长期施肥对黄土高原旱地黑垆土水稳性团聚体的影响

通过27年的长期定位试验,研究了长期施肥对黄土高原旱地黑垆土水稳性团聚体的影响.结果表明：与自然土壤相比,黑垆土开垦后,0～10 cm和10～20 cm土层＞0.25 mm的水稳性团聚体含量分别下降了21.35%和38.82%;0.5 mm以上各粒级的水稳性团聚体含量均呈下降趋势,其中>5 mm和5～2 mm大粒径团聚体的下降幅度最大;而0.5～0.25 mm的水稳性团聚体含量却增加了104.75%和23.13%.0～10 cm土层各粒级水稳性团聚体含量均高于10～20 cm土层.单施有机肥和有机无机肥配施处理5～2 mm粒级的水稳性团聚体含量增加最多,>5 mm粒级次之;增施有机肥、有机无机肥配合施用和秸秆还田处理能显著增加大粒径水稳性团聚体含量,改善土壤团聚体的结构.各处理0～10 cm土壤水稳性团聚体平均质量直径（MMD）均大于10～20 cm土层;自然土壤的团聚体MMD显著高于同层次耕作土壤,长期施肥处理MMD大于无肥对照,有机物质培肥处理明显高于化肥处理.土壤团聚体MMD与＞0,25 mm水稳性团聚体含量呈显著正相关.     

长期施肥对黄土高原旱地黑垆土水稳性团聚体的影响

通过27年的长期定位试验,研究了长期施肥对黄土高原旱地黑垆土水稳性团聚体的影响.结果表明：与自然土壤相比,黑垆土开垦后,0～10cm和10～20cm土层〉0.25mm的水稳性团聚体含量分别下降了21.35%和38.82%;0.5mm以上各粒级的水稳性团聚体含量均呈下降趋势,其中〉5mm和5～2mm大粒径团聚体的下降幅度最大;而0.5～0.25mm的水稳性团聚体含量却增加了104.75%和23.13%.0～10cm土层各粒级水稳性团聚体含量均高于10～20cm土层.单施有机肥和有机无机肥配施处理5～2mm粒级的水稳性团聚体含量增加最多,〉5mm粒级次之;增施有机肥、有机无机肥配合施用和秸秆还田处理能显著增加大粒径水稳性团聚体含量,改善土壤团聚体的结构.各处理0～10cm土壤水稳性团聚体平均质量直径（MMD）均大于10～20cm土层;自然土壤的团聚体MMD显著高于同层次耕作土壤,长期施肥处理MMD大于无肥对照,有机物质培肥处理明显高于化肥处理.土壤团聚体MMD与〉0.25mm水稳性团聚体含量呈显著正相关.     

秸秆还田对稻田土壤水稳性团聚体养分及其生态化学计量比的影响

以福州平原早、晚稻田为研究对象,分析了秸秆还田对早、晚稻田土壤不同粒级水稳性团聚中TC、TN、TP含量及其计量比的影响。结果表明:秸秆还田之后,早稻土壤各粒级水稳性团聚体中,TC、TN、TP含量以及TC∶TN均不同程度增加,且在1~2 mm粒级水稳性团聚体中,TC、TP含量及TC∶TN分别增加42.3%、22.2%和29.1%(P0.05);各粒级水稳性团聚体中,TN∶TP均不同程度减小,TC∶TP则无明显变化规律;秸秆还田后,晚稻土壤1~2 mm粒级水稳性团聚体中TC、TP显著降低(P0.05),而各粒级水稳性团聚体中TC∶TN基本无变化,TC∶TP和TN∶TP则在1~2 mm粒级水稳性团聚体中增大,其余粒级团聚体中减小;从团聚体粒级角度看,早、晚稻土壤中TC、TN、TP主要分布在水稳性大团聚体中(0.25~2 mm粒级),团聚体粒级越小,养分含量越少;秸秆还田后,晚稻土壤水稳性大团聚体对土壤养分贡献率增大,水稳性微团聚体(0.25 mm粒级)养分贡献率则降低;总体上,早、晚稻田中,1~2 mm粒级水稳性团聚体对秸秆还田响应显著;秸秆还田对福州稻田水稳性团聚体中养分含量有影响,对其化学计量比的影响则不明显。     

