FERTILIZING LAWNS DURING DROUGHT STRESS-2012

Nick Christians

August 9, 2012

On Friday July 20, 2012, I put up a blog post about some 1988 work that we did with an Iowa lawn care company, All American Turf Beauty, that involved putting lawn care treatments on dormant lawns.  After that post went up, I discussed the possibility of updating the work in the drought of 2012.  The same questions that arose in 1988 from customers worried about damage to their lawns by late-summer applications on dormant lawns are coming up again this year.

All American has changed their program since 1988 and now use granular fertilizer in their July/August treatments at a rate of 0.5 lb. nitrogen (N)/1000 ft².   The fertilizer is an 18-0-4 with 50% slow release N.

We applied the treatments separately to non-irrigated Kentucky bluegrass, tall fescue, and perennial ryegrass areas.  We left an untreated control, and then applied 1 plot at 0.5 lbs N/1000 ft² to one plot, 1.0 lb N/1000 ft², and 2.0 lb N/1000 ft².  We also applied 1.0 lb N/1000 ft²and 2.0 lb N/1000 ft² to separate plots using urea 46-0-0.

There are two questions.  Number 1, will any of the treatments do any harm?  Number 2 which treatments will prove to be beneficial?

The treatments were applied on August 8.  At the research area, we have had 3.4 inches of rain in the last 12 days.  The bluegrass and perennial ryegrass areas are just beginning to show recovery and the tall fescue has nearly recovered.  We had 0.3 inches of rain on the site shortly after treatment.

I will be following these plots over the next few weeks and I will be reporting on the effects of the treatments as the turf further recovers into the fall.

Thanks to All American Turf Beauty for their help with this project.

The next two pictures are of the bluegrass area by the turf building.  It was completely dormant and is just beginning to recover.

The perennial ryegrass is in the foreground and the tall fescue area in the background.  The tall fescue is recovering much faster than the rye.