This range will vary significantly from site to site based upon specific growing conditions, amount of traffic, species and composition of the turf, soil properties and expectations for the turf performance. Light and frequent applications of nitrogen coupled with the use of controlled release fertilizers is now a widely practiced approach to supplying turf with nitrogen during summer.

LIGHT AND FREQUENT Light and frequent (spoon-feeding) applications of nitrogen provide golf course superintendents good control over growth to maintain consistent green speeds and playing quality.

Usually, these are applied in a liquid form at rates ranging from 0.05 – 0.20 lbs. nitrogen/1,000 sq.ft. every 7 – 14 days. Spoon-feeding applications also enable the turf manager to respond to the need for rapid recovery or manage specific problems.

Research from Rutgers University has demonstrated that the incidence of anthracnose can be reduced by as much as 75 percent when summer nitrogen application is maintained at a rate of not less than 0.1 lbs. nitrogen/1,000 sq.ft. per week.

Products properly formulated for foliar absorption by the turfgrass leaves maximize nutrient use efficiency, and research from University of Nebraska indicates greater than 90 percent absorption can be realized within the first 15 minutes.

Foliar absorption is especially beneficial when roots may be compromised by summer stress, soil compaction is an issue or soil salinity is a concern.

Attributes of quality foliar fertilizers include natural chelating/complexing agents, low salt concentration, buffering capabilities and identifiable ingredients.

CONTROLLED RELEASE Controlled release, soil applied products also are an integral component of summer nitrogen management. Organic fertilizers, bridged organic products, coated materials and other slow release forms are all available in the marketplace.

The key is selecting a material with a predictable release mechanism to achieve growth when needed and to avoid flushes in growth that may lead to undesirable consequences.

A rapid release of nitrogen during summer heat can lead to excess growth and management difficulties. Granular applications provide a good backbone to the fertility program while in-season adjustments can be more easily made with light and frequent applications of sprayable formulations.

NITROGEN TIMING The use of too much nitrogen at one time in a quick release form can spur increased development of diseases like pythium or brown patch, not widely observed in the Intermountain West, but more prevalent in recent years with record-breaking July temperatures.

Too much nitrogen at one time also can cause puffy turf during summer that can lead to scalping injury and mechanical damage. Growth flushes also create a maintenance issue with excess clipping production.

RIGHT BALANCE Striking the right balance of nitrogen fertilization during the summer months involves proper product selection, regular observation of the turf, experience and a good plan capable of adjustments.

Monthly tissue testing is a tool that can help correlate nitrogen applications with plant uptake and refine application protocol as necessary.

Enough nitrogen needs to be supplied to maintain good turfgrass vigor for recovery from traffic and wear and to maintain plant function necessary for carbohydrate production.

Proper nitrogen fertilization also will help minimize disease risk and other pest problems. Developing a summer nitrogen feeding program that maintains consistent nutrient availability within a range suitable to your turf will provide the best results.

Focus on products that provide the best control and flexibility, while maximizing efficiency and minimizing waste. Some are in, some are out.

Editor’s note: Nelson is an agronomist with Grigg Brothers Fertilizers and co-owner of Magic Valley Bentgrass, a commercial sod farm. He can be contacted at matt.nelson@griggbros.com.