耕作方式和秸秆还田对华北地区农田土壤水稳性团聚体分布及稳定性的影响

本研究基于10年耕作措施的定位试验,利用湿筛法研究了不同耕作措施和秸秆还田条件下农田土壤水稳性团聚体的分布规律,并利用平均重量直径（MWD）和几何平均直径（GMD）评价了不同处理水稳性团聚体的稳定性。研究结果表明,不同耕作措施处理的水稳性团聚体在0~10cm,10~20cm和20~30cm土层表现出不同的分布趋势,随着土层的加深,各处理水稳定团聚体的分布呈粒径逐渐减小、分布范围逐渐扩大趋势,0~10cm土层的水稳性团聚体多集中于2~5mm粒径范围,10~20cm土层水稳性团聚体多集中在0.5~5mm粒径范围,以0.5~1mm最多,而20~30mm,则广泛分布在0.25~5mm粒径范围。通过MWD和GMD值可以看出,免耕、耙耕和旋耕措施更能有效地保护表层（0~10cm）土壤水稳定团聚体的稳定性,常规耕作和深松处理则显著降低了20~30cm水稳性团聚体稳定性。秸秆还田显著增加了土壤有机碳（SOC）含量,且显著影响了土壤表层水稳性团聚体的稳定性。作用力分析结果表明,在0~10cm表层,秸秆作用在土壤表层显著影响了水稳定大团聚体的数量及其稳定性（P<0.001）,多元回归分析说明其与土壤有机碳含量达到了极显著水平（P<0.01）,且同时也受到来自耕作和秸秆交互效应的影响（P<0.01）;但在10~20cm土层,影响其数量分布的主要因素是不同的耕作措施及耕作和秸秆的交互效应（P<0.001）;而在20~30cm,耕作措施、秸秆和两者的交互效应共同对水稳性大团聚体数量产生重要的影响,但主要作用力来自耕作措施（P<0.001）和两者的交互效应（P<0.001）。免耕秸秆还田措施能显著提高土壤的水稳性团聚体的比例和稳定性。     

不同施肥处理对土壤水稳定性团聚体及有机碳分布的影响

以国家褐潮土16 a的长期肥料试验为平台(北京昌平),研究长期不同施肥对耕层土壤水稳定性团聚体及其有机碳的影响。主要研究结果:与耕种农田土壤相比,长期撂荒(CK0)可以提高水稳定性大团聚体的含量及其有机碳含量和储量。而农田耕作后,破坏了水稳性大团聚体,相应地增加水稳性微团聚体的含量。与长期不施肥种植作物(CK)相比,长期施氮磷钾肥(NPK)、氮磷钾配施有机肥(NPKM)和氮磷钾秸秆还田(NPKS)处理对水稳性团聚体数量分布和平均重量直径(MWD)有显著影响,其中对2mm和0.25 2mm水稳性大团聚体的促进作用最明显,说明施肥处理增加的新碳主要向0.25 2mm和2mm团聚体富集。在不同水平水稳性团聚体中,2mm和0.25 2mm两个级别的水稳性大团聚体有机碳的含量显著高于0.0530.25mm和0.053mm水稳性微团聚体。化肥与有机肥配施(NPKM)处理可提高水稳性大团聚体含量,改善土壤团聚体的结构。长期小麦-玉米→小麦-大豆复种轮作并施氮磷钾化肥的处理(NPKF)各级团聚体中有机碳的含量高于长期小麦-玉米轮作并施氮磷钾化肥的处理(NPK)。     

中药渣蚓粪对玉米生长及土壤肥力特性的影响

采用盆栽试验,研究了中药渣蚓粪对玉米生长及土壤肥力的影响.结果表明: 随着蚓粪施用量的增加,玉米的株高、茎粗、叶面积、叶绿素含量均显著增加;生长60 d收获时,多数蚓粪处理的土壤容重显著降低;蚓粪处理的土壤pH显著高于对照和相应的化肥处理.蚓粪处理的土壤全氮、有机质含量也明显高于化肥处理,且随蚓粪施用量的增加,效果越趋显著.中药渣蚓粪可作为一种高效有机肥,其合理施用有助于改善土壤物理结构,缓解土壤的酸化进程,提高土壤有机质和氮素含量,有效促进作物生长.     

