BC₂F₃ lines containing homozygous Pi57+Pi69, Pi57 or Pi69, as well as their parental materials, through artificial spray inoculation at the seedling stage. Results showed that plants possessing homozygous Pi57+Pi69 were resistant to all blast strains used in this study, while those lines containing only homozygous Pi57 or Pi69 exhibited resistance or susceptible reactions consistent with their donor parents. These results indicated that pyramiding of blast resistance genes can significantly enhance the resistance of rice varieties against M. oryzae. The newly developed materials will provide valuable germplasm resources for blast-resistant rice breeding.

【Objective】Rice bacterial leaf streak (BLS) is a quarantine-regulated bacterial disease in China caused by Xanthomonas oryzae pv. oryzicola (Xoc), which has severely threatened rice yield and grain quality, becoming one of the main diseases in rice production areas. This study aims to utilize high-quality actinomycete strains to lay a theoretical foundation for developing the products of microbial origin to mitigate crop diseases.【Method】Actinomycete strains were isolated and purified from rhizosphere soil samples of various plants using the serial dilution plating technique. The inhibition ability of different strains against Xoc was compared by measuring the diameter of the inhibition zone. The target strain with the best inhibition effect was selected for preservation and identified through polyphasic characterization integrating morphological traits, physiological-biochemical experiments, and multi-gene alignment analysis. The effects of antagonistic actinomycete on the physiological characteristics of Xoc were investigated by scanning electron microscopy, Fourier-transform infrared spectroscopy (FTIR), intracellular β-galactosidase leakage determination and SDS-PAGE gel electrophoresis. The greenhouse pot control effect test was carried out to study the actual benefit of controlling BLS. The growth-promoting characteristics of antagonistic actinomycete were analyzed by designated medium, and its effects on the growth and development of rice seedlings were investigated by watering growth-promoting experiments.【Result】A total of 80 actinomycete strains were isolated. Among them, strain Sv-6 exhibited the most potent antagonism against Xoc, with inhibition zone diameter of (44.87±0.26) mm. Based on the morphological characteristics and phylogenetic analysis, strain Sv-6 was identified as Streptomyces virginiae. After treatment with the culture filtrate of Sv-6 strain, Xoc cells swelled, shrunk and aggregated. At the same time, the material composition of the membrane surface changed, the permeability increased, and the protein expression decreased. The results of greenhouse pot experiments showed that the lesion inhibition rates of susceptible rice varieties Yongyou 15 and Xiangliangyou 900 were 57.98%-88.25% after being treated with strain Sv-6 culture fluid, which exhibited a good preventive effect on rice infected with Xoc. The growth-promoting characterization confirmed that strain Sv-6 exhibited siderophore production, inorganic phosphate solubilization, and IAA production. The growth-promoting irrigation experiments confirmed that strain Sv-6 enhanced the growth of rice seedlings, and the root length increased by 48.50% after treatment.【Conclusion】S. virginiae Sv-6 exhibits a good control effect on BLS, and has the potential to be developed into green biocontrol agent and microbial fertilizer.

To investigate the accuracy of estimating rice leaf nitrogen concentration using multi-source satellite data, a rice LNC estimation experiment was conducted from 2020 to 2022 in Xiaogang Village, Fengyang County, Anhui Province. The HH2 spectroradiometer was used to obtain in situ hyperspectral data of rice leaves at different growth stages (tillering, booting, heading, flowering, and filling stages), while synchronous measurements of rice nitrogen content were collected. The band response functions of two satellite sensors, QuickBird and SPOT-6, were selected, and the reflectance data of these two sensors was simulated using ENVI/IDL resampling technology.Based on the simulated multispectral reflectance data of rice leaves, 12 spectral indices were constructed by combining any two bands. Spectral indices highly correlated with nitrogen content at each growth stage were screened through correlation fitting, and the established rice LNC estimation models were validated using the coefficient of determination (R²) and root mean square error (RMSE). The results showed that, across the entire growth period, rice LNC exhibited a gradually decreasing trend (except during the tillering stage) and was negatively correlated with spectral reflectance.For the QuickBird sensor, during the tillering and booting stages, the normalized difference spectral index (NDSI-BG) and ratio spectral index (RSI-BR) showed the highest correlations with LNC, with R² values of 0.351 8, 0.617 0 and 0.352 9, 0.628 1, respectively. During the heading, flowering, and filling stages, NDSI-RN and RSI-RN achieved the highest R² values, reaching 0.714 0, 0.553 2, 0.637 2 and 0.707 5, 0.542 9, 0.639 5, respectively. Similarly, for the SPOT-6 sensor, NDSI-BG and RSI-BR exhibited the highest R² values during the tillering and booting stages (0.351 8, 0.612 9 and 0.355 4, 0.622 2, respectively), while NDSI-RN and RSI-RN performed best during the heading, flowering, and filling stages (0.702 9, 0.543 6, 0.584 6 and 0.697 8, 0.537 9, 0.584 8, respectively).Model validation results indicated that the QuickBird-simulated data, R² = 0.56 and RMSE = 0.42, whereas for the SPOT-6 model, R²=0.54 and RMSE = 0.28. This suggests that the LNC estimation model based on QuickBird-simulated data achieved slightly higher accuracy than that of SPOT-6, though with a marginally larger RMSE. This method can be applied for relatively rough estimation of rice nitrogen content.

