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Tag: nitrogen

It’s Finally September – That Means Football and Fescue

(By Ward Upham and Jared Hoyle, KSU Research and Extension)


September is almost here and that means it is prime time for football and to fertilize your tall fescue or Kentucky bluegrass lawns. If you could only fertilize your cool-season grasses once per year, this would be the best time to do it.

These grasses are entering their fall growth cycle as days shorten and temperatures moderate (especially at night). Cool-season grasses naturally thicken up in the fall by tillering (forming new shoots at the base of existing plants) and, for bluegrass, spreading by underground stems called rhizomes. Consequently, September is the most important time to fertilize these grasses.

Apply 1 to 1.5 pounds of actual nitrogen per 1,000 square feet. The settings recommended on lawn fertilizer bags usually result in about 1 pound of nitrogen per 1,000 square feet. We recommend a quick-release source of nitrogen at this time. Most fertilizers sold in garden centers and department stores contain either quick-release nitrogen or a mixture of quick- and slow-release.

The second most important fertilization of cool-season grasses also occurs during the fall. A November fertilizer application will help the grass green up earlier next spring and provide the nutrients needed until summer. It also should be quick-release applied at the rate of 1-pound actual nitrogen per 1,000 square feet.


Time to Think About Managing Your Warm-season Home Lawn

Time to Fertilize Warm-Season Grasses    

    June is the time to fertilize warm-season lawn grasses such as bermudagrass, buffalograss, and zoysiagrass. These species all thrive in warmer summer weather, so this is the time they respond best to fertilization. The most important nutrient is nitrogen (N), and these three species need it in varying amounts.

buffalograss fairway

    Bermudagrass requires the most nitrogen.  High-quality bermuda stands need about 4 lbs. nitrogen per 1,000 sq. ft. during the season (low maintenance areas can get by on 2 lbs.). Apply this as four separate applications, about 4 weeks apart, of 1 lb. N per 1,000 sq. ft. starting in early May. It is already too late for the May application, but the June application is just around the corner. The nitrogen can come from either a quick- or slow-release source. So any lawn fertilizer will work.  Plan the last application for no later than August 15. This helps ensure the bermudagrass is not overstimulated, making it susceptible to winter-kill.

    Zoysiagrass grows more slowly than bermudagrass and is prone to develop thatch.   Consequently, it does not need as much nitrogen. In fact, too much is worse than too little. One and one-half to 2 pounds N per 1,000 sq. ft. during the season is sufficient. Split the total in two and apply once in early June and again around mid-July. Slow-release nitrogen is preferable but quick-release is acceptable.  Slow-release nitrogen is sometimes listed as “slowly available” or “water insoluble.”


    Buffalograss requires the least nitrogen of all lawn species commonly grown in Kansas. It will survive and persist with no supplemental nitrogen, but giving it 1 lb. N per 1,000 sq. ft. will improve color and density. This application should be made in early June. For a little darker color, fertilize it as described for zoysiagrass in the previous paragraph, but do not apply more than a total of 2 lb. N per 1,000 sq. ft. in one season. Buffalograss tends to get weedy when given too much nitrogen. As with zoysia, slow-release nitrogen is preferable, but fast-release is also OK. As for all turfgrasses, phosphorus and potassium are best applied according to soil test results because many soils already have adequate amounts of these nutrients for turfgrass growth. If you need to apply phosphorus or potassium, it is best to core aerate beforehand to ensure the nutrients reach the roots. 

Thatch Control in Warm-Season Lawns      

    Thatch control for cool-season lawn grasses such as bluegrass and tall fescue is usually done in the fall but now is the time we should perform this operation for warm-season turfgrasses such as bermudagrass and zoysiagrass. Because these operations thin the lawn, they should be performed when the lawn is in the best position to recover.  For warm-season grasses that time is June through July. Buffalograss, our other common warm-season grass, normally does not need to be dethatched.