长期施肥对黑土团聚体分布和碳储量变化的影响

用干筛与湿筛2种方法测定了22年长期田间定位试验地土壤风干及水稳性团聚体含量,研究了施肥对黑土团聚体组成、有机碳含量及有机碳库储量的影响。试验设不施肥（CK）、无机肥（NP、NPK）和无机-有机肥配施（NPK+OM）4个处理。结果表明,黑土团聚体以0.25～1 mm团聚体为主。经过湿筛法土壤各粒级水稳性团聚体含量重新分配,表现为以0.25～1 mm粒级为中心,大团聚体含量减少,微团聚体含量增加。与长期不施肥比较,长期施用化肥及有机-无机肥配施显著增加了>2 mm大团聚体含量和0.05～0.25 mm微团聚体含量,各级团聚体有机碳含量显著增加,总有机碳及各级团聚体储量增加,有机质积累,土壤结构得到改善,固碳潜力增加,有机-无机配施效果更加明显。     

两种代表性蚯蚓对设施菜地土壤微生物群落结构及理化性质的影响

不同生态型蚯蚓的取食偏好和生境有所差异,因此蚯蚓的生态型差异可能关乎其对土壤性质的不同影响;有关不同生态型蚯蚓对土壤性质尤其是微生物学性质影响的研究有助于了解蚯蚓生态功能的作用机制。在野外调控试验的第4年采集土壤,研究了牛粪混施和表施处理下内层种威廉腔环蚓(Metaphire guillelmi)和表层种赤子爱胜蚓(Eisenia foetida)对设施菜地土壤微生物群落结构和主要理化性质的影响。结果表明,土壤微生物群落结构同时受到蚯蚓种类和牛粪施用方式的影响。牛粪表施时,两种蚯蚓均显著降低了菌根真菌、真菌生物量和原生动物生物量(P0.05);牛粪混施时,不同蚯蚓的影响有所差异,威廉腔环蚓明显增加了菌根真菌、真菌生物量和放线菌生物量,而赤子爱胜蚓的作用不明显。此外,两种蚯蚓均提高了土壤孔隙度、团聚体稳定性和土壤p H、矿质氮以及微生物生物量碳氮水平,但提高幅度取决于蚯蚓种类和牛粪施用方式。冗余分析表明蚯蚓影响下土壤微生物群落结构的变化与团聚体稳定性、p H、速效磷、矿质氮呈正相关,而与土壤容重呈负相关。     

蚓粪和益生菌互作对土壤性状及番茄产量和品质的影响

本试验研究了两株益生细菌(巨大芽孢杆菌BM和解淀粉芽孢杆菌BA)与化肥和蚓粪配施对土壤性状、番茄产量和品质的影响．结果表明:与化肥相比,在等养分条件下蚓粪能够提高番茄产量、果实可溶性糖和蛋白质含量,并提高土壤pH和速效磷含量．与单施蚓粪相比,益生菌与蚓粪配施不仅能提高番茄产量、果实可溶性糖、蛋白质、维生素C含量和糖酸比,降低有机酸和硝态氮含量,而且增加了土壤pH和硝态氮含量,降低了土壤电导率;益生菌与化肥配施的效果不如益生菌与蚓粪配施．BA和BM与化肥或蚓粪配施时,番茄品质无显著差异,但BA配施蚓粪处理的番茄产量显著高于BM配施蚓粪处理;BM与化肥配施处理显著提高了土壤速效磷含量,而BA与蚓粪配施处理则显著提高了土壤速效钾含量．本研究表明,益生菌和蚓粪可替代化肥用于番茄生产和土壤肥力改良.     

植物篱-农作坡地土壤团聚体组成和稳定性特征

基于植物篱控制水土流失的长期定位试验,研究植物篱-农作坡地土壤团聚体组成和稳定性特征.结果表明： 与常规等高农作模式相比,植物篱-农作复合农业模式下土壤>0.25 mm机械稳定性和水稳性团聚体含量分别显著增加13.3%~16.1%和37.8%~55.6%,明显提高了各坡位粒级>0.25 mm土壤水稳性团聚体含量,改善了粒级>0.25 mm土壤水稳性团聚体在下坡位的相对富集和上坡位相对贫乏的状况.植物篱显著提高了土壤团聚体平均质量直径和几何平均直径,降低了土壤团聚体分形维数和>0.25 mm土壤团聚体破坏率,进而增强了土壤团聚体的稳定性和抗蚀性.坡度与植物篱类型对土壤团聚体组成、稳定性和坡面变化无显著影响.     

