科学素养与生活应用·英语30篇（4）

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闪电如何触发土壤固氮：大气化学与微生物协同作用

Lightning heats air to over 30,000°C, breaking nitrogen and oxygen molecules apart instantly.
Free nitrogen and oxygen atoms recombine into nitrogen oxides, which dissolve in rainwater.
This creates naturally occurring nitrate-rich rain that fertilizes soils without human input.
Plants absorb dissolved nitrates through roots, using them to build essential proteins and DNA.
Soil bacteria then convert excess nitrates into inert nitrogen gas via denitrification.
Each lightning strike produces about 10 kilograms of usable nitrogen compounds per square kilometer.
Scientists measure nitrate concentration spikes in rainwater collected immediately after thunderstorms.
Farmers in remote regions rely partly on this process to maintain crop fertility year after year.
Climate models now include lightning frequency data to estimate natural fertilizer inputs globally.
This atmospheric pathway complements biological nitrogen fixation by legume-root microbes.