USGA Green Section Site Visit – Cowan Creek
On Thursday (4/26/12) we invited Bud White (an agronomist from the USGA Green Section staff) out to Cowan Creek to take a look at our greens and discuss some of the issues we are dealing with. Below will be a brief summary of his conclusions, and solutions to our current issues:
There are two problems currently within the soil profile that were brought to our attention. The first of which pertains to what Mr. White called a “hard pan” layer in the greens mix about 6” deep in the soil profile where finer sands have accumulated over time, prohibiting water infiltration. A proper greens mix has a precise distribution of sands with varying particle size to allow room for air and water movement through the rootzone and soil profile. He suggested that we take two samples to be sent off and analyzed to determine if we have the correct sand mix for our greens. The samples will be used to test particle size, soil texture, organic matter, and water infiltration rates. On 4/27/12, we took one sample from the back of #17 green to represent a healthy stand of turf with proper drainage, and another sample from the left side of #9 green where we have been having drainage issues and turf quality problems.
The second issue involved a sodium buildup in the rootzone, where a black layer has formed. By using digital meters that measure total salts and sodium in the soil, we found that our sodium levels were higher than the accepted number for healthy turf. The origin of these unwanted salts comes from our irrigation water, which is effluent or “treated” water. Sodium molecules when absorbed by the roots prohibits water and nutrient uptake in the plant and can cause the plant to yellow, wilt, and eventually die if not treated. Mr. White suggested that we amend this issue by fertilizing with gypsum and flush the salts with water, which I will explain below.
Overall, with our current cultural practices to allow air and water to the roots and our fertilizer program, along with two of the recommendations from Mr. White, we should see improvement in the turf quality as we progress into the growing season. Many of our practices were validated, and we received supplemental insight on how to achieve a faster recovery from the spring transition.
“Hard Pan” Solution
Without proper drainage, greens more readily can seal off at the surface and create anaerobic conditions in the rootzone that cause these areas to become weak and bare. A deep tine aerification has been scheduled on 4/7/12 to penetrate through this hard pan to allow air and water movement through the entire soil profile. We will be using a hollow tine with a 13/16” outer width that will punch close to a .5” hole 10” deep into the soil profile. We will then add fertilizer amendments and topdress with greens-grade sand. Afterwards, we will verticut the greens at 1/8” depth to help close up the holes on the surface.
Sodium Flush
During our deep tine aerification, we will add gypsum (CaSO4) at a rate of 11 lbs / 1000 sq. feet to break off the sodium on the roots, and then flush the greens with very large quantities of water. This process is recommended in order to properly buffer the salts in the rootzone, and requires us to water every green constantly for up to 90 minutes. This will undoubtedly leave the greens surrounds and approaches wet for 2-3 days, but is a necessity for proper salt flushing. Afterwards, we will follow up the flush with potassium and magnesium amendments.
