Hollow Tine Cultivation, Compost Topdressing, and Compost Tea Effects on Turfgrass Quality and Soil Microbial Activity.

Compost incorporated into soil can benefit soil properties and turf development. However, little information is available on the effect of compost topdressing and/or its water extract application on lawn turf visual quality and microbial activity. In this study the effect of once a year compost topdressing, hollow tine cultivation and monthly compost tea application is being examined on tall fescue (Festuca arundinacea Schreb.) turf maintained as a home lawn. The study has been replicated at two sites in Maryland and is currently in its third year. Plots are hollow tined cultivated with 0, 1 or 2 passes prior to the application of either a biosolid compost (Orgro), a plant based compost (Leafgro) or a controlled release fertilizer (Signature 35-0-10) at the rate of 156 kg nitrogen ha^-1 (3.2 lbs N 1000ft^-2) in the fall of each year. Plots were split in year 2 of the study with monthly compost tea application made to one half of each main plot from March to November. Turf color and visual quality is being assessed monthly during the growing season while microbial activity was accessed twice in summer in year 2 and will be measured twice more in the summer of year 3 of the study (2014). Cultivation improved early spring turf color at both locations in the first two years. Plots receiving the controlled release fertilizer in year 1 and 2 had turf quality that was comparable, or higher, than those receiving either compost sources.  Compost tea had little effect on turf quality and color although some improvement in quality was seen with compost tea application on one rating date at each site in year 2. Aeration, N source and compost tea had no effect on soil microbial enzymatic activity in year 2. This study is continuing to further assess the use of compost and its water extract as a means of reducing synthetic fertilizer use on lawn turf.