Effects of fermented organic fertilizer application on soil N 2 O emission under the vegetable rotation in polyhouse

Vegetable field is one of the main sources of soil nitrous oxide (N O) emission, yet soil N O emission from vegetable rotation with combined application of fermented organic fertilizer with inorganic fertilizer in polyhouse is not well evaluated. In this study, we investigated the soil N O emission in cabbage-tomato rotation management system under different treatments of fertilizer nitrogen (N) sources, including: 100% inorganic fertilizer (IF), 75% IF+25% fermented organic fertilizer (OF), 50% IF+50% OF, 75% IF+25% OF, 100% OF, and no fertilizer (CK). The fertilization amount of N was 180 kg ha to cabbage and 200 kg ha to tomato. Results showed that soil N O emission flux was in a high level during 1-3 days after basal fertilization for cabbage, and decreased as the proportions of OF increased. During the whole cabbage-tomato rotated cultivation, N O emission flux was positively related to soil NO -N and NH -N contents, with correlation coefficients of 0.72 and 0.90, respectively. A higher proportion of OF increased the soil total carbon (C), organic C and C/N ratio, but decreased the soil nitrifiers and denitrifiers. The fertilizer N loss caused by N O emission under different OF treatments was 1.23-2.77%, significantly (p