Physical Performance Evaluation: The physical performance evaluation (PE) provides information concerning the infiltration rate, bulk density, and porosity characteristics of a proposed rootzone material. The methods used for determining the parameters are based on standard agronomic test methods and the USGA protocol. Conceptually, the method involves compacting a sample at field capacity and determining the listed parameters. The USGA protocol requires a particle density determination for every sample. The samples are compacted using a 14.3 ft-lbs/in2 force. Infiltration rates are determined using a constant head saturated hydraulic conductivity (K-SAT). The infiltration rates (K-SAT) are adjusted to a rate equivalent to 20C water temperature for consistency of reporting.
The PE analysis is a useful risk assessment tool in determining the suitability of submitted materials for use in gravity drained perched sand turf systems such as the USGA putting green system. Important parameters that aid in risk assessment are the K-SAT and capillary porosity values. The PE is performed on a compacted sample and represents a worst possible case scenario in regards to the rootzone performance. The USGA offers guides for selecting or designing acceptable rootzones. The PE analysis can be performed on field or lab blended mixes.
Lab Made Mix
Submitted components are used to make a mix in the lab and perform the PE analysis. The mix preparation and analyses are tailored to design agronomically acceptable rootzones for sand based systems. The bulk weights and moisture contents of each component are defined and reported with the PE results. Organic amendment bulk weights are usually based on the manufacturer criteria, while the bulk weights of sand and other amendment are determined in the lab. Since most mixes are defined as a volume ratio, we offer a volume conversion to provide an objective analysis. To offer a guide as to how much of each component is necessary to make the mix, an estimated yield report is provided. The actual yields of components may vary according to moisture contents of the respective materials on-site.
Field Blended Mix
There are times that rootzone mixes are already available and a determination of the physical performance is required. In this case, the PE analysis involves the determination of a submitted rootzone mix for suitability in perched sand based turf systems. Analysis of a submitted mix is offered at lower price than lab blend testing. If desired only the infiltration rate (K-SAT) will be provided.
The USGA protocol requires an organic matter content to be determined in conjunction with the PE analysis. This defines the mix ratio, and provides criteria for future quality control of construction programs. For quality control testing, the organic matter content and particle size analysis (PSA) are required to properly check the integrity of the rootzone as it is produced. These two analyses offer a quick, reliable, and affordable method of providing quality control for rootzone mixes.
Organic Matter Determination: Organic matter test results are determined via combustion. Results are reported on a dry weight basis. Temperature of combustion is defined by the material being tested and/or the specified test method. Organic soils, composts, and peats are combusted at 750C per ASTM D2974. Most soils and rootzone mixes are combusted at 360C per ASTM F1647.
The USGA has adopted this technique to define and provide benchmark data for the quality control of construction of sand based rootzones. We report the OM on mixes made in the lab as well as submitted mixes to compare to USGA confidence levels and to help interpret the physical evaluation data. The performance of the mix is directly related to the particle size analysis and the organic matter by weight.
Particle Density: Particle density is necessary for determining the total porosity of a soil core. Desiccators and pycnometers are used for particle density determination. A pycnometer is a specific gravity bottle capable of being filled accurately with a definite amount of liquid without any air space. Oven dry weight and volume of the sample are determined. Particle density, which equals the oven dry weight divided by the volume, is important in the calculation of total pore space.
Water Release Characterization: Used for moisture release and retention evaluation. Testing can be performed on undisturbed soil cores or laboratory compacted samples. Our lab is capable of producing a range of soil tensions from 15 bars (permanent wilt point), to 1/3 bar pressure (field capacity for continuous soil profile), or any range of soil tensions points between 15 bars to less than 1/3 bar. A series of moisture release points can be plotted to determine at which pressures a soil or amendment product releases moisture. The laboratory is also equipped with Tempe cells for low soil tension evaluation from 10 centimeters to 1000 centimeters.
Brief Descriptions of Some of our most common Soil Tests
Particle Size Analysis: Particle Size Analysis (PSA) is one of the most descriptive analyses performed on soil materials. The PSA analysis includes a determination of the clay content using a pipette method and a sand grain distribution. Parameters such as the diameter 15 (D15) and uniformity coefficient (Cu) are reported. A textural classification based on the United States Department of Agriculture (USDA) will also be provided. Sands for use in sand based turf systems and sand traps for golf courses will have a shape of sand particle provided according to United States Golf Association (USGA) - Green Section requirements. The PSA analysis is composed of two distinct phases.
Photomicrograph of Bunker Sand.
Bunker Sand Testing: The bunker sand testing package provides data indicating ball lie characteristics (fried egg lie testing), sand size shape & color, drainage characteristics, and maintenance needs. Everything a superintendent or suppplier needs to evaluate current or potential bunker sands. Our moisture column test is an innovative procedure that provides guidance concerning optimum bunker sand depths. We also offer angle of repose testing to evaluate whether sands are suitable steep bunker faces.
Some of our most common golf and sports turf tests are described below.
The first phase is the soil textural analysis and is defined by the sand, silt, and clay content. The USDA classification criteria define sand as the material retained on a 270 mesh (0.05mm) sieve. The second phase of the PSA is the sand grain distribution analysis. Sand grain distribution can be based on the USDA, USGA, or other specifications. All sand grain distributions are determined on the sand component that has had all the silt and clay removed. The results of the PSA are useful in estimating the physical and chemical performance of a sand or soil.
Particle size distribution and textural analysis can be performed as independent tests.
Soil Texture Test Cylinders with varying amounts of silt & clay