尿素及秸秆添加对华中地区茶园土壤CO_2和N_2O排放的影响

为了明确尿素和秸秆添加对茶园土壤CO_2和N2O排放的影响,为茶园合理施肥提供理论依据,本研究在室内培养条件下,以华中地区红壤丘陵区茶园土壤为对象,运用静态培养系统研究方法,研究该土壤在尿素输入和作物秸秆添加后CO_2和N_2O的排放特征。培养试验共设置对照、尿素、作物秸秆和尿素+作物秸秆4种处理。结果表明:不同处理下华中地区茶园土壤CO_2和N_2O排放呈显著差异。作物秸秆添加显著提高茶园土壤CO_2的排放,作物秸秆和作物秸秆+尿素处理分别是对照的5.57和4.99倍。尿素输入显著促进茶园土壤N_2O的排放,而秸秆添加却降低N_2O的排放。对照和添加尿素处理土壤N_2O排放通量与铵态氮含量呈显著正相关关系。无秸秆添加处理土壤N_2O排放通量与硝态氮含量呈显著的相关性,而添加秸秆处理二者无显著相关关系。土壤可溶性有机碳含量对CO_2排放有显著影响,二者之间呈极显著线性正相关关系。

Effects of Urea and Straw Application on CO2 and N2O Emissions in Tea Field Soil in Central China

In order to study the effect of urea and straw application on CO₂ and N₂O emission in tea field soil and provide theory basis for the rational fertilization, hilly area tea field of red soil in central China was took as study object, the emission characteristics were studied after the application of CO₂ and N₂O by the method of static culture system under indoor incubation condition. Four different treatments (control, urea, crop straw and urea crop straw) were designed. The results showed that soil CO₂ and N₂O emission presented significant differences among four different treatments. The application of crop straw could remarkably promote soil CO₂ emission, soil CO₂ emissions were 5.57 and 4.99 times higher than CK after the application of crop straw and urea crop straw respectively. The application of urea could significantly promote N₂O emission in the tea field soil, but the application of crop straw reduced soil N₂O emission. There was a significantly positive correlation between the N₂O emissions amount of CK and urea treatments and the NH₄ -N content. The soil NO₃^--N content had a close relationship with N₂O emission of the treatment without crop straw application, while the NO₃^--N content and N₂O emission of the treatment with crop straw had no significant correlation. Soil soluble organic carbon (DOC) had significant impact on CO₂ emission, the two had a significantly linear positive correlativity.