In fertilizer labels showing N-P-K, what does N stand for?
AnswerNitrogen
N is the chemical symbol for nitrogen, a nutrient plants need for healthy leafy growth.
Nature · Facts & stats
Fertility facts & stats
7 fact-checked facts about soil fertility, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
What is compost made from?
AnswerDecomposed organic material like food scraps and leaves
Compost forms when microbes break down organic matter into a dark, crumbly material that enriches soil.
Going deeper
In N-P-K, the K stands for which nutrient?
AnswerPotassium
K is the chemical symbol for potassium, from its Latin name 'kalium'.
The 'Fertile Crescent', where early farming began, is in which region?
AnswerThe Middle East
The Fertile Crescent arcs through the Middle East, including river valleys where early agriculture developed.
Roughly what percentage of Earth's air is nitrogen?
Answer78%
Air is about 78% nitrogen and 21% oxygen, yet most plants cannot use nitrogen gas directly.
Expert level
The Haber-Bosch process, key to making modern fertilizer, produces which compound?
AnswerAmmonia
Haber-Bosch combines nitrogen from the air with hydrogen to make ammonia, used to produce nitrogen fertilizers.
Gardeners add lime (ground limestone) to soil mainly to do what?
AnswerMake acidic soil less acidic
Lime is mostly calcium carbonate, which neutralizes acidity and raises soil pH.
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