| 摘要: |
| 【目的】研究微波消毒法对土壤病虫草害的处理效果，为实现农业绿色可持续发展提供技术支持。【方法】基于COMSOL Multiphysics软件建立微波加热土壤的电磁 传热物理场耦合仿真模型，研究微波处理下土壤温度随时间和空间的分布规律；基于仿真结果，利用700 W微波土壤加热试验装置对3种不同含水率（2%，10%和20%）土壤辐射5 min并静置30 min，通过传感器研究土壤温度随时间的变化情况，同时验证模型的正确性；选用2种常见杂草种子和镰刀菌作为试验样本进行土壤消毒试验，验证微波加热除草消毒效果。【结果】土壤加热试验中，分别对2%，10%和20% 3种含水率的土壤微波处理5 min，其中4 cm土层深处测温点的土壤最低温度依次为52，92和72 ℃，8 cm深处的测温点温度依次为44，50和46 ℃；在保温阶段，上层土壤热量的传导作用使8 cm深处的3种含水率土壤温度分别提升8，11和7 ℃。模型验证结果表明，测温点的试验温度与仿真温度相近，最大误差均在12%以内，说明微波加热土壤仿真模型基本正确。土壤除草消毒试验表明，对于黑麦草和狗尾草，2%含水率土壤4 cm深处的种子萌发率最高达到80%，10%和20%含水率土壤中的种子萌发率最高为8%；对于镰刀菌，3 min微波辐射条件下，3种不同含水率下镰刀菌孢子萌发率最高达到100%；5 min微波辐射条件下，4 cm深处土壤的镰刀菌孢子萌发率最高为5%，8 cm深处以2%含水率土壤的镰刀菌孢子萌发率最低（最高仅为32%），20%含水率土壤中镰刀菌孢子萌发率最高（最高63%）。【结论】微波加热法能有效抑制杂草种子和真菌萌发，其效果取决于微波对土壤的热效应，微波处理土壤温度的影响因素主要有土壤湿度、掩埋深度、辐射时间。 |
| 关键词: 物理场耦合仿真模型 微波消毒 土传病害 土壤杂草 消毒效果 除草效果 |
| DOI： |
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| 基金项目:陕西省自然科学基金项目(K3030321059)；西北农林科技大学校级优质高产及安全生产技术研究与示范项目(TGZX2021-27) |
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| Establishment of simulation model and weeding and disinfection effects of soil heating by microwave |
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MA Sipeng,JIN Hongling,ZHAO Yajun,et al
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| Abstract: |
| 【Objective】This study investigated the effect of microwave disinfection on soil diseases,pests and weeds to provide support for green and sustainable agricultural development.【Method】Based on COMSOL Multiphysics software,the electromagnetic and heat transfer multi-physical coupling model of soil heating by microwave was established,and the distribution of soil temperature along with time and space under microwave treatment was simulated.Based on the simulation results,the soil with three different moisture contents (2%,10% and 20%) was radiated for 5 min by a 700 W microwave test device,followed by 30 min standing still.The change of soil temperature with time was studied by a sensor,and the model performance was verified.Finally,2 kinds of common weed seeds and Fusarium were selected for soil disinfection test to verify the effect of weed disinfection by microwave heating.【Result】After microware treatment for 5 min in heating test,soil with moisture contents of 2%,10% and 20% had the lowest temperature of 52,92 and 72 ℃ at the depth of 4 cm and the temperature of 44,50 and 46 ℃ at the depth of 8 cm.In the insulation stage,the heat conduction from the upper soil increased the soil temperature with the three soil moisture contents at the depth of 8 cm by 8,11 and 7 ℃,respectively.The model verification results showed that the test temperatures at temperature measurement points were close to simulation results with maximum error of less than 12%,indicating that the simulation model was reliable.For ryegrass and setaria setaria,the seed germination rates were 80% in 2% soil at 4 cm depth and 8% in 10% and 20% soil at 4 cm depth.The highest germination rate of Fusarium under 3 different water contents reached 100% after 3 min microwave radiation.After 5 min microwave radiation,the highest germination rate of Fusarium in soil depth of 4 cm was 5%.In soil depth of 8 cm,the soil with water content of 2% had the lowest germination rate (maximum 32%),while the soil with water content of 20% had the highest germination rate (maximum 63%).【Conclusion】Microwave heating effectively inhibited the germination of weed seeds and fungi,and its effect depended on the thermal effect of microwave on soil.The soil temperature of microwave treatment was mainly affected by soil moisture,burial depth and radiation time. |
| Key words: physical field coupling simulation model microwave disinfection soil-borne diseases soil weeds disinfection effect weed control effect |
