Back to: Botany 400 Level
My sharp Afrilearn botanist! How your side today? I trust say your brain still dey fire like fresh ogbono soup on stove. Today’s gist go sweet you well because we dey talk about one big “invisible helper” wey dey work underground to help plants grow strong — the Nitrogen Cycle and its Significance in Plant Nutrition. No worry, I go yarn am for you in the most relatable Nigerian way so e go enter your head like story wey sweet belle!
Nitrogen cycle and its significance in plant nutrition
Have you ever wondered how that your grandmum’s ugu dey grow big and green even though nobody dey give am any special juice? One of the secrets na nitrogen. Nitrogen dey everywhere — in the air wey we breathe — but plants no fit use am directly like that. Na why nature build one special system called the nitrogen cycle to help change nitrogen into forms wey plants fit absorb and use.
Without nitrogen, plants no fit grow well. Their leaves go yellow, and dem no go fit make enough protein or chlorophyll to survive. So this cycle na like fuel station for plants — na from there dem dey collect food power!
The Nitrogen Cycle: Step by Step
Nitrogen Fixation
This na the first wahala wey nature help solve. Nitrogen gas (N₂) dey full for air, but plants no fit use am in that raw form. So some special bacteria in the soil (like Rhizobium) help change this gas into ammonia (NH₃) or ammonium ions (NH₄⁺), which plants fit use.
Example: Legumes like beans and groundnut dey house these bacteria inside small nodules on their roots — like small guest houses for their helpers.
Nitrification
Another set of bacteria (like Nitrosomonas and Nitrobacter) take over here. Dem convert ammonia into nitrites (NO₂⁻) and then into nitrates (NO₃⁻). Nitrates na the sweetest and most useable form of nitrogen for most plants.
Assimilation
This one na where plants carry the nitrates through their roots and use am to build proteins, enzymes, and chlorophyll. Na this protein go later enter our body when we chop the plant. So you see say nitrogen wey start for air don finally enter your amala!
Ammonification (Decay)
When plants and animals die, or when animals poo, decomposers like bacteria break down the waste and release ammonia back into the soil. This keeps the cycle going.
Denitrification
Finally, some bacteria return extra nitrates in the soil back into nitrogen gas (N₂) into the air, especially when the soil no get enough oxygen. This balances everything, like resetting the system.
Why E Important to Plant Nutrition
Plants use nitrogen to build proteins — for growth, strength and survival.
Nitrogen helps form chlorophyll, the green pigment for photosynthesis.
Without nitrogen, plants go weak, yellow, and unproductive.
Farmers even dey add nitrogen-rich fertilisers to soil to boost plant health.
If you’ve ever planted maize before and noticed that the one planted after beans dey grow greener and faster, na because beans dey fix nitrogen in the soil. That way, the maize just come chop better food wey dey already for ground — no stress!
Summary
Nitrogen dey important for plant growth, but plants no fit use nitrogen gas directly.
The nitrogen cycle helps convert nitrogen into usable forms like nitrates.
Key steps include fixation, nitrification, assimilation, ammonification and denitrification.
The cycle supports soil fertility and food production for humans and animals.
Evaluation
- Why can’t plants use nitrogen gas from the air directly?
- What is the role of Rhizobium in the nitrogen cycle?
- Name two forms of nitrogen that plants can absorb and use.
- What happens during denitrification?
Honestly, if plants could talk, dem for thank you for understanding their hustle. You’re becoming a true plant scientist — one lesson at a time. Keep feeding your brain this correct knowledge. With Afrilearn on your side, your future bright pass morning sun! Next class go sweet again — so keep coming back like NEPA light after 2 days!
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