The research on rice lodging resistance holds immeasurable value for achieving high yield, stable production, and superior quality of rice. To investigate the effects of mechanical properties and physicochemical characteristics of Japonica hybrid rice on its lodging resistance ability under natural field cultivation conditions, LY1052, LY9906, and GY1, which were mainly popularized in northern China, were selected as the experimental subjects, and NL313, Japonica hybrid rice prone to lodging, was taken as the control (NL313).The max bending force, breaking moment, bending section coefficient, single stem weight mass moment, bending strength, Young’s elastic modulus, inertia moment, and other mechanical indexes were measured by the bending test and tensile test, and the correlations between mechanical indexes, physicochemical indexes, and lodging index were studied. There was an extremely significant difference in the lodging index of experimental subjects and control (NL313) (p < 0.05). Therefore, it was concluded that the lower plant height and lighter panicle were not the stronger lodging resistance under appropriate cultivation conditions. Optimization of rice plant-type structure can achieve the unity of high culm and high yield. The lodging resistance of rice could be improved by shortening the internode length, increasing the tissue thickness and vascular bundle area, and increasing the content of cellulose and potassium in the stem. It was also found that the lodging resistance of rice plants was positively correlated with the maximum stem bending force, breaking moment, bending section coefficient, bending strength, and Young’s elastic modulus (p < 0.01) and negatively correlated with single stem weight mass moment and inertia moment (p < 0.01). It is feasible to select them as reference indexes of the lodging resistance of rice. The experimental results not only help to enrich the theoretical system of rice lodging resistance research but also provide an essential reference and basis for formulating scientific cultivation and management measures and breeding lodging-resistant rice varieties in practical production, which is of great significance for ensuring global food security and promoting sustainable agricultural development.

A comprehensive understanding of rice straw (RS) and biochar (BC) addition affecting soil quality, enzyme activities, bacterial community structure and grain yield is crucial. The objective of this study was to examine the dynamics of the soil microbial community impacted by the application of rice straw and biochar, and to understand the relationship between the microbial communities, soil enzymes, nutrients and grain yield of paddies. We conducted a field experiment with organic amendments under the direct seeding of paddies. The bacterial community structure in the rhizosphere was characterized using high-throughput 16S rRNA sequencing. The results showed that RS amendment increased grain yields by 8.5 and 9.9% more than with BC and the control without organic amendment (CK), respectively (p < 0.05). The abundance of bacteria associated with nitrate reduction in RS was higher than that in BC and CK, which further showed the significance of the RS-treated soil bacteria in rice nutrient utilization. A cladogram plotted using linear discriminant analysis effect size showed that Proteobacteria (Alphaproteobacteria), Acidobacteria, Firmicutes, Verrucomicrobia and Epsilonbacteraeota in the RS-treated soil increased in comparison with CK. Pearson’s correlation analysis showed that enzymes activities (cellulase activity and protease activity), soil nutrition content (soil hydrolyzable nitrogen), and bacterial phyla (Nitrospinae) were positively correlated with grain yield, suggesting that the RS-treated soil improved enzyme activities, soil nutrition content, and bacterial abundance, which in turn increased grain yield. The results indicated that RS-treated bacterial communities combined with soil enzymatic activities strengthen the transformation of nutrients, suggesting that the interactions play an important role in enhancing the grain yield of paddy rice. These results provide new insights and a theoretical basis for studying the changes in soil microbial communities with the application of RS and BC in Northeastern China.

Micro-nondestructive detection of the moisture and ion of rice seeds during germination under salt stress

Rice serves as the staple food for over 50% of the world's population, making its yield prediction crucial for food security. The number of panicles per unit area is a core parameter for estimating rice yield. However, traditional manual counting methods suffer from low efficiency and significant subjective bias, while unmanned aerial vehicle (UAV) images used for panicle detection face challenges such as densely distributed panicles, large scale variations, and severe occlusion. To address the above challenges, this paper proposes a rice panicle detection model based on an improved You Only Look Once version 11x (YOLOv11x) architecture. The main improvements include: 1) Introducing a Bi-level Routing Attention (BRA) mechanism into the backbone network to improve the feature representation capability for small objects; 2) Adopting a Transformer-based detection head (TransHead) to capture long-term spatial dependencies; 3) Integrating a Selective Kernel (SK) Attention module to achieve dynamic multi-scale feature fusion; 4) Designing a multi-level feature fusion architecture to enhance multi-scale adaptability. Experimental results demonstrate that the improved model achieves an mAP@0.5 of 89.4% on our self-built dataset, representing a 3% improvement over the baseline YOLOv11x model. It also achieves a Precision of 87.3% and an F1-score of 84.1%, significantly outperforming mainstream algorithms such as YOLOv8 and Faster R-CNN. Additionally, panicle counting tests conducted on 300 rice panicle images show that the improved model achieves R² = 0.85, RMSE = 2.33, and rRMSE = 0.13, indicating a good fitting effect. The proposed model provides a reliable solution for intelligent in-field rice panicle detection using UAV images and holds significant importance for precise rice yield estimation.

