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1.
AM真菌对桑树根围土壤团聚体的影响机制 总被引:3,自引:1,他引:2
为揭示丛枝菌根 (Arbuscular mycorrhizal,AM)真菌对植桑土壤的影响及机制,采用盆栽试验研究接种摩西管柄囊霉 (Funneliformis mosseae,Fm)和根内根生囊霉 (Rhizophagus intraradices,Ri)对土壤有机碳(Soil organic carbon, SOC)、球囊霉素相关土壤蛋白 (Glomalin related soil protein, GRSP)及团聚体组成与稳定性的影响。结果表明:⑴ 接种Ri显著增加土壤大团聚体百分比,并提高平均质量直径 (Mean weight diameter, MWD)和几何平均直径 (Geometric mean diameter, GMD)、显著降低团聚体破坏率 (Percentage of aggregate destruction, PAD)。⑵ 接种Fm和Ri均显著增加微团聚体SOC含量,接种Fm显著降低大团聚体总GRSP含量,而接种Ri却显著增加大团聚体和微团聚体总GRSP含量及易提取GRSP含量。⑶ 接种AM真菌对整体SOC的效应为负,土壤总GRSP对SOC占比在25.5%~76.5%之间,土壤易提取GRSP对SOC占比在4.87%~5.93%之间,且Ri的接种效应高于Fm。⑷ 总GRSP、易提取GRSP和SOC对团聚体组成表现均为正向显著影响,其中易提取GRSP是主要驱动因子,而总GRSP是土壤团聚体稳定性的主要影响因子。综上,AM真菌作用下桑树根围土壤团聚体得以改善并趋于稳定,Ri的接种效应明显大于Fm;土壤团聚体的形成主要依赖易提取GRSP,而其稳定性主要受总GRSP影响。 相似文献
2.
稻草及其制备的生物质炭对土壤团聚体有机碳的影响 总被引:11,自引:0,他引:11
向土壤中添加生物质炭已被认为是改善土壤质量,增加碳吸存的有效措施。通过模拟实验,利用同位素δ13C标记技术,研究稻草及其制备的生物质炭添加对土壤团聚体有机碳的影响。结果表明:稻草和生物质炭对土壤团聚体中新形成碳和原有机碳的影响截然不同。培养112 d,来自稻草或生物质炭的新碳主要进入到中团聚体(50 ~ 250 μm)中,比例为70.3% ~ 75.3%。与对照土壤相比,稻草添加显著促进了大团聚体(250 ~ 2 000 μm)原有机碳的分解(p <0.05),但对中团聚体和微团聚体(<50 μm)原有机碳的影响并不明显,而生物质炭添加(SB250和SB350)则对大团聚体和中团聚体原有机碳没有显著影响,但SB250处理(土壤中加入250℃热解制备的生物质炭)显著抑制了微团聚体原有机碳的分解(p <0.05),而SB350处理(土壤中加入350℃热解制备的生物质炭)的则无影响。对于同一粒级团聚体,稻草与生物质炭处理的区别,主要体现在新碳分配上,而对原有机碳的影响并不显著。 相似文献
3.
接种丛枝菌根真菌对土壤水稳性团聚体特征的影响 总被引:5,自引:0,他引:5
为了研究接种丛枝菌根真菌对土壤团聚体特征的影响,采用盆栽试验,以小麦(Triticum aestivuml)为宿主植物,在两个不同供磷水平条件下,分别接种丛枝菌根真菌Glomus intraradices和Glomus mosseae,收获后分析土壤团聚体数量、分布和分形维数,并运用通径分析对不同作用因子进行统计。结果看出,与对照相比,接种丛枝菌根真菌显著提高了土壤中有机质含量、球囊霉素相关土壤蛋白含量,土壤水稳性大团聚体数量也显著增加。接种处理提高了土壤的平均重量直径、几何平均直径,而且降低了土壤分形维数。通径分析表明,在影响土壤水稳性大团聚体的众多因子中,菌丝密度具有最大的作用,且以直接作用为主;有机质和球囊霉素相关土壤蛋白也表现出较大的作用。接种G. mosseae对改良土壤结构的作用优于接种G. intraradices。 相似文献
4.
