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1.
耕作与施肥对甘蔗地土壤微生物量碳、氮的影响   总被引:2,自引:0,他引:2  
何瑞清  王百群    张燕 《水土保持研究》2015,22(5):118-121
通过野外调查与室内分析,研究了云南蒲缥甘蔗地赤红壤不同耕作与施肥土壤剖面微生物量碳、氮特征。结果表明:不同耕作与施肥对土壤微生物量碳、氮均有一定影响,其中耕作对土壤微生物量碳、氮的影响较为一致,表现为免耕 > 翻耕。施肥对0—20 cm土层中微生物量碳的影响表现为翻耕施肥 > 翻耕,对20—40 cm,40—60 cm土层中微生物量碳的效应呈现为翻耕 > 翻耕施肥,而施肥对土壤微生物量氮影响则与其对微生物量碳的效应相反。耕作和施肥对各个土层土壤微生物商具有显著的影响(p<0.05),表现为免耕 > 翻耕,翻耕施肥条件下0—20 cm土层的微生物商稍高于翻耕,而其他土层均为翻耕 > 翻耕施肥;土壤微生物量氮与全氮的比值与微生物量氮的变化趋势相近。在不同的耕作和施肥条件下,免耕有利于提高土壤微生物量,施肥在一定程度上也利于提高土壤微生物量。  相似文献   

2.
红壤微生物群落结构及其演变影响因素的研究进展   总被引:2,自引:0,他引:2  
周赛  梁玉婷  孙波 《土壤》2015,47(2):272-277
南方红壤丘陵区面临土壤肥力和生物功能退化问题,研究红壤微生物资源分布及其演变规律是培育红壤生物肥力的理论基础。本文综述了环境和人为因素对红壤微生物群落组成及其演变的影响,提出了红壤微生物群落组成及其功能调控研究的重点。土壤微生物群落组成受历史因素(地理距离、土壤类型)和现代因素(气候和土壤条件的变化)的共同影响,但不同因素间的相对贡献仍不清楚。土地利用方式和耕作施肥的改变均影响了红壤微生物群落的结构特征,但微生物结构和功能在耕作施肥过程中的长期变化规律仍需进一步研究。未来需要加强土壤?根系?微生物系统中生物交互作用及其对养分协同代谢和转化的影响,建立最佳管理措施修复退化红壤的微生物功能。  相似文献   

3.
不同耕作措施对土壤微生物的影响   总被引:5,自引:1,他引:5  
土壤微生物作为土壤中活的有机体系,是衡量土壤质量的重要指标之一,可以表征土壤质量演变趋势,不同耕作措施对土壤微生物的影响引起了国内外学者的广泛关注。通过综述不同种植制度(连作、轮作和间作)、施肥制度(有机肥和无机肥配施、单施有机肥和单施化肥)、保护性耕作制度(秸秆还田和免耕)对土壤微生物数量、生物量和群落结构的影响,以期为农业的可持续发展提供一定的参考依据。  相似文献   

4.
化肥减施对荔枝园土壤微生物功能多样性的影响   总被引:1,自引:1,他引:0       下载免费PDF全文
为探明化肥减施对荔枝园土壤微生物功能多样性的影响,利用Biolog ECO技术对不同施肥处理[T0(果农习惯施肥处理)和T1~T9(不同化肥减施处理)]荔枝园土壤微生物的功能多样性进行了研究.结果表明,土壤微生物群落的平均颜色变化率(AWCD值)增长的拐点在培养120 h时,以此时的AWCD值为指标进行正交试验方差分析...  相似文献   