The japonica glutinous rice variety Wankennuo 1116 was used as the material, taking the spraying of plain water as the control (CK), Field experiments were conducted to investigate the effects of different types of foliar fertilizers [treatment 1, Miaodundun (bio-based); treatment 2, Meizhouxing (nutrient-based); treatment 3, Abscisic acid + Indolebutyric acid (regulation-based); treatment 4, Liquid enzyme fertilizer (fertilizer-pesticide combination); treatment 5, zhenfengrui combination (composite-based)] on the growth period, agronomic traits, yield, and economic benefits of rice. The results showed that in terms of growth period and agronomic traits, the total growth period of all treatments was 156 d, and no significant effect of foliar fertilizers on the growth period was observed. However, the application of foliar fertilizers was found to reduce plant height (109.7-115.6 cm) and increase panicle length (16.7-17.8 cm). In terms of factors contributing to rice yield composition, the number of panicles in the foliar fertilizer treatments ranged from 229 000 to 276 000 panicles per 667 m², the seed setting rate was between 86.1% and 88.5%, and the 1 000-grain weight was 26.4-27.1 g. The rice yield under different foliar fertilizer treatments ranged from 696.4 to 751.6 kg per 667 m², with a cost-benefit ratio of 3.4-7.3. Among them, the microbial foliar fertilizer Miaodundun, the regulatory foliar fertilizer Abscisic acid + Indolebutyric acid, and the compound foliar fertilizer Zhenfengrui combination demonstrated better yield increasing and income enhancing effects. This study provides a reference for efficient fertilization management in rice production.

Based on the current status of ratoon rice production in Qianshan City, Anhui Province, the aspects needing improvement were analyzed, and its corresponding industrial development strategies were proposed. The ratoon rice production was incorporated into the high quality agricultural development project in the study area, with a steady increase in planting area. In 2023, the demonstration planting of ratoon rice Quanyou 822 in Huangpu Town achieved a total yield of 13 609.5 kg/hm² and a profit of 10 341.27 yuan/hm². However, deficiencies were identified in varietal selection, cultivation techniques, brand building level, scale of operation, and socialized services. To address these issues, several countermeasures were proposed: lodging resistant and machine harvestable varieties were promoted; optimized sowing and seedling-raising techniques, precision fertilization, integrated “three-prevention and two-control” pest management, and simplified mechanical harvesting systems were implemented; regional public brands were established with “three certifications and one standard” accreditation, and agritourism demonstration parks were developed; new agricultural business entities were fostered, and “one-stop” agricultural machinery service cooperatives were established to improve the supply and marketing system and reduce production costs. This article provides reference for the high-quality development of the ratoon rice industry in the research area and similar regions.

This study aims to assess the salt tolerance of perennial rice varieties (lines) ‘PR23’, ‘PR24’, ‘PR25’, ‘PR26’, ‘PR101’, ‘PR107’, and ‘PR109’, and to screen out elite salt-tolerant germplasm. The experiment employed NaCl solutions at concentrations of 0, 50, 100, 150, and 200 mmol/L to conduct salinity stress treatments on perennial rice varieties (lines) and the parent ‘RD23’. The vitality parameters (seedling height, root length, fresh weight, dry weight, etc.) and salt tolerance coefficients of varieties were determined under different NaCl concentrations. Principal component analysis (PCA) and the membership function method were used to comprehensively evaluate the salt tolerance performance of the varieties (lines). The results showed that: (1) significant differences in salt damage levels among varieties (lines) were observed when NaCl concentration reached 150 mmol/L. Among all the phenotypic traits associated with salt stress, except for root length, all other traits under the 150 mmol/L NaCl treatment showed significant differences from the control group (P < 0.05), establishing this concentration as the optimal level for screening salt tolerance in perennial rice during the seedling stage. (2) PCA of the relative values of salt tolerance traits under the 150 mmol/L NaCl treatment generated membership function values. Combining with the principal component variance contribution rate weight, the comprehensive evaluation D value was obtained, showing that ‘Yun Da 107 (PR107) ’exhibited the strongest comprehensive salt tolerance ability at the seedling stage, while ‘PR101’ showed the weakest salt tolerance capacity. Other varieties (lines) had intermediate salt tolerance levels. This study provides high-quality germplasm resources for rice salt tolerance breeding and lays the foundation for future improvements in rice salt tolerance. This study not only identifies elite salt-tolerant rice germplasm resources through phenotypic and genotypic assessments, laying a foundation for genetic improvement of rice salt tolerance, but also provides critical data support for further research on salinity stress tolerance mechanisms.

To optimize the pesticide application parameters of plant protection drones, this study systematically evaluated the effects of different water application rates on the control efficacy against rice sheath blight and the economic benefits, aiming to provide a scientific basis for precise drone-based pesticide application. Using the DJI T40 drone, field experiments were conducted in Songjiang District, Shanghai, from 2023 to 2024. Three water application rate gradients (30, 45, and 67.5 L/hm²) were set, with pesticides applying at the jointing and heading stages of rice, and the control efficacy in terms of diseased plant rate and disease index was monitored. (1) At the jointing stage, there were no significant differences in control efficacy among the gradients (diseased plant control efficacy: 85.57%-87.68%; disease index control efficacy: 89.86%-91.34%). (2) At the heading stage, the control efficacy at 30 L/hm² was significantly lower than that at other gradients (P< 0.05), while there was no significant difference between 45 L/hm² and 67.5 L/hm² (P>0.05). In 2023, the diseased plant control efficacy ranged from 79.71% to 91.99%, and the disease index control efficacy ranged from 89.47% to 94.95%. In 2024, 7 days after pesticide application, the diseased plant control efficacy was 78.86%-95.01%, and the disease index control efficacy was 85.30%-94.93%; 15 days after application, the diseased plant control efficacy was 73.17%-93.12%, and the disease index control efficacy was 77.38%-92.46%. (3) In terms of economic benefits, the operation efficiency showed a decreasing trend with the increase of water application rate (30L: 4.0 hm² /h→67.5 L: 2.67 hm² /h), and the control cost increased by 71.4% with the increase of water application rate (from 1050 to 1800 yuan per application). A differentiated water application strategy is recommended: since the water application rate at the jointing stage has no significant impact on the control efficacy, 30 L/hm² is recommended (balancing efficiency and cost); as the water application rate at the heading stage has a significant impact on the control efficacy, 45 L/hm² is preferred (balancing control efficacy and economy).

