The management of organic matter is one of the more complex maintenance and renovation tasks for Course Managers around the world, due to its immediate conflict presenting smooth and fast putting surfaces.
European Turfgrass Laboratories (ETL) tests organic matter at 20mm segments for hundreds of golf courses annually, from over thousands of individual greens from local authority low budget courses to the world best championship courses. This data helps Course Manager communicate better with its stakeholders and make more informed decisions.
Specially-designed sampling kits are sent out to clients, for easy extraction from the golf green. It’s essential that the core remains intact. Upon receipt at the laboratory, each core is removed from the sampling core, and cut into the 4 increments: 0-20mm, 20-40mm, 40-60mm and 60-80mm and tested using ASTM 1647:11 (2018), “Standard Test Methods for Organic Matter Content of Athletic Field Rootzone Mixes
ETL wanted to put some of this data into perspective for clients, so in 2019 we reached out to our clients to provide added value and perspective on this data. The response was excellent with clubs providing information ensuring that the data base is continually growing
ETL will now follow with a series of articles investigating relationships between the amount of organic matter in greens and practical aspects such as sand topdressing amounts, available budgets, staff numbers, species and types of greens construction. We hope this helps provide added perspective for managing your greens.
Course Managers have been asked to categorise their sand topdressing applications into the following brackets of sand applied per annum for 0-2 years of maintenance (recent applications) and sand applied for 2-5 years of maintenance (historical applications):
From the results, we have been able to present data of averages at 0-20mm, 20-40mm, 40-60mm and 60-80mm.
Summary of Finding from Recent Sand Application Volumes and its Impact of Organic Matter Levels
- Volumes of sand applied from within the last two years dominantly affected organic matter levels in the upper 0-20mm.
- Greens applying less than 50 tonnes p/ha per year have significantly higher organic matter.
- Generally, courses which applied higher volumes of sand have lower amounts of organic matter at 0-20mm.
- Sand application ranges from 51-120 tonnes p/ha, per year, showed variable ranges but are, in general, lower. Continued data collection by ETL will provide ongoing clarity in this range.
- Historical sand applications of higher amounts continue to show that it produces lower organic matter results at 0-20mm.
- The middle range of applications from 51-120 tonnes p/ha per year, shows some variability but application in excess of 121 tonnes p/ha per year show clear reduction.
- Historical increases in sand application can result in burying of historical layers as new sand build up over inherited organic matter. This is shown at 20-40mm and 40-60mm depths where high application volumes have shown increases of organic matter depth.
Summary of Relationship Between Sand Application Volumes and Organic Matter Levels
The concept of application of higher volumes of sand resulting in lower organic matter levels is already widely established. The objective of this research was to provide harder evidence to help Course Managers engage club members in embracing higher volume of sand applications
Less known, is the trend that immediate increases in sand application volumes buries organic matter to lesser or greater extent. This Organic Matter then takes time to breakdown and remains buried in the profile and needs some levels of treatments; firstly, when at surface (0-20mm) levels and secondly, once slightly buried.
ETL will continue to collect sand application data along with Organic Matter tests results at 20mm segments. Hopefully this will provide more insight into the relationship between sand topdressing volumes applied and Organic Matter levels at 20-40mm and 40-60mm levels.