【国外标准】 Standard Test Methods for Saturated Hydraulic Conductivity, Water Retention, Porosity, and Bulk Density of Athletic Field Rootzones

AbstractThese test methods cover the standard procedures and related calculations for determining the saturated hydraulic conductivity, water retention, porosity, and bulk density of sand-based root zone mixtures used in the construction and topdressing of golf course putting greens including United States Golf Association (USGA) recommended greens, golf course tees, sand-based sports fields, and other highly trafficked turfgrass areas. These test methods are not designed for use with fine or medium textured soils such as sandy loams and loams. Test Method A is used to determine the saturated hydraulic conductivity by maintaining water flow through the core at a constant hydraulic head until a steady flow rate is achieved, at which time aliquots of the outflow are collected. Test Method B, on the other hand, is used to determine water retention and bulk density. Water retention is obtained at a soil suction, wherein water is extracted from a prepared core by means of a tension table or other water extraction apparatus. And when equilibrium is achieved after the core has been oven dried, the weight is recorded. Bulk density is, then, calculated from the mix or sand dry weight and volume. Test Method C is used to calculate the total porosity from the bulk density and particle density. And lastly, Test Method D is used to calculate the capillary and air-filled porosities. Capillary porosity is calculated from the bulk density and water retention information, while, the air-filled or aeration porosity is calculated from the difference of the total and capillary porosities.1.1 These test methods cover the measurements of saturated hydraulic conductivity, water retention, porosity (including distribution of capillary and air-filled porosity at a known soil suction), and bulk density on sand-based root zone mixes to be used for construction and topdressing of golf course putting greens including United States Golf Association (USGA) recommended greens, golf course tees, sand-based sports fields, or other highly trafficked turfgrass areas. These test methods are designed for sand-based mixes and are not intended for use with fine or medium textured soils, for example, sandy loams and loams.1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.