The objective of this study is to explore the agro meteorological conditions and suitable climatic zoning of rice cultivation under the complex mountainous terrain of Zhijin County. The correlation between rice meteorological yield and meteorological factors was analyzed by mathematical statistics, the key meteorological factors affecting the growth and development of rice were screened out, a localized rice meteorological yield forecast model was established, and the forecast results were tested. At the same time, according to the meteorological data and disaster weather data, combined with various disaster indicators, the zoning map of rice planting suitability in Zhijin County was comprehensively drawn. The result showed that eight meteorological factors, including average temperature and sunshine hours in late May, precipitation in late June, precipitation and sunshine hours in mid-July, average temperature and precipitation in early August, and precipitation in early September, had the best correlation with the growth and development of rice in Zhijin County. The average forecast accuracy of the established localized forecasting model is more than 90%, and the forecast results are credible, which is suitable for localized yield forecasting. The zoning map of rice climate suitability showed that the climate of southern and western townships in the central part of Zhijin County was the most suitable for rice planting, while the suitability of rice planting in the northern and eastern towns was poor. The prediction model established in this study has good prediction ability for rice yield in Zhijin County. The generated climate suitability zoning map clearly reveals regional differences, which can provide an intuitive decision-making basis for optimizing local rice planting layout, avoiding meteorological disaster risk and improving yield level.

The aim is to explore the effects of nitrogen fertilizer management on the yield and its constituent factors of ‘Chaoyou 1000’, and clarify the proportion of nitrogen fertilizer management and the yield increase mechanism of rice with high yield. Eight kinds of nitrogen fertilizer management treatments, including N₀ (no fertilization), N₁ (7:3), N₂ (6:4), N₃ (5:5), N₄ (4:6), N₅ (3:7), N₆ (2:8) and N₇(0:10), were used to study the effects of nitrogen fertilizer management on rice yield and yield components, leaf area index and dry matter with N₃ as the control. The results showed that the backward movement of nitrogen fertilizer increased the effective spike number, grain number per spike and nitrogen fertilizer agronomic efficiency, but had little effect on 1000-grain weight and seed setting rate. Under N₆, the yield and nitrogen agronomic efficiency were the highest, and the leaf area index reached the maximum value at the full heading stage. With the increase of nitrogen fertilizer backward migration at the critical leaf age, jointing stage and full heading stage of effective tillering, the leaf area index first increased, then decreased and then increased. The dry matter accumulation from full heading stage to maturity stage, the population growth rate increased first and then decreased with the increase of nitrogen fertilizer backward migration, and the harvest index gradually increased with the increase of nitrogen fertilizer backward migration. When the total amount of nitrogen application (pure nitrogen) was 420 kg/hm², the basic seedling was 28.95×10⁴/hm², and the transplanting density was 11.5 cm×30 cm, the ratio of nitrogen fertilizer was basal tiller: panicle fertilizer = 2:8, which was the most conducive to high yield.

This study explores the genetic basis and related functional genes of rice nitrogen use efficiency (NUE), highlighting the overuse of nitrogen fertilizers and summarizing the pertinent genes. NUE traits are divided into physiological traits (such as nitrogen uptake) and agronomic traits (such as tiller number) to elucidate key genes beneficial for nitrogen absorption. In physiological traits, genes affecting the absorption of NH₄⁺ and NO₃^- in rice are summarized. The absorption of NH₄⁺ in rice is primarily controlled by the AMT superfamily of proteins, whereas the proteins involved in NO₃^- transport mainly fall into two categories: NRT1 and NRT2, such as overexpression of genes like OsAMT1.1 and OsNRT1.1B can increase rice's nitrogen uptake. In agronomic traits, transcription factors such as GRF4 and NGR5 regulate the expression of nitrogen metabolism genes, promoting tiller development and grain growth, thus enhancing nitrogen use efficiency. These findings provide new genetic resources for rice breeding, promising the development of high NUE and environmentally friendly new varieties.

The research progress in rice germplasm innovation, variety breeding, and breeding technology development in Anhui Province since 1949 has been reviewed, and the future research directions in rice breeding have been prospected. In terms of germplasm innovation and variety breeding, Anhui rice germplasm (variety) innovation has gone through the stages of introducing and systematically selecting agricultural varieties and dwarf varieties, as well as selecting three-line sterile lines and two-line sterile lines; as of 2024, there were 1 539 self bred rice varieties in the research area, including three-line hybrid rice varieties such as 80 You 121, Xieyou 57, and Quanyou 822, two-line hybrid rice combinations such as Xingliangyou No.6 and Wandao 153, conventional rice varieties such as Huixiangruan No.1 and Huixiangjing 977, as well as strong drought resistant varieties such as Lyuhan No.1 and Lyuhanliangyou 21. In terms of breeding technology, mutagenesis technology has the characteristics of high mutation rate and light biological damage, enriched breeding resources; molecular marker assisted breeding technology can accurately select and efficiently recombine for the gene, improving the success rate of breeding; gene editing technology can precisely modify target genes according to specific breeding needs, further improving the precision and efficiency of breeding. The next step will focus on cultivating new varieties of green, high quality, high yielding, and multi resistant rice to meet diversified market demands.

