In the physical properties, suspended matter is one of the most important features. Suspended matters in natural waters are usually composed of plaques erosion, parts of organic matter and
planktons (Ayyildiz, 1990). Suspended matters are one of the most important things because they could cause obstructions in emitters in the sprinkler and drip irrigation. This kind of water should be filtered appropriately and then should be given to the system.
2.1.1 Chemical properties
The most important chemical properties in terms of irrigation is pH, the amount of solid matter dissolved in water (electrical conductivity), sodium adsorption ratio (SAR), residual sodium carbonate (RSC), Na % and amount of boron. pH is a measure that shows the acidity or alkalinity of water and it is required to be between 6.5 to 8.0 in irrigation water. The amount of dissolved solids is the degree of salinity in irrigation water. The degree of salinity in irrigation water is expressed as electrical conductivity (Ayyildiz, 1990). Salt in the irrigation water is important in terms of physical and chemical properties changes of the water and soil, making toxic and physiological effects on plant. Most water of acceptable quality for turfgrass irrigation contains from 140 to 560 pmhos/cm soluble salts (Cockerham & Leinauer, 2011). It is necessary to be careful when irrigating with highly salinity waters, especially higher than 2250 pmhos/cm.
Sodium is important in terms of blocking soil colloids and prevents the formation of a available air water balance in the soil. Ratio of sodium ion on total cations (Na %) and its ratio to magnesium and calcium ions (SAR), the two indicators are used in evaluation of irrigation waters. In order to create a condition of suitable soil in the root zone of the plants, the percentage of Sodium should not be more than 50-60%.
Sodium adsorption ratio is another important factor. As the increase of the sodium amount in the irrigation water breaks its physical properties, it is also important in terms of making alkaline the soil (Smith, 1996). In the analysis of irrigation water, due to the higher total salt concentration the higher effect of SAR will be, while estimating the effects of the SAR, the total concentration in the irrigation water should also be considered.
Boron is another important criterion, which is usually not available as element in nature, it is usually found as sodium borate or calcium borate. More than 0.5 mg/l in irrigation water may cause toxic effect on plants.