Deep Tine Aeration
Course and Grounds has scheduled a second deep tine aeration event on the evening of October 22nd and morning of October 23rd. Our selection of dates was somewhat limited by the contractor. In addition, it is crucial that we have our irrigation system running during aeration and we are scheduled to blow out the irrigation system during the last week of October.
Course conditions have varied significantly through the 2015 season. The poa on the greens has been performing very well this season; it is the Creeping Bentgrass that has been temperamental. To maintain turf health, mowing heights have been raised higher than I would like them to be and rolling frequency has been reduced. As a result, ball roll has not been where we would like it to be throughout most of the season. Superintendents can manage turf in many adverse conditions, however it is when these problems compound each other that we begin to see a decline in turf health and playing conditions. We have three agronomic challenges that magnify and compound some of our smaller challenges. The problematic areas have been identified as compaction, shade, and water quality and steps are being taken to improve in every area. Any improvement in these areas will result in turf that is better equipped to handle basic turf stresses. For the immediate future a sound agronomic plan has been developed that includes a back to basics approach. This includes continuing to improve sunlight, Deep Tine aeration, and Core Aeration. The benefits of the aeration event in August have been obvious and the greens that received both deep tine and core aerating preformed even better.
An aggressive aeration plan has been developed to improve the soil conditions and will assist in moving water through the profile more effectively. Greens will be deep tine aerated and core aerated 3 times a year. This will be done at times that will minimize the impact to course events and play. Exact dates still need to be finalized, but we anticipate aeration to occur at the end of April, end of August, and end of October. I would expect to see slight improvements after each aeration event, but it will take numerous events until I would consider conditions to be normal. Greens 4, 6, and 7 are unique and may require additional aeration. The soil in these greens lacks structure and after aeration will quickly revert to its previous compacted state. This is something we need to monitor through next season.
32 days after aeration roots are actively growing down 10 inch channels created by deep tine aeration.
So why is all this a problem now? As far as compacted soil goes, I am not aware of how exactly the greens were managed anything beyond 10 years ago. However, I do know that deep tine aerating was a large component of the turfgrass operations up until Drill and Fill started in 2009. While Drill and Fill offers numerous benefits, based on the evidence we have seen this season, it is safe to assume that Drill and Fill alone is not enough to keep compaction in check on our greens. Poa annua typically outperforms Creeping Bentrass in compacted soils and shaded conditions. Poa has no problem growing in a rootzone only 1-2 inches and more often than not will only ever have roots 3 inches under ideal conditions. Prior to the winter damage in 2013, the greens consisted of roughly 90% poa and 10% bentgrass, so the environmental conditions heavily favoured poa. Today, we are probably closer to 50% depending on which green you’re on. Ultimately, we are trying to grow Creeping Bentgrass in soil conditions that are more conducive to Poa Annua. All of this means that we need to re-evaluate the way in which we manage the soils, and be patient as we work on improving soil conditions to match the existing turf.