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为深入揭示陆地生态系统碳固定对大气氮沉降增加的响应机理,基于海北高寒草甸多形态（NH4Cl、(NH4)2SO4、KNO3）、低剂量（N 0、10、20、40 kg hm-2 a-1）的增氮控制试验平台,采集各处理不同深度土壤样品,利用颗粒分组法分离测定总土壤有机碳（SOC）以及各粒径组分的碳含量和δ13C值。研究结果表明：低氮显著增加了土壤粗颗粒态有机碳（MacroPOC）和矿质结合态有机碳（MAOC）的含量,而高氮处理正好相反。施氮一致降低土壤细颗粒有机碳（MicroPOC）含量。此外,添加硝态氮肥对SOC各组分含量和δ13C值的影响显著高于铵态氮肥。总体而言,低氮导致表层30 cm层SOC储量增加了4.5%,而中氮和高氮导致SOC储量分别下降了5.4％和8.8％。低氮处理新增的碳以MacroPOC为主,而高氮处理损失的碳主要是MicroPOC。连续5 a施氮促进了颗粒有机碳（POC）组分的分解,进而导致SOC稳定组分的比例增加。可以认为,大气氮沉降或低剂量施氮（10 kg hm-2 a-1）短期内有利于青藏高原高寒草甸土壤碳截留,硝态氮较铵态氮输入对土壤储量增加更为有益。 相似文献
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为探究长期氮输入对草甸草原土壤不同组分有机碳含量及化学结构影响，以内蒙古东北草甸草原为研究对象，于2010年设置0(CK)、30(N30)、50(N50)、100(N100)、150(N150)、200(N200)kg/(hm~2·a) 6个不同施氮水平处理，测定土壤不同组分有机碳含量及红外光谱特征。结果表明：(1)相比CK，长期氮输入条件下可提高土壤总有机碳(SOC)含量(增幅0.3%～13.6%)，且主要表现为颗粒有机碳(POC)含量的增加(9.22%～16.39%)，但降低土壤轻组有机碳(LOC)含量。(2)红外光谱主成分分析(PCA)结果表明，土壤LOC主要来源于脂肪碳、芳香碳、酚醇化合物，POC主要来源于芳香碳和酚醇化合物，矿物结合有机碳(MOC)主要来源于烷基碳和多糖。(3)相比CK，施氮处理凋落物和LOC官能团中烷氧碳(单糖+多糖)的相对强度降低，烷基碳、芳香碳相对强度增加；土壤POC和MOC官能团中烷氧碳、烷基碳及芳香碳相对强度增加，酚醇化合物相对强度降低；且施氮处理下凋落物及其不同土壤碳组分有机碳结构稳定性(芳香碳/脂肪碳)均高于CK。(4)结构方程模型(SEM)结果... 相似文献
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长期施用有机肥对稻麦轮作体系土壤有机碳氮组分的影响 总被引：5，自引：1，他引：4
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长期施用有机肥显著提升潮土有机碳组分 总被引：7，自引：0，他引：7
借助潮土36a长期定位施肥试验平台,利用物理化学相结合的方法,研究了不同施肥处理对耕层土壤有机碳组分的影响。试验处理包括不施肥(CK)、施氮磷钾肥不同组合(N、NP、NPK)、施有机肥(M)、施氮肥和有机肥(MN)、施氮磷肥和有机肥(MNP)及施氮磷钾肥和有机肥(MNPK)。结果表明:施肥能显著提高土壤易氧化有机碳(EOC)含量,与CK相比,MNPK处理提高效果最为显著,增幅为72.17%;NPK处理对颗粒有机碳(POC)和矿物结合态有机碳(MOC)含量的提升效果高于N处理,但低于施有机肥处理;施有机肥处理的POC含量较不施有机肥处理平均增加92.69%,与CK相比,MNPK处理的POC分配比例增加了13.33%;施有机肥条件下,所增加的总有机碳对MOC的贡献率明显提高,MNPK处理所增加的总有机碳可1︰1进入POC和MOC组分。有机肥施用尤其是氮磷钾平衡施用并增施有机肥,能有效改善土壤化学性质、提升土壤碳组分含量、促进新碳在各碳组分均衡分配。 相似文献
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外源有机碳对黑土有机碳及颗粒有机碳的影响 总被引：3，自引：3，他引：3
为了阐释外源有机碳在土壤有机碳运转中的作用机制,以黑土为供试材料,进行了5年的室外培养试验,并结合室内全土及颗粒组分单独矿化培养试验,研究了不同外源有机碳对黑土有机碳(SOC)、颗粒有机碳(POC)含量及其矿化特征的影响。试验包括单施化肥、牛粪配施化肥、鸡粪配施化肥、秸秆配施化肥和树叶配施化肥5个处理。结果表明:(1)单施化肥黑土SOC的损失主要来源于POC的损失,外源有机碳有利于SOC和POC的累积,与对照相比,禽畜粪便处理的SOC和POC平均增加幅度分别为16.6%和27.8%,植物残体处理的SOC和POC平均增加幅度分别为27.0%和46.4%;(2)一级动力学方程能较好地描述SOC和POC的矿化动态(R~20.9),且POC比SOC易矿化,POC的60d累积矿化量是SOC的3倍以上;(3)禽畜粪便处理和植物残体处理的POC平均矿化率分别为31.5%和29.8%,禽畜粪便处理的POC更易矿化;(4)外源有机碳有效降低了黑土有机碳的矿化,尤其是牛粪,其SOC矿化率为1.9%,比对照低了3.4%,其POC矿化率为24.8%,比对照低17.4%;(5)外源有机碳在黑土中的碳累积能力表现为树叶秸秆牛粪鸡粪。 相似文献
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温带针阔叶林土壤有机碳动态和微生物群落结构对有机氮添加的响应特征 总被引：1，自引：0，他引：1