旱地施有机肥对土壤有机质和水稳性团聚体的影响

通过渭北旱塬2007-2010年田间定位试验,研究了有机肥不同施用量(低量7500 kg·hm^-2、中量15000 kg·hm^-2、高量22500 kg·hm^-2)对连作玉米地土壤有机质、团聚体各层粒径分布和稳定性的影响.结果表明：0～20 cm土层,高量有机肥处理土壤有机质含量较低量有机肥处理提高4.1%～4.6%,高、中量有机肥处理较对照提高4.6%～11.2%,低量有机肥处理在施肥第4年（2010年）较CK提高4.7%～6.3%.0～30 cm土层,所有有机肥处理>5 mm水稳性团聚体的增幅最大,其含量随有机肥用量的增加而显著升高;有机肥处理显著提高了土壤>0.25 mm水稳性团聚体含量、团聚体平均质量直径和团聚体稳定率,且随有机肥用量的增加而显著增加;中、高量有机肥处理比单施化肥处理增加效果显著.     

Community analysis of arbuscular mycorrhizal fungi and bacteria in the maize mycorrhizosphere in a long-term fertilization trial

In this study, we investigated the impact of organic and mineral fertilizers on the community composition of arbuscular mycorrhizal (AM) fungi and bacteria in the mycorrhizosphere of maize in a field experiment established in 1956, in south-east Sweden. Roots and root-associated soil aggregates were sampled four times during the growing season in 2005, in control plots and in plots amended with calcium nitrate, ammonium sulphate, green manure, farmyard manure or sewage sludge. Fungi in roots were identified by cloning and sequencing, and bacteria in soil aggregates were analysed by terminal-restriction fragment length polymorphism, cloning and sequencing. The community composition of AM fungi and bacteria was significantly influenced by the different fertilizers. Changes in microbial community composition were mainly correlated with changes in pH induced by the fertilization regime. However, other factors, including phosphate and soil carbon content, also contributed significantly to these changes. Changes in bacterial community composition and a reduction in bacterial taxon richness throughout the growing season were also manifest. The results of this study highlight the importance and significant effects of the long-term application of different fertilizers on edaphic factors and specific groups of fungi and bacteria playing a key role in arable soils.     

干旱胁迫下覆膜和接种微生物对玉米生长与水分利用效率的影响

针对西北干旱半干旱地区土壤贫瘠与水分缺乏的问题,利用微生物与作物形成互惠互利的共生关系,本研究设置两个水分梯度:干旱胁迫(供试土壤最大持水量的35%)和正常水分(供试土壤最大持水量的75%),两个覆膜方式:无覆膜(NM)和覆膜(FM),4个接种微生物水平:单接AM真菌(AM)、单接解磷细菌(PSB)、联合接种AM真菌与解磷细菌(AM+PSB)以及对照(CK),研究不同水分和覆膜条件下4个接种微生物对玉米生长特性、地上养分吸收与水分利用效率的影响.结果表明: 与正常水分处理相比,干旱胁迫能够显著提高接种AM真菌处理的侵染率,但正常水分处理下土壤根外菌丝密度、总球囊霉素(T-GRSP)与易提取球囊霉素(EE-GRSP)含量明显提高.干旱胁迫下,单接AM真菌处理的促生作用和菌根效应表现最好,能够提高玉米生物量、水分利用效率和土壤有机碳含量,促进土壤N、P、K的吸收与运输,从而增加玉米地上部分N、P、K吸收量;而正常水分下,联合接种AM+PSB处理表现要好于单接AM和PSB处理,且其与覆膜的互作效果最好.相关分析结果表明,玉米生物量、叶片SPAD值和地上部分N、P、K吸收量均与土壤根外菌丝密度呈显著正相关,玉米水分利用效率与其呈显著负相关.     

Disentangling the impact of AM fungi versus roots on soil structure and water transport

The relative importance of roots and AM-fungi on soil physical processes was investigated by controlling the presence of roots and AM fungi in pot experiments using a mycorrhiza-defective tomato mutant and a wild-type tomato (Solanum lycopersicum L.). Root-Zone and Bulk Soil sections were established by splitting pots into two lengthwise halves using a nylon mesh that contained roots whilst allowing the free movement of fungal hyphae. Post-incubation microbial populations and fungal biomass were measured and related to soil stability, pore structure and water repellency. Unplanted controls consistently had the least fungal biomass, fatty acids, water-stable aggregates (WSA) and water repellency. Wild-type-planted treatments had significantly more WSA than mycorrhiza-defective treatments (P?<?0.01). Fluctuations in water content induced by transpiration caused significant changes in soil pore structure, measured using high-resolution X-Ray computer tomography. Porosity and mean pore size increased in soil aggregates from planted treatments, which had larger more heterogeneous pores than those in the unplanted soils. AM fungi accentuated soil stability. However, changes were not linked to repellency and fungal biomass. The presence of plants, regardless of AM fungi, appears to have the greatest impact on increasing soil stability.     