The mycelial growth rate method was used to determine the sensitivity of 4 major rice disease (bakanae disease, sheath blight, helminthosporium leaf spot, rice blast) pathogens to 6 fungicides (20% tricyclazole, 25% kresoxim-methyl, 25% phenamacril, 20% propiconazole, 20% zinc thiazole, 125 g/L epoxiconazole). The results indicated that 25% kresoxim-methyl and 125 g/L epoxiconazole exhibited strong inhibitory effects against bakanae disease and sheath blight pathogen, with median effective concentration (EC₅₀) both below 1 mg/L; the best fungicides for inhibiting rice sesame leaf spot pathogen were 20% propiconazole and 25% kresoxim-methyl, with EC₅₀ values of 0.000 7 and 0.003 5 mg/L, respectively; the fungicides with good inhibitory effects on rice blas fungicide were 25% kresoxim-methyl and 125g/L epoxiconazole, with EC₅₀ of 1.001 1 and 1.862 1 mg/L, respectively. Overall, all 6 fungicides had inhibitory effects on rice diseases. The fungicides with better inhibitory effects are 125 g/L epoxiconazole and 25% kresoxim-methyl. It is recommended to apply them in a mixed or alternating manner in production to avoid pathogens developing drug resistance.

Based on the occurrence and damage of the main rice diseases and insect pests, the comprehensive control technologies, including agricultural, biological, physical and chemical prevention and control were discussed. The primary diseases included rice blast (which infected leaves, nodes, and panicles), sheath blight (which infected basal leaf sheaths), and false smut (a panicle disease). The major pests included rice planthopper (which sucked sap), the rice leaf roller (which damaged leaves by rolling), and rice stem borers (which bored into stems). The integrated control was centered on the ecosystem and combined agricultural, biological, physical, and chemical technologies. Agricultural control involved selecting resistant varieties and implementing scientific field management; biological control generally utilized natural enemies and integrated crop-aquaculture systems; physical control often employed measures such as trapping and barrier methods; chemical control was focused on reducing application quantities and increasing efficiency by selecting low-toxicity agents. By comprehensively applying these control technologies, precise prediction and green management were achieved, which protected rice yield and quality and promoted sustainable agricultural development.

Leaves and glumes act as lateral organs and have essential effects on photosynthesis and seed morphology, thus affecting yield.  However, the molecular mechanisms controlling their polarity development in rice still need further study.  Here, we isolated a polarity defect of lateral organs1 (pdl1) mutant in rice, which exhibits twisted/filamentous-shaped leaves and cracked/filamentous-shaped lemmas caused by defects in polarity development.  PDL1 encodes a SUPPRESSOR OF GENE SILENCING 3 protein localized in the cytoplasmic granules.  PDL1 is expressed in the shoot apical meristem, inflorescence meristem, floral meristem, and lateral organs including leaves and floral organs.  PDL1 is involved in the synthesis of tasiR-ARF, which may subsequently modulate the expression of OsARFs.  Meanwhile, the expression levels of abaxial miR165/166 and the adaxial identity genes OSHBs were respectively increased and reduced significantly.  The results of this study clarify the molecular mechanism by which PDL1-mediated tasiR-ARF synthesis regulates the lateral organ polarity development in rice.

Adjustment of the sowing date is a widely used measure in rice production for adapting to high-temperature conditions.  However, the impact of a delayed sowing date (DS) on rice quality may vary by variety and ecological conditions.  In this study, we conducted experiments using four different sowing dates, the conventional sowing date 1 (CS1), CS2 (10 d later than CS1), DS1 (30 d later than CS1), and DS2 (30 d later than CS2), and three rice varieties, i.e., Yixiangyou 2115, Fyou 498, and Chuanyou 6203.  This experiment was conducted at four sites in the Sichuan Basin in 2018 and 2019 to evaluate the influence of DS on the pasting properties of rice, which are a proxy for the eating and cooking quality (ECQ).  In DS1 and DS2, the rice had a significantly greater amylose content (AC) but a lower protein content (PC), peak viscosity (PKV), cool paste viscosity (CPV), and hot paste viscosity (HPV) than in CS1 and CS2.  Moreover, except for CS2 and DS1 in 2018, DS1 and DS2 led to 2.15–11.19% reductions in breakdown viscosity (BDV) and 23.46–108.47% increases in setback viscosity (SBV).  However, the influence of DS on rice pasting properties varied by study site and rice variety.  In 2019, DS1 and DS2 led to BDV reductions of 2.35–9.33, 2.61–8.61, 10.03–17.78, and 2.06–8.93%, and SBV increases of 2.32–60.93, 63.74–144.24, 55.46–91.63, and –8.28–65.37% at the Dayi, Anzhou, Nanbu, and Shehong (except for SBV in CS2 and DS1) sites, respectively.  DS resulted in greater reductions in PKV, HPV, CPV, and BDV and greater increases in the AC and SBV for Yixiangyou 2115 than for Chuanyou 6203 and Fyou 498.  The correlation analysis indicated that PKV and HPV were significantly and positively related to the mean, maximum, and minimum temperatures after heading.  These temperatures must be greater than 25.9, 31.2, and 22.3°C, respectively, to increase the relative BDV and reduce the relative SBV of rice, thereby enhancing ECQ.  In conclusion, DS might contribute to a significant deterioration in ECQ in machine-transplanted rice in the Sichuan Basin.  A mean temperature above 25.9°C after heading is required to improve the ECQ of rice.

