共查询到19条相似文献,搜索用时 125 毫秒
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根结线虫接种对黄瓜植株根际土壤pH和微生物的影响 总被引:4,自引:1,他引:4
通过人工接种不同数量的根结线虫卵,测定了黄瓜植株根际土壤的pH和微生物数量。结果表明,随接种数量的增加,根际土壤好气性细菌数量、厌气性细菌数量、细菌总数及细菌/真菌(B/F)逐渐降低;真菌数量却逐渐升高;放线菌数量在接种量为2000个·株-1时显著升高,之后随着接种量的增加逐渐降低;放线菌/真菌(A/F)在接种量为2000个·株-1时略有升高,之后随着接种量的增加逐渐降低。接种根结线虫后,黄瓜植株根际土壤中好气性细菌数量和B/F值与pH呈显著正相关,厌气性细菌数量、细菌总数、放线菌数量以及A/F值与pH呈极显著正相关,真菌数量与pH呈显著负相关。根结线虫侵染黄瓜植株导致根际土壤发生"真菌化",显示土壤质量下降。 相似文献
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试验研究培肥方式对松嫩平原黑土生态系统中与N素转化有关的土壤微生物(好气性自生固氮菌、氨化细菌、亚硝酸盐细菌和反硝化细菌)数量的影响,结果表明:单独施入农肥可提高土壤好气性自生固氮菌、氨化细菌及反硝化细菌数量;化肥单独施用可降低土壤好气性自生固氮菌数量,提高反硝化细菌数量;农肥化肥等量配比施入土壤好气性自生固氮菌、亚硝酸盐细菌及反硝化细菌数量均增加。 相似文献
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本研究采用Gus 基因标记技术和常规方法跟踪考察了恶臭假单胞菌P861(Gus) 在缩影系统油菜根圈的定殖情况,以及缩影系统内土壤类型、土壤含水量对根部定殖的影响。土壤含水量分别为60% FC和75% FC时,P861(Gus) 在砂姜黑土中的定殖水平高于50% FC的,不但能散布至种子下8cm 以内的根段部位,且定殖水平分别为7.5102和2.8103cfug-1。在灰潮土缩影中,P861(Gus) 在油菜根圈的定殖动态表现为在油菜播种后3 ~6 天,定殖密度可达最高水平(5.5106cfug-1) ,然后急速下降,最后保持在一个相对稳定的较低水平(7.6102cfug-1) 。P861(Gus) 在不同根段部位的定殖密度并无从上到下逐渐递减的规律。 相似文献
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“旋松一体”耕作对潮土和砂姜黑土物理性质及作物生长的影响 总被引:1,自引:0,他引:1
为改善潮土和砂姜黑土容重大,穿透阻力强,犁底层紧实等结构障碍。研究提出一种“旋松一体”耕作方式,并在山东德州的典型潮土和安徽怀远的典型砂姜黑土进行试验。其中,潮土设置旋耕15 cm、旋松一体30 cm两个处理;砂姜黑土设置旋耕15 cm、深翻30 cm和旋松一体30 cm三个处理,研究旋松一体耕作对两种土壤0 ~ 40 cm土层土壤容重、紧实度、水分动态和小麦玉米根系及产量生长的影响。结果表明:与旋耕相比,旋松一体耕作显著降低了潮土和砂姜黑土容重和穿透阻力,与深翻相比,旋松一体耕作也显著降低了砂姜黑土容重和穿透阻力。旋松一体耕作显著提高了降水后土壤水分下渗速度、下渗量及下渗深度,进而提高潮土深层,砂姜黑土小麦季表层及玉米季深层土壤体积含水量。与旋耕相比,旋松一体耕作分别增加潮土和砂姜黑土小麦产量11.4%和7.1%,玉米产量6.7%和37%(受涝害胁迫),提高直接经济收益1748和3277元hm?2。旋松一体耕作有效改善了潮土和砂姜黑土物理性质,提高作物产量和经济效益显著,可作为华北平原土壤耕层结构改良的新型耕作模式。 相似文献
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黄褐土、潮土中不同氮素形态配比对烤烟根际土壤微生物数量的影响 总被引:10,自引:0,他引:10
试验采用盆栽控雨栽培和根网袋的方法 ,在两种土壤类型上初步研究了不同氮素形态配比与芝麻饼肥互作对烤烟不同生育时期根际土壤微生物数量的影响。结果表明 :在黄褐土中 ,当施入 40 %饼肥、NO-3 ∶NH+ 4为 1∶1时 ,土壤中真菌、氨化细菌和好气性纤维素分解菌数量最多 ,促进根系的生长发育。在潮土中 ,当施入 40 %饼肥、NO-3 :NH+ 4为 3∶1时 ,土壤中好气性纤维素分解菌、氨化细菌在移栽后 3 8天迅速上升 ,促进了根系对氮素的吸收利用 相似文献
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碳酸氢铵和尿素在山东省主要土壤类型上的氨挥发特性研究 总被引:11,自引:1,他引:11
采用全程密闭通气法研究了山东省四种主要土壤类型 (棕壤 ,褐土 ,潮土和砂姜黑土 ) ,尿素和碳酸氢铵表施后的氨挥发特点。结果表明 :碳酸氢铵初始的氨挥发强度大于尿素 ,而氨挥发总量小于尿素 ,尿素在四种类型土壤上铵挥发强度次序为 :褐土 >潮土≈砂姜黑 >棕壤 ,氨挥发总量次序为 :褐土 >潮土≈砂姜黑土 >棕壤 ;碳酸氨氢在四种类型土壤上氨挥发强度次序为 :褐土 >潮土≈砂姜黑土 >棕壤 ,挥发总量次序为 :褐土 >棕壤 >潮土≈砂姜黑土。影响氨挥发的因素主要有 :氮素形态 ,土壤 pH、CEC、粘粒含量和粘土矿物类型、有机质含量等 ,但在不同土壤中其影响的主导因素又有较大差异。 相似文献
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大田条件下,以砂姜黑土和棕壤为对象,研究了花生生育期内土壤主要肥力指标变化特点及相互关系,结果表明:不同土壤类型旱地花生生育期内土壤碱解氮、速效磷和速效钾含量呈逐渐降低趋势,生育中期下降速率明显高于生育前期和后期,与花生对主要营养元素吸收速率一致;土壤微生物数量(细菌、放线菌和真菌)、土壤呼吸速率及主要土壤酶(脲酶、蔗糖酶、酸性磷酸酶和过氧化氢酶)活性随生育进程的推进呈单峰曲线,高峰期多数出现在结荚中期.砂姜黑土细菌、放线菌及3种主要酶活性高于棕壤,真菌数量棕壤高于砂姜黑土;生育后期,棕壤碱解氮含量、速效钾含量、细菌和放线菌数量以及脲酶、蔗糖酶和过氧化氢酶活性下降速率高于砂姜黑土,速效磷含量和酸性磷酸酶活性两种土壤下降速率相近.因此,生育后期肥力下降较快,可能是棕壤花生易发生早衰的主要原因.土壤主要肥力指标间多数呈显著或极显著正相关关系,但不同土壤类型指标间相关性存在一定差异. 相似文献
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安徽省土壤有效硫现状及时空分布 总被引:1,自引:1,他引:1