Nitrogen input quality changes the biochemical composition of soil organic matter stabilized in the fine fraction: a long-term study

The chemical composition of soil organic matter (SOM) is a key determinant of its biological stability. Our objective in this study was to evaluate the effects of various sources of supplemental N on the chemical composition of SOM in the fine (<5 μm) mineral fraction. Treatments were fallow, maize/soybean in rotation, and continuous maize receiving no fertilizer (maize0N), synthetic fertilizer N (maize + N), or composted manure (maize + manure). The chemical structures in SOM associated with the fine fraction were determined using XANES spectroscopy at the C and N K-edges, which was assessed using multidimensional scaling. Analysis of amino sugar biomarkers were used to evaluate the fungal:bacterial contributions to the SOM. The addition of N to soils (i.e., maize + N, maize + manure, and maize/soybean treatments) resulted in the enrichment of proteinaceous compounds. Soils which did not receive supplemental N (i.e., fallow and maize0N treatments) were enriched in plant-derived compounds (e.g., aromatics, phenolics, carboxylic acids and aliphatic compounds), suggesting that decomposition of plant residues was constrained by N-limitation. Microbial populations assessed by amino sugar biomarker ratios showed that the highest contributions to SOM by bacteria occurred in the maize + manure treatment (high N input), and by fungi in the fallow treatment (low N input). The SOM in the maize + N and maize/soybean treatments was enriched in N-bonded aromatics; we attribute this enrichment to the abiotic reaction of inorganic N with organic C structures. The SOM in the maize + manure treatment was enriched in pyridinic-N, likely as a result of intense microbial processing and high SOM turnover. The presences of signals for ketone and pyrrole compounds in XANES spectra suggest their use as biomarkers for microbially transformed and stabilized SOM. The SOM in the maize + manure treatment was enriched in ketones which are likely microbial by-products of fatty acid catabolism. Pyrrole compounds, which may accumulate over the long term as by-products of protein transformations by an N-limited microbial community, were dominant in the fallow soil. A combination of molecular spectroscopy and biomarker analysis showed that the source of supplemental N to soil influences the stable C- and N-containing compounds of SOM in a long-term field study. Indeed, any increase in N availability allowed the microbial community to transform plant material into microbial by-products which occur as stable SOM compounds in the fine soil fraction.     

Effects of Manure Compost Application on Soil Microbial Community Diversity and Soil Microenvironments in a Temperate Cropland in China

The long-term application of excessive chemical fertilizers has resulted in the degeneration of soil quality parameters such as soil microbial biomass, communities, and nutrient content, which in turn affects crop health, productivity, and soil sustainable productivity. The objective of this study was to develop a rapid and efficient solution for rehabilitating degraded cropland soils by precisely quantifying soil quality parameters through the application of manure compost and bacteria fertilizers or its combination during maize growth. We investigated dynamic impacts on soil microbial count, biomass, basal respiration, community structure diversity, and enzyme activity using six different treatments [no fertilizer (CK), N fertilizer (N), N fertilizer + bacterial fertilizer (NB), manure compost (M), manure compost + bacterial fertilizer (MB), and bacterial fertilizer (B)] in the plowed layer (0–20 cm) of potted soil during various maize growth stages in a temperate cropland of eastern China. Denaturing gradient electrophoresis (DGGE) fingerprinting analysis showed that the structure and composition of bacterial and fungi communities in the six fertilizer treatments varied at different levels. The Shannon index of bacterial and fungi communities displayed the highest value in the MB treatments and the lowest in the N treatment at the maize mature stage. Changes in soil microorganism community structure and diversity after different fertilizer treatments resulted in different microbial properties. Adding manure compost significantly increased the amount of cultivable microorganisms and microbial biomass, thus enhancing soil respiration and enzyme activities (p<0.01), whereas N treatment showed the opposite results (p<0.01). However, B and NB treatments minimally increased the amount of cultivable microorganisms and microbial biomass, with no obvious influence on community structure and soil enzymes. Our findings indicate that the application of manure compost plus bacterial fertilizers can immediately improve the microbial community structure and diversity of degraded cropland soils.     