    When thatch is less than one-half inch thick, there is little cause for concern; on the contrary, it may provide some protection to the crown (growing point) of the turfgrass. However, when thatch exceeds one-half inch in thickness, the lawn may start to deteriorate. Thatch is best kept in check by power-raking and/or core-aerating. If thatch is more than 3/4 inch thick, the lawn should be power-raked. Set the blades just deep enough to pull out the thatch. The lawn can be severely damaged by power-raking too deeply. In some cases, it may be easier to use a sod cutter to remove the existing sod and start over with seed, sprigs or plugs.  If thatch is between one-half and a 3/4- inch, thick, core-aeration is a better choice.


    The soil-moisture level is important to do a good job of core-aerating. It should be neither too wet nor too dry, and the soil should crumble fairly easily when worked between your fingers. Go over the lawn enough times so that the aeration holes are about 2 inches apart. Excessive thatch accumulation can be prevented by not overfertilizing with nitrogen. Frequent, light watering also encourages thatch. Water only when needed, and attempt to wet the entire root zone of the turf with each irrigation.

    Finally, where thatch is excessive, control should be viewed as a long-term, integrated process (i.e., to include proper mowing, watering, and fertilizing) rather than a one-shot cure. One power-raking or core-aeration will seldom solve the problem.

When to apply spring preemergence and nitrogen to sports fields

(by Jared Hoyle; KSU Turfgrass Research and Extension)

This is an article a friend of mine at UNL wrote a little bit ago but contains some really great information for you Sports Turfgrass Managers.  Sorry for the delay in getting it out but I think it contains some good information for Kansas on planning your preemergence and nitrogen applications to sports fiends in this crazy spring we have been having.  Enjoy!

When to apply spring PREs and nitrogen

I had to throw this picture of Kauffman Stadium from the 2016 Sports Turf Managers Field Day!
I had to throw this picture of Kauffman Stadium from the 2016 Sports Turf Managers Field Day! Looks Great!

Buffalograss Divot Recovery as Affected by Nitrogen Source and Rate

(by Evan Alderman and Jared A. Hoyle; KSU Turfgrass Research and Extension)

With increasing drought conditions and decreasing water supplies, drought tolerant turfgrass species are being explored for use on golf courses. With over 1.2 million acres of irrigated turfgrass in the United States, water conservation has become an issue throughout the turfgrass industry (Throssell et al., 2009). In recent years, the conversion from cool- to warm-season turfgrass species has become more acceptable in the transition zone. Golf courses in the Kansas City area converting tees and fairways from creeping bentgrass [Agrostis stolonifera L.] to zoysiagrass [Zoysia japonica Steud.] could reduce irrigation annually by 5,767,570 gal while reducing irrigation costs by up to $28,403 (Fry et al., 2008). In Kansas, the Ogallala aquifer provides up to 80% of the water used, although years of pumping has led to a steady decline in water levels (Buchanan et al., 2001). The use of drought tolerant turfgrass species would help conserve water supplies.

Buffalograss [Buchloe dactyloides (Nutt.) Engelm] is a native, drought tolerant, warm-season turfgrass species used for lawns, parks, athletic fields, roadsides, and golf courses in the Great Plains (Wenger, 1943; Beard, 1973; Fry, 1995; McCarty, 1995; Fry and Huang, 2004). Utilization of buffalograss on golf courses could lead to reduced water consumption while maintaining a reasonably dense playing surface.


Previous research has demonstrated that buffalograss can be maintained as an acceptable fairway turf with proper management practices. Buffalograss responds to nitrogen (N) fertility, and studies in Nebraska and Colorado have shown increased buffalograss quality, color, and growth with increasing N (Falkenberg 1982; Frank et al., 2004).



Golf course turf is frequently damaged by divots produced by players’ clubs when striking the ball. Although acceptable fairway buffalograss quality and playability can be achieved through proper fertility, divot recovery is of concern due to slow growth characteristics and minimal fertility requirements. Research is needed to evaluate buffalograss fertility management to maximize divot recovery. The objective of this study was to determine the influence of N source and rate on ‘Cody’ buffalograss fairway divot recovery.

