Page 7 - Transitioning Turfgrass

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6 ETS Field Days
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Site-Specific Management for the

Reduction of Turfgrass Inputs

Gerald Henry, PhD, Professor-Environmental Turfgrass Science, University of Georgia

Turfgrass managers are often accused of exhib- tion measurement.
iting luxury consumption of several inputs such as The magnitude and frequency of spatial varia-
fertility, irrigation, cultivation etc. Recent research tion with respect to several agronomic conditions
has attempted to change this perception by en- present within turfgrass systems requires intense
hancing sustainability through the development sampling techniques for data acquisition. Research
and implementation of efficient, site-specific turf- was conducted to determine the minimal number
grass management. The spatial variability of soil of samples needed to accurately describe the spa-
and plant parameters common to turfgrass envi- tial variability of soil and plant parameters. Six
ronments makes it very difficult to oversee entire sampling grid sizes (2.4 m x 4.8 m, 4.8m x 4.8
areas under the same management plan (Fig. 1). m, 4.8 m x 9.6 m, 9.6 m x 9.6 m, 9.6 m x 19.2 m,
Therefore, the primary goal of site specific man- and 19.2 m x 19.2 m) were employed for the spatial
agement is to define boundaries of site specific analysis of VWC, PR and NDVI when areas were
management units (SSMUs) (i.e. management near field capacity and under drier soil conditions.
zones) through the use of precision agriculture
concepts, technologies, and products (Photo
1, page 4). Integrating current site assessment
equipment/sensors into daily management prac- Cation Exchange Capacity
tices will help turfgrass managers to apply inputs
to areas where needed, when needed, and in the
amount needed, resulting in management on a meq 100 g-1
smaller scale and reductions in overall inputs. 6,6-7,2
7,3-7,7
7,8-8,3
Extensive research has been conducted at the 8,4-8,8 0 15 30 60 m
8,9-9,4
University of Georgia to determine optimal sam- 9,5-10
11-11
pling technique, timing, and application. Re-
search was conducted to compare handheld and Organic Matter
mobile sensor data acquisition of soil moisture
[Volumetric Water Content (VWC)], soil com-
paction [Penetration Resistance (PR)], and turf- %
grass quality [Normalized Difference Vegetative 6,1-6,9
7-7,6
7,7-8,4
Index (NDVI)]. Spatial maps of VWC and NDVI 8,5-9,1 0 15 30 60 m
9,2-9,9
displayed similar patterns of variability between 10-11
12-11
handheld and mobile devices, while spatial maps
of PR were inconsistent due to device design and Figure 1 Kriged maps of Cation Exchange Capacity
user reliability. Consequently, mobile devices may (CEC) and Organic Matter (OM) content of a fairway at
provide the most reliable results for soil compac- the Georgia Club Golf Course in Statham, GA in 2016.

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