玉米秸秆还田对土壤丛枝菌根真菌群落的影响

为揭示农业管理活动对土壤丛枝菌根(AM)真菌的影响机制,基于Illumina Miseq高通量测序平台以及脂肪酸指纹图谱方法,研究了连续4年玉米秸秆还田后,AM真菌群落组成、AM真菌生物量及其与土壤环境因子间的相互关系.结果表明:所获得的2430个AM真菌OTUs从门到种依次分类,共分为1门、3纲、4目、8科、10属、143种,但不同处理间AM真菌群落丰富度(Chao1指数和ACE指数)、多样性(Shannon、Simpson多样性指数)没有显著差异.AM真菌中类球囊霉属、球囊霉属为优势属.随秸秆还田量的增加,球囊霉属丰度降低;3000、9000 kg·hm^-2秸秆还田量下,类球囊霉属、无梗囊霉属的丰度与对照(0 kg·hm^-2)间差异达极显著水平;原囊霉属、类球囊霉属、球囊霉属在3000 kg·hm^-2秸秆还田量下与对照间差异显著,非度量多维尺度(NMDS)分析表明,9000、12000 kg·hm^-2的秸秆还田量下土壤AM真菌β多样性与对照间聚集度较其他处理相差较远,秸秆还田量对AM真菌β多样性的影响显著.多元分析结果能在累积变量82.8%上揭示土壤主要理化性状与AM真菌丰富度、多样性的空间变化关系.土壤全氮、碱解氮是影响以磷脂脂肪酸表征的土壤主要微生物类群生物量以及以中性脂肪酸表征的AM真菌生物量的主要因子.持续玉米秸秆还田改变了AM真菌属水平上的分类学组成;随秸秆还田量的增加,AM真菌特有的微生物种类减少,AM真菌群落组成间的相似度下降;秸秆还田增加了土壤AM真菌生物量及其占土壤微生物总生物量的比例.     

不同施肥处理下水稻根际和非根际土壤中氨基糖积累特征

以水稻长期定位施肥试验土壤为研究对象,选取不施肥(CK)、化肥(NPK)、秸秆还田+化肥(NPKS)、30%有机肥+70%化肥(LOM)和60%有机肥+40%化肥(HOM)5种处理,分析水稻分蘖旺期根际土和非根际土中氨基糖积累特征.结果表明: 与CK和NPK处理相比,长期施用有机物料(NPKS、LOM、HOM)显著增加了水稻根际土和非根际土中有机碳、总氨基糖及其氨基单糖(胞壁酸、氨基葡萄糖和氨基半乳糖)含量.不同施肥处理下3种氨基单糖的积累规律不同,说明不同微生物对施肥处理的响应趋势和强度有所不同.受稻田翻耕等均匀化土壤的农事操作影响,各处理总氨基糖含量在根际土与非根际土间无显著差异.氨基糖碳对土壤有机碳积累的贡献范围为24.0～28.3 mg·g^-1,且以NPKS处理最高,HOM和CK处理最低.真菌氨基葡萄糖/胞壁酸比值范围为24.4～36.6,说明该试验点所有处理的根际土与非根际土中有机质的降解与转化过程以真菌为主导,且与NPK和CK相比,NPKS处理的真菌参与度提高,而施用HOM处理的细菌参与度提高.     

不同施肥条件下秸秆碳在表层和深层土壤团聚体中的分配与固存

长期施肥引起表层和深层土壤水、热、养分和微生物活性的分异,进而影响秸秆碳在土壤中的分解和周转过程。本研究基于沈阳农业大学长期定位实验站,分别将不同施肥处理表层(0～20 cm)和深层(40～60 cm)土壤与¹³C标记秸秆混合进行田间试验,通过分析团聚体中有机碳含量和δ¹³C值,对比秸秆碳在表层和深层土壤团聚体中分配的差异,探讨施肥对秸秆碳在土壤团聚体中固定的影响。结果表明: 与施肥(包括单施氮肥和有机肥配施氮肥)处理相比,不施肥处理分别使表层土壤<0.053 mm和深层土壤>0.25 mm团聚体中秸秆碳含量增加了106.7%和34.2%;秸秆碳对深层土壤>0.053 mm团聚体有机碳的贡献率约为表层土壤的2.0倍;秸秆碳分配到表层土壤>0.25 mm和<0.25 mm团聚体的比例平均分别为22.6%和11.4%,分配到深层土壤的相应比例分别为29.4%和8.8%。总之,秸秆添加促进了深层土壤大团聚体碳源的更新和固存,提高了深层土壤的固碳潜力。