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    Special Thesis & Basic Research
    Advantages, Challenges, and Development Strategies of the Double-Season Direct-Seeded Rice Production in China
    ZHANG Zhe, HUANG Kunming, CHU Guang
    2025, 31(5): 1-7.  DOI: 10.3969/j.issn.1006-8082.2025.05.001
    Abstract ( )   HTML ( )   PDF (1133KB) ( )  

    The rice production pattern of “double-season direct-seeded” boasts advantages, such as remarkable effects in labor and cost saving, full and efficient utilization of temperature and light resources, as well as high and stable yields. Currently, this production pattern has been gradually promoted and applied in China’s double-cropping rice regions, demonstrating a favorable development trend. This paper systematically reviews the advantages and existing problems of the “double-season, direct-seeded” production pattern for double-cropping rice in China and delves into strategies for its further development in the later stages for promoting the development of simplified cultivation patterns for double-cropping rice.

    Research Status and Development Trend of Water-Saving Irrigation for Rice in China
    WANG Boqing, YAN Tingqi
    2025, 31(5): 8-16.  DOI: 10.3969/j.issn.1006-8082.2025.05.002
    Abstract ( )   HTML ( )   PDF (1270KB) ( )  

    This paper provides a comprehensive review of the current contradiction between the supply and demand of agricultural water resources in China, as well as the research status of water-saving irrigation for rice. The study systematically summarizes and analyzes the research from two perspectives: water-saving irrigation technologies and water-saving irrigation equipment. It identifies existing problems, proposes corresponding solutions, and anticipates development trends, aiming to offer theoretical support for future research on rice stress resistance and water-saving irrigation in China. Rain-adapted irrigation and rainwater-storage irrigation are the most prevalent water-saving irrigation modes in rice cultivation. On large-scale farms, integrated water and fertilizer devices and sprinkler irrigation systems are the most commonly used rice irrigation machinery. Currently, research on water-saving irrigation for rice in China mainly faces the following challenges: there is a significant lack of independent research on irrigation technologies for specific terrains; the existing irrigation equipment is not accurate enough in determining the irrigation area, resulting in insufficient irrigation water supply; the water resource utilization efficiency of mechanical irrigation is low, and the effective irrigation rate needs further enhancement; the coverage of modernization renovation for irrigation districts is limited, and promotion efforts are insufficient; irrigation technologies in urban and rural areas are complex, and operational maintenance and technical support are inadequate. To address these issues, the following measures can be taken in the future. Firstly, vigorously develop intelligent irrigation devices suitable for different terrains. Secondly, optimize the structure of water emitters and promote research on constant-pressure technology in water conveyance pipelines. Thirdly, increase publicity efforts for water-saving irrigation technologies, improve relevant laws and regulations regarding subsidies for irrigation district renovation, and establish advanced demonstration parks for water-saving irrigation in urban and rural areas. Fourthly, intensify the promotion of technical services for water-saving irrigation in urban and rural areas. Through these initiatives, we can drive the high-quality development of China’s rice water-saving irrigation industry and inject strong momentum into rural revitalization.

    Research Progress of Degradable Film Rice Transplanting Machinery in North China
    LU Miao, ZHANG Weiping, HU Anrui, WANG Liuxihang, YANG Shengjie, ZHAN Yingchao, WEI Lixing, FU Shenghui, GUO Lei, LIU Shuangxi
    2025, 31(5): 17-25.  DOI: 10.3969/j.issn.1006-8082.2025.05.003
    Abstract ( )   HTML ( )   PDF (1324KB) ( )  

    The northern region of China has unique advantages in high-quality rice production due to natural conditions such as a large diurnal temperature range and sufficient light. However, due to factors such as low ground temperature, water shortage, excessive use of pesticides and fertilizers, and traditional plastic film pollution, rice cultivation in the north still faces many challenges in terms of sustainable development. The biodegradable film mulching rice transplanting machine uses biodegradable film as covering material, integrates high-efficiency transplanting technology with film mulching, realizes synchronous operation of film mulching and transplanting, and integrates functions such as temperature and moisture retention, weed inhibition and fertilizer saving, and pest and disease prevention and control. This technology can significantly improve the survival rate and early growth advantages of rice seedlings, promote the stable yield and quality of rice, and effectively reduce the residual pollution of plastic film, which is one of the key technologies for achieving the green and sustainable development of rice cultivation in northern China. This paper systematically reviews the research progress of biodegradable film mulching rice transplanting machinery at home and abroad, analyzes its mechanism and application effect in rice production in northern cold regions, summarizes the existing problems and technical bottlenecks, and prospects the future development direction, so as to provide theoretical support and technical reference for promoting the integration and development of rice planting mechanization and greening in northern China.

