Removing Sand from Putting Green Clipping Samples Substantially Reduces Clipping Weight Measurement Error

Abstract

ABSTRACTAccurate determination of turfgrass yield via clipping harvest can be problematic on closely mowed research putting greens because sand often contaminates samples. Scientists reporting putting green clipping yields rarely mention if or how sand was removed from clippings. The two objectives were: (i) evaluate the efficacy of three clipping cleaning methods (water decantation, forced air, and a vibrating pan method) and (ii) evaluate the effect of sand contamination on field data variability. All three clipping cleaning methods effectively removed coarse sand from the sample while only the vibrating pan method effectively removed the fine sand fraction. Turf clippings were collected from four different research putting greens, dried, weighed, cleaned, and reweighed to calculate percent sand and treatment variability. Debris mass ranged from 0.01 to 0.92 kg kg−1 (0.001–0.535 cm3 cm−3) and averaged 0.26 kg kg−1 sand with a standard deviation of 0.18 kg kg−1 Cleaning clippings reduced the standard deviation and coefficient of variation of all treatments (n = 104) by 0.92 g m−2 and 15%, respectively. Sand debris varied spatially across each green regardless of sand topdressing. Sand debris in golf putting green clipping samples constitutes a large enough percentage of total mass to justify its removal.