To effectively exploit valuable selenium-rich soil resources, promote the development of selenium-rich rice industries, maximize the functional role of selenium in rice, and improve public health, this study selected 27 rice lines as experimental materials and conducted field trials in strongly acidic soil with rich organic matter and available potassium. The results showed that the selenium content of the produced rice was at a relatively low level, ranging from 0.0086 to 0.0247 mg/kg, with an average of 0.0153 mg/kg, a coefficient of variation of 0.258, and a maximum/minimum ratio as high as 2.86. The selenium enrichment coefficients of the rice lines exhibited highly significant differences due to genotype variations, and were generally low, ranging only from 0.0169 to 0.0484, with an average of 0.0299. The average selenium content in rice was only 61.2% of the national average, significantly lower than that in other selenium-rich rice-growing regions. All tested rice lines exhibited selenium deficiency, which is relatively rare in similar studies. This indicates that, in addition to rice genotype, soil properties also have a considerable influence on the selenium enrichment capacity of rice. Therefore, attention should be paid to the reshaping effect of spatiotemporal ecological changes on rice selenium enrichment.

【Objective】The application of chemical fertilizers and organic materials is a crucial measure for increasing agricultural production. Rice-rapeseed rotation system is a primary paddy-upland crop rotation pattern in the Yangtze River basin of China. Clarifying the impact of chemical fertilizers and organic material inputs on the annual crop yield and nutrient utilization in rice-rapeseed rotation could provide a scientific basis for ensuring food and oil security and achieving green and sustainable agricultural development. 【Method】From 2017 to 2022, a continuous field experiment was conducted at the Huazhong Agricultural University's Shayang Experimental Station in Shayang County, Hubei Province. Four treatments were established: no fertilizer (CK), chemical fertilizer only (NPK), chemical fertilizer with straw return (NPK+S), and chemical fertilizer with straw return plus organic fertilizer (NPK+S+M). The crop yields, nitrogen (N), phosphorus (P) and potassium (K) nutrient absorption of rapeseed and rice were analyzed. The nutrient use efficiency, apparent nutrient balances, and their relationships with yield were also assessed.【Result】The average results over 6 years showed that compared with no fertilization, the application of chemical fertilizers and organic materials significantly increased the yield of rapeseed (493.5%-758.8%) and rice (94.3%-106.4%), and enhanced crop yield stability (24.6%-72.1%) and sustainability (17.2%-85.0%). Compared with the NPK treatment, the NPK+S treatment increased the yield of rapeseed by 6.3%, but decreased yield stability and sustainability; it decreased the yield of rice by 0.8%, but increased yield stability and sustainability. The NPK+S+M treatment increased the yield of rapeseed and rice by 44.7% and 5.4%, respectively, and improved the sustainability of yield. Throughout the rotation cycle, nutrient uptake by rapeseed was consistently lower than that by rice across all treatments. The addition of organic materials significantly enhanced nutrient uptake in both rapeseed and rice. Relative to the NPK treatment, the NPK+S+M treatment resulted in increases of 5.1%-91.2% in average nutrient uptake and 12.2%-100.4% in trend nutrient uptake. The NPK+S treatment did not significantly differ from the NPK treatment in average nutrient uptake but exhibited a 7.7%-25.4% higher trend nutrient uptake. The input of organic materials decreased the physiological nutrient use efficiency of rapeseed and rice. Compared with the NPK treatment, the physiological N use efficiency of rapeseed and rice in the NPK+S+M treatment decreased by 3.0 and 3.7 percentage points, respectively, and the physiological P use efficiency decreased by 19.3 and 25.5 percentage points, respectively. Further analysis revealed that the application of organic materials led to higher apparent nutrient surpluses, which caused the annual increase in the cumulative yield of crops in the rice-rapeseed rotation. The cumulative apparent nutrient surplus was significantly positively correlated with the cumulative crop yield. 【Conclusion】The application of chemical fertilizers and organic materials significantly increased crop yields and nutrient use efficiency, and its effects were jointly influenced by crop and nutrient type. Increasing organic fertilization along with chemical fertilizers and straw application could further enhance soil fertility and increase crop yield; however, efforts should focus on improving the physiological nutrient use efficiency to fully realize the potential of organic amendments for sustainable grain and oil production.

【Objective】The aim of this study is to elucidate the long-term effects of tillage practices and fertilization measures on annual crop yield and nutrient utilization in a rapeseed- rice rotation system in the Yangtze River Basin, for providing a scientific basis for sustainable nutrient management to achieve synergistic grain and oilseed production in the region.【Method】Based on a site-specific field experiment (2016-2023) with a rice-rapeseed rotation system, a split-plot design was adopted. The main treatments were different tillage methods: rotary tillage (RT, 12 cm depth) and deep tillage (DT, 20 cm depth). The sub-treatments included three fertilization regimes: no fertilization (CK), chemical fertilizer alone (F), and combined organic-inorganic fertilization (FM, where chemical fertilizer in the rice season matched the F treatment, while the rapeseed season received organic-chemical fertilization). This study analyzed the rapeseed and rice yields, nutrient uptake, and nutrient use efficiency, with a comprehensive evaluation incorporating yield stability index (YSI) and sustainability index (SYI).【Result】Compared with CK, fertilization application significantly increased rice and rapeseed yields by 47.6% and 288.1%, respectively, while improving yield stability (YSI increased by 6.1% and 10.6%) and sustainability (SYI increased by 14.7% and 16.7%). Fertilization was the primary factor influencing crop yield, with FM outperforming F. DT further enhanced rice (9.2%) and rapeseed (7.0%) yields compared with RT, while significantly improving rice and rapeseed yield stability (YSI decreased by 17.9% and 4.7%, respectively) and sustainability (SYI increased by 5.7% and 7.7%, respectively). Among all treatments, FM-DT achieved the highest yields, stability, and sustainability for both crops. Further analysis revealed that FM-DT most effectively promoted nutrient translocation to grains, increasing N and phosphorus (P) harvest indices. The N and P harvest indices reached 76.9% and 76.0% in rice and 68.5% and 69.5% in rapeseed, respectively. Organic fertilizer substitution reduced chemical fertilizer input but enhanced N and P use efficiency, increasing them by 23.1% and 24.5% in rice and 63.7% and 22.8% in rapeseed, respectively. DT combined with organic substitution further improved N and P apparent recovery efficiency. 【Conclusion】The integration of FM with DT significantly enhanced productivity, stability, and sustainability in the rice-rapeseed rotation system while improving nutrient use efficiency. This approach represented an effective nutrient management strategy for achieving sustainable development in rice-rapeseed rotation in the Yangtze River Basin.

