Cool Wet Spring! Aerification

Cool wet spring!

Last March spoiled us with unseasonably warm and dry weather, which was great for golf and maintenance work. This March has been the polar opposite, last year the average high and low temps were (70 F / 36 F) and this year it’s (53 F/ 35 F). That’s a 17 degree difference. February was also warmer in 2012 than this year. The rate of turfgrass growth is dependent on many factors including temperature, moisture, nutrition, and to some extent, day length. Optimum temperatures for leaf growth among the cool-season turfgrasses range from 60° to 75°F. Leaf growth increases with increasing day length as long as temperatures are within the optimum range and moisture is adequate. Application of nitrogen fertilizer can greatly increase leaf growth if moisture and temperature are not limiting. There’s an up-side and a down-side to this.

The up-side is that it shortens the growing season reducing the number inputs required to maintain it. This includes such things as labor for mowing, fertilizers, irrigation, pesticides, crabgrass pre-emergent and equipment cost. It allows us to focus on finishing winter projects and course clean up. Last year we were mowing grass when we would typically be finishing up off season project.

Some of the down-sides other than the less ideal golfing conditions are that the turf is the not actively growing yet and will remain sluggish until soil temperatures rise. Due to this, the healing process from aerification this year is going to be hampered by the cool conditions. Course conditions as a whole are expected to lag behind last year until Mother Nature decides otherwise. Even though the course is still in a bit of a slumber state it is still important to fix ball marks and use the sand and seed mix for your divots.

Aerification Scheduled for April 1,2&3

 

The Golf Course will be closed April 1 -3 for aerification if the weather permits.

Greens: For the greens this spring we have contracted Mid-Atlantic DryJect to use its patented sand injection technology. DryJecting uses high pressure water injection to suck sand directly into soil profile. After this process we will be doing a tradition coring and topdressing process.

 Fairways will again be aerified with solid tines and top-dressed with 12 tons of sand per acre. Once again, this is an aggressive aerification schedule and process. 

The aggressive nature of this aerification stems from the results of physical analysis testing done last summer; these test revealed the need for a corrective aerification process rather than a maintenance process. This summer we will retest, evaluate and make the proper adjustments.

The impacted or modified region of the greens mix (0-4 inch sample) taken last summer shows the results of the historic greens maintenance programs over time. The upper sand profile is not within USGA specifications. The organic matter content has increased significantly with corresponding reductions in water infiltration and air filled pore space. Air porosity represents the larger non-capillary porosity of the sample. This figure will greatly affect the percolation rate. It is this pore space that the plant occupies, and is therefore one of the major factors that dictate the success of a root-zone to support the plant. Our capillary space has increased dramatically as a result of the organic matter. Moisture retention at 30cm is 23.1%. The elevated organic matter in the upper profile is retaining too much water which is having a negative impact on on root development and moisture management. This also shifts the playing field in favor of poa annua.

This data has revealed several opportunities for improvement. The organic matter development in the upper profile has exceeded the cultural practices on the putting greens. The need to increase the aerification, needle tining, venting, and topdressing is evident. Spring and fall aerification with ½-5/8” tines is warranted. Venting should occur every three weeks throughout the growing season. We also need to find topdressing sand that is several degrees coarser than the material we are currently using. These efforts are intended to increase the air pore space and reduce the organic matter content in the upper profile of the greens. It will take a full 2 seasons to bend the organic matter curve that we are currently on.