田间陈化生物质炭提高稻田土壤团聚体稳定性和磷素利用率 总被引:3,自引:2,他引:1
5.
生物质炭对土壤结构改良、土壤肥力提升和农田温室气体排放具有重要意义。本研究以吉林省梨树县典型黑土为研究对象,通过培育实验,研究不同土壤水分含量(40%WHC和100%WHC)下,生物质炭种类(玉米秸秆生物质炭和稻壳生物质炭)和施加量(0%、1%和4%(w/w))对黑土N2O排放及硝化反硝化功能基因丰度的影响。结果表明,随着秸秆生物质炭施加量的增加,土壤N2O排放呈下降趋势,4%高量秸秆生物质炭添加下,土壤N2O排放量仅为1%低量秸秆生物质炭添加下的33.9%。同时土壤NO- 3-N也表现出一致性规律,4%高量生物质炭添加下土壤NO- 3-N含量显著低于1%低量生物质炭。在100%WHC土壤水分状况下,玉米秸秆生物质炭显著增加了土壤N2O排放,而稻壳生物质炭则显著降低了土壤N2O排放。高土壤水分显著促进了土壤N2O排放,进一步为实时荧光定量PCR结果所证实,高土壤水分通过增加nirS基因丰度进而促进了土壤反硝化作用过程,而4%高量稻壳生物质炭添加下nosZ基因丰度显著高于玉米秸秆生物质炭添加,表现出更强的N2O还原潜力。尽管amoA-AOA基因丰度在不同生物质炭添加量下并未发生显著变化,但amoA-AOB基因丰度在高量玉米秸秆生物质炭添加下显著下降。结果说明,土壤水分和生物质炭通过影响土壤硝化反硝化微生物的营养底物和代谢过程,进而影响土壤N2O排放特征。 相似文献
6.
在全球天然林面积持续下降而人工林面积不断增加的背景下,人工林是否能达到天然林的土壤固碳能力尚不清楚。以黄土高原子午岭林区的成熟人工和天然油松林为研究对象,比较分析了不同密度人工林和天然林0—20 cm土层的土壤团聚体组成、不同粒径团聚体土壤有机碳(SOC)、不同活性SOC及球囊霉素相关土壤蛋白(GRSP)的分布特征和相关性。结果表明:(1)人工林表层土壤全土的总SOC含量及其高活性、低活性、非活性SOC组分的含量均显著低于天然林,其中总SOC含量和非活性SOC含量随林分密度增加而增加,低活性SOC含量反之。(2)人工林表层土壤各粒径团聚体的总SOC含量及其组分含量均显著低于天然林。人工林大团聚体的重量百分含量、总SOC含量及非活性SOC含量随林分密度的增加而增加,但均显著低于天然林。(3)人工林表层土壤的SOC含量随林分密度增加而增加,其峰值17.95 g/kg,为天然林SOC含量的65.5%,其中大团聚体的数量及其SOC含量和稳定性的显著降低是导致两者差异的主要原因。活性SOC百分含量与总SOC含量的增加呈负相关关系,GRSP随林分密度增加而增加,但低于天然林,且通过提高大团聚体数量... 相似文献
7.
