development of a usga putting green rootzone mixture (Greensmix)
This test determines the ideal mix ratio of two or more components. We mix sand with 10, 15, and 20% peat (or three ratios of your choice) to develop a mix that meets USGA physical property recommendations for saturated hydraulic conductivity (perk rate) and porosity. Included with the recommended mix is an organic matter test so that field mixes can be verified against the recommended lab mix as well as uniformity coefficient (CU) and pH with lime recommendations. Mix designs can also be created using soil or an inorganic amendment.
Complete rootzone analysis
This test includes a complete physical and particle size analysis of a greensmix sample including organic matter, uniformity coefficient (CU), pH with lime recommendations, and USGA recommendations for a putting green rootzone mixture (greensmix). This is a deluxe quality control test of a greensmix that tests for all the physical quality properties considered important by the USGA.
Complete physical analysis
This test includes the saturated hydraulic conductivity (perk test), pore space distribution (porosity), bulk density, particle density, and water retention. This test assesses the physical properties of a rootzone mix to see if it meets USGA recommendations. Ideal physical properties of a green promote good turfgrass growth and optimum playability. This test can be used as a quality control test for a greensmix.
Complete particle size analysis
This test determines if the sand/rootzone mix meets USGA particle size recommendations for a rootzone mix. The particle size analysis consists of the percentage of gravel, sand, silt, and clay including the five sand fractions. Sands that are too coarse or too fine will not pass USGA particle size recommendations. Greens built with sands that are too coarse can be too loose, difficult to firm up, droughty, and difficult to retain fertilizer nutrients due to excessive leaching. Greens built with sands that are too fine can become hard, compacted greens with low water permeability rates.
Uniformity coefficient (CU)
This test uses grain diameter to help predict the firmness of sand used in green construction. Sands that are too uniform may lack sufficient particle packing to form a stable or firm surface. The lower the CU, the more uniform the particle size and the greater the risk for unstable or soft putting greens. Conversely, sands with high CU values will pack, potentially providing firmer surfaces. Sands with excessively high CU values may pack too tightly, adversely affecting drainage and rooting.
Organic Matter Test of rootzone mix
This test determines the organic matter in a rootzone mix. The USGA no longer recommends a range for the organic matter in a greensmix, however, this test is primarily used as a quality control test to determine if the on-site field mixes are within an acceptable range of the mix design or benchmark greensmix.
topdressing sand/greensmix test
This test includes a physical and particle size analysis including pH and USGA recommendations for topdressing sand. If the topdressing is a sand:peat mix we also run an organic matter test. The USGA recommended range for topdressing sand is predominately 1.0 - 0.15 mm. The USGA has recognized for many years that the medium sand fraction is the best sand fraction for topdressing sands.
bunker (trap) sand test
The USGA does not have formal recommendations for bunker sand as architectural styles, climatic conditions, lining materials, and golfer expectations are so varied. They do offer some guidelines based on nine characteristics to help when selecting a bunker sand. They are particle size, particle shape, uniformity coefficient, infiltration rate, penetrometer test, angle of repose, crusting potential and set-up, acid reaction, and color. These tests help predict the overall playing quality and maintenance requirements of bunker sands.
gravel particle size analysis
The USGA recommends two methods for golf green construction, with and without an intermediate (choker) layer. When the intermediate (choker) layer is used, a 4" layer of 1/4 X 3/8" (6.4 X 9.5mm) gravel (65% minimum) is placed above the drain tile. A 2 - 4" layer of 1 - 4mm intermediate layer material (90% minimum) is placed above the gravel. The 12" rootzone mix is placed above the intermediate layer.
When the intermediate layer is not used, a minimum 4" layer of generally 2-9.5mm gravel is placed above the drain tile. The 12" rootzone mix is placed above the gravel. The gravel must pass a uniformity factor as well as bridging and permeability factors. The gravel particle size test determines if the gravel used for these two methods passes USGA requirements which are based on adequate drainage and prevention of rootzone particles migrating into the gravel.
When the intermediate layer is not used, a minimum 4" layer of generally 2-9.5mm gravel is placed above the drain tile. The 12" rootzone mix is placed above the gravel. The gravel must pass a uniformity factor as well as bridging and permeability factors. The gravel particle size test determines if the gravel used for these two methods passes USGA requirements which are based on adequate drainage and prevention of rootzone particles migrating into the gravel.
Organic matter test of peat and other organic soils
The USGA recommends that the peat used in a greensmix should have a minimum of 85% organic matter content by weight and should be screened to no larger than 0.25 inches (6.4 mm). Organic composts, if used, should meet the requirements found in "USGA Recommendations for a Method of Putting Green Construction," and the mix must meet physical property recommendations. Organic matter quality plays an important role in the physical quality of a greensmix.
chemical analysis*
Our lab also provides soil fertility analysis with fertilizer recommendations and pH and lime recommendations for bermudagrass and bentgrass greens, warm-season grasses and cool-season grasses for fairways and tees, athletic fields, and lawns. Other chemical analyses include soluble salts and cation exchange capacity.
*Results provided by an outside lab and are not covered by our A2LA Accreditation
*Results provided by an outside lab and are not covered by our A2LA Accreditation