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1.
陈利军  孙波  金辰  蒋瑀霁  陈玲 《土壤》2015,47(2):340-348
施用有机肥是快速培育瘠薄土壤的一个重要措施。针对中亚热带第四纪红黏土发育的红壤旱地,建立了玉米和花生单作系统等碳量投入有机肥和生物炭的田间试验,利用聚合酶链式反应—变性梯度凝胶电泳(polymerase chain reaction-denaturing gradient gel electrophoresis,PCR-DGGE)方法研究了土壤细菌和真菌群落组成和多样性的变化,分析了土壤呼吸速率(CO2通量)的变化及其与微生物多样性的关系。两年的试验表明,不同施肥方式导致微生物群落结构显著分异,施用有机肥和生物炭显著增加了细菌多样性,但施肥第二年真菌多样性有下降趋势。秸秆和猪粪配施显著增加了土壤呼吸速率,土壤呼吸速率与细菌和真菌多样性呈显著正相关,细菌多样性对土壤呼吸的影响(相对贡献率为71%)显著高于真菌(29%)。土壤磷素(全磷和速效磷)含量的变化是驱动红壤微生物多样性变化的主导因素,其对细菌和真菌多样性的相对贡献率分别为44.8%和47.4%。因此,合理配施秸秆和猪粪可以快速提高瘠薄红壤的生物功能。  相似文献   

2.
以大棚黄瓜根区土壤为研究对象,测定了不同施肥方式下温室黄瓜地土壤微生物3大类群和主要功能群组成及土壤微生物量碳(microbial biomass carbon,MBC),研究了温室中不同施肥方式对黄瓜根区土壤微生物组成及土壤MBC(土壤微生物生物量碳)的影响,探讨了微生物发酵有机肥对土壤肥力的影响。结果表明,土壤中细菌、真菌、放线菌数量由高到低的顺序依次为:发酵肥>发酵肥+50%化肥>常规施肥>普通有机肥>CK;土壤微生物综合指标Shannon-Wiener指数以生物发酵肥最高;氨化细菌、固氮菌及纤维素分解菌数量以生物发酵肥最高,硝化细菌数量以发酵肥+50%化肥处理最高;生物发酵肥和发酵肥+50%化肥两处理的MBC均显著高于常规施肥。施用微生物发酵有机肥可显著增加土壤微生物数量及微生物的群落多样性,并有助于提高土壤综合肥力。  相似文献   

3.
不同气候条件对旱地红壤微生物群落代谢特征的长期影响   总被引:4,自引:0,他引:4  
李云  孙波  李忠佩  车玉萍 《土壤》2011,43(1):60-66
利用1988年设置的暖温带和中亚热带两种气候条件下的土壤置换试验,采用BIOLOG方法,研究了气候条件对红壤中微生物群落功能的影响。结果表明,长期处于不同的气候条件改变了红壤的pH和养分状况,从而影响红壤微生物群落的代谢特征。与中亚热带气候条件相比,暖温带气候条件下,红壤的pH和全磷含量显著升高,速效钾含量显著下降;红壤微生物群落活性(以AWCD值表示)也显著降低。主成分分析表明,不同气候条件下红壤微生物群落代谢特征显著不同,与暖温带气候相比,中亚热带气候条件下,红壤微生物群落对氨基酸、胺类和酚类化合物等含氮化合物的利用显著增加。相关分析表明,影响不同气候条件下红壤微生物代谢特征的主要因素有:温度和降雨量气候因子,土壤pH、速效钾和全氮含量等土壤因子。  相似文献   

4.
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   

5.
不同施肥和耕作制度下土壤微生物多样性研究进展   总被引:15,自引:3,他引:15  
本文主要介绍了运用Biolog GN、磷脂脂肪酸(PLFA)、核酸分析法进行土壤微生物群落分析的优缺点,综述了施肥、耕作两种农业措施对土壤微生物多样性影响的研究进展。指出不同施肥处理对微生物影响效果不同,合理施用有机肥有利于维持土壤微生物的多样性及活性;由于受其他环境因素(如土壤类型、农作制度、残茬量等)的影响,不同耕作措施对土壤微生物多样性影响有差异,但是大多试验结果显示免耕、少耕能增加微生物多样性和生物量,保持系统的稳定性。文章还指出了目前研究中存在的问题,并对今后的研究方向做了展望。  相似文献   

