This data set consists of periodic size measurements of permanently marked individual fluff grass plants. Measurements were taken in March, July, and September 1986. Twenty 6 x 6 m plots were established with a 3 m buffer between plots. Five plots were randomly assigned to one of four treatments: (1) chlordane amendment 100ml AI (active ingredients) per 10,000 ml) to exclude microarthropods, (2) sprinkler irrigation (6 mm per week), (3) sprinkler irrigation (6 mm/week) plus chlordate amendment (as above), (4) control (no treatment). Three randomly located subsamples were taken from each plot.