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有机质含量对石灰性黄潮土和砂姜黑土磷吸附–解吸特性的影响 总被引:9,自引:4,他引:5
通过往土壤中添加不同量小麦秸秆,经好气培养1年后,获得不同有机质含量梯度的系列土壤,研究有机质含量对石灰性黄潮土和砂姜黑土磷(P)相关吸附参数和不同水土比下解吸溶液P浓度的影响。结果表明,Langmuir方程能够较好地拟合不同有机质含量的两种土壤对P的等温吸附曲线,拟合度均达到显著(P 0.05)或极显著(P 0.01)水平。黄潮土和砂姜黑土P最大吸附量(Xm)、吸附结合能常数(K)、最大缓冲容量(MBC)、吸附饱和度(DPS)及相同水土比下P解吸溶液浓度与有机碳含量间均呈显著或极显著的二次抛物线关系。抛物线拐点之前,随有机质含量的提高,P的吸附能力增强,解吸能力降低;拐点之后,吸附能力降低,解吸能力增强。各水土比条件下,P解吸溶液浓度与Xm、K、MBC呈显著或极显著负相关,与DPS呈显著或极显著正相关。随有机质含量的提高,土壤P植物有效性和P流失风险呈先降低后增强的抛物线趋势;土壤供P缓冲能力则先增强后降低。砂姜黑土Xm、K、MBC均明显高于黄潮土,DPS明显低于黄潮土;且其抛物线拐点滞后,拐点横坐标有机碳含量明显高于黄潮土。不同有机质含量的解吸曲线较黄潮土排列紧密;砂姜黑土黏粒含量、碳酸钙含量明显高于黄潮土,全P和Olsen-P含量明显低于黄潮土,这可能是影响两种石灰性土壤P吸附–解吸特性差别的主要原因。 相似文献
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河南省潮土、砂姜黑土基本性质变化分析 总被引:2,自引:0,他引:2
通过对河南省潮土、砂姜黑土的室外采集与室内测定,对其基本性质的时空变化进行研究。结果表明:1潮土和砂姜黑土表层质地均以粉砂壤土为主,潮土颗粒大小级别以壤质为主,砂姜黑土颗粒大小级别以细壤质为主;21979—2012年,潮土表层p H平均值由8.3降为8.2,砂姜黑土表层p H平均值由7.8降为6.9,有机质、全氮平均含量均随时间变化上升,CEC均随时间变化而降低;砂姜黑土速效钾平均含量增加了51.3 mg/kg,潮土速效钾平均含量降低了21.2 mg/kg;潮土、砂姜黑土有效磷平均值分别由5.8 mg/kg和4.8 mg/kg上升至27.9 mg/kg和33.6 mg/kg,变化幅度较大,且变异系数较高,都达70%以上;3潮土、砂姜黑土不同地区及不同剖面层次的基本性质均存在较为明显的空间变化。 相似文献
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Ming Nie Jin-qing Wang Ji Yang Xin-hong Cui Bo Li 《Soil biology & biochemistry》2009,41(12):2535-2542
In this study, we compared the differences of bacterial abundance and diversity between rhizosphere and surrounding bulk soils under soil salinization and petroleum contamination in the Yellow River Delta on a 110-km-distance scale. In comparison with bulk soils, rhizosphere soils were mainly characterized by lower salinity and higher water content in saline soils. For bacterial abundance, the numbers of total bacteria and hydrocarbon degraders were significantly higher in rhizosphere soils than those in bulk soils. Although there was no significant difference in total petroleum hydrocarbon (TPH) concentration between the two types of soils, TPH had distinctly different effects on bacterial abundance in rhizosphere and bulk soils. TPH concentration was the major determinant of total bacterial abundance and had positive effects on abundances of hydrocarbon degraders. However, the abundances of total bacteria and hydrocarbon degraders in bulk soils were primarily determined by soil salinity and water content. Great abundance of rhizosphere bacteria suggested that plant roots could alleviate the stresses from soil salinization and provide more favorable microhabitats for bacterial growth. TPH had positive effects on bacterial diversity of both rhizosphere and bulk soils. Our results support the view that petroleum in the environments functions as both toxic chemicals and carbon sources to soil bacteria. Great abundance and diversity of total bacteria in plant rhizospheres would potentially improve the roles of bacteria in maintaining ecosystem functioning in the degraded ecosystems. Our results would improve our understanding of the relationships between rhizosphere effects and multiple environmental stresses that control the development of bacterial community in fragile anthropologically-affected ecosystems. 相似文献