    Research Progress on Rice Seedling Substrate Based on Different Mechanized Planting Methods
    LI Huixiu, ZHAO Xinhui, YE Yumeng, LIU Wen, JIN Shihao, FU Zhiqiang, XU Ying, WANG Yue, LONG Pan
    2025, 31(5): 26-32.  DOI: 10.3969/j.issn.1006-8082.2025.05.004
    Abstract ( )   HTML ( )   PDF (971KB) ( )  

    Mechanized production of agriculture is an important way to ensure food security in China. In the process of rice production, seedling raising determines the quality of seedlings and transplanting quality. Under the background of the rapid development of mechanization, the traditional field mud seedling raising method can no longer meet the production needs, and a special seedling raising matrix matching with mechanization is needed to adapt to the future development. This paper summarizes the development process, characteristics, current situation and existing problems of seedling raising substrates under the two mechanized transplanting modes of machine transplanting and machine seedling throwing, and puts forward the prospect of the development of the two substrates. Through the review, it is clear that the research of machine transplanting seedling raising matrix is more in-depth than that of machine throwing seedling raising, and the mature supporting technology of the product is advanced, but there are some problems such as high cost and uneven commodity quality. The machine-throwing seedlings have high requirements on the matrix, and too heavy substrate leads to difficulties in obtaining materials and inconvenient transportation. Too light substrate leads to problems such as shallow mud entry and easy floating of seedlings. In the future, the matrix utilization of agricultural waste materials should be considered to reduce the production cost and ensure the balance and stability of matrix nutrients. The machine-throwing seedling substrate should focus on the development of machine-throwing special substrate from the perspective of physical properties and nutrient balance of the substrate.

    Research Progress in Rice Leaf Lateral Asymmetry
    LI Jie, XU Guiling, FEGN Yuehua, HUANG Yougang
    2025, 31(5): 33-38.  DOI: 10.3969/j.issn.1006-8082.2025.05.005
    Abstract ( )   HTML ( )   PDF (702KB) ( )  

    Rice leaves, as the primary source of dry matter production and grain yield, exhibit a range of physiological functions, including photosynthesis, respiration, and transpiration. These leaves can be divided along the main vein, revealing distinct morphological and physiological traits on each side, such as variations in width, thickness, SPAD value, and nitrogen content, which manifest a striking and unique lateral asymmetry. Symmetry and asymmetry are widespread in nature, with biological asymmetry being categorized into three types: fluctuating asymmetry, directional asymmetry, and antisymmetry. Existing research has shown that rice leaf lateral asymmetry belongs to directional asymmetry, where one side of the main vein is wider, thicker, and rougher than the other, and also exhibits a lower SPAD value and nitrogen content. Moreover, the tillering characteristic of rice plants imparts a distinct location distribution to the lateral asymmetry of its leaves. Notably, within a rice population, the smooth side (the narrower and thinner side) of the leaf has an almost equal probability (approximately 50%) of appearing on either the left or the right. As such, the location distribution characteristics of rice leaf lateral asymmetry can be considered as exhibiting fluctuating asymmetry with an ideal distribution probability of 50%. Furthermore, certain regulatory genes that influence rice leaf width also affect the degree of rice leaf lateral asymmetry. One such gene is Leaf Lateral Symmetry 1 (LSY1), which has been clearly linked to rice leaf lateral asymmetry. In this paper, we review the progress of research on rice leaf lateral asymmetry from morphological, physiological, and genetic standpoints, and classify rice leaf transverse asymmetry into four levels: single leaf, single stem, single plant, and population. However, there is a limited amount of literature on rice leaf transverse asymmetry in the fields of crop science and plant physiology, and further exploration is needed to determine whether it significantly impacts rice yield and quality.