5.
农业管理实践会干扰土壤生态系统,对土壤微生物特别是根系周围微生物产生不同影响,保护性耕作被认为是对土壤扰动较小的耕作方式,在全球范围内应用广泛,但其可持续性受到了秸秆覆盖可能会增加土壤病原微生物的挑战,对土壤微生物多样性的影响仍存在争议。因此,为全面了解黄土高原旱作麦田长期保护性耕作对土壤生态系统的影响,本研究依托山西省临汾市长达27年的保护性耕作试验平台,采用高通量测序技术,开展了土壤真菌群落结构和多样性对传统耕作(TT1)、免耕覆盖(NTS)、深松+免耕覆盖(SNTS)的响应分析。结果表明:与TT1相比, NTS和SNTS处理小麦根围土壤真菌组成及相对丰度发生了显著变化, NTS处理出现了未知真菌类群;各处理土壤真菌的主要优势菌门为子囊菌门、担子菌门和接合菌门;从属水平物种分布热图可以看出,与传统耕作相比,该地区多年的保护性耕作会加大小麦赤霉病发生的风险;UPGMA(非加权组平均法)分析表明,2种保护性耕作土壤真菌群落组成相似;TT1中具有显著差异的关键优势物种属担子菌门,NTS和SNTS处理的属子囊菌门; NTS处理土壤真菌丰富度和系统发育多样性最高, SNTS处理土壤真菌多样性最高;但土壤真菌多样性和丰富度指数在各处理间并无显著差异。综上,长期保护性耕作显著改变了土壤真菌群落结构及组成,提高了土壤真菌的丰富度和多样性,但不存在显著差异。同时该地区多年的保护性耕作可能会加大小麦赤霉病发生的风险。本研究对黄土高原旱作麦田区推广保护性耕作及土壤管理具有一定的指导意义。  相似文献   

6.
保护性耕作具有良好的生态效益,有利于农业生态系统的可持续发展。本文对比分析了国内外有关常规耕作和保护性耕作措施对土壤团聚体、土壤有机碳、土壤微生物及土壤线虫影响的研究进展。结果表明:保护性耕作减少土壤大团聚体的破坏,降低团聚体周转速率,提高土壤结构的稳定性;保护性耕作提高表层土壤总有机碳及活性有机碳含量;保护性耕作可以提高耕层微生物生物量,尤其对真菌生物量影响显著;保护性耕作不同程度地提高了团聚体中微生物量和微生物多样性,但并未改变微生物在团聚体中的分布模式;保护性耕作可提高土壤线虫多度,提高原状土壤和土壤各粒级团聚体中线虫群落的成熟度指数和结构指数,但并未改变线虫总数、营养类群、功能团及生态指数在团聚体中的分布模式。针对目前国内外研究现状,展望了保护性耕作今后的研究重点,以期为因地制宜选取保护性耕作措施提供理论支持,推进我国农业可持续发展。  相似文献   

7.
耕作措施对陇中旱农区土壤细菌群落的影响   总被引:4,自引:2,他引:4  
为探究耕作措施对陇中旱农区麦豆轮作系统土壤细菌多样性的影响,借助2001年在陇中旱农区建立的不同耕作措施长期定位试验,应用高通量测序技术比较传统耕作(T)与3种保护性耕作(免耕(NT)、传统耕作+秸秆还田(TS)和免耕+秸秆覆盖(NTS))对麦豆轮作体系土壤有机碳、全氮、微生物生物量碳、微生物生物量氮及细菌群落结构影响。结果表明:1)相对于传统耕作,秸秆还田显著增加0~10 cm、10~30 cm土壤有机碳、全氮、微生物量碳和微生物量氮含量,其中NTS处理0~10 cm、10~30 cm土层有机碳、全氮、微生物量碳和微生物量氮含量较传统耕作分别提高28.27%、114.16%、13.51%、49.14%和39.86%、98.05%、10.78%、40.72%。2)酸杆菌门(26.42%)、变形菌门(19.86%)和放线菌门(19.44%)为陇中旱农区麦豆轮作系统土壤细菌的主要优势种群,NTS处理下酸杆菌门、放线菌门和变形菌门丰度较传统耕作显著提高35.11%、33.77%和30.17%。3)与传统耕作相比,保护性耕作提高了0~30cm土层土壤细菌的Observedspecies指数、Chao指数、香农指数、辛普森指数,以NTS处理提高最为显著。因此,在陇中旱农区推广以免耕秸秆覆盖为主的保护性耕作措施有利于增加土壤碳氮固存、提高土壤细菌群落丰度和多样性和土壤的生物活性,促进农业的可持续发展。  相似文献   

