Comparing nitrous oxide losses from three residential landscapes under different management schemes following natural rainfall events

Abstract

Lawn management practices that produce aesthetically appealing landscapes may also create environmental conditions that stimulate soil nitrous oxide (N2O) fluxes. The purpose of this exploratory study is to investigate the effects of lawn management practices on N2O fluxes from three non-replicated distinctly different residential landscapes: a high maintenance fescue (Festuca arundinacea) lawn (HMFL), a low maintenance fescue lawn (LMFL), and a mixed hardwood forested residential landscape (FRL) located in Cary, North Carolina. The specific objectives are (1) to measure the N2O fluxes from three residential landscapes within a fixed 24-h period following natural rainfall events; and (2) to determine the effect of lawn maintenance, season, water filled pore space (WFPS%), temperature, and days after fertilization on N2O flux. The mean N2O fluxes for HMFL (14.3 ± 2.28 μg N2O-N m−2 h−1), LMFL (3.14 ± 0.68 μg N2O-N m−2 h−1) and FRL (0.43 ± 0.08 μg N2O-N m−2 h−1) indicate that residential lawns receiving the recommended amount of fertilizer and frequent irrigation exhibit higher N2O fluxes than non-irrigated fertilized lawns or forested landscapes. Patterns of N2O fluxes from the HMFL and LMFL were associated with timing of fertilizer applications, presence or absence of irrigation, and seasonal fescue growth patterns. For the FRL, lower N inputs and the presence of a decomposing litter layer potentially limited N2O production. Our findings suggest that lawn management practices (i.e., fertilizer applications and irrigation) can create differences in the N2O flux following natural rainfall events.