Qianqian Chen

The dynamic response of soil bacterial communities to fertilization throughout the entire crop growth cycle remains inadequately characterized. To address this, we conducted a long-term field experiment in Jiangle County, Fujian Province, China, and collected soil samples across four rice growth stages (tillering, elongation, filling and maturity) under five fertilization regimes: no fertilization (CK); chemical fertilizer (NPK); and NPK supplemented with extra nitrogen (NPKN), extra phosphorus (NPKP) and rice straw (NPKS). Bacterial communities were analyzed by high-throughput sequencing. Our results revealed that soil bacterial diversity decreased progressively throughout the growth stages, with fertilization exerting only a minor influence. Structural equation modeling (SEM) identified daily mean temperature (DMT) as the factor with the strongest direct and total effects on the diversity. In contrast, fertilization regimes were the primary determinant of the community structure. Mantel test and redundancy analysis (RDA) indicated that soil pH was the most important factor shaping the community structure. Soil bacterial network attributes also varied mainly with fertilization: fertilizer addition reduced the complexity but enhanced stability, with NPK and NPKS showing the greatest stability. Regarding rice yields, all fertilized treatments were comparable but considerably higher than CK. In conclusion, rice growth stages primarily influenced soil bacterial diversity, while fertilization regimes predominantly shaped the community structure and network attributes. Further, we recommend NPK and NPKS as optimal strategies for balancing crop production, agroecosystem sustainability and environmental health.

Nitrification inhibitors are essential in agricultural and environmental production practices. They play a crucial role in promoting agricultural and environmental sustainability by enhancing nitrogen use efficiency, boosting crop yields, and mitigating the adverse environmental effects of nitrogen losses. This bibliometric analysis covers the period from 2004 to 2023, offering a detailed examination of the development of nitrification inhibitor research. The study demonstrates a consistent growth in research publications, indicating sustained interest and dedication to advancing the field. It identifies key contributors, such as institutions and researchers, and underscores the significance of their work through citation analysis. Keyword co-occurrence analysis reveals four distinct clusters focusing on enhancing crop yields, understanding microbial community dynamics, exploring grazing pasture applications, and addressing environmental impact mitigation. The cutting-edge area of keyword burst detection research has transitioned from fundamental research to comprehensive nitrogen management practices. This analysis provides insights into the current research landscape of nitrification inhibitors and proposes future research directions, underscoring the critical role of this field in tackling global agricultural and environmental challenges.

BACKGROUND: As feeding probiotics, Bacillus subtilis FJAT‐4842 and Lactobacillus plantarum FJAT‐13737 were employed to improve the nutritional value and reduce the risk of contamination in the solid‐state fermentation of soybean meal (SBM).RESULTS: After fermentation with bacterium starters, the crude protein, free amino acid and lactic acid increased, with higher protease and cellulose activity. The addition of L. plantarum could increase the crude protein and lactic acid content by 50.1% and 94.9%, respectively. After fermentation, the contents of crude fiber and phytic acid decreased by 45.9% and 48.1%. Compared with control treatment, the addition of both B. subtilis FJAT‐4842 and L. plantarum FJAT‐13737 could effectively elevate the production of free amino acid and esters. Moreover, the addition of bacterium starter could prevent the production of mycotoxin and promote bacterial diversity of the fermented SBM. Especially, the addition of B. subtilis could reduce the relative content of Staphylococcus. After fermentation for 7 days, lactic acid bacteria including Pediococcus, Weissella and Lactobacillus became the main bacteria in the fermented SBM.CONCLUSION: The addition of bacterium starter is of benefit with respect to improving the nutritional value and reducing the risk of contamination in the solid‐state fermentation of soybean. © 2023 Society of Chemical Industry.