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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 The Sand Putting Green - Construction and Management* by Cooperative Extension University of California Division of Agriculture and Natural Resources Publication 21448 Introduction A mature putting green should always present a firm, fast, true grass surface. Given reasonable management, a putting green should not have to be rebuilt due to the failure of the growing medium. It should not be especially susceptible to diseases, root growth should not be restricted, and moisture content of the medium should not effect putting quality. The green must accept and drain away excess water rapidly and at the same time retain enough when irrigated so that frequent watering is unnecessary. In the mid-1960s, researchers at the University of California explored the possible use of sand and amended sands that could resist compaction and provide a growing medium for grass. This research, combined with field observations, led to the conclusion that unamended was the best and most practical foundation for putting-green turf. The sand that is used, however, must be the "right" sand; not all sands are a suitable as a growing medium for putting greens. The right sand will need no amending and will meet all the requirements to produce an easily managed, high-quality putting surface... Should the sand be amended? Since the right sand already has favorable physical properties for a putting green, amending it to improve physical properties is not necessary. Amending just to improve nutritional balance is also unnecessary, since a proper nutritional balance for strong, healthy turf growth depends primarily on a well-managed fertilization program... Analyzing the sand The first step in analyzing the sand quality is to determine its particle size distribution... It may be necessary to have a laboratory run a particle size analysis using the USDA sieve sizes... The second step is to determine the infiltration rate of a compacted sand sample... Interpretation of laboratory tests and recommendations Using laboratory tests and field observations, guidelines for selecting sands based on their particle-size distribution have been formulated. These guidelines are shown in Table 2 and indicate the particle size range of suitable putting green root-zone sands. Within these ranges it is possible to have sands that have unacceptable infiltration rate or water retention values. It is, therefore, essential that a compacted infiltration test be run. This will help separate those sands that might be questionable. Table 2 is a helpful guide to selecting a sand for further laboratory testing to see if it would be adequate as a growing medium. It is not meant to be specifications for bids by sand and gravel companies.A putting-green sand ideally should have 90 to 100 percent of its particles between 0.1 and 1.0 mm. Within this range the medium-sized particles, with a diameter of 0.50 to 0.25 mm, should comprise 50 to 70 percent... Table 2. Particle size of sands acceptable for putting green construction
Infiltration measurements made on newly established but relatively low-use putting greens have shown a reduction in their infiltration rate of 25 to 40 percent compared to laboratory determined infiltration rates. This reduction in infiltration rate is caused by root growth that can fill pores near the surface of the sand profile. Over time, materials from decomposing thatch will reduce pore size, causing a greater reduction in the infiltration rate of the green. A relatively high (greater than 20 inches per hour) laboratory infiltration rate usually indicates an adequate to high field infiltration rate...
*This web page contains excerpts concerning sand selection that were taken verbatim from Publication 21448 from Univ. of Calif. Division of Agriculture and Natural Resources. Publication 21448 contains a considerable amount of additional information, about the construction and maintenance of pure sand putting greens, that is not presented here. |
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