森林生态系统土壤有机碳(soil organic carbon,SOC)转化和碳储量动态对大气氮沉降增加的响应是具有特异性的,取决于土壤初始氮状态、施氮类型、剂量与持续时间。过去相关研究主要集中在无机氮沉降效应方面,对有机氮沉降如何影响温带针阔混交林SOC及其组分含量尚不清楚,鲜有研究关注氮素富集条件下SOC变化的微生物学机制。以长白山温带针阔混交林为研究对象,设置4个尿素添加水平(0、40、80、120 kg·hm~(–2)·a~(–1),以N计,下同)的原位控制试验。施肥三年后,采集0～10 cm矿质层土壤样品,测定土壤不同形态氮含量、土壤团聚体比例和不同粒径SOC含量;利用磷脂脂肪酸(PLFA)技术测定土壤微生物不同种群相对丰度与群落结构,探讨SOC含量变化与微生物群落变化之间的相关关系。结果表明,施氮三年显著增加了土壤NO_3~--N、DON和TN含量,土壤酸化明显。施氮虽然未显著增加表层土壤总SOC含量,但是显著增加活性SOC组分(颗粒态有机碳和团聚体结合态有机碳)含量,增幅介于27.5%～96.3%,导致SOC组分发生累积的大气氮沉降临界负荷为80kg·hm~(–2)·a~(–1)以N计下同。SOC含量的变化(ΔSOC)与团聚体结合态有机碳、颗粒态有机碳含量的变化正相关。除好氧细菌丰度外,施氮总体上未改变微生物种群丰度,但是显著改变了微生物的群落结构,革兰氏阳性细菌/革兰氏阴性细菌(G+/G–)丰度比例增加而好氧/厌氧细菌(A/AN)丰度比例下降。有机氮富集倾向于促进温带针阔混交林土壤团聚体的形成,局域产生厌氧微环境,好氧/厌氧细菌(A/AN)丰度比例下降。活性SOC组分含量、土壤团聚体百分比和微生物PLFA丰度之间显著相关,暗示微生物群落结构与SOC积累和稳定之间关系密切。上述研究结果表明,氮素富集会改变温带针阔混交林土壤微生物群落结构,进而导致土壤碳积累。 相似文献
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为明确秸秆配施膨润土对旱作农田0～40 cm土层土壤有机碳(SOC)、活性有机碳组分及其分配比例和碳库管理指数的影响,于2019—2021年在内蒙古清水河县一间房试验基地连续3年进行田间定位试验。分别设置不施膨润土和秸秆(CK)、单施秸秆(T1)、单施膨润土(T2)和秸秆配施膨润土(T3)4个处理。结果表明:土壤SOC及活性碳组分在年际间表现为先降低后升高[除颗粒有机碳(POC)含量]的变化趋势,不同土层间表现为10～20 cm > 0～10 cm > 20～40 cm;各处理均提高了0～40 cm土层土壤有机碳及其活性组分含量,秸秆配施膨润土效果优于单施。与CK相比,在0～40 cm土层,T3处理土壤SOC、可溶性有机碳(DOC)、易氧化有机碳(LOC)和POC 3年平均提高了7.16%～9.63%、12.35%～18.05%、15.55%～41.97%和100.73%～127.90%,同时提高了不同土层DOC/SOC、LOC/SOC和POC/SOC以及土壤碳库管理指数;土壤SOC及各组分之间均呈显著正相关关系,以LOC相关系数最大,表明LOC可较好地反映出SOC的变化情况。可见,在旱作区采取秸秆配施膨润土措施能够显著提高土壤SOC及其活性组分含量以及碳库管理指数,对土壤肥力提升、质量改善具有重要意义。 相似文献
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内蒙农牧交错带地区土地利用方式和施肥对土壤碳库的影响 总被引：2，自引：0，他引：2
内蒙武川是我国典型的内蒙农牧交错带地区,土地利用方式转变和施肥是影响该地区农业生产和土壤碳储量的重要人类活动。选取内蒙武川地区,针对不同土地利用方式(耕地、退耕还林/还草)和施肥措施(化肥、有机肥)的长期定位试验土壤,分析土壤有机碳(SOC)、土壤无机碳(SIC)和全氮(TN)含量和储量,结合13C和15N稳定同位素方法,研究土地利用方式和施肥措施对于该地区土壤碳氮转化的影响规律。研究表明,退耕还灌/还草后,SOC储量较耕地均有显著提高(提高幅度0.60~0.98 Mg hm-2 a-1),SIC储量也增加或保持相同水平(柠条地除外)。相比不施肥处理,施用有机肥能显著增加SOC(1.08~1.19 Mg hm-2 a-1),施化肥处理则会降低SIC(0.06~0.16 Mg hm-2 a-1),且主要影响次生碳酸盐。施肥SIC中原生碳酸盐比例(0~23%)低于自然土壤(3%~29%)。施肥措施对于土壤碳氮的转化强度远大于土地利用方式的改变。对于内蒙等干旱半干旱地区土壤,土地利用和施肥措施对于土壤有机和无机碳的影响应该在区域固碳管理中给予全面考虑。 相似文献
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冻融对青藏高原高寒草甸土壤碳氮磷有效性的影响 总被引：4，自引：0，他引：4
以青藏高原高寒草甸土壤为研究对象,通过室内模拟冻融循环过程,研究不同土壤含水量条件下冻融频次和冻结温度对土壤碳氮磷有效性的影响。结果表明:(1)土壤可溶性氮(DTN)、硝态氮(NO-3-N)和有效磷(PO3-4-P)含量随冻融频次增加呈下降趋势,但铵态氮(NH+4-N)和可溶性磷(DTP)含量呈现上升趋势;(2)在冻融频次相同情况下,高含水量土壤在-15℃/5℃冻融循环处理下的可溶性有机碳(DOC)、DTN和NH+4-N含量显著高于-5℃/5℃冻融循环处理下的含量;(3)含水量高的土壤在冻融处理后,DOC、DTN、NH+4-N、DTP和有效磷(PO3-4-P)的含量通常高于含水量低的土壤,但NO-3-N则相反。由此可见,冻融频次、冻结温度和土壤含水量都是影响高寒草甸土壤冻融效应的关键因子,在评价冻融作用对高寒草甸土壤碳氮磷有效性影响时,还应充分考虑这些因子间交互效应。 相似文献
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土壤团聚体的形成与分散及其在农业生产上的应用 总被引：8，自引：2，他引：8
土壤团聚体是保持土壤水分和土壤透性的基本单元.本综述的目的是通过围绕团聚体理论的讨论,明确影响团聚体形成的因素,为农田维护提出可靠的理论依据.首先总结了团聚体形成的主要理论,即Emerson的粘团理论、Edwards和Bremner的微团聚体理论和Oades 及Waters的团聚体分级构建理论,然后讨论了土壤有机质、可溶性阳离子和氧化铁、铝3个影响团聚体形成的主要因素,最后分析了团聚体破坏的机理和评价团聚体稳定性的主要方法,指出保持土壤颗粒的凝聚状态、增加各种形态的土壤有机质是增加土壤团聚性的主要措施. 相似文献
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B. L. M. Leroy H. M. S. K. Herath S. Sleutel S. De Neve D. Gabriels D. Reheul & M. Moens 《Soil Use and Management》2008,24(2):139-147
