1.1 本试验方法旨在通过测量饱和密度、持水量和孔隙度，评估泥炭在现场饱水条件下的通气、渗水和保水性能。 1.2 以国际单位制表示的数值应视为标准值。国际单位制后括号中给出的值仅供参考，不被视为标准值。 1.3 所有观察值和计算值应符合实践中确定的有效数字和舍入准则 D6026 . 1.3.1 本标准中用于规定如何收集/记录或计算数据的程序被视为行业标准。此外，它们代表了通常应保留的有效数字。 使用的程序不考虑材料变化、获取数据的目的、特殊目的研究或用户目标的任何考虑因素；通常的做法是增加或减少报告数据的有效位数，以与这些考虑因素相称。考虑工程设计分析方法中使用的有效数字超出了本标准的范围 1.4 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 本试验方法测量了饱和条件下泥炭在质量和体积基础上的充气空间（孔隙度）和持水量。如果存在较大的空间，水和空气很容易渗透。如果空间较小，则持水能力会增加。湿润泥炭材料（小颗粒间空间）（腐土）的持水能力较大，而非湿润泥炭（较大颗粒间空间）（纤维土）的水和空气渗透性较大。这些空间也可以指示植物根系可用的氧气。因此，持水量和孔隙度特性的相互作用决定了收获的有机土壤材料的最佳使用以及有机土壤的最佳管理实践。 这些土壤的水分保持关系对涉及这些土壤的灌溉、排水和承载力的决策至关重要。 注1: 本标准产生的结果的质量取决于执行该标准的人员的能力，以及所用设备和设施的适用性。符合实践标准的机构 D3740 通常认为能够胜任和客观的测试/采样/检查等。本标准的用户应注意遵守惯例 D3740 本身并不能保证可靠的结果。可靠的结果取决于许多因素；实践 D3740 提供了一种评估其中一些因素的方法。 5.2 保水值在有机土壤管理中尤为重要。 文献中关于以各种基表示的保湿值存在很多混淆；以体积百分比表示；以烘箱干燥质量的百分比表示；或湿质量的百分比。在一些管理决策中，由于有机土壤的体积密度不同，有必要以体积为基础表示其含水量，但由于干燥时体积减小，含水量也必须以现场收集的湿体积为基础表示。然而，在其他管理决策中，水分保持值最好以干质量为基础表示。例如，湿样品和烘干样品之间的质量差是保持的水分。这些值最好在干质量基础上表示。 由于有机土壤中的分解程度不同，持水能力表现出显著差异。纤维状土壤中的水质量可能高达固体颗粒质量的20倍，而保存在腐土中的水质量不到固体颗粒质量的两倍。如果持水能力以体积表示，则这些差异就不那么明显。

1.1 This test method was designed to evaluate the aeration, water penetration, and water retention properties of peat under field conditions of water saturation by measurement of the saturated density, the moisture holding capacity, and the porosity. 1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.3 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 . 1.3.1 The procedures used to specify how data are collected/recorded or calculated in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analysis methods for engineering design 1.4 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. 1.5 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. ====== Significance And Use ====== 5.1 This test method measures the air-filled spaces (porosity) and the moisture-holding capacity of peat on both a mass and a volume basis under conditions of saturation. If large spaces are present, water and air can penetrate easily. If spaces are smaller, the water holding capacity is increased. Water holding capacity is larger in humified peat materials (small inter-particulate spaces) (sapric soil), whereas water and air-penetration is larger in unhumified peat (larger inter-particulate spaces) (fibric soil). The spaces can also be an indication of the oxygen available to the plant roots. As such, the interplay of the properties of moisture holding capacity and porosity dictate the best use of the harvested organic soil material as well as the best management practices for organic soils. The moisture retention relationships of these soils are critical to decisions involving irrigation, drainage, and bearing capacity of these soil. Note 1: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors. 5.2 Water retention values are particularly important in the management of organic soils. There is much confusion in the literature about the moisture retention values being expressed in various bases; as a percent by volume; as a percent of oven dry mass; or as the percent of the wet mass. In some management decisions, it is necessary to express the water contents of organic soils on a volume basis because of their varied bulk densities, but because of the volume reduction occurring on drying, the water contents must also be expressed on a wet volume basis as collected in the field. Whereas, in other management decisions, moisture retention values are best expressed on a dry mass basis. For example, the difference in mass between the wet and oven dry sample is the moisture held. These values are best expressed on a dry mass basis. Water holding capacities show a marked difference due to the degree of decomposition in an organic soil. The mass of water in fibric soil may be as much as 20 times the mass of the solid particles, whereas that held in a sapric soil contains less than twice the mass. If the water holding capacity is expressed on a volume basis these differences are much less apparent.