    Research Progress on the Influencing Factors of Regenerated Bud Germination and Growth in Ratoon Rice
    WU Yajin, LI Yang, WANG Benfu, ZHANG Zhisheng, XIE Yi, ZHANG Zuolin, CHENG Jianping
    2025, 31(5): 39-46.  DOI: 10.3969/j.issn.1006-8082.2025.05.006
    Abstract ( )   HTML ( )   PDF (928KB) ( )  

    Ratoon rice is a planting pattern that involves taking specific cultivation measures after the harvest of the first-season rice to enable dormant buds to tiller, form panicles, and set grains again, thus achieving a second harvest. This planting pattern can make full and efficient use of temperature and light resources, effectively increase the multiple cropping index, and raise the grain yield per unit area. It is one of the important ways to improve the planting efficiency of paddy fields in China. Among the yield-contributing factors, the number of effective panicles has a significant impact on the yield and its stability in the ratoon season. The number of effective panicles in the ratoon season mainly depends on the survival number of ratoon buds and the number of established seedlings. Therefore, improving the survival rate and seedling establishment rate of ratoon buds is the key to increasing the yield in the ratoon season. This paper elaborated the growth characteristics and physiological basis of ratoon buds in ratoon rice, reviewed various factors affecting the growth and development of regenerated buds, thoroughly explored possible ways to improve the sprouting and panicle-forming rate of regenerated buds, and look forward to future research directions. The aim is to provide valuable theoretical references for high-yield research of ratoon rice.

    Research Progress on Cultivation Techniques for High-Yield and High-Quality of Double-Cropping Late Rice
    JIANG Xintong, DOU Zhi, LIAO Ping, GAO Hui
    2025, 31(5): 47-50.  DOI: 10.3969/j.issn.1006-8082.2025.05.007
    Abstract ( )   HTML ( )   PDF (537KB) ( )  

    The yield and quality of double-cropping late rice are comprehensively influenced by numerous factors, including the status of stubble connection, conditions of temperature and light resources, inherent characteristics of rice varieties, as well as cultivation techniques and measures. This paper systematically analyzed the key elements affecting the production of double-cropping late rice and focused on elucidating the research progress in key technologies such as rationally selecting rice varieties, determining suitable sowing dates, optimizing transplanting methods, scientifically managing nitrogen fertilizer application, and precisely controlling water management. Research indicated that by meticulously optimizing cultivation measures, the yield of double-cropping late rice can be significantly increased, and the quality of rice grains can be effectively improved. In the future, research should place emphasis on strengthening the selection and promotion of early-maturing and high-quality rice varieties, as well as the innovation and application of cultivation techniques for high yield, superior quality, and stress resistance. This will facilitate the coordinated advancement of high yield and high quality in double-cropping late rice, providing advanced and applicable technological support for increasing yield per unit area and enhancing quality on a large scale.

    Effects of Low Temperature and Insufficient Light during the Early Stage of Early Rice on Growth and Development and its Regulatory Techniques
    TANG Xinxin, ZHANG Zhouna, XIAO Deshun, CHEN Liping, WANG Danying, ZHU Yijun, ZHANG Xiaoguo, XU Chunmei
    2025, 31(5): 51-57.  DOI: 10.3969/j.issn.1006-8082.2025.05.008
    Abstract ( )   HTML ( )   PDF (925KB) ( )  

    Early rice is one of the important food crops in the southern China, and the stability of its yield is of great significance for ensuring food security. However, the intensifying global climate change has led to an increasing frequency of extreme weather events, posing unprecedented challenges to early rice production. During the growth cycle of early rice, low temperature and insufficient light in the early stage often result in impeded seed germination, retarded seedling growth, decreased tillering, and reduced heading rates, severely constraining early rice yields. This paper reviewed the effects of low-temperature and insufficient light in the early stage on the growth, physiological metabolism, and expression of related stress resistance gene in early rice. It also discussed the evaluation indicators for early rice varieties resistant to low temperature and insufficient light, summarized cultivation and regulation techniques to enhance early rice’s tolerance to low temperatures and insufficient sunlight, and put forward suggestions for future research directions.

    Eeffects of Foliar Nitrogen Application on Yield and Quality of the Ratoon Crop of Ratoon Rice under Mechanized Harvesting Conditions for the Main Crop
    CHEN Zifang, LI Jintao, CAO YuXian, HOU jun
    2025, 31(5): 58-64.  DOI: 10.3969/j.issn.1006-8082.2025.05.009
    Abstract ( )   HTML ( )   PDF (662KB) ( )  

