Rhizosphere soil microarthropods may have a major role in determining soil nitrogen availability. Desert soil microarthropods are consumers of soil bacteria, fungi, and nematodes, thus they accelerate mineralization processes by causing turnover in immobilized nitrogen. 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). The effects of these treatments on soil and fluffgrass plant characteristics were investigated. This dataset includes periodic size measurements made of permanently marked individual fluff grass plants taken in March, July, and September 1986. For additional data from this larger study, refer to other JRN packages: 210385003, 210385008, 210385005, 210385006, 210385007, and 210385001. This study is complete.