Abstract:
In recent years, with the rapid advancement of agricultural intensification and scale, the planting area of high value-added crops has been increasing year by year. However, the large accumulation of insect eggs and pathogenic bacteria in the soil has led to more and more problems in agricultural production that has become a key factor restricting the sustainable development of high value-added crops in China such as continuous cropping obstacles and soil borne pests and diseases. Soil disinfection is one of the important measures for preventing and controlling soil borne diseases and pests. However, traditional chemical disinfection methods often come with ecological pollution and risks to human and animal health. Therefore, there is an urgent need to develop green and pollution-free physical prevention and control technologies. As a green physical disinfection method, microwave soil disinfection technology has broad application prospects in sustainable agricultural development. It can effectively kill pests and pathogens in soil through the synergistic effect of the thermal and non-thermal effects of microwave radiation, while avoiding residual pollution of chemical agents. Microwave soil disinfection technology conforms to the requirements of agricultural green development. And it has become one of the important research directions in the field of soil disinfection. This study systematically reviewed the research progress of microwave soil disinfection technology. Firstly, the concepts of microwave technology and the thermal and non-thermal effects of microwave radiation were introduced. And then the penetration characteristics of microwave radiation in soil at different frequency bands (915 MHz and
2450 MHz) and their application differences in various depths of soil were analyzed. Among them, 915 MHz microwave can penetrate soil at a deeper level, while
2450 MHz microwave is suitable for shallow disinfection. In addition, this study also started from the mechanism of microwave soil interaction, summarized the influence of microwave working parameters (frequency, power, exposure time, etc.) and soil physical properties on electromagnetic field distribution and disinfection effect. And elucidated the regulatory effect of microwave treatment on soil physicochemical properties and microbial communities. Furthermore, in terms of equipment research and development, this study provided a detailed comparison of the technological differences between microwave soil disinfection equipment in China and other countries. And among them, the microwave disinfection equipment developed by developed countries has achieved commercial production, while the development of microwave disinfection equipment in China is still in the experimental prototype stage, and there is a significant gap in development level. Then, it also pointed out that China has certain technological shortcomings in core components such as high-power microwave generators (microwave power supplies, magnetrons, etc.) and intelligent control systems. At present, the main challenges faced by microwave disinfection technology include uncontrolled depth of microwave disinfection, lack of uniformity, absence of core equipment components and intelligent systems, and insufficient ecological safety assessment. To overcome these bottlenecks, this study suggested that future research should focus on the following directions: 1) Revealing the mechanism of microwave soil interaction and conducting in-depth research on non-thermal effects mechanisms; 2) Breakthrough the key technology of microwave deep, uniform and efficient disinfection, and promote energy efficiency optimization; 3) Accelerate the research and development of core components such as high-power microwave generators and the intelligent upgrade of equipment. This study provides theoretical reference and technical route guidance for the optimization and upgrading of microwave soil disinfection technology.