8.
农田管理措施对农田生态系统碳循环影响显著,进而制约土壤肥力、农业生产及粮食安全,影响气候变化和环境健康。本文综述了不同农田管理措施(施肥方式、种植制度、耕作模式)对农田土壤有机碳、含碳温室气体排放和土壤微生物的影响。发现有机肥与无机肥配施情景下土壤有机碳增速最快,且施肥量与土壤碳库存在阈值效应;有机肥的施用增加了土壤中CO2排放通量,磷、钾两种肥料的施用与施用氮肥相比更能降低农田土壤排放温室气体产生的全球增温潜势;提高有机肥和磷肥的施用比例有利于土壤中微生物丰富度的提高和微生物量碳的积累。种植结构和种植密度均会影响农田土壤的碳储量,种植结构对农田生态系统温室气体排放影响显著,轮作和间作的种植模式与传统单一作物种植相比可有效减少农田含碳温室气体的排放,同时,轮作与连作相比更有利于土壤微生物多样性的增加。保护性耕作措施有利于农田土壤固碳效率的提高,可降低农田温室气体的排放,且对微生物活性、多样性、群落结构以及碳源利用情况均有积极影响。最后总结了国际主流碳模型在农田生态系统的应用概况,并提出了未来发展展望。  相似文献   

9.
在日光温室栽培条件下,采用Biolog检测法研究了不施肥(CK)、习惯施肥(CF)、秸秆还田(RS)和膜下滴灌(DI)等不同施肥措施下土壤微生物多样性的变化,及其对黄瓜产量、品质的影响。结果表明,反映微生物代谢活性的平均颜色变化率(AWCD)以RS处理最高,CK最低。微生物培养72 h代谢旺盛,各处理AWCD值在0.494~0.881之间,其中RS处理AWCD值较CF显著增加,是CF的1.3倍;DI处理AWCD比CF略低,但差异不显著。不同处理下土壤微生物多样性不同,土壤微生物物种丰富度指数(H)和均匀度指数(E)均以CF最低,通过秸秆还田调控土壤C/N和滴灌措施对习惯施肥模式进行改进,两指数显著提高。主成分分析结果表明,不同处理土壤微生物碳源代谢特征发生分异,秸秆还田处理分布于第1主成分正方向,得分系数在4.91~5.50之间;其他处理分布在第1主成分负方向,得分系数在-3.26~-0.18之间。与CF相比,RS和DI处理黄瓜产量和品质均无显著变化。多样性指数中优势度指数(Ds)和碳源利用丰富度指数(S)与黄瓜产量、果实可溶性糖、Vc含量成正相关,其中S与黄瓜果实Vc含量的相关系数达0.692。综合考虑,秸秆还田措施有助于改善土壤微生态环境,推动设施农业的可持续发展,较滴灌措施更有应用价值。  相似文献   

10.
为揭示新型纳米碳增效剂对柑橘产量的影响及其机理和研究对土壤微生物种群结构影响,本研究以三峡库区万州柑橘园为对象,以常规施肥为对照(ZJ1),采用正交优化实验确定柑橘产量的最佳施用量,同时基于Hiseq 2500高通量测序方法,分析不同施肥处理条件下的土壤细菌种群多样性。研究结果发现,柑橘产量的最佳施肥组合为ZJ5(A_2B_1C_2);微生物多样性受复合肥用量影响最大,纳米碳次之,腐植酸保水剂影响最小。最佳施肥组合(ZJ5)放线菌门(Actinbacteria)丰度最高,疣微菌门(Verrucomicrobia)丰度最低;通过对环境因子的分析发现,影响微生物种群多样性变化的环境因素顺序为p H有机质水解性氮。  相似文献   

11.
核酸分析方法在土壤微生物多样性研究中的应用   总被引:3,自引:0,他引:3  
土壤微生物多样性一般包括微生物分类群的多样性、遗传(基因)多样性、生态特征多样性和功能多样性。传统的分离培养方法和土壤微生物的生化研究手段具有一定的局限性,核酸分析方法为土壤微生物多样性研究注入了新活力。本文主要综述了近年来国内外研究土壤微生物多样性所采用的核酸提取方法及核酸分析方法。重点阐述了基于PCR的分子指纹技术、核酸杂交技术、基因芯片等核酸分析方法的原理、优缺点和应用。各种土壤微生物多样性研究方法的综合应用可扬长避短,起到相互补充的作用,从而能够提供更加丰富而准确的土壤微生物群落结构及种群丰度变化等方面的信息,也将成为这一领域今后的发展趋势。  相似文献   

