Question

State two artificial ways of returning nitrates to the soil ?

Answer 1

Nitrogen gas from the air is converted to nitrate componds by nitrogen-fixing bacteria in soil or root nodules. The Haber process is a man made process where nitrogen gas is converted into ammonia which is used to make fertilisers . In some ways deintrifying bacteria in the soil break down nitrates back to the air This is usually in waterlogged soil. Improving drainage reduces this effect , making the soil more fertile by retaining more nitrates.

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Answer 2

Ammonia is convert into nitrates by nitrifying Bacteria from the soil. Plants absorb nitrates from soil . In several cases,fertilizer compound artificially enriched in 15N have been used to successful . Either way, the compounds are then absorbed through the roots of the plant .Once the plant dies its nitrogen compound are also converted back into ammonia or nitrate.They are then returned to soil and eventually used by another plant.
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