    The ratoon crop of ratoon rice, after the mechanical harvesting of the main crop, often faces issues such as low yield and high broken rice rates. Foliar nitrogen application is a simplified fertilization technique that effectively supplements the crop's nitrogen requirements, enhancing both quality and yield. This study investigated the effects of different foliar nitrogen application rates on the growth, yield, and quality of ratoon crop rice, aiming to provide a theoretical basis for achieving high yields through mechanical harvesting and simplified fertilization in ratoon rice production. A field split-plot design with two factors was employed following the main crop rice harvest in both high-fertility (HF) and low-fertility (LF) fields. The main plot factor was rolling status (rolled and non-rolled), and the sub-plot factor was foliar nitrogen application rate, with six nitrogen gradients: 0 (N0), 1.0 (N1), 3.0 (N3), 5.0 (N5), 7.0 (N7), and 9.0 kg/hm2(N9). The results showed that, in HF, foliar nitrogen application treatments increased yields by 13.6%-37.4% in rolled areas and 35.1%-39.7% in non-rolled areas compared to N0, with the highest yields in N9 and the lowest in N1. In LF, yields increased by 15.6%-38.8%(rolled areas) and 22.3%-38.6%(non-rolled areas), respectively. Specifically, in the rolled area, the highest yield was observed in N9 and the lowest in N1, while in the non-rolled area, the highest yield was in N3 and the lowest in N1. Compared to the N0 treatment, foliar nitrogen application improved both milling and appearance quality of the ratoon crop rice to varying degrees. In rolled areas of HF, foliar nitrogen treatments significantly increased milled rice rate and head milled rice rate by 31.6%-37.5% and 65.3%-71.5%, respectively, and significantly reduced chalkiness by 20.4%-35.3%. In non-rolled area of HF, milled rice rate and head milled rice rate increased significantly by 27.2%-32.2% and 46.7%-57.0%, respectively, with chalky grain rate significantly decreased by 22.8%-38.5%. In rolled area of LF, milled rice rate and head milled rice rate increased significantly by 31.8%-37.9% and 53.4%-70.3%, respectively, with chalky grain rate significantly decreased by 20.5%-35.5%. In non-rolled area of LF, milled rice rate and head milled rice rate increased significantly by 34.9%-40.8% and 49.4%-60.2%, respectively, with chalky grain rate significantly decreased by 22.8%-38.5%. Based on the results, the optimal foliar nitrogen application rates for the ratoon crop rice under mechanical harvesting conditions of the main crop were recommended as 4.1 kg/hm2 for rolled areas and 3.0 kg/hm2 for non-rolled areas.

    Effects of Foliar Application of Nano-Silicon on Rice Yield and Physiological Characteristics under Salt Stress
    WEI Renyuan, LI Rongkai, TAN Bin, CUI Maoya, LIU Zhibo, LIU Jiatong, WEI Huanhe, DAI Qigen, XU Ke, CHEN Yinglong
    2025, 31(5): 65-70.  DOI: 10.3969/j.issn.1006-8082.2025.05.010
    Abstract ( )   HTML ( )   PDF (689KB) ( )  

    In this experiment, Nanggeng 9108 was used as the test variety. During the seedling-raising period, treatments of nano-silicon spraying (5.5 g/L) and water spraying (as control) were applied. Subsequently, the seedlings were transplanted into buckets with three salt concentration gradients (0%, 0.2%, and 0.3%). The objective was to investigate the effects of foliar application of nano-silicon on rice yield and its physiological characteristics under salt stress conditions. The results showed that compared with the control, salt stress significantly inhibited rice growth, manifested by a notable decrease in photosynthetic rate(Pn), transpiration rate(Tr), intercellular CO2 concentration(Ci), and stomatal conductance(Gs), while promoting an increase in malondialdehyde (MDA) content. Under 0.2% and 0.3% salt concentration treatments, rice yields decreased by 44.75% and 74.45%, respectively. Foliar application of nano-silicon effectively promoted rice growth under salt stress, enhanced the photosynthetic capacity of leaves during the heading stage, further increased antioxidant enzyme activity, inhibited the accumulation of reactive oxygen species(ROS), and significantly reduced MDA content, thereby alleviating oxidative damage in rice. Under 0.2% and 0.3% salt concentration conditions, foliar application of nano-silicon treatment increased yield by 15.15% and 16.54%, respectively, compared to foliar application of water treatment. In summary, exogenous application of 5.5 g/L nano-silicon can alleviate the inhibitory effect of salt stress on rice growth to a certain extent and increase rice yield in saline-alkali soil.

