水稻土裂缝的生成对N2O释放的影响

通过土柱试验模拟了3种水稻土从淹水到日渐变干过程中的N2O日变化和时变化规律.相同质地的粉质黏壤土青紫泥和黄斑田有相似的N2O日释放规律,区别于粉质壤土的小粉土.24h内开裂土壤青紫泥和黄斑田的释放高峰分别在14:00和凌晨2:00,未开裂的小粉土释放高峰仅在凌晨2:00.裂缝的产生使N2O释放高峰提前出现.在培养过程中开裂的青紫泥和黄斑田的N2O日排放通量与含水量之间存在显著的指数关系,而未开裂的小粉土则未呈现明显相关关系.在裂缝产生过程中,裂缝的平均体积与N2O日排放通量之间存在极显著的乘幂关系.裂缝的平均面积与N2O日排放通量存在显著的乘幂关系,裂缝的平均深度与N2O日排放通量之间呈显著的线性关系.

The influences of generation of paddy soil cracks on N2O emissions

Through soil column experiments the daily and hourly change rule of N2O of three kinds of paddy soils in the course from floating to daily dry was simulated. Qingzini and Huangbantian, the silty clay loam of same texture had similar N2O daily emission rule; but Xiaofentu with silty loam was different without the similar rule. The emission high peak appeared on 14 and 2 oclock in a day for cracked Qingzini and Huangbantian, respectively; but Xiaofentu on 2 oclock only. The generation of cracks stimulated the appearance of the high peak of N2O emissions in advance. There existed in the course of cultivation significant index correlation between soil water content and N2O daily emission flux in Qingzini and Huangbantian, but Xiaofentu had no significant correlation. During the cracks producing, there existed very significant power correlation between the average volume of cracks and N2O daily emission flux. There appeared significant linear correlation between crack average depth and N2O daily emission flux.