首页分享施氮量对海南燥红壤和砖红壤N2O/CO2排放的影响

施氮量对海南燥红壤和砖红壤N2O/CO2排放的影响

来源：花匠小妙招时间：2024-12-25 18:48

摘要： 利用室内培养实验，分析燥红壤和砖红壤中分别施加N0（不添加氮素）、N1（氮添加量为100mg·kg−1）、N2（氮添加量为200mg·kg−1）和N3（氮添加量为300mg.kg−1）4个水平氮后对土壤性质及N2O、CO2排放的影响。结果表明：氮肥添加显著降低了土壤pH和有机碳含量。相较于N0，燥红壤N1、N2和N3处理pH和有机碳降幅分别为8%～18%和4%～12%，砖红壤降幅分别为5%～23%和3%～15%；添加氮肥后各处理土壤全氮含量显著增加，燥红壤和砖红壤分别增加15%～54%和13%～52%。氮施入增加了土壤NH4+−N和NO3−−N含量，各处理土壤铵态氮和硝态氮含量均表现为N3>N2>N1>N0。氮添加促进土壤N2O和CO2排放，相较于N0，燥红壤N2O和CO2累积排放量分别增加1176%～2425%和124%～281%，砖红壤分别增加1054%～1887%和138%～256%。施氮量和土壤类型是影响农田土壤N2O和CO2排放的重要因素。土壤N2O和CO2排放与施氮量呈线性显著相关，减少施肥是降低土壤N2O排放最直接和最有效的措施。与砖红壤相比，燥红壤N2O和CO2排放对氮素添加的响应更敏感。

关键词: 燥红壤, 砖红壤, 施氮量, N2O排放, CO2排放

Abstract: The effects of four levels of nitrogen, N0 (without nitrogen), N1 (100mg.kg−1), N2 (200mg·kg−1) and N3 (300mg·kg−1) on soil properties, N2O and CO2 emissions in dry red soil and latosol were analyzed by laboratory incubation experiments. The results showed that nitrogen fertilizer significantly declined soil pH and organic carbon content. Compared with N0, N1, N2 and N3 treatments decreased pH and organic carbon by 8%−18% and 4%−12% in dry red soil, respectively, and latosol decreased by 5%−23% and 3%−15%, respectively. The total nitrogen content in dry red soil and latosol increased by 15%−54% and 13%−52%, respectively. Nitrogen application increased the contents of NH4+−N and NO3−−N, and the contents of NH4+−N and NO3−−N were N3>N2>N1>N0. Nitrogen addition promoted soil N2O and CO2 emissions. Compared with N0, cumulative N2O and CO2 emissions in dry red soil increased by 1176%−2425% and 124%−281%, respectively, and those in latosol increased by 1054%−1887% and 138%−256%, respectively. Nitrogen application rate and soil type are important factors affecting soil N2O and CO2 emissions. There was a significant linear correlation between soil N2O and CO2 emissions and nitrogen application rate. Reducing fertilization is the most direct and effective measure to reduce soil N2O emissions. Compared with latosol, N2O and CO2 emissions were more sensitive to nitrogen addition in dry red soil.

Key words: Dry red soil, Latosol, Nitrogen fertilizer rate, N2O emissions, CO2 emissions