    Interactive Effects of Soil Fertility and Nitrogen Application Rate on N2O Emissions from Double-Cropping Rice Paddies
    ZHU jianmin, FU Wentao, SUN Wenxia, ZHANG Yuxiang, HUANG Shan, SUN Yanni
    2025, 31(5): 71-75.  DOI: 10.3969/j.issn.1006-8082.2025.05.011
    Abstract ( )   HTML ( )   PDF (632KB) ( )  

    Soil fertility and nitrogen application rate are important factors influencing nitrous oxide (N2O) emissions from paddy fields, but the interaction effects between these two remain unclear. In this study, three types of field plots (FL, low-fertility soil; FM, medium-fertility soil; FH, high-fertility soil) were selected based on the soil organic matter content, and four levels of nitrogen application rates were set (i.e., 0, 90, 150, and 210 kg/hm2, represented by N0, N90, N150, and N210, respectively), aiming to elucidate the interaction effects of soil fertility and nitrogen application rate on N2O emissions from double-cropping rice paddies. The results showed that improving soil fertility significantly reduced N2O emissions from double-cropping rice paddies, whereas increasing nitrogen application rate increased N2O emissions during the early rice season. For N2O emissions during the early rice season, FH and FM decreased emissions by 34.3% and 16.7%, respectively, compared to FL. Compared with N0 treatment, N150 and N210 treatments during the early rice season increased N2O emissions by 11.3% and 21.8%, respectively, while there was no significant difference between N90 and N0 treatment. For N2O emissions during the late rice season, FH and FM decreased emissions by 30.0% and 13.7%, respectively, compared to FL, while no significant differences among different nitrogen fertilizer treatments. There was a significant interaction effect between nitrogen application rate and soil fertility on N2O emissions during the early rice season. In the FL plot, compared to N0 treatment, the N210 treatment significantly increased N2O emissions by 50.7%, while the N90 and N150 treatments showed no significant difference. In the FM and FH plots, none of the nitrogen fertilizer treatments had significant effects on N2O emissions. Therefore, improving soil fertility combined with appropriate nitrogen application rate is beneficial for mitigating N2O emission in paddy fields.

    Effects of Irrigation and Drainage Methods During the Soaking Period on Soil Salinity and Rice Yield in Coastal Saline-Alkali Land
    YAN Sitong, ZHU Jizou, ZHANG Xiang, WANG Lulu, ZUO Boyuan, MENG Tianyao, CHEN Yinglong, DAI Qigen, WEI Huanhe
    2025, 31(5): 76-80.  DOI: 10.3969/j.issn.1006-8082.2025.05.012
    Abstract ( )   HTML ( )   PDF (523KB) ( )  

    The experiment was carried out in the salt ponds (containing three types of soil: mild, moderate, and severe saline-alkali soil) at the experimental farm of the College of Agriculture, Yangzhou University. Using the salt-tolerant rice variety Nangengyan 1 as the experimental material, two irrigation and drainage treatments (T1 and T2) were set up to explore the impacts of different irrigation and drainage methods during the ponding period in coastal saline-alkali land on soil salinity and rice yield. T1: The soil in the salt ponds was plowed once; after 24 hours, a 3-4 cm water layer was irrigated; after another 24 hours, the field was allowed to dry; after 12 hours, a 3-4 cm water layer was irrigated again, and after 24 hours, the water was drained; this cycle was repeated twice. T2: The soil in the salt ponds was plowed twice; after 48 hours, a 3-4 cm water layer was irrigated; after another 48 hours, the field was harrowed to a depth of 5 cm and then allowed to dry; after 12 hours, a 3-4 cm water layer was irrigated again, and after 24 hours, the water was drained; this cycle was repeated three times. The results showed that the desalination rates of mild, moderate, and severe saline-alkali soils under T1 treatment were 20.3%, 25.7%, and 34.5% respectively; under T2 treatment, they were 24.5%, 32.4%, and 42.4% respectively. It can be seen that both irrigation and drainage treatments had good desalination effects, with T2 treatment showing a better effect. As the degree of salt stress increased, the population tiller number, tillering panicle rate, leaf area index, dry matter weight, effective panicle number, grains per panicle, seed setting rate, 1000-grain weight and yield of rice at the jointing, heading, and maturity stages showed a decreasing trend, while the harvest index showed an increasing trend. Compared with T1 treatment, T2 treatment increased the population tiller number, tillering panicle rate, leaf area index, dry matter weight and rice yields (with increases of 1.2%, 6.0%, and 9.1% respectively) at key growth stages under mild, moderate, and severe saline-alkali conditions. Compared with mild saline-alkali land, the reductions in rice yield under moderate and severe saline-alkali conditions were 17.4% and 31.1% respectively, mainly due to its positive effects on each component of rice yield. This study indicates that reasonable irrigation and drainage methods during the ponding period help to rapidly reduce soil salinity in coastal saline-alkali land and thereby increase rice yield.