【Objective】Rice-rapeseed rotation is an important paddy-upland crop rotation in China, and the application of nitrogen (N), phosphorus (P) and potassium (K) fertilizer plays an important role in guaranteeing high and stable crop yields. This study systematically assessed the effects of different types of nutrient inputs on the yield and nutrient utilization of the annual crop of a continuous term rotation, so as to provide a reference to the management of nutrients in rice-rapeseed rotation.【Method】A rice-rapeseed rotation field trial was carried out for 8 continuous years from 2016 to 2024, with 4 treatments of equal application of N, P and K (NPK), and no N (-N), no P (-P), and no K (-K), to analyze the yield of annual crops, yield components, nutrient utilization, and apparent balance.【Result】Imbalanced fertilization significantly reduced crop yields, compared with the NPK treatment, the -N, -P and -K treatments reduced yields by 26.7%, 36.7% and 2.8% in rice and 57.4%, 86.4% and 12.3% in rapeseed, respectively, and the reduction in the number of effective number of panicles in rice and the number of pods in rapeseed were the main reasons for the crop yields reduction. With the increase of rotation year, the cumulative crop yield under -N, -P and -K treatments gradually increased the degree of yield reduction; compared with NPK treatment, the yield stability and sustainability of rice and rapeseed were significantly reduced under -P treatment. In terms of annual nutrient allocation in crop rotation, the N, P₂O₅ and K₂O accumulation in rice was higher than that in rapeseed, and the trends of nutrient accumulation in rice, rapeseed and crop annual rotation under imbalanced fertilizer application conditions were consistent with yields. Fertilizer use efficiency analysis showed that the fertilizer contribution rates of N, P and K fertilizers were lower in rice than in rapeseed, while the agronomic efficiency of N and P fertilizers, and the recovery efficiency of P and K fertilizers were higher than those of rapeseed. From the nutrient apparent balance of the annual rotation, the nutrient surpluses of the soil in the rice season were all lower than those of the soil in the rapeseed season, and the annual rotation of the NPK treatment had surpluses of 135.1 kg N·hm^-2, 49.6 kg P₂O₅·hm^-2, and deficits of 225.1 kg K₂O·hm^-2, deficiency of a single nutrient exacerbated the surplus of other nutrients.【Conclusion】In the rice-rapeseed rotation system, the deficiency of any single essential nutrient notably diminished crop yield as well as the utilization of nutrients, and the rate of yield reduction was related to the basic soil fertility level. Under the conditions of this study, the -P treatment had the largest yield reduction, followed by the -N treatment, while the -K treatment showed the smallest reduction. The magnitude of yield reduction in rapeseed was significantly higher than that in rice. Therefore, it was necessary to pay attention to the input of N and P fertilizers to achieve high and stable crop yields, and appropriate supplementation of K fertilizer to alleviate the depletion of soil K reservoirs, in order to realize high yield, high efficiency and sustainable development of the long-term rice-rapeseed rotation system.

