Monitoring and Managing Putting Green Firmness on Golf Courses

摘要

Since many golf course superintendents today are maintaining putting greens as dry as possible, it is critical to understand the relationship between firmness and soil volumetric water content (VWC) of putting greens. A series of firmness studies wereconducted to meet three objectives. For the first objective, to evaluate methodology using the Clegg Impact Soil Tester (CIST), it was determined that one drop of the 2.25-kg hammer was the preferred method to measure green firmness when using a CIST. For the second objective, to compare the 2.25-kg CIST and TruFirm devices, it was determined that a significant, inverse relationship (R~2 = 0.75, P < 0.001) existed between the devices. Therefore, both devices were useful tools in measuring green firmness. For the third objective, to better describe the relationship between firmness and VWC of putting greens, over 2000 samples from 53 golf courses were analyzed and it was determined that a significant inverse linear relationship existed between firmnessand VWC. However, the R~2 values for the relationship had a broad range (0.19 to 0.70), which indicated that there was significant variability associated with these estimates. This variability may be due, in part, to differences in sampling depth between the CIST and VWC probes. More likely sources of this variability were factors such as turf variety, verdure, thatch, mat, soil texture, and soil bulk density which impacted putting green firmness in addition to VWC.