长期定位条件下秸秆还田对土壤有机碳及腐殖质含量的影响

为了探讨不同秸秆还田条件对土壤有机碳与腐殖物质含量的影响,利用连续进行6年的莱阳潮土区长期定位秸秆还田试验,研究了小麦-玉米秸秆还田条件下,施用氮肥以及不施肥或单施有机肥对土壤有机碳及腐殖物质的影响。结果表明,在供试的5个处理中,两季秸秆还田施肥处理(WCN)的有机碳以及腐殖物质含量最大,为最优处理。主要效应从大到小依次是氮肥、有机肥、秸秆还田+氮肥、秸秆还田。与对照(CK)相比,氮肥与秸秆配施大幅增加土壤胡敏酸(HA)、胡敏素(HM)、富里酸(FA)含量并使之处于稳定水平上,与单施有机肥相比,随着年限增加,秸秆与氮肥配施(WN、WCN)能够显著增加土壤腐殖质各组分含量,其中两季秸秆还田施氮肥(WCN)处理增幅最显著。通过对不同秸秆还田模式下土壤有机碳、腐殖质含量变化趋势的研究,表明秸秆还田与氮肥配施能够提高土壤有机碳含量,提高土壤腐殖质品质。

The Effect of Long-term Straw Returning Treatments on Soil Organic Carbon and Humus Content

In order to study the effects of different straw returning on soil organic carbon and humus content,we have regard Laiyang long-term straw returning to the soil in aquic soil treatment as the research object of study,ex-plore the effect of application nitrogen fertilizer or organic fertilizer in straw returning to field on soil organic carbon (SOC) and humus content.The results were as follows:In the 5 experiment treatments,the WCN treatment′s organ-ic carbon and humic substances were the maximum,was the optimal treatment.The main effect from the maximum to minimum values were:nitrogen fertilizer,organic fertilizer,straw returning +nitrogen fertilizer and straw returned to the soil.Compared with CK,straw with nitrogen fertilizer applicating to the soil substantial increased HA,HM,FA contents and made it in a stable level.Compared with the single application of organic fertilizer,WN,WCN treatment could significantly increase the content of soil humus fractions.As time goes by,straw and nitrogen fertilizer(WN, WCN) could significantly increase the content of soil humus fractions.