6.
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   

7.
采用大田试验,探讨生物有机肥对秦巴山区核桃园土壤微生物群落结构及其代谢、 酶活性和土壤理化性质的影响。结果表明,施入生物有机肥可改变土壤微生物群落结构,改变微生物对各大类碳源的利用,提高微生物碳源利用率、物种多样性和丰富度,常规施肥对土壤微生物群落结构影响不显著。生物有机肥可显著提高土壤蔗糖酶、酸性磷酸酶和脱氢酶活性,但对过氧化氢酶的影响不显著;常规施肥可提高土壤脲酶和脱氢酶活性,对其他酶活性没有显著影响。生物有机肥可显著提高土壤有机质, 全量氮、磷、钾和速效磷含量,提高土壤pH值,使土壤理化性质得到改善;常规施肥也可在一定程度上提高土壤养分含量,但其效果不如生物有机肥。  相似文献   

8.
长期不同施肥条件下红壤性水稻土微生物群落结构的变化   总被引:10,自引:2,他引:10  
以位于江西省红壤研究所内长期定位试验的水稻土(始于1981年)为研究对象,运用磷脂脂肪酸(phospholipid fatty acid,PLFA)和BIOLOG分析技术研究了不施肥(CK)、单施化肥(NPK)及有机肥与化肥混施(NPKM)三种施肥方式对土壤微生物群落结构的影响。结果表明:长期施化肥和有机肥与化肥混施处理的PLFA总量均高于未施肥处理,两者分别较未施肥处理高91%和309%;PLFA主成分分析(PCA)显示施肥促进了土壤微生物群落结构的变化,其中NPKM处理增加了革兰氏阴性细菌(G-细菌)、真菌、放线菌和原生动物的数量,NPK处理增加了革兰氏阳性细菌(G+细菌)的数量,不施肥处理较施肥处理提高了真菌/细菌比例,CK和NPK处理的微生物群落结构更为相似;各施肥处理间土壤的AWCD值(平均每孔颜色变化率,average well color development,AWCD)表明,NPKM处理能够促进土壤微生物群落对碳源的利用能力,进而增加土壤中微生物的整体活性,而NPK处理减弱了土壤微生物的活性。代谢功能多样性分析同时表明,NPKM处理增加了微生物群落的多样性,而NPK处理使土壤微生物的多样性降低;土壤PLFA与土壤养分的相关性分析显示,土壤总PLFA量与土壤有机质和全氮呈极显著相关(p0.01),与速效养分相关性不大。  相似文献   

9.
保护性耕作对黑土微生物群落的影响   总被引:9,自引:2,他引:7  
耕作方式通过影响土壤微生物群落而影响土壤生态系统过程。本研究以传统耕作玉米连作处理为对照,通过测定土壤微生物量碳及磷脂脂肪酸含量,分析了保护性耕作(包括免耕玉米连作和免耕大豆-玉米轮作)对黑土微生物群落的影响。结果表明,保护性耕作可显著增加土壤表层(0~5cm)全碳、全氮、水溶性有机碳、碱解氮和微生物量碳(P0.05),为微生物代谢提供了丰富的资源。同时,保护性耕作显著提高了土壤表层(0~5cm)总脂肪酸量、真菌和细菌生物量(P0.05),提高了土壤的真菌/细菌值,有利于农田土壤生态系统的稳定性。研究结果对于探讨保护性耕作的内在机制具有重要意义。  相似文献   

10.
土壤微生物生物地理学:国内进展与国际前沿   总被引:8,自引:2,他引:8  
土壤微生物生物地理学是研究土壤中微生物空间分布格局及其随时间变化的一门科学,是土壤微生物学和微生物生态学等领域的研究前沿。近年来,尽管土壤微生物生物地理学研究取得了巨大进展,目前仍面临诸多难题与挑战。本文简要回顾了土壤微生物生物地理学的发展历程,重点介绍近年来我国在森林、草地和农田生态系统中土壤微生物生物地理学研究的主要进展。同时进一步阐述了目前土壤微生物生物地理学研究的国际前沿方向,包括微生物群落空间分布及其驱动机制、群落构建过程与共存网络、微生物地理分布与生态系统功能的关联以及预测微生物群落对全球变化的响应。最后,对土壤微生物生物地理学未来的研究方向进行了展望,强调了清晰的微生物物种定义、微生物群落的时间动态、多组学与合成生物学技术以及高精度的预测模型在土壤微生物生物地理学研究中的重要性。  相似文献   