12.
《Applied soil ecology》2001,16(3):251-261
Reduced tillage of agricultural soils has been shown to result in greater macroaggregation, microbial biomass and microbial diversity. While it has been shown that macroaggregates contain more microbial biomass per unit soil mass than microaggregates, it is unclear how microbial diversity varies with soil aggregation. We investigated the functional diversity (catabolic potential) of bacteria, evaluated by calculating Shannon’s diversity index (H′), substrate richness (S) and substrate evenness (E) from potential substrate utilization patterns, in whole soil (i.e. not separated into different aggregate sizes) and aggregates of different sizes (2–4, 1–2, 0.5–1, 0.25–0.5, and 0.1–0.25 mm diameter) in loam and silt loam soils grown to barley and managed for 6 years under conventional tillage (CT) or zero tillage (ZT) systems in northern British Columbia. There were no significant tillage effects on bacterial diversity in whole soils. In soil aggregates, H′ and E were significantly higher under CT than under ZT on the loam at barley planting time, with no significant aggregate size effects. However, at barley-heading stage, all diversity indices in both soils were significantly higher under ZT than under CT, and they tended to increase with increasing aggregate size. Cluster analysis and principal component analysis of substrate utilization patterns also revealed differences in bacterial community structures between CT and ZT, but the substrates that were utilized differently between the two tillage systems were not the same between soil types or sampling times. The results during the cropping cycle imply that deterioration of soil structure is probably one factor that explains the adverse effects of soil tillage on soil microbial biomass and diversity.  相似文献   

13.
 We investigated the influence of tillage (conventional, minimum and reduced) on selected soil microbial properties of a fine-sandy loamy Haplic Chernozem over a period of 8 years. The microbial biomass and soil microbial processes were affected mostly by type of tillage and to a lesser extent by the date of soil sampling. Whereas xylanase activity was significantly higher in the 0 to 10-cm soil layer of the reduced and minimum tillage systems within the first year of the experiment (protease and phosphatase activities were significantly higher in the second year), significant treatment effects on microbial biomass, N mineralisation and potential nitrification were observed after a 4-year period. The slow response of substrate-induced respiration to the change in type of tillage may have been due to the differences in the biomass C turnover rates. After a 4-year period, the stratification of the soil microbial biomass within the profile of reduced and minimum tillage systems was probably responsible for the more intensive soil microbial processes near the soil surface compared with conventional tillage. In the 20 to 30-cm layer, N mineralisation, potential nitrification and xylanase activity in the conventional treatment were significantly higher than in the minimum and reduced tillage plots due to buried organic materials. Discriminant analysis underlined the similarity of the enzyme activity patterns in the top layer of the reduced and minimum tillage treatments, and in both layers of the conventional tillage system. The trend towards a significant increase in functional diversity caused by reduced tillage became obvious within the first year of the experiment, and this effect was still manifest after 8 years. All relationships suggested that there were differences in available resources (e.g. organic matter) along the sequence of different tillage systems; this was reflected in part by enhanced enzymatic and microbial activities in the soil layers. In conclusion, this study showed that soils affected by tillage may be classified on the basis of their functional diversity. Therefore, the soil microbial properties chosen for microbiological soil monitoring (microbial biomass, N mineralisation and enzyme activities involved in C, N and P cycling) provide a reliable tool with which to estimate early changes in the dynamics and distribution of soil microbial processes within soil profiles. Received: 3 February 1998  相似文献   

