Boardroom Yarn # 56 - Questions and Answers
Recently, while being interviewed for a documentary on golf green failures, it occurred to me that some of the questions, in fact many of the questions that the interviewer was asking needed to be put into an article. The following are a few of the questions and answers that I feel everyone in a management position on a golf course would like to ask if they knew how, and my answers to the questions.
QUESTION: After 26+ years what is the most important thing that you have learned?
ANSWER: “Plants need Oxygen and Standard Water is not a good thing.” I first heard that statement almost 30 years ago from my mentor Dr. James Watson so I cannot take credit for it, however what we have discovered is how much oxygen a plant needs and the amount of water that needs to be retained in the greens mix.
QUESTION: What is the main cause of Greens failure ?
ANSWER: Lack of Oxygen.
QUESTION: What is the main cause of lack of oxygen in the root zone of a greens mix ?
ANSWER: Lack of space in the air pores……. For the answer to be understood we must first understand what makes up a greens mix. A greens mix is composed of solids and pores [pores are the spaces between the solids]. The larger pores hold oxygen and the smaller pores hold water. Since roots take in oxygen they can only live in the larger air pores of the greens structure. The roots of a grass plant produce organic matter [much like our skin produces oil] and since roots can only live in air pores the organic discharge is deposited in these air pores thus reducing the amount of air pores available to hold oxygen. As this organic grows it can reduce the amount of space in an air pore to the point where there is very little room for oxygen.
QUESTION: What do Physical Properties refer to in regards to a golf green ?
ANSWER: Most people think of infiltration rates when looking at or discussing physical properties, however I personally am more interested in the air and water pores being in balance with each other, preferably a one to one ratio. The next thing I am interested in is the percent of water holding. Physical Properties should include: Infiltration rates, air pores, water pores, total porosity, compaction, and organic content measured in one inch increments.
QUESTION: You mentioned that physical properties change. What are the main causes of these changes ?
ANSWER: Organic build up and quality of irrigation water.
QUESTION: Considering these changes how often should a golf green be tested for Physical Properties?
ANSWER: Every year for the first 5 or 6 years until the ageing process stabilizes and we have steady results from our agricultural program. After the stabilization every other year will be sufficient.
QUESTION: Would you say that by maintaining balanced Physical Properties we will contribute to improving the environment ?
ANSWER: If balanced Physical Properties lead to healthier turf than the answer is YES. Plants take in CO2 and produce oxygen. The more plants, the more oxygen. Denser turf equals more plants. Research has shown that greens with balanced Physical Properties and healthy turf require 20 to 25% less in their need for chemicals.
QUESTION: You said that with these tests from ISTRC we can now be pro-active in our agriculture practices. What do you mean by being pro-active ?
ANSWER: In the past we waited until our turf started to stress before taking corrective action but now by monitoring the Physical Properties on a regular basis and understanding how the green is ageing we can take action before the turf starts to stress.
QUESTION: If the Physical Properties are always balanced air to water, am I to understand that the turf will always be healthy?
ANSWER: NO…..Balanced Physical Properties are the foundation and a must for healthy turf. However, we have found that the air pores can become contaminated with sewer gas [CO2, Methane and Hydrogen Sulfide are the main components of sewer gas] and I personally believe that as many greens fail from this contamination as they do from excessive organic build up.
QUESTION: Where do these sewer gasses that cause green failure normally come from ?
ANSWER: Drain Tiles. Most greens built over the last 40 years have a drain tile system under the greens mix imbedded in gravel. As water passes through a green it enters this system of drain tiles and is carried away from the green to some distant destination. If this drain system is compromised and the water cannot travel away to its designated destination it sits and becomes anaerobic because of lack of oxygen. The gasses produced by the anaerobic water will rise and travel up through the drain tile system and into the greens mix where they will reside in our air pores. Once the sewer gasses replace the oxygen in our air pores it means stressed turf and disease.
I hope that the above questions and answers will help with your ongoing effort to better understand your greens. NEVER STOP LEARNING.
David L. Doherty Copyright May, 2016