11.
The combination of high input costs and low commodity prices is forcing some farmers to consider reducing crop inputs like seed, fertilizer and herbicides. In a field trial in which different canola (Brassica napus L.) and barley (Hordeum vulgare L.) inputs were subtracted from a full package, or added to an empty package, we studied the effects of full or reduced fertilizer and herbicide inputs on soil microbiological characteristics at two sites from 2005 to 2008. The full package consisted of a high-yielding crop variety seeded at an optimum rate, with fertilizers and herbicides applied at recommended rates. The empty package consisted of a less expensive, low-yielding crop variety seeded at a low rate, with no fertilizer or herbicide applied. Between these two extremes were treatments in which fertilizers or herbicides were applied at 50% of recommended rates or not at all. Each treatment was repeated year after year in the same plot, i.e., treatment effects were cumulative. Fertilizer effects on soil microbial biomass C (MBC), β-glucosidase enzyme activity and bacterial functional diversity (based on community-level physiological profiles) were usually positive. Reduced fertilizer application rates reduced the beneficial fertilizer effects. Significant herbicide effects on soil microbiological properties occurred less often, were smaller in magnitude than fertilizer effects, and were mostly negative. Reduced herbicide rates reduced the deleterious herbicide effects. These significant fertilizer and herbicide effects were observed in canola more than barley, and mostly in the final year of the study, indicating the cumulative nature of treatment effects over time. Therefore, repeated applications of agricultural inputs like fertilizers and herbicides can have more significant effects on soil biology and biological processes than single applications indicate.  相似文献   

12.
Microbial biomass, microbial respiration, metabolic quotient (qCO2), Cmic/Corg ratio and nutrient status of the microflora was investigated in different layers of an aspen (Populus tremuloides Michx.) and pine forest (Pinus contorta Loud.) in southwest Alberta, Canada. Changes in these parameters with soil depth were assumed to reflect successional changes in aging litter materials. The microbial nutrient status was investigated by analysing the respiratory response of glucose and nutrient (N and P) supplemented microorganisms. A strong decline in qCO2 with soil depth indicated a more efficient C use by microorganisms in later stages of decay in both forests. Cmic/Corg ratio also declined in the aspen forest with soil depth but in the pine forest it was at a maximum in the mineral soil layer. Microbial nutrient status in aspen leaf litter and pine needle litter indicated N limitation or high N demand, but changes in microbial nutrient status with soil depth differed strongly between both forests. In the aspen forest N deficiency appeared to decline in later stages of decay whereas P deficiency increased. In contrast, in the pine forest microbial growth was restricted mainly by N availability in each of the layers. Analysis of the respiratory response of CNP-supplemented microorganisms indicated that growth ability of microorganisms is related to the fungal-bacterial ratio.  相似文献   

13.
以1989年建立的中国科学院封丘农田生态系统国家试验站的长期定位试验为平台,研究经18a连续不同施肥处理后玉米季土壤微生物生物量碳氮和微生物活度的动态变化及其与土壤有机碳之间的相互关系,并探讨施肥措施对土壤微生物及其活性的影响。施肥处理包括:(1)有机肥(OM);(2)1/2化肥和1/2有机肥(1/2OM+1/2NPK);(3)氮磷钾肥(NPK);(4)氮磷肥(NP);(5)磷钾肥(PK);(6)氮钾肥(NK);(7)不施肥,即对照(CK)7个处理。结果表明,微生物生物量碳氮和微生物活度在玉米生长期内均有明显的时间变异性,其中微生物生物量碳与微生物活度的动态变化比较一致,其间的极显著相关关系表明潮土微生物生物量碳的变化可以在很大程度上代表土壤微生物活度的变化。施肥制度显著影响微生物生物量碳氮和微生物活度的变化,总体趋势为OM1/2OM+1/2NPKNPKNPPKNKCK,表明OM有利于保持土壤的生物化学环境及促进土壤的生物学活性;与OM处理相比,化学肥料的长期施用有降低土壤微生物生物量和微生物活度的趋势,尤其是缺素处理的表现更为明显,其中以缺磷处理的表现最为严重。土壤微生物生物量碳氮、微生物活度与土壤有机碳变化均呈极显著正相关。  相似文献   

14.
乔洁  毕利东  张卫建  沈仁芳  张斌  胡锋  刘艳丽 《土壤》2007,39(5):772-776
利用化肥长期定位试验,研究了施肥对土壤微生物生物量、活性及其群落结构的影响.结果表明:与不施肥相比,长期施用化肥不仅增加了土壤微生物生物量,而且导致了土壤微生物群落结构的分异.其中,有机无机配施处理和2倍NPK配施处理显著提高了土壤有机质含量、全N含量、土壤微生物生物量和土壤微生物活性.NPK均衡施肥处理对土壤有机质、土壤微生物生物量及其活性的影响小于非均衡施肥的处理(NP、NK、N、P、K),适当增施K肥有利于提高土壤微生物中真菌的比例.  相似文献   