14.
为明确黄土高原旱作麦田长期保护性耕作对土壤肥力和土壤原核微生物的效应,以位于山西省临汾市实施保护性耕作26年的小麦田为试验基地,采用Illumina Hiseq 2500高通量测序等手段,开展了不同耕作措施[免耕覆盖(NTS)、深松免耕覆盖(SNTS)和传统耕作(TT1)]对土壤理化性质和土壤原核微生物多样性的影响分析。研究结果表明:1)NTS和SNTS处理比TT1处理显著提高了土壤全氮、碱解氮、速效磷及速效钾的含量,降低了土壤pH,提高了土壤贮水能力和水分含量,降低了0~10 cm土层的土壤容重,但提高了10~20 cm土层的土壤容重;同时,SNTS处理显著增加了土壤的有机质含量。2)Illumina Hiseq高通量16S rRNA基因V4区测序结果表明:NTS和SNTS处理比TT1处理显著降低了绿弯菌门的相对丰度;NTS比SNTS处理显著降低了土壤中疣微菌门和绿弯菌门的相对丰度;NTS处理显著增加了土壤原核微生物群落的多样性,但未显著改变原核微生物群落的丰度;SNTS对原核微生物群落的多样性和丰富度均未有显著改变;NTS处理的显著性差异物种(Biomarker)高于其他2个处理;其他原核微生物门的相对丰度,在3个处理间尚未有明显差异。3)聚类分析可见:NTS和SNTS处理与TT1处理的微生物群落结构差异较大;NTS处理与SNTS处理间的微生物群落结构差异较小。4)CCA分析可知:土壤pH、有机质、速效氮、速效磷、速效钾含量对土壤原核微生物群落遗传多样性的变化起着重要作用;与TT1处理相比,NTS和SNTS处理在一定程度上改变了土壤原核微生物群落结构,但仍存在结构的相似性。综上所述,长期进行NTS和SNTS处理对黄土高原旱地麦田土壤微生物多样性、丰富度以及土壤肥力因子等的正效作用明显。  相似文献   

15.
为了解东北黑土旱田改种稻田后土壤团聚体中微生物群落功能多样性的变化,将东北黑土旱田(种植玉米为主)改种为稻田(简称“旱改稻”),采用Biolog-Eco微平板技术,研究了“旱改稻”后不同粒径土壤团聚体微生物的多样性指数以及其对碳源利用能力的变化。结果表明,“旱改稻”显著增加了黑土土壤水稳性微团聚体数量,增加了不同粒径土壤团聚体内有机碳(SOC)的含量。旱田和稻田不同粒径土壤团聚体内的土壤微生物群落平均颜色变化率(AWCD)表现为旱田淤泥+粘土>旱田大团聚体>旱田微团聚体>稻田大团聚体>稻田淤泥+粘土>稻田微团聚体。“旱改稻”明显降低了各粒径土壤团聚体微生物的多样性指数以及碳源利用能力,尤其对氨基酸与碳水化合物最为明显。主成分分析结果表明,旱田和稻田不同粒径土壤团聚体微生物群落功能多样性差异显著。综上,“旱改稻”明显改变了黑土土壤团聚体微生物群落功能多样性,降低了以碳源为底物的土壤微生物代谢活性。本研究结果为东北黑土区土壤可持续利用提供了理论参考。  相似文献   

16.
ABSTRACT

The effects of straw retention on soil bacterial community structure, microbial function, and biochemical properties were assessed. Terminal restriction fragment length polymorphism (T-RFLP) and community-level physiological profile (CLPP) assays were used to assess the bacteria community structure and microbial function respectively. Treatments included straw removal with conventional tillage (CT), straw retention with conventional tillage (SRCT) and straw retention with no tillage (SRNT). SRCT and SRNT significantly (p < 0.05) increased soil organic carbon by 8.9% and 9.7%, and microbial biomass carbon by 44.7% and 330.8%, respectively, compared with CT. T-RFLP analysis indicated that straw retention had no favourable effect on soil bacterial diversity, and SRCT significantly (p < 0.05) decreased bacterial diversity compared to CT. Among the three treatments, SRNT had the highest activity of urease, invertase, cellulase, and β-glucosidase. SRCT significantly (p < 0.05) increased the activity of invertase and β-glucosidase compared to CT treatment. CLPP analysis showed that microbial functional diversity was significantly (p < 0.05) increased by straw retention. Enzyme activity and microbial functional diversity were not correlated with bacterial diversity. Therefore, according to this study, SRNT is a better farming practice because it improves soil fertility and biological quality.  相似文献   

