Numerous nitrogen (N) addition studies suggest that anthropogenic N deposition is one of the most prominent factors driving global change. Our understanding of the effects of N deposition on ecosystem structure and function however, has been derived from studies concentrated in temperate mesic systems, thus leaving us relatively incomplete understanding on how N deposition can impact drylands, the largest terrestrial surface on earth. Dryland response to N enrichment is likely to differ from more mesic systems, due to the unique climatic and environmental characteristics that drylands possess. Drylands are frequently characterized as being primarily water limited or co-limited by water and N but they also contain low standing stocks of soil organic matter. Therefore, in addition to N, other critical resources, such as carbon © and biologically derived phosphorous (P) may also be limiting to dryland biota. Knowledge of resource limitation is fundamental to our understanding of how ecosystems respond to change. In this study, we seek to determine if dryland soil microbes are limited by C, N and/or P when given sufficient water. We conducted a short-term (16-day), fully factorial C, N and P addition laboratory incubation experiment using soil collected from a semi-arid Chihuahuan Desert grassland, located at the Carlsbad Caverns National Park. Measurements include soil microbial biomass C, N and P (MBC, MBN and MBP respectively). After 16 days, MBC increased when N or P were added (alone and in combination), where the greatest increase was observed under the C, N and P combination treatment, suggesting that the dryland microbial community is nutrient limited. When C, N and P where added in combination MBN (i.e., N storage by soil microbes) increased. MBP increased with the addition of N, suggesting N-limitations to P uptake by microbes. Overall, our results suggest that soil microbial communities in this dryland ecosystem are indeed limited by multiple resources. Therefore, while ecosystem function can be altered by N deposition, responsiveness to N enrichment may be dependent on the system’s ability to overcome other resource limitations. In sum, multiple resource limitations may constrain our ability to predict the effects of anthropogenic N deposition in dryland ecosystems.