The Effect of Organic & Inorganic Fertilizers on the Quality of Kentucky Bluegrass Turf and Soil Chemical Properties 2010-2015

Pamela Sherratt, Dr. John Street, Arly Drake, Tom Jacques, and Mark Danneberger. Dept. of Horticulture & Crop Science

Sponsored by The Ohio Lawn Care Association (ohioturfgrass.org)

Objectives: To compare the quality response of Kentucky bluegrass (Poa Pratensis) following the application of fertilizer with various nitrogen (N) sources and to monitor soil chemical and physical changes over time.

Introduction

One of the most critical things that we do in turfgrass management is to fertilize the turf to maintain a healthy sward and to prepare the turf so that is can withstand traffic and recuperate from it. It is the role of the turf manager to determine turf fertilizer needs based on annual soil tests and by having a clear understanding of how fertilizers work.

In addition to understanding the complexities of fertilizer types, rates and timings, turf managers may also be working with products in the future that do not contain phosphorus. Another trend in fertilizer management is the desire of some homeowners and public facility administration to move away from synthetic fertilizers in favor of natural organic fertilizers. Natural fertilizers are derived from sources such as manure or compost and they typically do not have nitrogen contents higher than 8%. Natural fertilizers cost more money per lb. of nitrogen than synthetic sources and they are reliant upon soil temperatures for release. Still, there is a belief that natural sources not only feed the turf, but that they can improve the soil health in a turfgrass system. Natural fertilizers that contain organic material may help to improve a soil’s bulk density and nutrient status overtime, which will be monitored in this study.

Measurements:

·  Quality: Visual quality (color and density) is rated on a scale of 1-9, with 1 representing poorest and 9 representing best (Tables 1 and 2). The visual assessment is based on NTEP Guidelines (www.ntep.org) and is performed every 1-2 weeks, starting in early spring (Figure 1).

·  Soil Chemical Properties. Some of the fertilizers do not contain all of the macro nutrients P or K needed for sustained turf growth, so it will be interesting to see what effects no P or K has on the quality of the turf over time. Organic matter content, pH, cation exchange capacity, and available nutrients are also monitored (Table 3).

Figure 1: The effects of various fertilizers on the spring green-up of Kentucky bluegrass turf. Photograph taken 3/30/2011.