17.
No-till (NT) management greatly reduces soil physical disturbance and can result in a stratification of nutrients and organic matter in the soil profile due to the retention of crop residues on the soil surface potentially affecting the dynamics of microbial interactions in the soil. Microbial abundance and diversity can be used to assess the relative impact of management on the long-term sustainability of cropping systems. The objective of this study was to assess the impact of long-term NT vs. conventional tillage (CT) management on soil microbial community structure at four different sites on the Canadian prairies using phospholipid fatty acid analysis (PLFA) and DNA fingerprinting. Analysis of 16S and 18S rDNA using denaturing gradient gel electrophoresis revealed high inherent variability within bacterial and fungal community fingerprints among replicate field plots. Differences in bacterial and fungal phylogeny were related to depth in the soil profile but not to tillage management. Abundance of individual PLFA biomarkers were 7 to 86% greater in NT surface soils (0- to 5-cm depth), except at the Ellerslie site in 2005 where biomass was greater in CT. Responses at the 5- to 10-cm and 10- to 15-cm depths were more varied, in some cases with greater biomass in CT than NT soils. Ordination analysis of PLFA profiles showed clear community separation with depth but not tillage. Physiological stress biomarkers were correlated with simple measures of nutrient concentration and indicated that resource availability was likely the main factor determining community structure. It was concluded that tillage disturbance was not an overriding factor in determining microbial community composition in the long-term NT and CT soils studied. Further study of the interaction of cropping frequency with tillage management is needed to understand the effects of tillage disturbance on microbial turnover of plant derived residues.  相似文献   

18.
Microbial diversity might be a good indicator of ecosystem disturbance and functioning. We determined the effect of soil disturbances, such as N fertilization and tillage management, on soil microbial communities in a Typic Argiudoll of the El Salado river basin (Argentina). Microbial activity and substrate utilization provided a metabolic fingerprint of the soil microbial community. Univariate and multivariate analyses were used to differentiate responses to N fertilization and tillage at each of three growth stages of wheat (Triticum aestivum L.). Tillage had an adverse effect on microbial diversity, in which reduced and conventional tillage treated soils had different populations. However, N fertilization also altered microbial diversity depending on the crop developmental stage considered. Metabolism of carboxylic acids and carbohydrates were the main indicators of functional microbial activity and diversity. Although the substrate consumption profile of 32 C substrates did not provide insights into the fundamental ecological interactions that may induce changes in microbial population, it allowed us to demonstrate the alterations of microbial diversity as a result of tillage. We conclude that tillage and N fertilization altered microbial diversity.  相似文献   

19.
As glyphosate-resistant (GR) crops are becoming common in agro-ecosystems, their effects on non-target soil organisms need to be monitored. We evaluated soil microbial biomass C (MBC), bacterial functional diversity and community structure, and dehydrogenase enzyme activity in a field experiment conducted at six sites on the Canadian prairies. Treatments consisted of a factorial arrangement of three GR wheat and GR canola crop frequencies and two tillage systems. GR crop frequencies were arranged in 4-yr wheat-canola-wheat-pea rotations, with GR wheat and GR canola in zero of four, two of four, or three of four possible GR crop frequencies. The two tillage systems were either low soil-disturbance direct-seeding (LDS) or conventional tillage (CT). MBC increased with increasing frequency of GR crops in two of 20 site-years in the rhizosphere, and had no effects in bulk soil. Depending on tillage, GR crop frequency also affected the functional diversity of rhizosphere soil bacteria in only two of 20 site-years, and had no effects in bulk soil. Shifts in the structures of bacterial communities related to GR crop frequency were detected, but they were few and inconsistent. In three of 22 cases (10 in rhizosphere+12 in bulk soil), the activity of dehydrogenase enzyme decreased with increasing frequency GR crops in both the rhizosphere and bulk soil. In five of 20 site-years, soil MBC in the rhizosphere was greater under CT than under LDS, regardless of GR crop frequency. In bulk soil, tillage affected soil MBC in five site-years, three of which had greater MBC under CT than LDS, and vice versa in the other two. Tillage affected the functional diversity of soil bacteria in the rhizosphere in three site-years, but the effects were not consistent. Similar inconsistent tillage-related patterns were observed in the community structures of bacteria. There were no tillage effects on bacterial diversity in bulk soil. Dehydrogenase enzyme activity was greater under LDS than under CT in three of four cases in which tillage had significant effects. Overall, GR crop frequency effects on soil microorganisms were minor and inconsistent over a wide range of growing conditions and crop management.  相似文献   

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