土壤质地及环境因子对农田N_2O排放的影响

Effect of Soil Texture and Environmental Factors on Farmland N_2O Emission

[目的]研究土壤质地与环境因素对N2O排放通量的影响情况。[方法]采用实验室培养法,设4种土壤质地,8个土壤深度梯度(5～40 cm),6个温度梯度(10～35℃)、5个湿度含水量等进行试验研究。[结果]相同培养条件下,粘土类N2O排放通量高于粘壤土和粘砂质壤土,最低的为砂质土壤;在不同培养深度条件下的N2O排放通量,壤土类明显高于砂质土壤,两土壤类加入氮肥后的N2O排放通量高于对照土壤;土壤的N2O排放通量随温度的增加而增长,在相同温度下壤土类土壤N2O排放通量高于砂质土壤;N2O排放通量随土壤含水量的上升随之增加,至田间持水量时N2O排放通量达到最大;在相同的湿度条件下,N2O排放通量壤土类高于砂质土壤。[结论]重质地旱作土壤N2O排放通量要高于轻质地土壤。

[Objective] The aim was to study the effect of soil texture and environmental factors on N2O emission flux.[Method] The lab culture experiment was conducted by setting up 4 kinds of soil texture,8 soil depth gradients（5-40cm）,6 temperature gradients（10-35 ℃）and 5 humidity conditions.[Result] Under the same culture conditions,the N2O emission flux of clay soil type was higher than that of clay loam and sandy loam soil types,and that of sandy soil was lowest.Under different soil culture depth conditions,N2O emission flux of the loam soil type was higher obviously than that of sandy one,and that of the two soil types after adding nitrogen fertilizer were more than that of the control soil.The soil N2O emissions flux was increased with the temperature increasing,and that of the loam soil type was higher than that of sandy one under the same temperature conditions.The N2O emissions flux was increased with the rise of soil water content,and up to the maximum under the humidity condition of the field moisture capacity.The N2O emissions flux of loam soil type was higher than that of sandy one under the same humidity conditions.[Conclusion] The N2O emissions flux of heavy texture loam in dry land was higher than that of light texture soil.