Table 1: Effects of Various Fertilizers on the Quality of Cool Season Turf - 2010
Treatments / 5/14 / 5/28 / 6/11 / 6/25 / 7/16 / 7/30 / 8/13 / 8/27 / 9/15 / 10/1 / 10/15 / 10/29 / 11/12 / 11/23
Urea 46-0-0 / 6.3 / 6.3 / 6.0 / 6.7 / 6.7 / 8.3 / 7.7 / 6.3 / 5.3 / 7.7 / 7.7 / 7.7 / 5.3 / 5.3
Ecosential 5-2-4 / 6.3 / 5.7 / 6.0 / 5.0 / 6.0 / 7.0 / 7.0 / 6.0 / 5.3 / 7.3 / 6.0 / 7.0 / 4.3 / 4.3
Nature Safe 10-2-8 / 6.3 / 6.0 / 6.7 / 5.7 / 6.7 / 8.0 / 8.0 / 6.3 / 5.3 / 7.7 / 7.0 / 7.7 / 5.3 / 5.3
Nature’s Helper 2-1-1 / 6.7 / 6.0 / 6.0 / 5.7 / 6.0 / 7.0 / 6.7 / 6.0 / 5.0 / 6.3 / 5.0 / 5.7 / 4.0 / 4.0
Spring Valley Pro 20-2-5 / 6.3 / 7.0 / 6.7 / 6.3 / 7.0 / 8.7 / 8.7 / 7.0 / 5.3 / 7.7 / 7.7 / 8.0 / 5.3 / 5.0
Sustane 5-2-10 / 6.3 / 7.0 / 7.0 / 6.0 / 7.3 / 8.0 / 7.3 / 6.3 / 5.0 / 7.0 / 6.7 / 7.3 / 5.0 / 5.0
Milorganite 5-2-0 / 6.7 / 6.7 / 6.7 / 6.7 / 7.5 / 8.3 / 8.0 / 7.7 / 5.0 / 6.3 / 6.0 / 7.0 / 4.3 / 4.3
Corn Gluten Meal 10-0-0 / 6.3 / 6.3 / 6.7 / 7.0 / 6.3 / 8.3 / 7.7 / 7.0 / 5.0 / 6.0 / 6.5 / 7.7 / 4.8 / 4.2
Comtil Plus 3-2-1 (0.25” depth 2 x year) / 6.3 / 7.7 / 8.0 / 8.0 / 8.3 / 9.0 / 8.7 / 7.7 / 5.3 / 7.3 / 6.3 / 7.7 / 5.3 / 5.0
Advanced Turf Solutions (ATS) 22-3-11 / 6.3 / 7.3 / 7.0 / 7.0 / 7.0 / 8.7 / 8.0 / 7.0 / 5.0 / 7.3 / 7.3 / 8.0 / 5.0 / 4.3
ATS 22-0-5 / 6.3 / 6.7 / 6.3 / 6.3 / 7.0 / 8.0 / 7.3 / 6.3 / 5.3 / 7.0 / 6.7 / 6.3 / 4.7 / 4.7
Andersons 37-0-0 / 6.7 / 6.7 / 6.7 / 6.0 / 6.7 / 7.7 / 7.7 / 6.3 / 5.3 / 7.7 / 7.3 / 8.0 / 5.0 / 4.7
Spread it & Forget it 35-0-0 (1 x) / 6.3 / 6.0 / 6.7 / 6.0 / 6.7 / 7.0 / 7.0 / 6.0 / 5.0 / 5.7 / 5.0 / 5.3 / 4.0 / 4.0
Spread it & Forget it 35-0-0 (2 x) / 6.0 / 5.7 / 7.0 / 6.7 / 7.0 / 7.3 / 7.0 / 6.0 / 5.0 / 6.7 / 6.7 / 7.3 / 4.8 / 4.7
Untreated / 6.0 / 5.7 / 5.3 / 5.3 / 6.0 / 7.3 / 6.7 / 5.7 / 4.7 / 5.3 / 4.7 / 5.7 / 4.0 / 4.0
LSD (0.05) / NS / 0.9 / 0.9 / 0.9 / 0.7 / 0.7 / 0.7 / 0.8 / NS / 1.6 / 1.2 / 0.8 / 0.6 / 0.7

Denotes top statistical group

Treatment Dates: 5/14/2010 (All), 7/16/2010 (#'s 1-12), 10/1/2010 (#'s 1-8, 10-12, 14), 11/23/2010 (#'s 1-8, 10-12)

Table 2: Effects of Various Fertilizers on the Quality of Cool Season Turf - 2011
Treatments* / 4/15 / 6/2 / 6/8 / 6/14 / 6/21 / 6/28 / 7/6
Urea 46-0-0 / 9.0 / 6.0 / 8.0 / 7.8 / 8.0 / 6.8 / 6.1
Ecosential 5-2-4 / 5.8 / 6.3 / 7.3 / 6.6 / 6.8 / 6.1 / 6.3
Nature Safe 10-2-8 / 8.3 / 6.0 / 7.0 / 6.3 / 7.1 / 6.6 / 6.6
Nature’s Helper 2-1-1 / 5.0 / 6.6 / 7.0 / 6.0 / 6.0 / 5.1 / 5.6
Spring Valley Pro 20-2-5 / 9.0 / 6.0 / 8.0 / 7.8 / 8.3 / 7.0 / 6.6
Sustane 5-2-10 / 8.6 / 7.0 / 7.6 / 7.0 / 7.0 / 6.5 / 6.5
Milorganite 5-2-0 / 8.6 / 7.0 / 7.3 / 7.0 / 7.0 / 6.8 / 6.6
Corn Gluten Meal 10-0-0 / 8.6 / 7.3 / 7.0 / 7.0 / 7.6 / 6.6 / 6.6
Comtil Plus 3-2-1 (0.25” depth 2 x year) / 8.0 / 7.0 / 8.6 / 9.0 / 9.0 / 8.0 / 7.8
Advanced Turf Solutions (ATS) 22-3-11 / 9.0 / 6.6 / 8.0 / 7.3 / 8.0 / 6.6 / 6.6
ATS 22-0-5 / 8.6 / 6.3 / 8.0 / 7.6 / 7.5 / 6.3 / 6.3
Andersons 37-0-0 / 8.6 / 6.6 / 7.6 / 7.5 / 7.5 / 6.6 / 6.3
Spread it & Forget it 35-0-0 (1 x) / 5.0 / 6.0 / 7.0 / 6.6 / 6.6 / 6.8 / 6.5
Spread it & Forget it 35-0-0 (2 x) / 6.1 / 6.3 / 7.0 / 6.0 / 6.6 / 6.8 / 6.1
Untreated / 4.3 / 6.6 / 6.6 / 5.3 / 6.0 / 5.5 / 5.5
LSD (0.05) / 0.9 / 1.1 / 0.7 / 1.1 / 0.9 / 0.7 / 0.8

