Thatch and Soil Microbial Activity as Influenced by Turf Cultivation Practices.

Hollow tine core cultivation and vertical mowing can dramatically change the chemical and physical properties of thatch and soil. Little is known however about how these two practices may alter microbial activity within thatch and soil. This study examined thatch and soil microbial activity over a 56 to 58 day period following hollow tine cultivation and vertical mowing of two turfgrass sites. Microbial activity was assessed by measuring the rate of fluorescein diacetate hydrolysis of small thatch and soil plugs that were removed from non-cultivated plots, and from plots where the hollow tine core cultivation and vertical mowing treatments had been imposed. The moisture content and organic matter of each plug was also determined at the time microbial activity was measured. Thatch moisture content was a better predictor of thatch microbial activity than was thatch organic matter content. A consistent enhancement in thatch microbial activity was observed 13 to 15 days after performing hollow tine cultivation. The enhancement in activity was associated with higher moisture levels within the thatch samples collected from the hollow tine cultivated plots compared to the non-cultivated control plots. Hollow tine cultivation had no consistent effect on soil microbial activity or on thatch microbial activity beyond the first collection date. Vertical mowing had no consistent effect on thatch or soil microbial activity.  While hollow tine cultivation and vertical mowing are important and necessary management practices used to improve soil physical properties and restore turf vitality, the results of this study do not extend the benefits associated with these two cultivation practices to include an extended enhancement in microbial activity.