15.
不同类型水稻土微生物群落结构特征及其影响因素   总被引:4,自引:1,他引:4  
选取基于我国土壤地理发生分类的不同类型土壤发育的四种水稻土,利用15N2气体示踪法测定生物固氮速率,采用实时荧光定量PCR(Real-time PCR)技术测定细菌丰度,通过16S rRNA基因高通量测序分析微生物群落组成和多样性。结果表明:变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、绿弯菌门(Chloroflexi)和蓝藻门(Cyanobacteria)是水稻土中优势微生物类群。四种类型土壤发育的水稻土细菌群落结构差异显著(Stress<0.001),群落结构分异(NMDS1)与土壤pH存在极显著正相关关系(P<0.01)。土壤有机碳和碱解氮含量显著影响水稻土中细菌丰度和群落多样性(P<0.01)。红壤发育的水稻土细菌16S rRNA基因拷贝数显著高于其他三种类型水稻土,但OTU数量、Chao1指数和PD指数均低于其他三种类型水稻土。土壤pH对水稻土生物固氮速率有显著影响(P<0.01),紫色土发育的水稻土具有最高的生物固氮速率(3.2±0.7 mg×kg-1×d-1),其中优势类群细鞘丝藻属(Leptolyngbya)可能是生物固氮的主要贡献者。研究结果丰富了对水稻土微生物多样性的认识,为通过调控土壤pH和微生物群落组成来提高稻田生物固氮潜力提供了理论依据。  相似文献   

16.
城市与郊区森林土壤微生物群落特征差异研究   总被引:1,自引:0,他引:1  
陈帅  王效科  逯非 《土壤通报》2012,(3):614-620
森林是具有重要服务功能的生态系统之一,在城区和郊区都普遍存在,但对于森林土壤微生物群落特征的城郊差异研究却很少。本研究在北京城市与郊区选择三种相同树种(油松Pinus tabulaeformis、侧柏Platycladus orientalis和毛白杨Populus tomentosa)的森林,主要研究比较了土壤微生物量碳、微生物群落结构和功能多样性的城郊差异。结果表明,郊区森林的土壤微生物量碳含量显著高于城区(郊区微生物量碳为367.29 mg kg-1,城区为294.23 mg kg-1)。同一树种下郊区微生物活性高于城区,差异未达到显著。微生物多样性和均匀度城郊差异不明显;但树种间存在一定的差异,城区毛白杨林下土壤微生物群落的均匀度显著低于柏树与油松,多样性指数显著低于柏树。结果表明城市化过程对城市土壤微生物量以及微生物群落的结构和功能有一定影响,且不同树种对于这种影响存在差异。随着城市化加快,城乡梯度上土壤微生物量碳的城乡差异明显,而土壤微生物群落结构、功能的差异有减小的趋势。  相似文献   

17.
The response of the soil microbial biomass to seasonal changes was investigated in the field under pastures. These studies showed that over a 9-month period, microbial biomass carbon, phosphorus and sulphur (biomass C, P, S), and their ratios (C:P, C:S, and P:S) responded differently to changes in soil moisture and to the input of fresh organic materials. From October to December (1993), when plant residues were largely incorporated into the soils, biomass C and S increased by 150–210%. Biomass P did not increase over this time, having decreased by 22–64% over the dry summer (July to September). There was no obvious correlation between biomass C, P, and S and air temperature. The largest amounts of biomass C and P (2100–2300μg and 150–190μgg–1 soil, respectively) were found in those soils receiving farmyard manure (FYM or FYM+NPK) and P fertilizer, whereas the use of ammonium sulphate decreased biomass C and P. The C:P, C:S, and P:S ratios of the biomass varied considerably (9–276:1; 50–149:1; and 0.3–14:1, respectively) with season and fertilizer regime. This reflected the potential for the biomass to release (when ratios were narrow) or to immobilize (wide ratios) P and S at different times of the year. Thus, seasonal responses in biomass C, P, and S are important in controlling the cycling of C, P, and S in pasture and ultimately in regulating plant availability of P and S. The uptake of P in the pasture was well correlated with the sum of P in the biomass and soil available pools. Thus, the simultaneous measurement of microbial biomass P and available P provide useful information on the potential plant availability of P. Received: 25 May 1996  相似文献   

