This data package contains nematode abundance in soils subjected to an irrigation experiment in mesquite coppice dune habitats during the early years of Jornada Basin LTER (LTER-I and II). The purpose of this study was to quantify total nematode abundance, and the abundance of nematode functional groups, in irrigated and non-irrigated (control) soils beneath mesquite plants (Prosopis glandulosa). Soil cores were taken from three depths (0-50cm, 50-100cm, and 100-150cm) then divided into subsamples for nematode investigation. Nematodes were quantified via a semi-automatic elutriator with sugar flotation-sieving and the Baerman Funnel technique. Nematodes were counted and separated into trophic groups: fungal feeders, bacterial feeders, plant parasites, and omnivore-predators. The data collection began in March 1988 and ended in October 1988. This dataset is complete.