In a latest Wholesome Backyard article, Paula Gross mentions analysis indicating that mulches of oak leaves and pine needles don’t acidify the soil. In view of the tendencies of woodlands in my space to have a pH of 5 to six, whereas lawns and fields (admittedly lots of which have been limed) are typically round 6.8, I’d have an interest within the specifics of the analysis.
—Will Ferrell, Kernersville, North Carolina
Paula Gross responds: In digging deeper for this text, I used to be reminded that soil pH could be very steady and that it takes loads to alter it. After we need to change soil pH in both course, we flip to inorganic supplies—limestone to extend pH, and sulfur to decrease it—as a result of natural supplies merely received’t have a robust sufficient impact in our lifetimes.
I believe it’s more likely that the pH distinction Mr. Ferrell observes is because of the liming of turf, as he suspects. North Carolina’s Piedmont soils are likely to run acidic, however in fact all of it depends upon the precise soil he’s testing. Pockets of extra and fewer acidic soils definitely exist.
The impact of oak leaves on soil pH has been studied extensively. A paper revealed by Nikolai, Rieke, and McVay of Michigan State College documented no change in soil pH after six years of mulching oak leaves into established turf grass. Abigail A. Maynard’s analysis on the Connecticut Agricultural Experiment Station additionally documented no distinction in soil pH when uncomposted leaves had been added to vegetable plots. (Editor’s observe: You’ll find summaries of those research on-line by trying to find the authors’ names together with the key phrases “leaves” and “soil pH.”)
Laborious analysis on pine needles and soil pH is missing, but all college extension companies I researched dispute the declare that pine needles acidify soil.
If Mr. Ferrell needs to attempt an experiment of his personal over 5 to 10 years with pine needles, I can let you know he’d have an viewers on-line!