The phrase "percent nitrogen" refers to the amount of nitrogen present in a certain substance or material, measured as a percentage of its total weight or volume. Full definition
Fish emulsion contains up to 5 percent nitrogen with several trace elements that help improve soil microbes, resulting in more plant building blocks. (hunker.com)
Earth's atmosphere differs from the atmospheres of most other rocky planets and moons in our solar system in that it is rich in nitrogen gas, or N2; Earth's atmosphere is 78 percent nitrogen gas. (sciencedaily.com)
It breaks down slowly, fertilizing the plants with a generous nitrogen content of a whopping 17 percent compared with the 6 percent nitrogen in commercial turf products. (discovermagazine.com)