丛枝菌根真菌侵染对紫色土水稳性团聚体特征的影响 总被引:1,自引:0,他引:1
为了研究接种丛枝菌根真菌对土壤团聚体特征的影响,采用盆栽试验,以白三叶草(Trifolium pratense)为宿主植物,在两不同供磷水平条件下,分别接种丛枝菌根真菌Glomus intraradices和Glomus mosseae,收获后分析土壤团聚体数量、分布和分形维数,并运用通径分析对不同作用因子进行统计。结果表明:与对照相比,接种丛枝菌根真菌显著提高了球囊霉素相关的土壤蛋白含量,土壤水稳性大团聚体数量也显著增加。接种处理提高了土壤的平均重量直径,几何平均直径,而且降低了土壤分形维数。通径分析表明,在影响土壤水稳性大团聚体的众多因子中,菌丝密度具有最大的作用,且以直接作用为主,球囊霉素相关土壤蛋白也表现出较大的作用系数,但以间接作用为主。同时接种的两种菌种表现出对土壤结构改良作用大小的不同,在实际运用中需要考虑到此点。 相似文献
8.
生物炭对侵蚀黑土团聚体的影响 总被引:2,自引:1,他引:1
[目的] 探讨生物炭对侵蚀黑土团聚体的修复效果,揭示生物炭对侵蚀黑土团聚体的影响机制,为修复侵蚀黑土提供科学依据。[方法] 以侵蚀黑土为研究对象,研究未剥离农田(CK)、未剥离农田施生物炭(CK+BC)、模拟侵蚀土壤(RS)、侵蚀土壤施生物炭(RS+BC)4个处理生物炭对黑土团聚体的影响。[结果] 与CK处理相比,CK+BC处理中0.25~2 mm粒级团聚体含量增加了14.01%,RS+BC处理中0.25~2 mm粒级团聚体含量比RS处理增加了12.11%,生物炭提高了团聚体的几何平均直径(GMD)和大于0.25 mm团聚体含量,增加了CK+BC和RS+BC两个处理的原土和>0.25 mm粒级团聚体中的土壤有机碳含量(SOC),GMD分别与SOC和交换性钠呈正相关和负相关,且SOC对团聚体的胶结作用大于交换性钠的分散作用,提高了侵蚀黑土团聚体稳定性。[结论] 生物炭改善黑土侵蚀后的结构,促进了土壤团聚化,对侵蚀土壤具有良好的修复作用,是修复侵蚀黑土的有效措施。 相似文献
9.
生物质炭的性状与原料中木质纤维含量密切相关,为探明不同原料生物质炭对土壤腐殖质组成的影响,选取玉米秸秆和紫茎泽兰分别作为纤维类和木质类原材料制备生物质炭,向酸性紫色土分别添加5%玉米秸秆生物质炭(MB)和5%紫茎泽兰生物质炭(EB),测定90 d室内培养期间土壤胡敏酸(HA)、富里酸(FA)、胡敏素(HM)含量以及HA光学性质和元素组成变化。结果表明:MB和EB的比表面积分别为2.32 m2·g-1和0.72 m2·g-1,总孔体积分别为42.71 mm3·g-1和12.59 mm3·g-1,碳与氢元素摩尔比(C/H)分别为1.91和1.46,氧、硫之和与碳元素摩尔比[(O+S)/C]分别为0.09和0.16,玉米秸秆生物质炭的吸附能力更强、有机质成分的缩合度更大且氧化度更小。与对照(不添加生物质炭,CK)相比,培养结束后,施入生物质炭的土壤HA、FA和HM含量分别显著增加(P<0.05)65.59%~102.82%、85.87%~118.54%和137.25%~161.23%,MB处理对这3种腐殖质含量的增加效应较EB处理更明显。培养结束时添加生物质炭的土壤HA/土壤有机碳(SOC)降低13.53%~27.06%,FA/SOC降低6.81%~18.03%,其中EB处理的降低效应达显著水平;HM/SOC则增加4.58%~11.40%,其中MB处理的增加效应达显著水平。添加生物质炭的土壤HA色调系数(ΔlgK)增加2.40%~5.60%,HA的缩合度(C/H)降低3.51%~11.81%,(O+S)/C增加1.51%~8.74%。总体来看,施入生物质炭均能相对增加腐殖质各组分含量,降低C/H,提高HA的氧化度[(O+S)/C],且纤维类原料(玉米秸秆)生物质炭的效果更明显。纤维类原料(玉米秸秆)生物质炭显著提高了稳定性较高的土壤胡敏素碳比例(HM/SOC),但降低了土壤HA的稳定性[HA的C/H降低,(O+S)/C增加];木质类原料(紫茎泽兰)生物质炭显著降低土壤胡敏酸碳比例(HA/SOC)和富里酸碳比例(FA/SOC),对HM/SOC增加效益不显著,反之提高了土壤易分解有机碳比例。 相似文献
10.
