This dataset contains gravimetric soil water content measurements from harvester ant nests and reference soils in three nesting habitats at the Jornada Basin LTER site in 1987. The purpose of this investigation was to answer three general questions: 1. How does the modification of soil properties and the ratios of resources (e.g., water-N) by ants alter species assemblages of winter annual plants at the edge of the ant nests? 2. How does the "spring cleaning", clipping, predation or herbivory by ants affect success of the winter annual plants at the edge of ant nests? 3. Are there significant differences in the floristic assemblage and belowground standing crop (root biomass) between the edge of ant nest and the surrounding unaffected soils? Five ant nests and paired (non-nest) reference soils were sampled in three study locations on a monthly schedule from January to May 1987. This dataset contains percent (%) soil water content in these samples determined using the gravimetric method. This study was completed in 1987.