Field studies were initiated in August of 2014 at the Rocky Ford Turfgrass Research Center (RF) in Manhattan, KS and July 2014 at Council Grove Country Club (CG) in Council Grove, Kansas. Mowing was conducted twice weekly at 0.625 in and 1.00 inch at RF and CG, respectively. After study initiation, irrigation was only applied to prevent drought stress and water in fertilizer treatments. To prevent drought stress, approximately 1.5 inch of supplemental irrigation was applied at each site over the experimental periods.

IMG_1955 IMG_1957

Treatments consisted of two N sources and four rates. Nitrogen sources were a quick release urea fertilizer (46-0-0) and a 120-day controlled release polymer-coated urea (PCU) (43-0-0). Nitrogen rates were 0, 1, 2, and 3 lb N/1,000 ft2. Nitrogen from urea was applied in two equal applications; one at study initiation and the other four weeks after initiation (WAI). All N from PCU was applied at trial initiation. Prior to treatment application, divots were created using a custom built edger.


Buffalograss’ low water requirements and its ability to be maintained at fairway mowing heights make it very valuable in low input turfgrass management systems. From the data collected in this study, applying a quick release N fertilizer at 1 to 3 lb N/1,000 ft2 will result in a shorter duration to reach 50% divot recovery compared to buffalograss receiving no N. Applying 1lb N/1,000 ft2 of a quick release product was determined to be the optimal fertilization rate to reach 50% divot recovery (2.5 weeks). This study has shown that under limited irrigation situations and with minimal fertilization, buffalograss exhibits improved divot recovery and, thus, playability in low input turfgrass management systems.

Literature Cited

Beard, J.B. 1973. Turfgrass: science and culture. Prentice-Hall, Inc., Englewood Cliffs, New Jersey.

Falkenberg, D.F. 1982. Buffalograss, blue grama, and fairway wheatgrass for dryland turf. M.S.Thesis. Colorado State Univ., Fort Collins, Colorado.

Frank, K.W., R.E. Gaussoin, T.P. Riordan, R.C. Shearman, J.D. Fry, E.D. Miltner, and P.G. Johnson. 2004. Nitrogen rate and mowing height effects on turf-type buffalograss. Crop Sci.44:1615-1621.

Fry, J.D. 1995. Establishing buffalograss. Golf Course Management. 63(4): 58-62.

Fry, J.D. and B. Huang. 2004. Applied turfgrass science and physiology. John Wiley & Sons, Inc., Hoboken, New Jersey.

Fry, J.D., M. Kennelly, and R. St. John. 2008. Zoysiagrass: economic and environmental sense in the transition zone. GCM May 2008, 127 – 132.

McCarty, L.B. 1995. Buffalograss, description and use. University of Florida CooperativeExtension Service. p. 1-4.

Throssell, C.S., G.T. Lyman, M.E. Johnson, and G.A. Stacey. 2009. Golf course environmental profile measures water use, source, cost, quality, and management and conservation strategies. Online. Applied Turfgrass Science doi:10.1094/ATS-2009-0129-01-RS.

Wenger, L.E. 1943. Buffalo grass. Agricultural Experiment Station. Kansas State College of Agriculture and Applied Science. Manhattan, KS. Bulletin 321.

Tis the Season

(By Zane Raudenbush1, Jared Hoyle1 and Robert Florence2; 1KSU Turfgrass Research and Extension, 2Dept. of Agronomy – Soil Lab Manager)

Fall is an important time for cool season turfgrass species because air and soil temperatures are optimal for carbohydrate accumulation and root growth. However, adequate plant nutrition is essential for these processes to operate at maximum efficiency. The importance of using soil test reports to guide fertilization programs cannot be emphasized enough.  The Kansas State Soil Testing Lab (http://www.agronomy.k-state.edu/services/soiltesting/) provides a variety of high quality testing services for turfgrass managers. Testing for pH, phosphorus (P), and potassium (K) can be done for $6.50. A good sampling method is necessary to ensure the soil test results are accurately representing the sampled area. To sample, use a soil probe an extract a 4” to 6” core. The leaf and thatch material should be discarded from the core (see picture). Eight to ten individual cores should be extracted and combined into a single sample for testing. Results are typically sent back within a week of the lab receiving the sample.  Fertilizer recommendations will also be provided by a county agent or K-State horticulturalist.