【Objective】To explore the potential of optimizing fertilization under rice-rapeseed rotation for increasing crop yield and efficiency in medium and low yield fields, this study analyzed the effects of optimized fertilization on yield, nutrient absorption, and soil fertility in rice-rapeseed rotation, as well as the effectiveness of rice-rapeseed rotation in improving soil fertility. This study aimed to identify fertilization strategies suitable for medium and low yield fields and the potential for improving quality and efficiency in rice-rapeseed rotation, so as to provide the theoretical guidance for reducing obstacles in medium and low yield fields, promoting efficient production in rice-rapeseed rotation, and achieving sustainable development of rice-rapeseed rotation.【Method】The experiment was conducted at the Agricultural Science Research Institute in Rugao City, Jiangsu Province from 2017 to 2024, with low yield fields as the research objects. Through small-scale experiments, no fertilization treatment (CK), no nitrogen treatment (PK), no phosphorus treatment (NK), farmer's habitual fertilization treatment (FFP), and optimized fertilization treatment (OPT) were set up. By analyzing the annual yield of crops in both water and drought seasons, the nutrient absorption of aboveground parts during maturity, and soil nutrient content, the yield change rules under different fertilization systems of rice-rapeseed rotation were clarified, and the main influencing factors were explored.【Result】During the seven year rotation period, compared with FFP, the yield and yield composition of rice and rapeseed treated with OPT were more stable with increasing rotation cycles. Compared with FFP, OPT treatment significantly increased the nitrogen and phosphorus partial productivity of rice and rapeseed, with rice showing 51.5%-73.3% and 81.8%-107.9% higher nitrogen and phosphorus partial productivity, respectively; rapeseed was 137.2%-152.3% and 89.8%-101.9% higher, respectively. During the four-year rotation period, the aboveground biomass of rice and rapeseed treated with OPT was higher than that treated with FFP. Comparing the two annual rotation periods at the beginning and end of the comparative experiment, it was found that the accumulation of nitrogen, phosphorus, and potassium in the aboveground parts of rice and rapeseed treated with OPT was higher than that under FFP treatment, and OPT treatment had a better effect on improving soil organic matter, total nitrogen, and available potassium than FFP treatment. After 7 years of rice-rapeseed rotation, the soil fertility index significantly increased (63.8%-117.2%) under all treatments. Compared with FFP treatment, the average membership degree of five soil chemical indicators in the rice season treated with OPT was higher than that under FFP treatment, and its comprehensive fertility index increased by 13.4%-19.2%. In addition, the soil phosphorus activation coefficient during the three-year rotation period was monitored, and it was found that the OPT treatment had a higher soil phosphorus activation coefficient than under FFP treatment. 【Conclusion】Compared with the traditional fertilization practices of farmers, optimizing fertilization could be achieved by optimizing fertilizer management. Based on reducing nitrogen and phosphorus fertilizer application by 40% and 50% in rice and 60% and 50% in rapeseed, stabilizing their yield composition, maintaining high biomass and nutrient absorption, and achieving stable annual yield in the rice-rapeseed intercropping system; the performance of optimized fertilization treatment in improving fertilizer utilization efficiency and soil fertility was better than that of farmers' habitual treatment. Therefore, optimizing fertilization under long-term fertilizer reduction could coordinate crop nutrient needs and nutrient supply, maintain stable or increased crop yields, and improve fertilizer utilization efficiency. Rice-rapeseed rotation could improve soil fertility in medium and low yield fields, achieve obstacle reduction in medium and low yield fields, and promote sustainable development of rice-rapeseed rotation.

【Objective】By studying the effects of nitrogen fertilizer application rates on the annual crop yields, stability, and nitrogen uptake in the rice-rapeseed rotation system, this study explored the changing trends of the appropriate annual nitrogen fertilizer application rates for rice and rapeseed, so as to provide a theoretical basis for rational fertilization in the rice-rapeseed rotation in the middle reaches of the Yangtze River region.【Method】This locational trial was located in Wuxue City, Hubei Province, and was started in 2016. In this study, eight consecutive years of field locational trials were selected from 2016 to 2024. Five nitrogen fertilizer application rate gradients of 0, 90, 180, 270, and 360 kg N·hm^-2 were set up for both crops in the two seasons. The yields and their stability, nitrogen accumulation amounts, nitrogen fertilizer use efficiency, apparent nitrogen surplus, and the annual trends of appropriate nitrogen fertilizer application rates in the rice-rapeseed rotation system were analyzed. 【Result】Nitrogen fertilization significantly enhanced crop productivity in rice-rapeseed rotation systems. Compared with the nitrogen-free treatment, in each nitrogen-applied treatment, the average annual yield of rice increased by 1 035-1 769 kg·hm^-2, with an increase range of 19.4%-33.2%. The application of nitrogen fertilizer had a significant yield-increasing effect on winter rape; compared with the nitrogen-free treatment, the average annual winter rape yield increased by 1 041-2 208 kg·hm^-2, and the yield increased by 1.3-2.8 times. Aboveground nitrogen accumulation in rice and rapeseed increased progressively with elevated N inputs, averaging 36.8-108.2 kg·hm^-2 and 43.4-139.3 kg·hm^-2 higher than that under the zero-N control, respectively. Continuous observations indicated rising trends in both N accumulation and N recovery efficiency (NRE) for both crops under continuous rotation. During the rice season, with the increase in nitrogen fertilizer application rate, compared with the previous year, the average annual increase in nitrogen accumulation increased from 2.6% to 9.8%. In the rapeseed season, the increase in nitrogen accumulation in the nitrogen-free treatment was not significant among years. After applying nitrogen fertilizer, the nitrogen accumulation increased by an average of 3.4%-5.1% annually compared with the previous year. NRE in rice remained stable during the first three years but exhibited a parabolic rise starting from the fourth year. For rapeseed, NRE under 90-270 kg N·hm^-2 N rates increased by 5.6% annually, whereas no significant improvement occurred at 360 kg N·hm^-2. Apparent N balance in the zero-N treatment consistently showed deficits, while N-surplus in fertilized plots declined annually by 3.6%-8.3% (rice) and 2.4%-6.7% (rapeseed). Systematic analysis revealed an annual increase of 2.3% in optimal N rates for rice (annual mean: 146.8 kg N·hm^-2) and 0.9% for rapeseed (annual mean: 198.0 kg N·hm^-2).【Conclusion】In the continuous rice-rapeseed rotation planting mode, it was necessary to apply fertilizers with appropriate nitrogen application rates according to the nitrogen absorption characteristics of the crops in the rotation system, and to dynamically adjust the annual nitrogen allocation amount according to the soil nitrogen status.

