Bioscience Methods 2025, Vol.16, No.4, 204-217 http://bioscipublisher.com/index.php/bm 209 genotypes. For example, by replacing the key nucleotides of japonica rice OsNRT1.1B with indica rice types through base editing, a new strain with stronger nitrogen absorption capacity was successfully cultivated, and the yield was significantly improved under low nitrogen fertilizer supply (Liu et al., 2023). For another example, a study targeted the regulation of a gene DNR1 that affects auxin balance and obtained high-NUE and high-yield materials. Aggregating multiple favorable sites is also an effective strategy. Gene editing can be used to simultaneously knock out negative regulatory genes and introduce excellent alleles in a variety, thereby improving nitrogen efficiency in all aspects. Some scholars have proposed a "gene pyramid" scheme, combining favorable genes for different links such as nitrate nitrogen absorption, ammonium assimilation and growth regulation. At present, emerging technologies for improving rice nitrogen efficiency also include genomic selection and epigenetic regulation. Molecular breeding and biotechnology are accelerating the breeding process of nitrogen-efficient rice. In the future, through the precise improvement of key genes and the aggregation of multiple genes, it is expected that new rice varieties with high and stable yields under low input conditions will be cultivated. 4 Exploration of Green Fertilization Management Technologies in Field Applications 4.1 Optimization and configuration of controlled-release fertilizer technologies Traditional nitrogen application methods such as one-time basal application or multiple broadcasting are prone to cause excessive nitrogen supply in the early stage, insufficient supply in the later stage, and serious nutrient loss. Controlled-release fertilizer (CRF) delays nitrogen release through coating or chemical inhibitors, which can achieve fertilizer supply in synchronization with crop nutrient demand. The application of slow-release fertilizer on rice can reduce the number of applications of tillering fertilizer and panicle fertilizer and even achieve the effect of "one-time fertilization". Studies have shown that compared with multiple applications of traditional urea, one-time basal application of CRF can increase rice yield by about 15%-30%, and significantly improve nitrogen fertilizer partial productivity and nitrogen recovery rate. Gil-Ortiz et al. (2020) reported that in rice field experiments, controlled-release nitrogen fertilizer treatment increased yield by about 35% compared with conventional fertilization, and increased the nitrogen content and other nutrient content of plant leaves. A large number of domestic experiments have also confirmed that slow-release fertilizers can increase rice yield and nitrogen fertilizer utilization efficiency. For example, experiments have shown that a one-time application of a formula fertilizer containing slow-release nitrogen can increase yield by 8% compared with applying urea in batches. Another example is that Xu (2021)'s research shows that the application of controlled-release fertilizers combined with conventional nitrogen fertilizers can significantly increase the nitrogen absorption and nitrogen utilization rate of rice plants. In demonstrations in Jiashan and other places, controlled-release fertilizers with different release rates were scientifically proportioned with quick-acting nitrogen fertilizers, and mechanical side deep fertilization technology was used to achieve a one-time concentrated application of base fertilizer and tillering fertilizer, so that rice can still obtain sufficient nutrient supply in the middle and late stages of growth. Compared with the traditional "three fertilizers and two topdressing", this model greatly reduces the number of fertilizations and labor inputs, while significantly increasing production and efficiency. Therefore, the optimized application technology of controlled-release fertilizers is an important way to reduce nitrogen and increase efficiency in rice fields, and can provide strong support for green fertilization. 4.2 Integration with green pest control technologies While reducing the application of chemical fertilizers, optimizing plant protection technology to achieve the coordination of fertilizer management and pest and disease control is one of the directions for green and efficient rice production. Excessive nitrogen application often leads to the growth of lush plants, which increases the adaptability of pests and diseases, thereby increasing the use of pesticides. Studies have shown that appropriately reducing the use of nitrogen fertilizer can reduce the risk of rice blast, sheath blight, etc., and improve the plant's resistance to lodging (Deng et al., 2023). In order to achieve fertilizer reduction without reducing production or increasing diseases, it is necessary to combine fertilizer management with plant protection technology to formulate a comprehensive management plan. For example, in the demonstration fields in Jiashan, Zhejiang, the "unified fertilizer supply and unified plant protection" model is promoted: slow-release fertilizer is applied deep
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