Turf toughie: nitrogen and fertilizers

Doug Soldat, soil scientist at the University of Wisconsin-Madison, poses a deceptively simple question to his students: Of the nitrogen in a grass plant, how much comes from applied fertilizer and how much comes from the soil?

Before you answer, keep in mind that Soldat is not looking for a precise percentage – rather an understanding of where grass gets its N. And, of course, the answer will vary depending on the soil type on your golf course…a sandy Florida soil will be different from a Northern loam.

“Up to half of a grass plant’s N comes from the soil,” Soldat says.

“The point this question tries to make is that there is a lot of available N in the soil for the turf,” he explains.