One of the biggest problems the putting greens encounter is high sodium (salt) content; this is a byproduct of reclaimed water, which is the golf course's irrigation water supply. High levels of sodium prohibit the roots from properly up taking nutrients, and the grass displays characteristics of drought and nutrient deficiencies.
One thing we do to help this is apply calcium; the calcium simply binds itself to the sodium as not to interfere with plant's uptake of nutrients. When the calcium is attached it also is easier to leach out the sodium and move it down the soil profile and into the drainage system.
There are side affects to the application of calcium, the biggest being that the pH of the soil goes up, making it more alkali. The creeping bentgrass on the course prefers slightly acidic soils; from 5.0 pH – 6.5 pH. As an example, pure water has a neutral pH at 7.0.
On November 15, a significant rain downpour was forecasted for later in the week, and we used this as an opportunity to address the pH and sodium levels of the soil on the greens.
Before the rain, readings were taken to record the pH and the TDS (Total Dissolved Solids) of the greens. The TDS has to do with EC (Electrical Conductivity), and it is the easiest way to judge the sodium levels in the soil.
As a bench mark the greens would be the healthiest at a pH from 5.0 to 6.5 and an EC reading of 0.75 to 1.50.
Before the rain the average reading for all the greens was 8.0pH
Before the rain the reading of the greens TDS mS/cm was .8 which = an EC of 3.0.
On November 18th, we applied 2,000 lbs of limestone (calcium) to the greens. This is a sound practice that many golf courses use to help leach out excess salts.
As it started to rain we applied a synthetic acid to lower the pH of the greens. Both of these practices require watering, which is why the timing of the chemical applications along with the storm played a big factor in our success.
Today the reading recorded from the greens is at 6.2pH.
The post rain recording of the greens TDS mS/cm was .2 which = an EC of 1.3.
This is a substantial improvement in a very short period of time.
