Climate change is increasing the variability of precipitation, altering the frequency of soil drying-wetting events and the distribution of seasonal precipitation. These changes in precipitation can alter nitrogen (N) cycling and stimulate nitric oxide (NO) emissions (an air pollutant at high concentrations), which may vary according to legacies of past precipitation and represent a pathway for ecosystem N loss. To identify whether precipitation legacies affect NO emissions, we excluded or added precipitation during the winter growing season in a Pinyon-Juniper dryland and measured in-situ NO emissions following experimental wetting. We found that the legacy of both excluding and adding winter precipitation increased NO emissions early in the following summer; cumulative NO emissions from the winter precipitation exclusion plots (2750 ± 972 µg N-NO m^-2) and winter water addition plots (2449 ± 408 µg N-NO m^-2) were higher than control plots (1506 ± 397 µg N-NO m^-2). The increase in NO emissions with previous precipitation exclusion was associated with inorganic N accumulation, while the increase in NO emissions with previous water addition was associated with an upward trend in microbial biomass. Precipitation legacies can accelerate soil NO emissions and may amplify ecosystem N loss in response to more variable precipitation.

This data accompianies the mauscript entitled: Precipitation legacies amplify ecosystem nitrogen losses from nitric oxide emissions in a Pinyon-Juniper dryland, which is published as a Report in Ecology. The methods for data collection can be found within the manuscript. Briefly, NO efflux was measured from 24 plots within the Pinyon Flats rainfall manipulation experiment three time in 2020. NO emissions are made by recirculating air from an enclosed chamber headspace through a NO analyzer and measuring the change in trace gas concentrations over time. These data are in the "combined_fluxes.csv" document. We also measured soil inorganic N conctrations, soil moisture, soil microbial biomass, and ammonia oxidizing gene abundance in parallel to the NO efflux measurements.

Empty columns refer to samples that were lost in the data collection process. Most sampes are lost from the N mineralization and nitrification measurements, which require intact soil cores to be left in the field for one month. Some of these cores were removed by wildlife during the one month incubation, leading to missing data.