    Terraced Rice Bowl Seedlings Light Simplification Throwing Technology
    YING Junjie, QIN Yebo, GU Tianfei, ZHU Guiping, HE Haohao, MA Yihu, XU Chunchun, YANG Yajun
    2025, 31(5): 81-86.  DOI: 10.3969/j.issn.1006-8082.2025.05.013
    Abstract ( )   HTML ( )   PDF (875KB) ( )  

    Terraced fields are important farmland resources in mountainous and hilly regions. However, in recent years, rice cultivation in terraced fields has encountered a series of issues, such as low economic returns, a shortage of rural labor, inadequate mechanized supporting facilities, and poor irrigation conditions, which have resulted in the inefficient utilization of a large amount of terraced field resources. The technology for raising seedlings in bowl trays and simplified throwing-transplanting of rice in terraced fields fully leverages the ecological advantages of mountainous terraced fields and takes high-quality rice varieties as the foundation, utilizes factory-based bowl tray seedling production and supply along with simplified throwing transplantation methods, effectively enhancing labor productivity and reduces labor intensity. Meanwhile, this technology, combined with scientific fertilizer and water management as well as green pest and disease prevention and control measures, ensures stable rice yields and improves rice quality. Additionally, by optimizing storage and processing steps and engaging in brand marketing, it extends the industrial chain and enhances the value chain. This technology has achieved remarkable economic, social, and ecological benefits and is suitable for promotion and application in the hilly and mountainous regions of Southern China.

    Study on the Material Production Characteristics of High Yield Population of Different Types of Rice Variety in Cold Region
    CAI Yongsheng, XUE Jingfang, DU Xiaodong, XU Lingqi, ZHAO Haixin, YANG Limin, FENG Yanjiang, CHEN Shuqiang
    2025, 31(5): 87-92.  DOI: 10.3969/j.issn.1006-8082.2025.05.014
    Abstract ( )   HTML ( )   PDF (641KB) ( )  

    In this study, two types of rice varieties with differences in tillering capacity and panicle size were selected as materials to conduct an in-depth exploration of the material production characteristics of high-yielding populations (with a yield higher than 9 750 kg/hm2) of super rice and conventional rice varieties in cold regions. The results showed that high-yielding populations exhibited the following notable characteristics at the heading stage: the population biomass, leaf weight, and stem-sheath weight were all at high levels, accounting for relatively large proportions of the total biomass and grain yield; simultaneously, they possessed a relatively large leaf area index and a high efficient leaf area ratio. From the heading stage to the maturity stage, high-yielding populations demonstrated the characteristic of a relatively high net accumulation of dry matter, accounting for a relatively large proportion of the total biomass and grain yield; they had a strong ability to produce photosynthetic substances, specifically manifested as a low leaf area decline rate, and relatively high values of leaf area duration, population growth rate, and net assimilation rate; in addition, the output and translocation of stem-sheath substances were coordinated and orderly, with relatively high values of filled grain number per unit leaf area and grain weight per unit leaf area. During the late growth stage, high-yielding populations not only needed to have a large population sink capacity but also should maintain relatively high levels of plumpness and total plumpness, while retaining strong lodging resistance.

    Effects of Different Chemical Priming and Sowing Methods on the Seedling Emergence of Hybrid Japonica Rice
    WU Xuefan, HAN Jiajun, HU Weimin, LI Maobai, GUAN Yajing, LOU Jianfeng
    2025, 31(5): 93-99.  DOI: 10.3969/j.issn.1006-8082.2025.05.015
    Abstract ( )   HTML ( )   PDF (783KB) ( )  

    Improving sowing quality is an important guarantee for achieving high efficiency, superior quality, and high yield in rice production. In this study, seeds of the hybrid japonica rice varieties Huayou 14 and Shenyou 28 were used as experimental materials. Different concentrations of citric acid(CA) and gamma-aminobutyric acid (GABA) were applied for seed priming and soaking treatments, aiming to screen out the optimal treatment concentrations for these two agents. Subsequently, through two sowing methods—direct seeding in the field and seedling raising in trays—the effects of different sowing methods on the emergence of seeds treated with the agents were thoroughly investigated, with the goal of identifying the agents and treatment techniques that can effectively improve the field seedling emergence rate of the two hybrid japonica rice varieties. The results showed that both CA and GABA treatments promoted the germination rate and seedling growth of Huayou 14 and Shenyou 28 seeds. The optimal treatment concentration for both agents was 0.5 mmol/L. Moreover, priming treatment demonstrated significant advantages over soaking treatment in promoting seedling establishment and improving seedling quality. Field trial results indicated that CA priming treatment had a better effect on both the seedling establishing percentage and seedling quality of the two varieties under direct seeding conditions, while its effect under tray seedling raising conditions was relatively insignificant. GABA priming treatment significantly promoted the seedling establishing percentage and seedling quality of Huayou 14, and although it had no significant effect on the seedling emergence rate of Shenyou 28, it enhanced its seedling quality. The effects of GABA priming treatment were relatively consistent under both direct seeding and tray seedling raising conditions. In summary, in practical production processes, it is necessary to screen out suitable priming agents and their concentrations based on different hybrid japonica rice varieties and sowing methods.

