有效碳源和氮源对黄土性土壤N_2O逸出量的影响

Effects of available carbon and nitrogen concentration on the N_2O flux of the Loessal soil

用乙炔抑制原状土柱法 ,就不同碳、氮质量分数对黄土性土壤水稻土和旱地农田土壤反硝化作用的影响进行了研究。结果表明 ,在适宜的氮质量分数和水分条件下 ,两种土壤的反硝化强度随碳质量分数的增大而增加 ,在有效碳源最高加入量 2 0 0 m g/kg时达到最大 ;而在一定的碳质量分数和水分条件下 ,供试土壤的反硝化强度并不随土壤 NO- 3- N质量分数的增加而增加 ,在水稻土和农田土壤上最大反硝化作用的氮源加入量分别为 30 0和 15 0 mg/kg;当氮源为亚硝态氮时 。

By using C 2H 2 inhibition soil cores,these experiements studied the effects of available carbon and nitrogen concentration on the denitrification loss of normal grain field and peddy soil field of loessal soil.The results showed that:the denitrification loss increased with the available carbon concentration increased for both soils under the suitable nitrate nitrogen concentration and mositure content.Whereas the denitrificaion loss decreased with the NO - 3-N concent reaching a certain level under the suitable available carbon and water content,the highest denitrification loss took place when available nitrogen content was N 300 and N 150 for the paddy soil and the dryland of grain field,respectively.However,when we used nitrate nitrogen as the nitrogen sources,the denitrification loss raised with the NO - 2 concentration increased.