We examined the short-term effect of five organic amendments and compared them to plots fertilized with inorganic fertilizer and unfertilized plots on aggregate stability and hydraulic conductivity, and on the OC and ON distribution in physically separated SOM fractions. After less than 1 year, the addition of organic amendments significantly increased ( P < 0.01) the aggregate stability and hydraulic conductivity. The stability index ranged between 0.97 and 1.76 and the hydraulic conductivity between 1.23 and 2.80 × 10−3 m/s for the plots receiving organic amendments, compared with 0.34–0.43, and 0.42–0.64 × 10−3 m/s, respectively, for the unamended plots. There were significant differences between the organic amendments (P < 0.01), although these results were not unequivocal for both soil physical parameters. The total OC and ON content were significantly increased ( P < 0.05) by only two applications of organic fertilizers: between 1.10 and 1.51% OC for the amended plots versus 0.98–1.08% for the unamended and between 0.092 and 0.131% ON versus 0.092–0.098% respectively. The amount of OC and ON in the free particulate organic matter fraction was also significantly increased ( P < 0.05), but there were no significant differences ( P < 0.05) in the OC and ON content in the POM occluded in micro-aggregates and in the silt + clay-sized organic matter fraction. The results showed that even in less than 1 year pronounced effects on soil physical properties and on the distribution of OC and ON in the SOM fractions occurred. 相似文献
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耕作对土壤有机物和土壤团聚体稳定性的影响 总被引：17，自引：8，他引：17
Agricultural sustainability relates directly to maintaining or enhancing soil quality. Soil quality studies in Canada during the 1980‘s showed that loss of soil organic matter (SOM) and soil aggregate stability was standard features of non-sustainable land management in agroecosystems. In this study total soil organic carbon (SOC), particulate organic matter (POM), POM-C as a percentage of total SOC, and aggregate stability were determined for three cultivated fields and three adjacent grassland fields to assess the impact of conventional agricultural management on soil quality. POM was investigated using solid-state ^13C nuclear magnetic resonance (NMR) to determine any qualitative differences that may be attributed to cultivation. Results show a highly significant loss in total SOC, POM and aggregate stability in the cultivated fields as compared to the grassland fields and a significant loss of POM-C as a percentage of total SOC.Integrated results of the NMR spectra of the POM show a loss in carbohydrate-C and an increase in aromatic-C in the cultivated fields, which translates to a loss of biological lability in the organic matter. Conventional cultivation decreased the quantity and quality of SOM and caused a loss in aggregate stability resulting in an overall decline in soil quality. 相似文献