采用分根装置研究了丛枝菌根真菌侵染白三叶草(Trifolium repens)后对中性紫色土12 mm土壤水稳性团聚体(WSA1-2mm)含量的影响,并运用通径分析对其主要影响因子进行了量化比较。结果表明,接种Glomus intraradices、G. mosseae和G. etunicatum的菌根室土壤有机质、球囊霉素相关土壤蛋白(GRSP)含量均有增加的趋势; 接种3种菌种都显著增加了菌根室土壤WSA1-2mm含量。通径分析结果表明,菌丝密度对WSA1-2mm含量有较大的直接效应(直接通径系数 0.678),而GRSP对WSA1-2mm的影响系数较小,既有直接效应又有间接效应,但以直接效应为主。菌丝和GRSP对12mm 土壤水稳性团聚体作用大小的差异可能源于二者作用机制的不同。 相似文献
11.
《Communications in Soil Science and Plant Analysis》2012,43(15-16):2413-2425
The effects of soil aggregate size and mycorrhizal colonization on phosphorus (P) accumulation and root growth of Berseem clover (Trifolium alexandrinum L.) were studied. Root length and dry weight decreased with increasing aggregate diameter. Colonization of clover plants by arbuscular mycorrhizae (Glomus intraradices Schenck and Smith) improved root growth and P accumulation in all aggregate‐size classes. Although total root length of either mycorrhizal or nonmycorrhizal plants decreased with increasing aggregate diameter, the length of living external hyphae was not affected by aggregate size. Thus, colonized root length was improved by 20% as soil aggregate diameter increased. Total P accumulation per plant decreased with increasing aggregate size. However, total P accumulation per unit root length improved as the size of soil aggregate increased. In our study, mycorrhizal colonization improved total P accumulation and root growth in soil with large aggregates and compensated, in part, for the effect of soil strength. 相似文献
12.
Linking sorghum nutrition and production with arbuscular mycorrhizal fungi and alternative soil amendments
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Mounting fertilizer costs are disproportionally affecting farmers in developing countries. Alternative soil fertility amendments [worm compost, pyrolyzed carbon (biochar)] and arbuscular mycorrhizal fungi have the potential to reduce these costs while promoting soil health. Our greenhouse study investigated the role of mycorrhizal associations and alternative fertility amendments on the productivity and plant nutrition of grain sorghum. We assessed sorghum (Sorghum bicolor cv. Macia) grown with ten different treatments (combinations of biochar, worm compost, and commercial N and P fertilizers) plus a non‐amended control. An amendment blend containing worm compost, biochar, and 50% of the typically recommended commercial fertilizer rate produced similar plant biomass and protein, similar total tissue mineral contents (Ca, Fe, K, Mg, P, and Zn), and supported ≈ 60% more mycorrhizal fungi in the host plant's roots, compared to sorghum grown with the recommended rate of commercial fertilizer (N and P). Our results indicate the potential of biochar and worm compost to enhance the benefits of mycorrhizal fungi for grain sorghum production and plant nutrition while reducing commercial fertilizer applications. 相似文献
13.