【Objective】The rice-rapeseed rotation is a typical paddy-upland rotation cropping pattern in the Yangtze River Basin of China. The seasonal wet-dry alternation in soil affects the transformation of soil nitrogen and the application effect of nitrogen fertilizers. From the perspective of annual rotation, this study explored the differences in the effects of nitrogen fertilizer management on crop yield and nitrogen distribution in the rice-rapeseed rotation system, so as to provide a scientific basis for the efficient utilization of annual nitrogen fertilizer in the rice-rapeseed rotation system.【Method】The field experiment was located in Wuhan, Hubei Province, and was founded in 2012. This study selected 11 consecutive rice-rapeseed rotation years from 2012 to 2023 to conduct the experiment, four nitrogen fertilizer treatments were designed in the experiment: (1) no nitrogen application in both the rapeseed and rice seasons (N0-0); (2) applying 150 kg N·hm^-2 of nitrogen fertilizer in both the rice and rapeseed seasons (N150-150); (3) adding 75 kg N·hm^-2 of nitrogen fertilizer to the rice season on the basis of treatment (2) (N225-150); (4) adding 75 kg N·hm^-2 of nitrogen fertilizer to the rapeseed season on the basis of treatment (2) (N150-225). The related indicators such as crop yield, annual system energy yield, yield components, nitrogen accumulation and soil nitrogen supply capacity were analyzed.【Result】There were differences in the response of yield and nitrogen accumulation to nitrogen fertilizer management between rapeseed and rice. When the nitrogen application rate was N150-150 in both rice and rapeseed seasons, compared with no nitrogen application, the yields of rapeseed and rice increased by an average of 207.1% and 92.4%, respectively, and the nitrogen accumulation increased by an average of 253.2% and 114.7%, respectively. Compared with the N150-150 treatment, further application of nitrogen fertilizer during the rice season increased rice and rapeseed yields by 9.6% and 6.6%, respectively, while application of nitrogen fertilizer during the rapeseed season increased yields by 4.4% and 23.7%, respectively. Nitrogen application mainly increased crop yield by increasing the number of siliques per plant in rapeseed, the number of effective panicles per area in rice, and the number of grains per panicle, with rapeseed having a higher yield increase effect. In addition, from the analysis of the annual nitrogen fertilizer yield-increasing effect in the rotation system, compared with the application of 150 kg·hm^-2 of nitrogen in both rice and rapeseed seasons, the system energy yield and nitrogen accumulation of the rotation system under N225-150 treatment increased by 8.4% and 13.5%, respectively, and those under N150-225 treatment increased by 10.6% and 18.4%, respectively; at the same time, the annual nitrogen fertilizer utilization rate in the rice season with additional nitrogen application was 2.7 percentage points lower than that in the rapeseed season with additional nitrogen application, which might be related to the fact that the soil basic nitrogen supply in the rice season was 91.1% higher than that in the rapeseed season, resulting in a lower demand for high nitrogen input.【Conclusion】Therefore, in actual production, the annual nitrogen allocation should be adjusted according to the crop nitrogen requirements and soil nitrogen supply characteristics of the rotation system. In the rapeseed season, the nitrogen fertilizer application could be appropriately increased to achieve high yield, while in the rice season, the soil nitrogen supply capacity should be fully utilized, and the nitrogen fertilizer application should be appropriately controlled to achieve stable and efficient production of the rice-rapeseed rotation system.

【Objective】The aim of this study was to investigate the effects of potassium (K) fertilizer application rates on crop productivity, K utilization, and apparent K balance under the rice-rapeseed rotation system in the Yangtze River Basin, so as to provide a scientific basis for the rational application and distribution of potassium fertilizer in the rice-rapeseed rotation system.【Method】A field experiment was carried out from 2016 in Wuxue City, Hubei Province, China. Five treatments were set up with 0 (K₀), 60 (K₆₀), 120 (K₁₂₀), 180 (K₁₈₀) and 240 (K₂₄₀) kg K₂O·hm^-2, respectively. The crop yield, K uptake, K fertilizer utilization and apparent K balance were studied from 2016 to 2024.【Result】K fertilization significantly increased crop yield and aboveground K uptake, with the increase in rapeseed yield and aboveground K uptake being greater than that of rice. Compared with K₀, K application significantly increased rice and rapeseed yield by 18.1%-32.7% and 46.7%-93.1%, respectively, and K uptake by 72.3%-240.1% and 124.6%-512.2%, respectively. K fertilization significantly reduced yield stability index of rapeseed yield by 24.2%-41.2%, and markedly increased yield sustainability index (SYI) by 23.2%-45.7%. The yield stability index of rice yield across all treatments was lower than that of rapeseed, and SYI was comparatively higher. The annual energy yield under the K₀ treatment exhibited a progressive decline with each successive year of crop rotation. The increase in rapeseed yield was primarily attributed to an increase in pod number and seed number, whereas in rice, it was mainly due to an increase in effective panicles and filled grains per panicle. As the K fertilizer application rates increased, the proportion of K uptake in rapeseed within the annual system rose, with the average K uptake ratio between rice and rapeseed being 3:2. The agronomy efficiency and the recovery efficiency of K fertilizer in rice were on average 4.5 kg·kg^-1 and 2.5 percentage points higher than those in rapeseed, respectively. Conversely, the K fertilizer dependency of rapeseed was 11.6 percentage points higher than that of rice. K application shifted the annual K apparent balance from deficit to surplus. When the K fertilizer application rate increased to 180 kg K₂O·hm^-2 during the rice season, the K balance transitioned from deficit to surplus, while in the rapeseed season, 60 kg K₂O·hm^-2 was required to achieve surplus. Fitting with a linear-plus-plateau model, the optimal K fertilizer application rates were determined to be 102 kg K₂O·hm^-2 for the rice season and 147 kg K₂O·hm^-2 for the rapeseed season. 【Conclusion】In summary, the application of potassium fertilizer increased the yield of rapeseed better than that of rice. The recommended annual potassium fertilizer application rate for the rice-rapeseed rotation system was 250 kg K₂O·hm^-2, with the fertilization ratio between the rice season and the rapeseed season being approximately 2:3.