18.
Here we studied the effects of gut transit through the earthworm Eudrilus eugeniae, on the physicochemical, biochemical, and microbial characteristics of pig slurry, by analyzing fresh casts. The reduction in the dissolved organic C contents in casts we recorded suggests that during digestion, earthworms assimilated labile organic C preferentially, which is a limiting growth factor for them. Furthermore, both microbial biomass and activity in pig slurry were significantly decreased by earthworm gut transit. It appears that E. eugeniae is able to digest microorganisms, although the addition of glucose to the food increased respiration, indicating that growth of microorganisms in casts could be limited by depletion of labile C. Despite reduced microbial biomass and activity, the metabolic diversity of microbial communities was greater in casts than in original pig slurry. Community level physiological profiles obtained from Biolog Ecoplate data revealed that, after earthworm gut transit, the microbial communities in casts and pig slurry were clearly differentiated by their physiological profiles. The results indicate that first stage in vermicomposting of pig slurry by E. eugeniae, i.e., casting, produced changes that will influence the dynamics of the organic matter degradation by reducing forms of N and C available to microorganisms, hence restricting their growth and multiplication. Nevertheless, the reduced microflora of casts was characterized by an increased catabolic potential that might lead to thorough degradation of pig slurry.  相似文献   

19.
The present study was conducted to determine the spatial heterogeneity of bulk density, soil moisture, inorganic N, microbial biomass C, and microbial biomass N in the ridge tillage system of Turiel compared to conventional mouldboard ploughing on three sampling dates in May, July, and August. The soil sampling was carried out under vegetation representing the ridge in a high spatial resolution down the soil profile. Bulk density increased with depth and ranged from 1.3 g cm−3 at 10 cm depth to 1.6 g cm−3 at 35 cm in ploughed plots and from 1.0 g m−3 at 5 cm to 1.4 g m−3 at 35 cm in the ridges. In the ploughed plots, the contents of microbial biomass C and microbial biomass N remained roughly constant at 215 and 33 μg g−1 soil, respectively, throughout the experimental period. The microbial biomass C/N ratio varied in a small range around 6.4. In the ridged plots, the contents of microbial biomass C and microbial biomass N were 5% and 6% higher compared to the ploughed plots. Highest microbial biomass C contents of roughly 300 μg g−1 soil were always measured in the crowns in July. The lowest contents of microbial biomass C of 85–137 μg g−1 soil were measured in the furrows. The ridges showed strong spatial heterogeneity in bulk density, soil water content, inorganic nitrogen and microbial biomass.  相似文献   

20.
In a mesocosm experiment, we studied decomposition rates as CO2 efflux and changes in plant mass, nutrient accumulation and soil pools of nitrogen (N) and phosphorus (P), in soils from a sub-arctic heath. The soil was incubated at 10 °C and 12 °C, with or without leaf litter and with or without plants present. The purpose of the experiment was to analyse decomposition and nutrient transformations under simulated, realistic conditions in a future warmer Arctic.Both temperature enhancement and litter addition increased respiration rates. Temperature enhancement and surprisingly also litter addition decreased microbial biomass carbon (C) content, resulting in a pronounced increase of specific respiration. Microbial P content increased progressively with temperature enhancement and litter addition, concomitant with increasing P mineralisation, whereas microbial N increased only in the litter treatment, at the same time as net N mineralisation decreased. In contrast, microbial biomass N decreased as temperature increased, resulting in a high mobilisation of inorganic N.Plant responses were closely coupled to the balance of microbial mineralisation and immobilisation. Plant growth and N accumulation was low after litter addition because of high N immobilisation in microbes and low net mineralisation, resulting in plant N limitation. Growth increased in the temperature-enhanced treatments, but was eventually limited by low supply of P, reflected in a low plant P concentration and high N-to-P ratio. Hence, the different microbial responses caused plant N limitation after litter addition and P limitation after temperature enhancement. Although microbial processes determined the main responses in plants, the plants themselves influenced nutrient turnover. With plants present, P mobilisation to the plant plus soil inorganic pools increased significantly, and N mobilisation non-significantly, when litter was added. This was presumably due to increased mineralisation in the rhizosphere, or because the nutrients in addition to being immobilised by microbes also could be absorbed by plants. This suggests that the common method of measuring nutrient mineralisation in soils incubated without plants may underestimate the rates of nutrient mobilisation, which probably contributes to a commonly observed discrepancy of measured lower rates of net nutrient mineralisation than uptake rates in arctic soils.  相似文献   

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