With the continuous improvement in living standards, consumers’ demand for rice quality has been increasingly growing. This study analyzed the quality characteristics of different rice varieties under various cultivation methods. This study examined the rice variety Liaoxing 21 (LX21), the upland rice variety Han 9710 (H9710), and the hybrid rice variety Liaoyou 7362 (LY7362) from Liaoning Province to evaluate the effects of transplanting (TP) and direct seeding (DS) on processing, appearance, nutritional, and tasting quality. The results indicated that the planting method (PM) had a relatively minor impact on processing quality. Compared to TP, DS significantly increased grain length (GL) by 1.19%, grain width (GW) by 2.69%, appearance (A) by 2.61%, stickiness (Ss) by 7.15%, degree of balance (DB) by 3.19%, apparent amylose content (AAC%) by 6.20%, fa by 0.66%, fa/fb₃ by 5.34%, and protein content (PC) by 19.93%. However, DS significantly reduced the grain length/width ratio (GL/W) by 1.03%, chalky grain rate (CGR) by 46.00%, chalkiness (CH) by 52.76%, and fb₃ by 4.23%. Compared to DS, TP resulted in a higher peak viscosity (PV), final viscosity (FV), and pasting temperature (PaT), whereas setback (SB) was lower. Among the tested varieties, LX21 exhibited superior milled rice rate (MRR), head rice rate (HRR), GL, GL/W, A, Ss, DB, taste value (T), and FV compared to H9710 and LY7362, while demonstrating significantly lower CGR, CH, hardness (H), fa, trough viscosity (TV), and peak time (PeT). Under the same planting conditions, the conventional rice variety LX21 demonstrated excellent processing, appearance, and taste quality, whereas H9710 exhibited favorable nutritional quality and Rapid Visco Analyzer (RVA) characteristics. Meanwhile, we also analyzed the correlation between temperature/light conditions and nutritional quality, as well as RVA profiles. The results showed that variations in temperature and light were closely associated with amylopectin accumulation and starch pasting properties. This study highlights the findings that selecting the appropriate PMs and japonica rice varieties can effectively enhance overall rice quality. In the medium maturing regions of Liaoning Province, adopting DS with medium–early maturing japonica rice varieties offers an optimal production strategy for achieving high quality, high yield, and efficient utilization of temperature and light resources.

The quality of rice, one of the most important food crops in the world, is directly related to people’s dietary experience and nutritional health. With the improvement in living standards, consumer requirements for the taste quality of rice are becoming increasingly strict. Japonica rice occupies an important position in rice production due to its rich genetic diversity and excellent agronomic characteristics. In this study, LJ433, JY653, LJ218, LJ177, LY66, and LX21, which are mainly popularized in northern China and have different taste values, were selected as the experimental subjects, and YJ219, which won the gold award in the third China high-quality rice variety taste quality evaluation, was taken as the control (CK). Low-field nuclear magnetic resonance and spectral analysis were adopted as the main detection techniques. The effects of free water (peak area increased by 13.24–86.68% when p < 0.05), bound water, appearance characteristics (such as chalkiness, which decreased by 18.48–86.48%), and chemical composition (amylose content decreased by 3.76–26.47%) on the taste value of rice were systematically analyzed, and a multi-dimensional “appearance–palatability–nutrition” evaluation system was constructed. The experimental results indicated that increasing the free water content, reducing the chalkiness and chemical component content could significantly improve the taste value of rice (p < 0.05). The results of this research provide a theoretical basis for breeding new high-yield and high-quality rice varieties and have guiding significance for the practice of rice planting and processing.