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

Lucy Bell-Reeves, NPK Recovery's co-founder, said using a waste product to grow trees was "a circular solution that can revitalise our struggling native species."

From BBC • Apr. 2, 2026

"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

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

While Russia is Brazil's main supplier of the NPK fertilizer mixture of nitrogen, phosphorus and potassium, Canada is Brazil's main source of potash used to raise crop yields.

From Reuters • Mar. 10, 2022

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