Orlando, Fla. - Water is needed to keep a golf course green, but keeping a course watered doesn’t ensure healthy turfgrass.
Thomas A. Ruehr, professor at Cal Poly State University, spent the opening morning of the 2005 GGSAA Educational Conference teaching superintendents how to manage bad water quality and maintain good playing conditions. Ruehr identified six problem areas: high bicarbonate water; reclaimed municipal wastewater; rain water or snow melt water; brackish or high sodium water; iron, manganese and sulfur in water; and fertilizer treated water.
Unhealthy turf can be caused by clogged soil pores, which don’t allow additional water to penetrate deep enough to benefit the soil.
The bicarbonate level of water is controlled by the pH of the water, so the higher the pH level in the water, the higher the bicarbonate content of the water. Most water has a pH of 8.3 or lower, with bicarbonates at a pH less than 6.5, generally not creating any irrigation problems, according to Ruehr.
But one problem with bicarbonates in water is the possible formation of lime, which can clog pores. If this is the case, an acid treatment might be needed.
Acid treatment of high bicarbonate water causes the carbon dioxide to bubble out of the soil pores, according to Ruehr. This carbon dioxide loss prevents the formation of lime, keeping the pores open to allow for air, water and root movement.
Wastewater use also presents some unintended problems. When pure water is lost from the soil by evaporation or from plants by transpiration, soluble salts in the soil pores are left behind.
An acid treatment also might be helpful with wastewater to counter the high amounts of sodium. Much of the sodium results from the flushing of soapy water and detergents.
Another possible problem is the sodium absorption ratio. This value is calculated from the concentrations of the calcium, magnesium and sodium ions in water. Using gypsum can change the SAR, but should only occur after the acid treatment eliminates the bicarbonate problem, Ruehr says. Adding gypsum without first treating the water to remove the bicarbonate would make the problem worse.
Snow melt or rain water can be too pure, according to Ruehr. When water has too little salt, the clay mineral particles and humus swell with water. Water swollen clay minerals and humus move downward and clog pores, decreasing water, air and root movement.
Aerification or mechanical mixing are temporary fixes. But the best way to counter this too pure water is a soluble calcium, such as gypsum, Ruehr says.
Brackish or high sodium water might result from sea water intrusion or partially diluted sea waters in low-lying coastal regions or salty water carried into surface ponds in arid regions. High sodium is often a result of inadequate drainage. Soluble calcium helps counteract clogged pores as water flushes out the salts, according to Ruehr.
Additionally, well water might have high levels of soluble iron or manganese. The only effective method for dealing with water quality due to high iron or magnesium is to pump this water into a surface reservoir, Ruehr says. Chlorine bleach or hydrogen peroxide can be added to the water, but exposure to oxygen in the air will precipitate insoluble oxides, causing them to fall to the bottom of the lake. Clear surface waters can be pumped in, making sure the bottom sediments aren’t disturbed.
Like clay and humus, fertilizers also can clog soil pores. Inappropriate application of some fertilizers and soil amendments might aggravate water infiltration and soil permeability problems.