* Treatments applied June 2nd, 2011 All treatments applied at 1 lb N per 1,000 sq.ft., except Comtil Plus, which was applied at 0.25” inch depth.

Table 3: Effects of Various Fertilizers on Soil Chemical Properties - Spring 2011
Fertilizer Treatments / Soil pH
(6.5-7.5) / lbs per acre available nutrient & sufficiency ranges / CEC
(10-22) / % OM
P
(35-85) / K
(250-350) / Ca
(1000-8000) / Mg
(150-800) / Fe
(50-150) / Mn
(20-50) / Zn
(3-6) / Cu
(1-5)
Urea 46-0-0 / 7.2 / 51 / 337 / 3827 / 572 / 49 / 6 / 2.6 / 1.5 / 12.4 / 5.7
Ecosential 5-2-4 / 7.3 / 72 / 452 / 3688 / 612 / 43 / 7 / 2.7 / 1.4 / 12.4 / 5.9
Nature Safe 10-2-8 / 7.4 / 44 / 336 / 3607 / 531 / 41 / 5 / 2.3 / 1.3 / 11.7 / 4.8
Nature’s Helper 2-1-1 / 7.6 / 78 / 442 / 3844 / 571 / 42 / 4 / 2.6 / 1.9 / 12.5 / 5.3
Spring Valley Pro 20-2-5 / 7.5 / 76 / 303 / 3729 / 497 / 47 / 7 / 2.8 / 1.6 / 11.8 / 5.3
Sustane 5-2-10 / 7.6 / 79 / 426 / 3925 / 547 / 38 / 6 / 2.6 / 1.6 / 12.6 / 6.1
Milorganite 5-2-0 / 7.7 / 85 / 319 / 4105 / 484 / 33 / 5 / 2.4 / 1.4 / 12.7 / 5.5
Corn Gluten Meal 10-0-0 / 7.8 / 77 / 285 / 4048 / 429 / 30 / 4 / 2.4 / 1.2 / 12.3 / 5.5
Comtil Plus 3-2-1 (0.25” depth 2 x year) / 7.6 / 136 / 323 / 3827 / 562 / 35 / 4 / 3.2 / 1.4 / 12.5 / 6.2
Advanced Turf Solutions (ATS) 22-3-11 / 7.5 / 83 / 371 / 3860 / 512 / 34 / 5 / 2.1 / 1.2 / 12.3 / 5.6
ATS 22-0-5 / 7.3 / 69 / 387 / 3615 / 627 / 47 / 5 / 2.4 / 1.6 / 12.2 / 6.3
Andersons 37-0-0 / 7.5 / 64 / 279 / 3835 / 555 / 47 / 7 / 2.3 / 1.6 / 12.3 / 5.8
Spread it & Forget it 35-0-0 (1 x) / 7.6 / 73 / 328 / 4047 / 531 / 48 / 6 / 2.9 / 1.7 / 12.8 / 5.3
Spread it & Forget it 35-0-0 (2 x) / 7.6 / 70 / 346 / 3990 / 555 / 40 / 6 / 2.2 / 1.6 / 12.7 / 5.2
Untreated / 7.3 / 63 / 409 / 3909 / 628 / 61 / 6 / 2.6 / 1.7 / 12.9 / 6.1
Chickety-Doo-Doo 5-3-2.5 / 7.4 / 51 / 362 / 4153 / 629 / 37 / 6 / 1.8 / 1.3 / 13.5 / 5.6