NPK

American  

[en-pee-key] / ˈɛnˈpiˈkeɪ /

abbreviation

1. Horticulture. a ratio of percentages of the three nutrients—nitrogen, phosphorus, and potassium—that are especially important in a plant fertilizer. A fertilizer’s NPK is given as a series of three numbers, for example, 24–6–6, which means the content is 24 percent nitrogen, 6 percent phosphorus, and 6 percent potassium, so the NPK expressed as a simple ratio is 4:1:1.

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Etymology

Origin of NPK

First recorded in 1900–05; from the chemical symbols for nitrogen ( def. ) (N), phosphorus ( def. ) (P), and potassium ( def. ) (K)

Example Sentences

"Urine does naturally contain all of the nutrients that plants need such as nitrogen, phosphorus and potassium, but it also contains a variety of contaminants," explained Olivia Wilson, NPK Recovery's research and development scientist.

From BBC • Apr. 2, 2026

Bristol-based start-up NPK Recovery collects urine from portable toilets during festivals and events, transforming it into fertiliser to help grass grow back on the fields afterwards.

From BBC • Apr. 2, 2026

Because organic fertilizers like fish emulsion have very low concentrations of nitrogen and other elements, he recommends a monthly application of a water-soluble food labeled with a 20-20-20 NPK ratio instead.

From Seattle Times • May 1, 2024

The firm currently makes 2.7 million tonnes of ammonia, 3.4 million tonnes of urea and 350,000 tonnes NPK fertiliser per year, making it among the Asia-Pacific's biggest producers.

From Reuters • Mar. 10, 2023

The strategy also likes the price, as NPK trades for just 12.4 times earnings and 1.6 times book value.

From Forbes • Jun. 2, 2014