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Soil water repellency affects the hydrological functions of soil systems. Water repellency is associated with the content and the composition of soil organic matter. In the present study, we examined the effects of hydrophobic and hydrophilic organic matter contents, the hydrophobic/hydrophilic organic matter ratio and the total organic matter content on water repellency using model sandy soils. Stearic acid and guar gum were used as the hydrophobic and hydrophilic organic compounds, respectively. Water repellency was estimated using the sessile drop method. Hydrophobic organic matter content was found to be the dominant factor affecting soil water repellency. Hydrophilic organic matter was found to increase the contact angle to some extent without the presence of hydrophobic organic matter. With the presence of both hydrophobic and hydrophilic organic matter, the effects of the hydrophilic organic matter content on contact angle were found to be dependent on the hydrophobic organic matter content of the soil. This relationship was explained by the differences in the surface free energies of different organic matter and mineral surfaces. The contact angle increased with increasing hydrophobic/hydrophilic organic matter ratio when the hydrophilic organic matter content was constant. When the hydrophobic organic matter content was constant, contact angles were roughly comparable, irrespective of the hydrophobic/hydrophilic organic matter ratio. The contact angles were not comparable at each total organic matter content. Accordingly, the hydrophobic/hydrophilic organic matter ratio and the total organic matter content in soil may not provide satisfactory information about soil water repellency. 相似文献
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The effect of cereal straw with added mineral N fertilization on crop yields, N uptake, total organic C content and hot water soluble C content in topsoil and on the relationships between organic C content in topsoil and organic matter balance was evaluated in a long-term field experiment established in 1966. The effect of straw plus mineral N fertilization was similar to the effect of farmyard manure (FYM) in the dry matter yields and also in the N uptake by plants. The effect of straw and mineral N fertilization on the organic C accumulation in soil was inferior to the effect of farmyard manure. Relationships between organic matter balance and total organic C content in the topsoil was positive and statistically significant. A favourable effect of mineral NPK fertilization on the C sequestration to soil was related to the effect of FYM fertilization. 相似文献