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Amanda J. Bennett Sally Hilton Gary D. Bending David Chandler Peter Mills 《Biology and Fertility of Soils》2014,50(8):1267-1279
Glasshouse bioassays were conducted to assess the impact of different inputs of oilseed rape plant material on soil and rhizosphere microbial diversity associated with subsequently grown oilseed rape (Brassica napus) plants. The first bioassay focussed on the effect of oilseed rape rhizodeposits and fresh detached root material on microbial communities, in a rapid-cycling experiment in which oilseed rape plants were grown successively in pots of field soil for 4 weeks at a time, with six cycles of repeated vegetative planting in the same pot. Molecular analyses of the microbial communities after each cycle showed that the obligate parasite Olpidium brassicae infected the roots of oilseed rape within 4 weeks after the first planting (irrespective of the influence of rhizodeposits alone or in the presence of fresh detached root material), and consistently dominated the rhizosphere fungal community, ranging in relative abundance from 43 to 88 % when oilseed rape was grown more than once in the same soil. Fresh detached root material also led to a reduction in diversity within the soil fungal community, due to the increased relative abundance of O. brassicae. In addition, rhizosphere bacterial communities were found to have a reduced diversity over time when fresh root material was retained in the soil. In the second glasshouse experiment, the effect of incorporating mature, field-derived oilseed rape crop residues (shoots and root material) on microbial communities associated with subsequently grown oilseed rape was investigated. As before, molecular analyses revealed that O. brassicae dominated the rhizosphere fungal community, despite not being prevalent in either the residue material or soil fungal communities. 相似文献
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施肥及秸秆还田对砂姜黑土细菌群落的影响 总被引:18,自引:1,他引:18
利用Illumina平台Miseq高通量测序技术对小麦分蘖期砂姜黑土耕层土壤细菌进行高通量测序,结合相关生物信息学分析,探讨了不施化肥秸秆不还田(CK)、施化肥秸秆不还田(F)以及不施化肥秸秆还田(W)3种处理土壤细菌群落组成、多样性和结构的变化。结果显示,测序共获得14 873个OTUs,计173 323条读数,平均读长439 bp。砂姜黑土细菌优势门(相对丰度10%)为变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、放线菌门(Actinobacteria)和拟杆菌门(Bacteroidetes);优势纲(相对丰度10%)为α-变形菌纲(Alphaproteobacteria)、β-变形菌纲(Betaproteobacteria)、酸杆菌纲(Acidobacteria)、鞘脂杆菌纲(Sphingobacteriia)和γ-变形菌纲(Gammaproteobacteria);优势属(相对丰度1%)共47个,3个处理中均有分布的优势属21个,F处理的细菌优势属的种类最多,为39个。相对丰度最大的门、纲和属分别是变形菌门(38.7%~43.1%)、α-变形菌纲(14.5%~18.1%)和鞘氨醇单胞菌属(Sphingomonas)(4.6%~7.7%)。F处理细菌丰富度指数(Chao1指数和ACE指数)显著低于CK及W处理,W处理和CK处理土壤细菌丰富度指数无显著差异,与CK处理相比,F处理ACE指数降低22.8%。W处理土壤细菌Shannon多样性指数显著大于CK及F处理,W处理Shannon指数较CK处理提高4.1%,而F处理土壤细菌Shannon指数与CK处理无显著差异。F处理Simpson指数显著高于CK及W处理;F处理Simpson指数较CK处理提高38.1%,而W处理细菌Simpson指数最小,显著低于CK处理,较CK降低23.8%。分层聚类图显示在属的水平上,W处理和CK处理土壤细菌群落结构相似性较高,F处理与CK处理及W处理细菌群落结构差异较大。施化肥对土壤细菌优势类群组成、相对丰度及群落结构的影响大于秸秆还田,施化肥显著降低了土壤细菌丰富度,秸秆还田显著提高了土壤细菌的多样性。 相似文献