Yixuan CHEN Zhonghua WEN Jun MENG Zunqi LIU Jialong WEI Xiyu LIU Ziyi GE Wanning DAI Li LIN Wenfu CHEN 《土壤圈》2024,34(2):361-373
Phosphorus (P) is an essential element for plant growth but is often limiting in ecosystems; therefore, improving the P fertilizer use efficiency is important. Biochar and arbuscular mycorrhizal fungi (AMF) may enhance P cycling in paddy soils that contain high content of total P but low content of available P (AP). In this study, the effects of biochar addition and Rhizophagus irregularis inoculation on the organic and inorganic P contents and phosphatase activities in paddy soils, rice seedling growth, and AMF colonization were investigated. Compared with no biochar addition, biochar addition enhanced the percentage of spore germination at day 7, hyphal length, most probable number, and mycorrhizal colonization rate of R.irregularis by 32%, 662%, 70%, and 28% on average, respectively. Biochar and R. irregularis altered soil P cycling and availability. Biochar and R. irregularis, either individually or in combination, increased soil AP content by 2%-48%. Rice seedlings treated with biochar and R. irregularis produced greater biomass, improved root morphology, and increased nutrient uptake compared with those of the control without biochar and R. irregularis. The results suggest that combined application of biochar and R. irregularis is beneficial to rice cultivation in paddy soils with high content of total P but low content of AP. 相似文献
14.
Jinsheng LI Xinqing SHAO Ding HUANG Kesi LIU Jianying SHANG Qian ZHANG Tianci ZHAO Xiaomeng YANG 《土壤圈》2022,32(3):426-437
Soil remediation is an important part of the restoration process of degraded terrestrial ecosystems. Due to its unique properties, biochar is being used widely as an effective soil modifier in agricultural systems, but research is still rare on biochar application in grassland ecosystems, especially in degraded alpine grasslands. In this study, we conducted a plot experiment to investigate the effect of biochar application on soil physicochemical properties and microorganisms at the 0–20 cm soil depth of a degraded alpine grassland in Qinghai-Tibet Plateau, China. The experiment consisted of four corn straw biochar application levels (0%, 0.5%, 1% and 2%, with the percentage representing the ratio of biochar weight to the dry weight of soil in the surface 20 cm soil layer). When the biochar addition increased from 0% to 2%, total nitrogen, total organic carbon and available phosphorus in the 0–10 cm soil layer increased by 41%, 55% and 45%, respectively, in the second year after biochar addition. Meanwhile, soil electrical conductivity decreased, and soil water content increased. Total microbial, fungal and bacterial biomasses in the 0–10 cm soil layer increased from 9.15 to 12.68, 0.91 to 1.34, and 3.85 to 4.55 μg g-1, respectively. The relative biomasses of saprophytic fungi and methanotrophic bacteria decreased, while the relative biomasses of ectomycorrhizal fungi and arbuscular mycorrhizal fungi increased. These results indicate that biochar has a great potential in improving microbial activity and soil fertility in soil remediation of the degraded alpine grassland. 相似文献
15.
It is increasingly believed that substantial soil organic carbon (SOC) can be sequestered in conservation tillage system by manipulating the functional groups of soil biota. Soil aggregates of different size provide diverse microhabitats for soil biota and consequently influence C sequestration. Our objective was to evaluate the contributions of soil biota induced by tillage systems to C sequestration among different aggregate size fractions. Soil microbial and nematode communities were examined within four aggregate fractions: large macroaggregates (>2 mm), macroaggregates (2–1 mm), small macroaggregates (1–0.25 mm) and microaggregates (<0.25 mm) isolated from three tillage systems: no tillage (NT), ridge tillage (RT) and conventional tillage (CT) in Northeast China. Soil microbial and nematode communities varied across both tillage systems and aggregate fractions. The activity and abundance of microbes and nematodes were generally higher under NT and RT than under CT. Among the four aggregate fractions, soil microbial biomass and diversity were higher in microaggregates, while soil nematode abundance and diversity were higher in large macroaggregates. Structural equation modelling (SEM) revealed that the linkage between microbial and nematode communities and their contributions to soil C accumulation in >1 mm aggregate fractions were different from those in <1 mm aggregate fractions. Higher abundance of arbuscular mycorrhizal fungi (AMF) could enhance C retention within >1 mm aggregates, while more gram-positive bacteria and plant-parasitic nematodes might increase C accumulation within <1 mm aggregates. Our findings suggested that the increase in microbial biomass and nematode abundance and the alteration in their community composition at the micro-niche within aggregates could contribute to the higher C sequestration in conservation tillage systems (NT and RT). 相似文献
16.
