Effects of Nitrogen and Phosphorus Additions on Soil N 2 O Emission and Soil Carbon Storage in Lakeshore Zone

This study examined the short-term effects of nitrogen (N) and phosphorus (P) addition on soil N 2 O flux and organic carbon content in the lakeshore zone of an arid inland lake, Daihai. Treatments included control (N0P0), N addition (N1P0), P addition (N0P1), and NP co-addition (N1P1). Using the static chamber method and lab analyses, we measured soil N 2 O flux and organic carbon content at different growth stages. Results showed that, in the early growing season, short-term N and P addition had no significant effect on soil N 2 O flux, with all treatments acting as N 2 O sources. However, N and NP treatments significantly increased soil organic carbon (SOC) storage, improving carbon sequestration benefits by 72.7% to 98.1%. During the peak growing season, N and NP treatments significantly enhanced soil N 2 O emissions, while NP treatment further increased SOC storage, the carbon sequestration benefits of all treatments ranging from 49.0% to 56.5%. At the late growing season, N and P addition had no significant impact on soil N 2 O flux or organic carbon storage, with all sites acting as N 2 O sinks and SOC storage showing no significant change across treatments (carbon sequestration benefits ranged from 0.3% to 38.5%). The study highlights that the response of soil N 2 O flux to short-term N and P addition varies at different growth stages, while overall, N and P addition promotes soil carbon sequestration throughout the growing season in the lakeshore zone.