摘要
研究了不同施肥方式对农田土壤有机碳（SOC）及其组分的影响,为提高土壤肥力提供依据。以5年定位试验为对象,研究了不施肥（N1）、常规施氮（N2）、推荐施氮（N3）、减量施氮（N4）,增量施氮（N5）和推荐施氮＋秸秆覆盖（N3＋S）等六个不同施肥方式对土壤有机碳不同组分的影响。结果表明,0~20 cm土层内以N3处理土壤总有机碳（TOC）含量最高,为14.732 g kg-1,较N1显著增加12.44%,其次是N5处理,为14.39 g kg-1,较N1显著增加11.92%;0~20 cm土层内,不同处理土壤水溶性有机碳（WSOC）含量不尽相同,但差异未达到显著水平,而在20~40 cm土层中,表现为N3＋S〉N3〉N1〉N4〉N2〉N5,20~40 cm土层中,N4处理的WSOC含量较0~20 cm有所减少,其降幅达37%;不同施肥方式土壤微生物量碳（SMBC）在0~20 cm土层中表现为：N3＋S〉N4〉N2〉N3〉N5〉N1,而在20~40 cm土层中,与N1比较其他四种施肥方式达到显著水平;土壤易氧化有机碳（ROC）含量在0~20 cm土层表现为：N3＋S〉N3〉N5〉N4〉N2〉N1,而在20~40 cm土层中为N3〉N4〉N3＋S〉N5〉N2〉N1。总体而言,N3有利于耕层土壤有机碳及其组分的积累,配施秸秆还田效果更佳。
The effects of different fertilization methods on soil organic carbon（SOC） content and its fractions in farmland were studied to provide a basis for establishing a sustainable soil fertility system.Soil samples were taken at 0-20 and 20-40 cm depths after five years treatment in a fertilization experiment with treatments of no fertilization（N1）,conventional fertilization（N2）,optimized fertilization（N3）,reduced N fertilization（N4）,increased N fertilization（N5） and optimized fertilization plus straw mulching（N3＋S）.N3 and N5 treatments had 14.73 kg-1 and 14.39 kg-1 SOC,and 12.44 % and 11.92 % higher than that in control treatment,respectively,and were at the highest level.The WSOC in 0-20 cm soil layer differs among different fertilizing methods,but there was no significant difference.In 20-40 cm soil horizon,the magnitude ranked as N3＋S N3 N1 N4 N2 N5,the WSOC in the 20-40 cm soil horizon was less than that in 0-20 cm soil horizon by 37%.To determine the effects of different fertilization methods on SMBC content in 0-20 cm soil horizon,the magnitude ranked as N3＋S N4 N2 N3 N5 N1.In 20-40 cm soil horizon,the SMBC of the other four treatments was significantly higher than that of the control treatment.In 0-20 cm soil horizon,the concentration of the readily-oxidized organic carbon of fertilization treatments（N3＋S N3 N4 N5 N2 N1）were significantly different from that of the N1 treatment.In 20-40 cm soil horizon,the magnitude ranked as N3 N5 N3＋S N4 N2 N1.Overall,N3 was better for the accumulation of soil organic carbon and its components,especially combined with straw mulching.
出处
《土壤通报》
CAS
CSCD
北大核心
2012年第6期1461-1466,共6页
Chinese Journal of Soil Science
基金
国际植物营养研究所(IPNI)中国项目部
国家科技支撑计划项目(2006BAD05B07)资助
关键词
土壤有机碳
长期不同施肥方式
有机碳组分
Soil organic carbon
Long-term fertilization
Soil organic carbon fraction
