Handheld Vs. Mobile Data Acquisitions for Spatial Analysis of Natural Turfgrass Sports Fields.

Research compared handheld and mobile data acquisitions of soil moisture (VWC), soil compaction (penetration resistance), and turfgrass vigor (NDVI) of four natural turfgrass sports fields using two sampling grid sizes (4.8 x 4.8 m and 4.8 x 9.6 m). Differences between the two sampling grid sizes were minimal, indicating that sampling with handheld devices using a 4.8 x 9.6 m grid (120-130 samples) would achieve results similar to the smaller grid size. Central tendencies and data distributions varied among the handheld and mobile devices. Moderate to strong correlation coefficients were observed for VWC and NDVI; however, weak to moderate correlation coefficients were observed for penetration resistance at three of the four locations.  Kriged maps of VWC and NDVI displayed similar patterns of variability between handheld and mobile devices, but at different magnitudes. Spatial maps of penetration resistance were inconsistent due to device design and user reliability. Consequently, mobile devices may provide the most reliable results for penetration resistance of natural turfgrass sports fields.