Nitrogen Cycle Crossword

3. Substance added to soil by humans to increase nitrogen levels for plant growth.
4. The process of converting N₂ gas into ammonia or other usable compounds.
7. Process that converts nitrates back into nitrogen gas, releasing it into the atmosphere.
11. Environmental issue caused by excess nitrogen causing algae blooms.
13. The process of decomposers turning nitrogen from waste into ammonium.
14. The process by which plants absorb nitrates and incorporate them into proteins.
17. Process by which excess nitrogen is carried from soil to water sources.
18. A compound produced by bacteria during the breakdown of nitrogen-rich waste.
19. A usable form of nitrogen, NO-3, that plants take in through their roots.
20. Small bumps on the roots of legumes where nitrogen-fixing bacteria live.

1. The process of ammonium getting changed into nitrates by bacteria.
2. Organisms that break down dead matter and release nitrogen back into the soil.
5. NO-2, an intermediate product in nitrification.
6. Essential organic molecules that plants use nitrogen to build.
8. How animals get nitrogen compounds by eating plants or other animals.
9. Where 78% of nitrogen is found, but mostly unusable by organisms.
10. Genetic material that requires nitrogen to form.
12. Organisms that play a critical role in all four stages of the nitrogen cycle.
15. The close, long-term interaction between nitrogen-fixing bacteria and plants.
16. Plants like soy, peas, and clover that have a symbiotic relationship with nitrogen-fixing bacteria.