淋洗水的钠吸附率对高尔夫球场果岭根层基质饱和导水率的影响

摘要

Soil salinization is a maj or problem threatening turfgrass management.Alternative water sources such as recycled water (RW)usually have elevated salt content.With high exchangeable sodium in soil,rain or irrigation with fresh water can cause soil dispersion,and thus reduce water infiltration and permeability.The ob-j ective of this study was to determine the effect of salt composition in irrigation water on saturated water con-ductivity (Ksat)of putting green root zone materials and constructions.Three root zone materials,clay (Fargo, North Dakota,USA),clay loam (Garick Corp.,Cleveland,OH),and sand/peat mixture (Dakota Peat,North Dakota,USA)(90/10 v/v)were tested alone,as well as tested in different root zone construction,i.e.soil push-up green (40 cm deep),sand/peat mixtures in USGA-putting green style (30 cm of root zone over 10 cm gravel) and California putting green style (40 cm deep).Saturated water conductivity was determined after the root zone materials and construction were leached with water of five levels of SARw(0,2.5,5.0,15.0,and ∞).All except the SARw 0 had an ECw of 1 1 .0 dS/m.The results showed severe soil dispersion may happen when SARw of leaching water is greater 5 for clay and clay loam.A laboratory test may predict the severity of dispersion but further study is needed to quantify the effect of soil organic matter (OM)and clay mineralogy.Generally,sand/peat mixtures used in root zones of either California or USGA putting green style is not vulnerable to dispersion by salt in irrigation water.%土壤盐渍化是草坪管理中危害草坪草健康的严重问题。盐渍化是由于灌溉用的再生水等非传统水源常含有较高的盐分。在土壤可交换钠累积高的情况下,用雨水或者清水灌溉会导致土壤颗粒分散,降低土壤水分入渗与渗透。试验目的为：研究灌溉用水中的盐分组成对高尔夫果岭根层基质及根基系统的饱和导水率(Ksat)的影响。试验对粘土(Fargo,North Dakota,USA),粘壤土(Garick Corp., Cleveland,OH)和泥炭/砂混合物(Dakota Peat,North Dakota,USA)(90/10 v/v),其在3种根层的基质建筑系统40 cm深自然型果岭,USGA标准的泥炭/砂基果岭的30 cm根层和10 cm砾石层和加利福尼亚标准果岭的40 cm深泥炭/砂根层进行了测定。材料经过5个钠吸附率水平(SARw)(0,2.5,5.0,15.0,and ∞)溶液的淋洗预处理或灌溉后测定了饱和导水率。除SARw 0外,所有溶液的导电度(ECw )都为11.0 dS/m。结果表明：使用SARw>5的溶液灌溉淋洗易导致粘土和粘壤土发生较严重的土壤颗粒分散。实验室测定虽然可以估测土壤分散的严重程度,但还需进一步的研究来量化土壤有机物含量和粘土矿物组成对其影响。总之,用于加利福尼亚和 USGA 标准果岭根层的泥炭/砂混合物不易产生由含盐灌溉水源导致的土壤结构分散及饱和导水率降低。