    Effects of Reducing Nitrogen and Increasing Density under Long-Term Straw Returning on Soil Quality and Rice Yield
    LIANG Xuanhe, Li Shanlong, ZHAO Xin, WANG Jianxin, LI Tao, XIN Yuwei, CAO Tiehua
    2025, 31(5): 100-104.  DOI: 10.3969/j.issn.1006-8082.2025.05.016
    Abstract ( )   HTML ( )   PDF (572KB) ( )  

    Rice straw returning is an effective strategy for soil amelioration, fertility enhancement, and agro-ecosystem conservation. Straw returning combined with chemical fertilizer application synergistically improves soil productivity and crop yields. Using Jigeng 81 as experimental material, we systematically compared the effects of five fertilizer-density treatments on paddy soil quality and rice yield under long-term straw returning through a positioning experiment. The results showed that prolonged straw returning significantly enhanced soil physicochemical properties. Compared with initial values, contents of total nitrogen, total phosphorus, total potassium, available nitrogen, available phosphorus, available potassium, and organic matter increased substantially, while soil pH demonstrated a decreasing trend. These changes collectively indicated remarkable improvement in soil comprehensive quality. Among the five treatments, T3 treatment(20% increased density+conventional fertilization) and T5 treatment (20% increased density+20% reduced nitrogen) exhibited pronounced yield-increasing effects. Notably, T5 treatment achieved 17.88% and 16.74% higher yields than T1 treatment (normal density + conventional fertilization) across two consecutive years. T5 treatment demonstrated superior agronomic efficiency and partial productivity of nitrogen fertilizer compared to other treatments. This study demonstrated that under long-term straw returning, adopting a cultivation model combining 20% nitrogen reduction with 20% density increase (T5) could effectively balance yield, economic, and ecological benefits, thereby achieving increased yield, enhanced efficiency, and sustainable development in rice production.

    Varieties & Technology
    Effects of CO2 Aqueous Solution on the Growth and Yield of Rice under Film Mulching Drip Irrigation
    ZHAO Shuangling, WANG Shengyi, WANG Xiaojuan, MA Chenhu, HAO Yufeng, ZHU Jiangyan, BAO Fangjun
    2025, 31(5): 105-107.  DOI: 10.3969/j.issn.1006-8082.2025.05.017
    Abstract ( )   HTML ( )   PDF (368KB) ( )  

    Using the rice variety Ninggeng 53 as material, this study investigated the effects of drip-applying CO2 aqueous solution on the growth period, tillering dynamics, plant height, and agronomic traits of rice under film mulching drip irrigation. The results showed that, compared with conventional irrigation, drip-applying CO2 aqueous solution shortened the growth period of rice under film mulching drip irrigation by 3 days but significantly increased its plant height (by 7.14%-8.19%), SPAD value (by 10.56%-11.20%), the diameter of the second node from the top (by 6.14%-7.23%), effective tiller number (by 10.11%-10.34%), effective panicle number (by 1.33%-1.52%), and 1000-grain weight (by 1.64%-2.07%), ultimately, increased the yield by 10.39%-12.21%.

    Effects of Seedling Age and Planting Densities on Growth and Yield Formation of Mechanical Transplanted Early Indica Rice Zhongzu 143
    LI Hui, LAN Tianming, WANG Jingqing, TANG Chenghan, ZHANG Yuping, WANG Yaliang
    2025, 31(5): 108-111.  DOI: 10.3969/j.issn.1006-8082.2025.05.018
    Abstract ( )   HTML ( )   PDF (604KB) ( )  

