**1. Introduction**

The increase of the world's population and the decrease of freshwater resources have led to increased use of alternate water resources. In contrast, as the population increases, wastewater production increases. In many arid and semiarid areas in USA, Australia, and Israel, using freshwater for turfgrass and landscape irrigation has become rare. Consequently, using treated wastewater (effluent water) for irrigation has become a common practice to alleviate freshwater shortage. In addition to the growing concerns of the future water supply, the more stringent wastewater discharge standards make use of effluent water increasingly attractive.

is needed to determine the effect of using effluent water on sand-based root zones on putting greens. Most golf course putting greens are constructed based on the United States Golf Association (USGA) putting green construction recommendations. USGA putting green consists of 30 cm sand-based root zone that contains 90% sand and 10% organic matter by volume. The sand-based root zone overlays a 10-cm-deep gravel blanket to provide the best soil conditions for turfgrass growth and to minimize compaction and optimize drainage. Sandbased putting greens allow for good aeration and drainage, and that is important to maintain a good playing surface. Sand is suitable for the putting green's function because it is resistant to soil compaction and has good filtration and percolation rates. However, it has low organic matter, which may affect its ability to hold nutrients [12]. Organic matter, typically peat, is often added to improve water and nutrient-holding capacity [13]. With putting green's special nature, using effluent water for irrigation needs to be investigated over the long term to

Long-Term Effects of Effluent Water Irrigation on Soil Chemical Properties of Sand-Based...

http://dx.doi.org/10.5772/intechopen.72227

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**1.** Assess changes in soil chemical properties of sand-based greens following conversion

**2.** Identify potential concerns related to long-term use of effluent water on sand-based greens.

The study was conducted at Heritage Golf Course in Westminster, Colorado, which is located north of metro Denver (39° 53′ 59.34″ N 105° 07′ 00.04″). The course started to use effluent water for irrigation in 2000. Nine out of 18 (1, 3, 5, 7, 9, 11, 13, 15, 17) greens were selected for soil sample collection. Soil samples (0–10 cm below soil surface) were collected in September

Soil samples were analyzed for soil pH, extractable salt content (Ca, Mg, K, Na, Fe, Mn, Cu, Zn, P, and B), base saturation percent of Ca, Mg, K, and Na, soil organic matter (SOM), and cation exchange capacity (CEC) by Brookside Laboratories, Inc. (New Knoxville, OH). Soil

pH. It is performed by mixing an equal volume of soil and deionized water. Soil samples

NO3 + 0.013 M HNO3 + 0.0005 M EDTA chelating agent) to determine Ca, Mg, K, Na, Fe, Mn, Cu, Zn, B, and P by inductively coupled plasma-emission spectrophotometry instrumentation. Mehlich III is a procedure widely used for extraction of plant available macro- and micro-nutrients in soils that have an acidic or neutral pH, by using a dilute acid-fluoride-EDTA solution with pH 2.5 extracted [14]. Mehlich III extracted Ca, Mg, K, and Na plus soil buffer pH data are used to calculate CEC. Base saturation percent of Ca, Mg, K, and Na was calculated by dividing the extracted Ca, Mg, K, and Na by the calculated CEC, respectively. Base saturation percent of Na is considered the exchangeable sodium percentage (ESP). Soil

O procedure; 1:1 is the most common ratio used for soil-water

F + 0.20 M CH3

COOH + 0.25 M

address the impact of effluent water on putting green soil properties.

from freshwater irrigation to effluent water irrigation.

were extracted using the Mehlich III extract (0.015 M NH4

The objectives of this study were to:

**2. Materials and methods**

**2.1. Study location**

of 1999, 2003, and 2009.

NH<sup>4</sup>

pH was analyzed using 1:1 H<sup>2</sup>

Golf courses are the leading urban landscape users of effluent water. A survey conducted by the National Golf Foundation (NGF) reported that approximately 13% of golf courses in the US use effluent water for irrigation, with 34% of golf courses in the Southwest US doing so [1]. In Colorado, approximately 25% of golf courses are using effluent water for irrigation.

Effluent water is any water after residential and sometimes industrial use that undergoes significant treatment at a sewage treatment plant, to meet standards set by federal or state water laws and regulations. This water is usually suitable for various reuse purposes including irrigation. During treatments, suspended solids are removed, pathogens are disinfected, and partial to substantial reduction in nutrient concentrations occurs, depending on treatment stage [2, 3]. Currently, effluent water used for turf and landscape irrigation must be disinfected [4].

However, using effluent water has some disadvantages. Public health is the first concern due to the pathogens it may contain, but that is less of a concern if used for nonedible plants. Effluent water may contain different levels of dissolved solids, ions, nutrients (NO3 and P2 O4 ), and other elements. Increases in soil salinity and sodium are potential problems associated with using effluent water irrigation. Salinity has harmful effects on nonhalophyte plant growth and development as well as making soil water less available for the plants. Increased sodium level (sodicity) in the soil leads to disaggregation of soil to its components and damages the soil structure. In addition, researchers suggest that using effluent water for irrigation may affect soil chemistry over time [5–9]. Accordingly, the use of effluent water for irrigation requires monitoring and the use of management practices to minimize any potential adverse effects on soil and plants.

On the other hand, using effluent water for irrigation has some advantages. Effluent water contains some nutrients that can be used by plants. Nitrogen (N) and phosphorus (P) as well as some small amounts of micronutrients are found in effluent water. Studies have showed that plant yields increased by using effluent water when compared to freshwater irrigation [10]. This increase is due to the nutrient concentrations such as N and P in effluent water and their effect on plant growth [10]. High-quality effluent water has become available for golf course irrigation, and it decreases the fertilizer cost because of nutrient availability in the water [4]. Also, using effluent water is less expensive when compared to other alternative irrigation resources such as desalinized seawater [11].

Many studies have been published regarding the effect of using effluent water on soils in urban landscapes. However, no research is available regarding the impacts of effluent water irrigation on sand-based root zones on golf course putting greens and sports fields. Research is needed to determine the effect of using effluent water on sand-based root zones on putting greens. Most golf course putting greens are constructed based on the United States Golf Association (USGA) putting green construction recommendations. USGA putting green consists of 30 cm sand-based root zone that contains 90% sand and 10% organic matter by volume. The sand-based root zone overlays a 10-cm-deep gravel blanket to provide the best soil conditions for turfgrass growth and to minimize compaction and optimize drainage. Sandbased putting greens allow for good aeration and drainage, and that is important to maintain a good playing surface. Sand is suitable for the putting green's function because it is resistant to soil compaction and has good filtration and percolation rates. However, it has low organic matter, which may affect its ability to hold nutrients [12]. Organic matter, typically peat, is often added to improve water and nutrient-holding capacity [13]. With putting green's special nature, using effluent water for irrigation needs to be investigated over the long term to address the impact of effluent water on putting green soil properties.

The objectives of this study were to:

