[Short-Term Effects of Different Fertilization Treatments on Greenhouse Gas Emissions from Northeast Black Soil]

A 7-day incubation experiment was conducted at 25℃ with 60% water holding capacity (WHC) to study the short-term effects of different fertilization treatments on the regularity of greenhouse gas emissions from northeast black soil. The results showed that application of chemical N fertilizer had no effect on CO₂ emission, as compared with the non-fertilizer control treatment; however, a combined application of N fertilizer with pig manure or straw increased CO₂ emissions by one magnitude compared to that of the chemical N fertilizer treatment, with the effect of chemical N fertilizer and straw being more prominent. Nitrification was the main process resulting in N₂O emission for the non-fertilizer control and chemical N fertilizer treatments, and the application of chemical N fertilizer had no significant effect on N₂O emission, as compared with the non-fertilizer control. The combined application of N fertilizer with pig manure or straw promoted the occurrence of denitrification and increased N₂O emissions by two magnitudes compared to that of the chemical N fertilizer treatment, with the effect of chemical N fertilizer with straw being more remarkable. Compared with the non-fertilizer control, the application of chemical N fertilizer inhibited CH₄ emissions and promoted the slightly absorption of CH₄, while the combined application of chemical N fertilizer with pig manure or straw increased significantly the emission of CH₄.