USGA Greens

This website sponsored by Turf Diagnostics & Design. The complete source for soil and material testing for golf courses, landscapes, and sports fields (both natural and artificial turf).

Excerpts from

USGA Recommendations for a

Method of Putting Green Construction

(2004 Revision)

Rootzone Components

Table 1 Particle Size Distribution of USGA Root Zone Mix.

Fraction	U.S. Standard	Diameter of Sieve	Allowable Range
Size Name	Sieve Mesh	(mm)	% Retained on Sieve
Gravel	10	2.00	< 3%*
Very Coarse	18	1.00	< 7% to 10%*
Coarse	35	0.50	At least 60%
Medium	60	0.25	particles in this range
Fine	100	0.15	20% Maximum
Very Fine	270	0.05	5% Maximum
Silt		0.002	5% Maximum Allowable
Clay		< 0.002	3% Maximum Allowable

* Gravel plus Very Coarse should not exceed 10% total.

Soil Component (Optional)

"If soil is used in the root zone mix, it shall have a minimum sand content of 60%, and a clay content of 5% to 20%. The final particle size distribution of the sand/soil/peat mix shall conform to that outlined in these recommendations, and meet the physical properties described herein."

Organic Matter Selection

Peats - "If selected, it shall have a minimum organic matter content of 85% by weight as determined by loss on ignition (ASTM D 2974-87 Method D)."

Other Organic Sources

"Organic sources such as rice hulls, finely ground bark, sawdust, or other organic waste products are acceptable if composted through a thermophilic stage, to a mesophilic stabilization phase, and with the approval of the soil physical testing laboratory. Composts shall be aged for at least one year. Furthermore, the root zone mix with compost as the organic amendment must meet the physical properties as defined in these recommendations. Composts can vary not only with source, but also from batch to batch within a source. Extreme caution must be exercised when selecting a compost material. Unproven composts must be shown to be non-phytotoxic using a bentgrass or bermudagrass bioassay on the compost extract."

Inorganic and Other Amendments:

"Porous inorganic amendments such as calcined clays (porous ceramics), calcined diatomites, and zeolites may be used in place of or in conjunction with peat in root zone mixes, provided that the particle size and performance criteria of the mix are met. Users of these products should be aware that there are considerable differences between products, and long term experience with some of these materials is lacking. It should also be noted that the USGA requires any such amendment to be incorporated throughout the full 12-inch (300 mm) depth of the root zone mixture. Polyacrylamides and reinforcement materials are not recommended.

Physical Properties of the Root Zone Mix:

The root zone mix shall have the properties summarized in Table 2, as tested by USGA protocol (proposed ASTM Standards).

Table 2

PHYSICAL PROPERTIES OF THE ROOT ZONE MIX

Physical Property	Recommended Range
Total Porosity	35% - 55%
Air-filled Porosity	15% - 30%
Capillary Porosity	15% - 25%
Saturated Hydraulic Conductivity	Minimum of 6 inches/hr (150 mm/hr)

Drain Field Material Selection

Table 3 Materials for Drain Field with an Intermediate Sand Layer

Gravel	No less than 90% passing a 1/2 inch sieve. At least 65% Passing 3/8" and Retained on 1/4". No more than 10% passing a 10 mesh (2.0mm).
Intermediate Sand	No less than 90% passing a No.5 (4mm) sieve and retained on a No. 18 (1mm).

Table 4 Materials for Gravel Drain Field without an Intermediate Sand Layer

U.S. Standard	Diameter of Sieve	Allowable Range
Sieve Mesh	(mm)	% Passing
1/2 "	12.5	100 %
10	2.0	< 10%
18	1.0	< 5%
Uniformity Coefficient (Cu)	< 3.0
Bridging	D15 Gravel < 5 x D85 Sand
Permeability	D15 Gravel > 5 x D15 Sand

Uniformity Coefficient_gravel (Cu) = D90/D15

The intermediate sand (choker) layer can be omitted provided suitable gravel materials are available. Soft limestones and shale materials are not suitable. Questionable materials should be evaluated using a sulfate soundness test (ASTM C-88) or LA Abrasion Test (ASTM C-131).

Test Method	Criteria
Sulfate Soundness (C-88)	Not to exceed 12% Loss
LA Abrasion (ASTM C-131)	Not to exceed 40

Related Concerns

IT IS ABSOLUTELY ESSENTIAL TO MIX ALL ROOT ZONE COMPONENTS OFF-SITE. No valid justification can be made for on-site mixing, since a homogeneous mixture is essential to success.

A QUALITY CONTROL PROGRAM DURING CONSTRUCTION IS STRONGLY RECOMMENDED. Arrangements should be made with a competent laboratory to routinely check gravel and root zone mixtures during production and blending. It is imperative that these materials conform to the recommendations approved by the laboratory in all respects.

Care should be taken to avoid overshredding the peat, since it may influence performance of the mix in the field. Peat should be moist during the mixing stage to ensure uniform mixing and to minimize peat and sand separation.

Note

The information contained in this document was compiled verbatim from the 2004 USGA recommendations for a method of putting green construction. These excerpts are primarily related to material selection criteria. The USGA recommendations are more extensive than the material selection criteria. For more information concerning the complete USGA document, contact your USGA representative or USGA Golf House. The complete USGA recommendations can be found at http://www.usga.org/turf/course_construction/green_articles/putting_green_guidelines.html.

For more information feel free to contact us at info@sandfinder.com.