Nitrous oxide flux from a tea field amended with a large amount of nitrogen fertilizer and soil environmental factors controlling the flux
Nitrous oxide flux from a tea field amended with a large amount of nitrogen fertilizer and soil environmental factors controlling the flux
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DOI：
10.1080/00380768.2004.10408490
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发表时间：
2004-02
影响因子：
2
通讯作者：
Shin-ichi Tokuda;M. Hayatsu
中科院分区：
文献类型：
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作者：
Shin-ichi Tokuda;M. Hayatsu
摘要氧化亚氮（N2 O）是主要的温室气体之一，准确估算施肥农田N2 O排放通量是一个重要的研究课题。酸性茶园土壤N_2O的产生活性高于中性耕地土壤，茶园可能是N_2O的主要来源。为此，采用密闭箱法对不同施肥条件下茶园4个样地（Std、2N、2Ca和−Ca样地）的N2 O排放通量进行了为期2年的测定，并分析了N2 O排放通量与土壤环境因子之间的关系。施入标准地块的氮肥和石灰材料（白云石）的量分别为600 kg N ha−1 y−1和1，500 kg ha−1 y−1。2N区的施氮量是标准区的2倍，与日本茶园的常规水平相当。在2N小区中，由于大量施氮，土壤酸化。2Ca图用两倍于Std图的石灰材料量进行修正，在−Ca图中不施用石灰材料。各样地的N2 O排放通量差异显著，2N样地的N2 O排放通量最高，为8.785 mg N m−2 h−1。2N小区N2 O年排放速率和排放因子分别为25.22 kg N2 O-N ha−1和2.10%。长期大量施氮和土壤酸化均可能增加了茶园N2 O排放通量。茶园N2 O排放通量具有明显的时间变化特征，即12月至3月，茶园N2 O排放通量相对较低，这可能与土壤温度较低有关; 3月以后，茶园N2 O排放通量随着土壤温度的升高而逐渐增加，土壤温度升高10°C以上，茶园N2 O排放通量逐渐增加。N2 O通量在7月达到第一个高峰，8月由于土壤干燥而短暂下降，9月或10月再次上升并达到第二个高峰，11月以后又下降。多元线性回归分析表明，茶园N2 O排放通量与土壤环境因子之间存在显著相关关系。N_2O产生活动的时间变化与N_2O通量的时间变化相对应。
Abstract Nitrous oxide (N2O) is one of the main greenhouse gases, and accurate estimation of the N2O flux from fertilized arable land is required. It is known that acidic tea field soil displays a higher N2O production activity than neutral arable soil and that tea fields could be a major source of N2O. Therefore, N2O fluxes from four plots (Std, 2N, 2Ca and −Ca plots) in a tea field that had been subjected to different conditions of fertilizer management were measured using the closed chamber method over a period of two years, and the relationships between the N2O flux and soil environmental factors were analyzed. The amounts of nitrogen fertilizer and liming material (dolomite) applied to the Std plot were 600 kg N ha−1 y−1 and 1,500 kg ha−1 y−1, respectively. The amount of nitrogen fertilizer applied to the 2N plot was two-times larger than that applied to the Std plot and corresponded to the conventionallevel in Japanese tea fields. The soil was acidified due to heavy nitrogen fertilization in the 2N plot. The 2Ca plot was amended with two-times the amount of liming material of the Std plot and in the −Ca plot no liming material was applied. There were significant differences among the N2O fluxes from the plots, and the highest value of N2O flux was 8.785 mg N m−2 h−1 in the 2N plot. Annual emission rate and emission factor of N2O in the 2N plot were 25.22 kg N2O-N ha−1 and 2.10%, respectively. Both long-term heavy nitrogen fertilization and subsequent soil acidification possibly enhanced the N2O flux from the tea field. The N2O flux from the tea field showed temporal variations, namely the N2O flux was relatively low from December to March possibly due to the low soil temperature and it increased gradually after March as the soil temperature increased over 10°C. The N2O flux reached the first major peak in July, decreased transiently in August presumably due to the drying of soil, increased again and reached the second peak in September or October, and then decreased after November. Multiple linear regression analysis of the relationships between the N2O flux and soil environmental factors indicated that the N2O production activity was significantly related to the N2O flux from the tea field. The N2O production activity showed temporal variations corresponding to the temporal variations of the N2O flux.