Of all the possible nutrients, potassium is of particular interest as temperatures continue to decline, because it helps the plant acclimate to cold temperatures. Some soils, especially golf greens, throughout Kansas are low in potassium, leaving turfgrass more susceptible to winter injury. Deficiencies can be addressed by applying K containing fertilizers, such as, potassium chloride (KCl), potassium sulfate (K2SO4), and potassium nitrate (KNO3). Remember, soil tests are a relatively inexpensive tool, but provide a wealth of knowledge.


Influence of Nitrogen Rate and Source on Buffalograss Divot Recovery

(By Evan Alderman and Jared Hoyle, KSU Turfgrass Research and Extension)

Buffalograss Fairway

In recent years, water conservation has been a growing trend in the golf course industry.With the spotlight on the golf course industry to become more conscious of the environment, one of the classic prairie grasses may be able to help low-budget golf course operations save water and money. buffalograss, Buchloe dactyloides, is known for being drought tolerant, which is why it fits into the discussion as a viable option for water conservation. Additionally, buffalograss is also known for its disease resistance, as well as its slow growing characteristics.

Buffalograss is very versatile and can be utilized on the golf course in native areas, roughs, and fairways. Many courses in Kansas are currently using this species in one of these three ways, however limited research exists to explore buffalograss management.

In order to explore buffalograss in further detail, we decided to look at how fertility influences recovery from divot injury. Furthermore, we looked at the influence of quick and slow release nitrogen fertilizers and their rate on the divot recovery.

Currently, we have three different divot studies in progress; two at the Rocky Ford

Divot making tool

Turfgrass Research Station in Manhattan, KS, and one at the Council Grove Country Club, in Council Grove, KS. Divots were made using a modified edger with 13 circular blades. This device was able to produce a divot similar to a real divot one would find on the course.

Field Trial at Rocky Ford Turfgrass Research Center; Manhattan, KS

Each study consists of eight treatments arranged in a two by four factorial. Factors included nitrogen rate and nitrogen source.  Nitrogen rates were 0, 1, 2, and 3 lbs N /1000ft2. Nitrogen sources were Urea and Polymer Coated Urea (Table 1).

Table.1  Influence of Nitrogen Rates and Sources on Buffalograss Divot Recovery Study Treatment List.

Treatment Source Rate
1 Urea* 0 lbs N/1000ft2
2 Urea 1 lbs N/1000ft2
3 Urea 2 lbs N/1000ft2
4 Urea 3 lbs N/1000ft2
5 Polymer Coated Urea*** 0 lbs N/1000ft2
6 Polymer Coated Urea 1 lbs N/1000ft2
7 Polymer Coated Urea 2 lbs N/1000ft2
8 Polymer Coated Urea 3 lbs N/1000ft2

*The quick release fertilizer that was used was a 46-0-0 Urea, and to achieve the 1lbs, 2lbs, 3lbs two half-rate applications were made, one on the initiation date, and the second four weeks after initiation.

**The slow release fertilizer used was a 120 day controlled release polymer coated Urea, with an analysis of 43-0-0. Just one application of the slow release was made.

Divot filled with pink sand to easier analyze divert recovery with digital image analysis.

Pictures of each divot are analyzed with digital image analysis software to measure how quickly the divot recovers. Other data taken include visual color, quality, and percent recovery.

Since the initiation of the study, we were able to see a definite flush of green from the application of the quick release fertilizer at all rates. In terms of quality, the plots that received 2lbs and 3lbs resulted in the highest quality.  Plots receiving 1lbs of N/1000ft2 also resulted in acceptable turfgrass color and quality although lower than the 2lbs and 3lbs N/1000ft2 treatments.  As far as the nitrogen rates influencing divot recovery, we hope to find at which nitrogen application rate and source will result in the quickest buffalograss divot recovery.