【作者】 冷延慧；

【导师】 汪景宽；

【作者基本信息】 沈阳农业大学 ， 土壤学， 2008， 博士

【摘要】 本文通过两种不同团聚体分离方法（干筛法与湿筛法）及三种团聚体破碎方法（快速湿润、湿润振荡及慢速湿润）进行室内实验,分别在沈阳农业大学20年长期定位试验地采集的6种不同肥力水平棕壤及海伦22年长期定位实验站的4种不同肥力的黑土,对棕壤和黑土长期定位试验的不同肥力水平土样进行团聚体分级,并对这两种土壤团聚体、团聚体碳、团聚体碳储量分布特征、δ¹³C值和团聚体稳定性进行研究,通过培养实验研究不同施肥处理对团聚体保护碳及团聚体碳库变化的影响。目的是比较在长期不同施肥方式下的黑土和的棕壤团聚体的分布特征、有机碳氮含量、储量的变化。主要研究结果表明:1.棕壤、黑土团聚体均以0.25～1mm团聚体为主,有机—无机肥配施能有效地提高棕壤0.05～0.25mm团聚体含量,以及黑土1～2mm团聚体含量。2.土壤各处理团聚体有机碳储量最高的均在0.25～1mm粒级团聚体,新增加的碳主要向0.05～0.25mm团聚体富集。黑土有机—无机配施处理有机碳储量增加的最明显,新碳主要向1～2mm、0.05～0.25mm团聚体富集。3.无论是棕壤还是黑土,各有机、有机—无机施肥处理均显著增加了耕层土壤全氮的含量。就团聚体而言,有机—无机施肥处理显著增加了0.25～1mm粒径团聚体全氮的含量。黑土各处理C/N比均低于对照,说明总氮的积累速度大于总碳的积累速度,而棕壤与黑土正好相反。4.棕壤和黑土中团聚体平均当量直径,各处理均表现出快速湿润明显低于湿润振荡及慢速湿润破碎处理。3种破碎处理平均当量直径棕壤中中量有机肥处理明显大于其他处理,黑土中氮磷钾处理明显大于其他处理。根据相对糊化指数（RSI）和相对机械破碎指数（RMI）,棕壤中不施肥与无机肥处理的团聚体稳定性最强,在黑土中最稳定的则是氮磷钾处理。5.棕壤与黑土团聚体在不同的破碎机制下均表现出快速湿润处理对团聚体结构的破坏程度最大,湿润时间对团聚体稳定性影响明显。团聚体中有机碳对快速湿润和湿润震荡下团聚体稳定性有明显提高作用。6.有机肥、有机—无机配施能够明显增加土壤大团聚体未保护碳和微团聚体未保护碳的含量,大团聚体对于微团聚体碳的保护有积极作用,增加土壤大团聚体的含量有利于土壤碳的保护。更多还原

【Abstract】 This paper deals with the effects of long-term fertilization on aggregate distribution,δ¹³C value of aggregate and aggregate stability by aggregate separation methods（wet sieving and dry sieving ）and aggregate breakdown methods（fast wetting,wet stirring and slow wetting）. Soils samples were collected from two long-term experiment locations in Shenyang Agricultural University and Jilin Academy of Agricultural Sciences.The fertilization treatments in the Brown earth experiment location included control（no fertilizer）,chemical fertilizer（inorganic fertilizers）,high manure（high-rate organic fertilizers） chemical fertilizer plus high manure（high-rate organic- inorganic fertilizers ）,and the fertilization treatment in the Black soil experiment location included control（no fertilizer）,chemical fertilizer（NP, NPK） and chemical fertilizer plus manure（high-rate organic- inorganic fertilizers）.The effects of different fertilization treatments on aggregate-protected C and change of carbon pool were studied using incubation experiment.The objectives of the study were to compare the changes of aggregate distributions and SOC,total N content and storage between the Brown earth and the Black soil under long-term different fertilization.The main results are as follows:1.Aggregate size distributions in Brown earth and Black soil were all dominated by 0.25～1mm.Inorganic fertilizer plus manure application effectively enhanced micro-aggregate 0.05～0.25mm content in Brown earth and micro-aggregate 1～2mm content in Black soil.2.The most storage of SOC was in aggregate 0.25～1mm in all treatments..Great amounts of the new SOC were accumulated in the aggregates 0.05～0.25mm.Increase of SOC storage was the most obvious in inorganic fertilizer plus manure（organic- inorganic fertilizers） treatment of Black soil,and the new SOC was greatly accumulated in the aggregates 1～2mm and 0.05～0.25mm.3.Whether Brown earth or Black soil,manure and chemical fertilizer plus manure application increased total N content in soil.Chemical fertilizer plus manure application significantly increased total N content associated with 0.25～1mm aggregate.C/N in fertilizers treatments of Black soil was lower than those in no fertilizer,which indicated that the accumulation rate of total N was larger than the accumulation rate of total C in Black soil.4.Mean weight diameter（MWD） of aggregates in fast wetting treatment in Brown earth and Black soil was lower than that in wet stirring and slow wetting treatments.MWD of aggregates in M2 treatment of Brown earth was significantly higher than other treatments. MWD of aggregates in medium-rate organic fertilizers treatment of Black soil was significantly higher than other treatments.According to relative slaking index（RSI） and relative mechanical breakdown index（RMI） of aggregates,aggregate stability in Brown earth and Black soil was the most stable in no fertilizer,inorganic fertilizers and NPK treatment, respectively.5.The fast wetting caused the most severe disruption to aggregates under different wetting treatments in aggregates of Brown earth and Black soil.The wetting time had obvious effect on aggregate stability.The effect that SOC improved aggregate stability was more evidence under fast wetting and wet stirring.6.Manure and inorganic fertilizer plus manure application could increased the contents of unprotected macro-aggregate C and unprotected micro-aggregate C.Macro-aggregate had positive effect on microaggregate-protected C.Increasing of macro-aggregate content could contribute to protection of soil C.更多还原