    Extending the seedling age can lead to a decrease in the yield of mechanically transplanted early rice, while different planting densities significantly affect the production of machine-transplanted rice with extended seedling age. This study aims to clarify the effects of different planting densities in alleviating yield loss caused by prolonged seedling age. This experiment used the conventional early indica rice variety Zhongzu 143 as the research subject. Two different seedling ages for mechanical transplantation were established: 20 days (B1) and 35 days (B2), and three planting specifications for mechanical transplantation were set: 30 cm × 12 cm (D1), 30 cm × 16 cm (D2), and 30 cm × 18 cm (D3). The changes in tillering dynamics, dry matter accumulation, and yield as well as its components of rice populations under different planting densities were investigated. The results showed that for early rice with extended seedling age under mechanical transplantation, the dry matter accumulation decreased, tillering slowed down, and the number of effective panicles reduced, leading to a decrease in yield. For early rice with extended seedling age under mechanical transplantation, increasing the planting density could enhance the number of effective panicles and dry matter accumulation, thus increasing the yield. In summary, increasing the planting density can compensate for the reduction in the number of effective panicles and dry matter accumulation under extended seedling age, thereby effectively alleviating the yield loss associated with mechanical transplantation of rice with extended seedling age.

    Effects of Rice-Morel Rotation on Rice Yield and Quality
    LI Dongmei, JIN Meijuan, WANG Haihou, LV Zhiwei, LU Changying, DONG Minghui
    2025, 31(5): 112-116.  DOI: 10.3969/j.issn.1006-8082.2025.05.019
    Abstract ( )   HTML ( )   PDF (590KB) ( )  

    Selecting Suxianggeng 100 as the experimental variety and using the conventional rice-wheat model as a control, this study explored the effects of the rice-morel rotation model on rice yield and quality under different rotation durations. The results showed that compared to the rice-wheat model, neither the three-year nor the one-year rice-morel rotation significantly affected rice yield. However, the rice-morel rotation significantly improved rice milling quality (brown rice rate, milled rice rate, head rice rate) and eating quality (gel consistency, taste value), while significantly reducing cooking characteristics (water absorption of cooked rice, volume expansion rate, dry matter content of rice soup, iodine blue value). In summary, compared to the rice-wheat model, the rice-morel rotation model can improve rice quality without affecting rice yield, resulting in higher overall benefits.

    Local Rice
    Strengthening the Research and Application of the “Rice +” Model to Promote the Coordinated Development of Grain Crop and Cash Crop in Low-Latitude Plateau Areas
    LI Xiaolin, QU Yunhui, DONG Wei, DENG Wei, KUI Limei, TUjian , SHEN Xiqiong
    2025, 31(5): 117-120.  DOI: 10.3969/j.issn.1006-8082.2025.05.020
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    This paper analyzes the development trends and existing problems of the “rice-plus” grain-economy synergistic model in Yunnan, and proposes future development strategies focusing on breeding specialized varieties, researching synergistic models, and developing high-yield, high-efficiency production technologies. Strengthening the research and application of the “rice+” model holds significant importance for effectively addressing the numerous challenges faced by low-latitude plateau regions, with Yunnan as a representative example. These challenges include prominent conflicts over land use between grain crops and cash crops, immense pressure on grain production, and relatively low comprehensive returns. By promoting the “rice+” model, it is possible to drive the coordinated development of grain crops and cash crops, thereby playing a leading role in safeguarding food security and enhancing the quality of cultivated land.

    Inspiration and Suggestions from the Rapid Development of Ratoon Rice in Huoqiu County, China
    FENG Yupeng
    2025, 31(5): 121-124.  DOI: 10.3969/j.issn.1006-8082.2025.05.021
    Abstract ( )   HTML ( )   PDF (516KB) ( )  

    Huoqiu County is located in the western part of Anhui Province and lies within an ecological zone for rice cultivation where “two crops a year are insufficient, but one crop leaves surplus.” In recent years, the production of ratoon rice in Huoqiu County has shown a vigorous development trend. The planting area has developed to 4.5×104 hm2, occupying 25.4% of rice planting area and 15.0% of grain production area in the county, and grain production increased 17×104 t, and it is now the largest ratoon rice planting country in China. This article provides a comprehensive review of the development history of ratoon rice in Huoqiu County and offers an in-depth analysis of the remarkable achievements in terms of enhancing ratoon rice production capacity, demonstration and promotion, as well as overall benefits. Furthermore, from key perspectives such as demonstration-led development, technology empowerment, and policy support, the article systematically summarizes the successful experiences and effective practices that have facilitated the rapid development of the ratoon rice industry in Huoqiu County. Meanwhile, the article also delves into the issues faced during the rapid development of local ratoon rice and puts forward practical and feasible suggestions, aiming to offer important experience and references for other counties suitable for developing ratoon rice.