This data package contains data on nitrogen mineralization potential of the rhizosphere of fluffgrass (_Dasyochloa pulchella_) at the Jornada Basin CDCC in 1987. The study was conducted on twenty 6 x 6 meter plots. Five plots were randomly assigned to one of 4 treatments: 1. Chlordane amendment (100ml Al per 10,000ml) to exclude microarthropods; 2. Sprinkler irrigation (6mm/week); 3. Sprinkler irrigation (6mm/week) + chlordane (same as first treatment); 4. Control. Three randomly located subsamples were taken from each plot and consisted of the fluff grass plant, a 10 cm in diameter and 15 cm deep soil core centered on each plant. Some samples were incubated for 0, 2, 4, or 8 weeks. This data set contains information on the incubation time, soil nitrate- NO3, soil ammonium- NH4, and soil water content for each subsample. This dataset was collected in May 1987 and is complete.