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Chunling Chang Wen Chen Shasha Luo Lina Ma Xiujun Li 《Archives of Agronomy and Soil Science》2019,65(1):74-87
Soil microbial community composition is determined by the soil type and the plant species. By sequencing the V3-V4 region of the bacterial 16S rRNA gene amplicons, the current study assessed the bacterial community assemblage in rhizosphere and bulks soils of wild (Glycine soja) and cultivated (Glycine max) soybeans grown in the suspensions of three important soil types in China, including black, red and soda-saline-alkali soils. The alpha-diversity of the bacterial community in the rhizosphere was significantly higher than that of the bulk soils suggesting that bulk soil lacks plant nurturing effect under the current study conditions. Black and red soils were enriched with nitrifying and nitrogen-fixing bacteria but the soda-saline-alkali soil suspension had more denitrifying bacteria, which may reflect agronomic unsuitability of the latter. We also observed a high abundance of Bradyrhizobium and Pseudomonas, enriched cellulolytic bacteria, as well as a highly connected molecular ecological network in the G. soja rhizosphere soil. Taken all, the current study suggest that wild soybeans may have evolved to recruit beneficial microbes in its rhizosphere that can promote nutrients requisition, biostasis and disease-resistance, therefore ecologically more resilient than cultivated soybeans. 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(19-20):1675-1682
Abstract Microbial parameters of rhizosphere soil, such as bacterial numbers or microbial activities, depend on the distance that microbes have to the root surface. In this study we show that the number of bacteria found in rhizosphere soil from white clover is highly correlated with root length density of the rhizosphere soil. In contrast, bacterial numbers, microbial activity (measured as fluorescein diacetate hydrolytic activity), and the amount of extractable carbon (C) in the rhizosphere of perennial ryegrass were independent of the amount of soil recovered from the roots. The missing rhizosphere effect in perennial ryegrass soils can be explained by the high rooting density of ryegrass, whereas the low rooting density of white clover results in gradients of microbial numbers and activities in soils. Results of these studies indicate that it is important to express microbial parameters on root length and soil weight bases, especially for less densely rooted soils. 相似文献