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土壤中溶解性有机物及其影响因素研究进展 总被引：2，自引：1，他引：1
溶解性有机物(DOM)是陆地生态系统中极为活跃的有机组分,是土壤圈层与相关圈层(如生物圈、大气圈、水圈和岩石圈等)发生物质交换的重要形式。它不但是土壤微生物最重要的能量与物质来源,影响微生物的新陈代谢,而且对土壤营养元素(如C,N,P)和污染物的化学活性与生物活性也有直接影响。因此,土壤中溶解性有机物的消长动态已成为当前农业生态学领域的研究焦点问题之一。本文综述了土壤中溶解性有机物的迁移转化规律和主要影响因素,并指出未来的研究重点应在以下几个方面:(1)土壤有机质性质对DOM释放的影响。(2)有机质对DOM数量和质量的影响(3)生物和物理化学因素对土壤中DOM吸附和解吸的影响(4)DOC、DON和DOP迁移转化的差异。 相似文献
18.
不同耕作制度对紫色水稻土活性有机质及碳库管理指数的影响 总被引：13，自引：1，他引：13
以长期定位试验点的紫色水稻土为研究对象，研究了耕作制度对紫色水稻土活性有机质和碳库管理指数的影响。结果表明：稻田长期垄作免耕0～10cm土层有机质含量比常规平作高，10～60cm土层有机质含量则比常规平作低；表明稻田长期垄作免耕土壤有机质具有表层富集现象；水旱轮作各土层有机质含量均比常规平作低。垄作免耕各土层活性有机质含量普遍增加，水旱轮作表层（0～10cm）活性有机质含量减少，其余土层变化不大。对活性有机质组分含量的研究表明：与常规平作相比，垄作免耕增加了土壤表层活性有机质各个组分的含量，在其余土层增加了低活性有机质含量，而减少了高活性有机质含量；水旱轮作增加了各土层低活性有机质含量而减少了中活性和高活性有机质含量。垄作免耕所有土层的碳库管理指数都在100以上，水旱轮作除表层（0～10cm）小于100以外，其余土层都在100以上。由此可见，农业管理措施对土壤有机质、活性有机质及碳库管理指数有较大影响。 相似文献
19.
Cícero Célio de Figueiredo Walda Monteiro Farias Bruno Araújo de Melo Jhon Kenedy Moura Chagas Ailton Teixeira Vale Thais Rodrigues Coser 《Archives of Agronomy and Soil Science》2019,65(6):770-781
One of the main advantages of using biochar for agricultural purposes is its ability to store carbon (C) in soil for a long-term. Studies of labile and stable fractions of soil organic matter (SOM) may be a good indicator of the dynamics of biochar in soils. This study evaluated the effects of applying sewage sludge biochar (SSB) in combination with mineral fertilizer on fractions of SOM. To conduct this evaluation, 15 Mg ha?1 of SSB combined or not with mineral fertilizer (NPK) was applied to the soil in two cropping seasons. Apart from total organic C (TOC), the labile and stable fractions of SOM were also determined. The combined use of SSB and NPK resulted in higher TOC, a 22% to 40% increase compared to the control and to the NPK treatments, respectively. The SSB produced at a lower temperature increased the labile fractions of SOM, especially the microbial biomass C, showing its capacity to supply nutrients in the short-term. The stable pools of SOM are increased after adding SSB produced at a higher temperature. It was concluded that pyrolysis temperature is a key-factor that determines the potential of SSB to accumulate C in labile and stable fractions of SOM. 相似文献
20.
Corn straw is an important source of carbon (C),and when applied to soil,it alters the accumulation and distribution of organic C.However,the mechanistic pathways by which newly added C is stored and stabilized in soil remain a subject of interest and debate among scholars.In this study,we investigated the chemistry of organic matter in different density fractions of Haplic Cambisol (sandy clay loam) in a field experiment with corn straw at8 900 kg ha-1year-1under no tillag... 相似文献