生物炭和氮肥配施提高土团聚体稳定性及作物产量 总被引:1,自引:1,他引:0
17.
生物炭施用下潮土团聚体微生物量碳氮和酶活性的分布特征 总被引:1,自引:1,他引:1
18.
研究生物炭和丛枝菌根(arbuscularmycorrhizal,AM)真菌对连作辣椒生长和土壤养分的影响,可为辣椒连作土壤改良和新型肥料的开发提供理论依据。采用温室盆栽试验,设置4个生物炭添加水平(0、1%、2%、3%), 2个接菌水平[接菌(+AM)和不接菌(-AM)]。辣椒生长60 d后收获并测定其生理指标、土壤酶活性及土壤养分含量。结果表明,施加生物炭和接种AM真菌处理促进了连作辣椒的生长,提高了辣椒叶片净光合速率、蒸腾速率、气孔导度和叶绿素含量。接种AM真菌对辣椒的促生效果弱于生物炭,而生物炭和AM真菌配施的促生效果最佳。接种AM真菌促进辣椒对P吸收的效果优于生物炭;但对于K吸收来说,施加生物炭的效果优于接菌。生物炭(3%)和AM真菌配施条件下,辣椒根部N、P、K含量分别较对照(0生物炭和-AM处理)显著提高74.04%、106.42%和78.82%。生物炭(3%)与AM真菌配施处理菌根侵染效果最佳,侵染率高达58.96%,较0生物炭+AM处理提高41.59%。土壤pH随生物炭添加量的增加呈增加趋势,但差异不显著。土壤脲酶、蔗糖酶活性随生物炭添加量的增加呈增加趋势,且差异显著,接种AM真菌处理对其影响不显著。土壤速效钾、有效磷、有机质含量随生物炭添加量的增加而增加,接种AM真菌对土壤有机质含量、阳离子交换量(CEC)无显著影响。土壤速效钾、有效磷、碱解氮含量均在生物炭(3%)和AM真菌配施条件下达最大。与单一处理相比,生物炭和AM真菌配施在促进连作辣椒生长、改善连作土壤养分方面具有显著的协同增效作用,尤其是3%生物炭与AM真菌配施条件下效果最佳。 相似文献
19.
Maize roots are colonized by arbuscular mycorrhizal fungi, but less mycorrhizal symbiosis is expected as the plant-available phosphorus (P) concentration of soil increases, based on greenhouse and growth bench experiments. The objective of this study was to evaluate maize root colonization by arbuscular mycorrhizal fungi in a sandy loam soil with a gradient of plant-available P concentrations resulting from P fertilizer inputs. The field experiment received inorganic and organic P fertilizers for 3 years, and this created a 20-fold difference in the plant-available P concentration, from 12 to 204 mg Mehlich-3 extractable P kg−1. The proportion of maize roots colonized with arbuscular mycorrhizal fungi increased from 26 ± 2% during vegetative growth (V8 and VT growth stages) to 46 ± 2% in the reproductive R2 and R6 stages. The P fertilizer input did not affect maize root colonization by arbuscular mycorrhizal fungi. More arbuscular mycorrhizal fungi colonization of maize roots occurred in soil with increasing plant-available P concentrations (r = .12, p = .05, n = 237), and this was associated with greater P uptake in the maize shoots (r = .53, p < .001, n = 240). We conclude that the root-mycorrhizal symbiosis was more strongly related to maize growth than the plant-available P concentration under field conditions. 相似文献