John Mascaro is President of Turf-Tec International
These one-foot green circles on this St. Augustine grass lawn in southwest
Florida are a great indicator showing insufficient nitrogen amounts on the turf.
The yellow, chlorotic turf shows very low amounts of nitrogen while the green
spots were actually caused by dog urine that delivered just the right amount
of nitrogen to green up the turf in these spots. The amount of nitrogen in this
homeowner's healthy puppy shows just how nutrient deficient this St. Augustine
lawn has become. Many times female dogs get blamed for damaged turf or
"brown dog spots" as compared to male dogs. For years I heard the reason for
this was a factor of pH. The reason many people have given the female dogs a
bad reputation killing more grass than male dogs is not actually based on pH. In
fact, there are three primary reasons why dog urine burns grass: the alkalinity of
the urine, the concentration of the urine (how well hydrated the dog is) and its
nitrogen load. Concentrated urine has more solutes (particles of nitrogen) than
dilute urine, which can adversely affect grass health. The reason why female dogs
create more damage as compared to male dogs is actually because females typi-
cally squat and pee in one spot (depositing a whopper load of nitrogen solutes),
whereas males tend to urinate in smaller amounts as they wander from spot to
spot. Now, if this homeowner can train their dog to alternate the favorite spots
better, perhaps they can continue to save money on fertilizer.
Photo from John Mascaro's collection.
John Mascaro's Photo Quiz Answers from page 33
www.stma.org January 2016 | SportsTurf 37
If you would like to submit a photograph for John Mascaro's Photo Quiz please send it to John Mascaro, 1471 Capital Circle NW, Ste # 13, Tallahassee,
FL 32303 call (850) 580-4026 or email to john@turf-tec.com. If your photograph is selected, you will receive full credit. All photos submitted will
become property of SportsTurf magazine and the Sports Turf Managers Association.
