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作 者 ：徐明岗1;于荣1;孙小凤2;刘骅3;王伯仁1;李菊梅1

期 刊 ：植物营养与肥料学报 2006年 12卷 4期 页码：459-465

关键词：长期施肥；红壤；垆土；活性有机质；碳库管理指数(CMI)；

Keywords:long-term fertilization, red soil, loessial soil, labile organic matter, carbon management index(CMI),

摘 要 ：对我国重点农区的6种典型土壤—红壤、灰漠土、垆土、潮土、褐土、黑土长期耕作施肥后的活性有机质及碳库管理指数(CMI)进行了研究,探讨施肥对不同土壤活性有机质和CMI的影响。土壤活性有机质用KMnO₄氧化法测定,采用3种浓度KMnO₄(33、1673、33.mmol/L)将土壤活性有机质分为高活性有机质、中活性有机质和活性有机质3部分。结果表明,只耕作不施肥(CK)10年后土壤活性有机质含量降低,CMI下降11.1～63.6,其中垆土、褐土下降幅度最大、黑土最小。施用化肥也使土壤活性有机质下降,其中单施氮(N)的潮土活性有机质下降最大,达31.3%;化肥配合施用(NPK)的红壤活性有机质下降最大,其余土壤相对较小。施肥使土壤活性有机质和总有机质含量增加,高于初始土壤和CK。施用有机肥或有机肥配施化肥,土壤活性有机质含量和CMI均显著增加,CMI以红壤上升最大,达91.4,潮土最小,仅为4.6。土壤活性有机质的数量及CMI变幅大于土壤总有机质的变化幅度,以CMI变化为大,说明CMI是评价施肥耕作对土壤质量影响的最好指标。土壤活性有机质分组结果表明,红壤活性有机质组成以高活性有机质为主;垆土、灰漠土活性有机质以高活性和中活性两部分为主;潮土以中活性有机质为主。施肥对红壤、灰漠土活性有机质组分影响明显,对垆土、潮土影响相对较小。

Abstract:Effects of long-term fertilization on labile organic matter and carbon management index(CMI) in red soil,grey-desert soil,loessial soil,fluvo-aquic soil,cinnamon soil and black soil were studied in order to assess soil quality.Soil labile organic matter was measured by oxidation of KMnO₄ with three fractionations,namely,high labile organic matter(measured by oxidation of 33(mmol/L) KMnO₄),middle labile organic matter(measured by oxidation of 167(mmol/L) KMnO₄),and low labile organic matter(measured by oxidation of 333(mmol/L) KMnO₄).The results indicated that after 10 years long term cultivation with no fertilization(CK),the labile organic matter in soils diminished and CMI decreased by 11.1—63.6 in different soils,among which loess soil and cinnamon soil decreased the most and black soil the least.Soil labile organic matter also decreased after chemical fertilizer was applied,among which the decrease in fluvo-aquic soil was the most under single application of nitrogen(N),accounting for 31.3%,while it decreased most in red soil under mixed-application of chemical fertilizers(NPK). Soil total organic matter and labile organic matter content in these treatments of fertilizer applied were higher than that in CK and original soils,and there was significant increase in soil(labile) organic matter and CMI under application of manure or co-application of manure and chemical fertilizers,with the most increase of CMI in red soil(91.4) and the least increase in fluvo-aquic soil(4.6).The change amplitudes of soil labile organic matter content and CMI were lager than that of soil total organic matter,with the largest change for CMI,which suggested that CMI was the best index to assess influence of fertilization and cultivation on soil quality.The fractionation of soil labile organic matter showed that high labile organic matter in red soil,high and middle labile organic matter in loess soil and grey-desert soil,and middle labile organic matter in fluvo-aquic soil were main parts among labile organic matter.There were apparent effects of long-term fertilization on labile organic matter fractionations in red soil and grey-desert soil,while its effects were less in loess soil and fluvo-aquic soil.

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