土壤微生物多样性研究的新进展

土壤微生物是土壤生态系统的一个重要组成部分,在维持整个土壤生态系统能量流动和物质循环中发挥着关键作用,同时,土壤微生物多样性影响土壤生态系统的结构、功能和过程。因此,对土壤微生物多样性的研究有着重大意义。本文从土壤微生物多样性的影响因素以及目前该领域研究所采用的研究方法等方面阐述了国内外土壤微生物多样性的研究现状,同时对各种研究方法的适用范围、优缺点等作了较为详细的分析、比较,并对该领域未来研究工作的重点方面作了展望。     

咪唑乙烟酸对土壤微生物生态的影响

通过实验室培养研究了除草剂咪唑乙烟酸对土壤微生物生物量和群落结构的影响.结果表明:咪唑乙烟酸在土壤中的降解动态符合一级动力学方程,而且原药比制剂降解的更快,半衰期更短.除草剂咪唑乙烟酸显著增加了土壤微生物的生物量碳和总的磷脂脂肪酸(PLFA)含量,而且原药的增加作用更加显著.原药显著提高了土壤微生物的GN/GP值和压力指数(Stress level);原药和制剂显著降低了微生物的真菌/细菌值和多样性指数(Shannon指数).除草剂咪唑乙炯酸显著影响了土壤微生物的群落结构,而且原药比制剂的影响更加显著.     

矿区复垦土壤微生物群落和功能多样性分析

采用复合基质和丛枝菌根真菌对矿区土壤进行九个月的复垦。为评估复垦效果,利用Biolog方法分析不同复垦时期土壤微生物群落和功能多样性。借助SPSS17．0等软件进行分析,发现微生物群落各项指标在不同复垦阶段的变化明显;对比复垦稳定土和校园绿地土可知,土壤微生物活性及群落功能多样性得到显著改善,并恢复至正常水平。究其原因,是复垦基质中添加30％的污泥以及接种丛植菌根真菌。     

有机质对果园土壤质量影响的研究

简要综述了土壤活性有机质及其应用的研究进展,包括活性有机质的概念及其测定方法、活性有机质与土壤养分供应、土壤理化性质的关系及其活性有机质在反映土壤肥力综合评价土壤质量等方面的应用。在此基础上,通过对果园土壤活性有机质含量测定,研究了其对果园土壤以及果实的影响,提出了固本培源,因地制宜增加果园土壤活性有机质的对策。     

多粘类芽孢杆菌在黄瓜叶面和土壤中定殖能力及其对土壤微生物的影响

研究了康地蕾得有效成分多粘类芽孢杆菌在黄瓜叶面和土壤中的定殖情况及其对土壤微生物的影响。结果表明：在田间条件下,多粘类芽孢杆菌在黄瓜叶片上的定殖菌量为0．9×10^6～2．3×10^6cfu／g鲜叶,在土壤中的定殖菌量为0．8×10^7～1．6×10^7cfu／g土;施用该药剂30d后,仅使土壤中细菌菌数有明显增加,对真菌、放线菌无明显影响。     

增值尿素的氨挥发特征及其对土壤微生物量碳和脲酶活性的影响

通过向普通尿素中添加风化煤粉、腐植酸钾和脱盐液,利用熔融造粒工艺制备出普通尿素（U）、风化煤尿素（F U）、腐植酸尿素（H A U）、脱盐液尿素（T U）3个增值尿素试验产品,在25℃条件下,进行土壤培养试验,研究了增值尿素的氨挥发特征及其对土壤微生物量碳、脲酶活性的影响。结果表明,与普通尿素相比,各增值尿素氨挥发累积量降低29.52%～39.78%,延迟了氨挥发的峰值;各增值尿素处理,在培养的前7天内土壤的脲酶活性降低,延缓了尿素态氮在土壤的转化速率;延缓了土壤微生物量碳峰值出现时间;风化煤和腐植酸尿素处理在整个培养期内表现处理了较好的稳定性,减少氨挥发效果明显。     

腐植酸微生物菌剂在滨海盐渍化土壤上的应用效果

通过筛选能够在高渗透压条件下生长繁殖的巨大芽孢杆菌和枯草芽孢杆菌,将它们作为功能微生物接种到腐植酸中,应用于滨海盐碱地改良,同化学改良法比较,盐碱地土壤理化性状显著改善,土壤微生物数量明显增多,生物量碳、土壤的呼吸作用和酶活性也有一定增加;枣长势良好,植株健壮,叶色浓绿,未出现盐碱化症状。3年生枣和7年生枣,平均株产达1.8 kg和28.6 kg,增产幅度明显。试验表明利用腐植酸微生物菌剂进行滨海盐碱地改良是一种经济有效的办法。     

P/O-丁酰基苯酚的土壤微生物生态效应

研究了P／O-丁酰基苯酚对土壤微生物活性的影响,结果表明：P／O-丁酰基苯酚在所设计的浓度下,对土壤呼吸作用、过氧化氢酶和脲酶活性没有显著影响。对土壤放线菌数量没有影响;对真菌数量影响不大;对细菌数量的影响则为先抑制,且随浓度增大抑制作用增强,后逐渐恢复稳定。     

土壤调理剂及复合微生物菌剂防治烟草青枯病盆栽试验

通过盆栽试验研究了土壤调理剂及复合微生物菌剂对防治烟草青枯病的效果,并与PPF促生真菌试验效果进行了对比。试验结果表明,复合微生物菌剂和土壤调理剂对烟草青枯病均有较好的防治效果,其中复合微生物菌剂在促进烟株生长和防治烟草青枯病方面表现更好。     

Soil organic carbon (SOC) management for sustainable productivity of cropping and agro-forestry systems in Eastern and Southern Africa

In Eastern and Southern Africa, the shifting from the no-external input agriculture (shifting cultivation through slash and burn) to intensified agricultural systems has resulted in widespread agro-ecosystems with high soil organic carbon and nutrient depletion. This is quite evident in farming systems with reduced fallow period or those that practice continuous cropping without or with little inputs. Long-term experiments indicate that losses of up to 0.69 t carbon ha⁻¹ yr⁻¹ in the soil surface layers are common. Such losses are commonly reported by farmers engaged in participatory community-based research development projects. This calls for judicious strategies for recapitalization or replacement of these depletions. Such strategies include direct SOC replenishment through addition of organic materials, notably manures, wastes, residues and plant litter; biomass transfer; incorporation of improved fallows in the farming systems. Indirect contribution to SOM replenishment or recapitalization may be achieved through inorganic fertilizations and amendments; legume integration in the production system; and combined inorganic and organic inputs. Research is required to identify inputs that help meet both nutrients availability while contributing to SOC build up at the same time. This revised version was published online in June 2006 with corrections to the Cover Date.     

介质泄漏对循环冷却水中微生物多样性的影响

以循环冷却水作为接种水对生物粘泥进行培养,向循环冷却水中加入柴油以模拟炼油厂中的介质泄漏现象,对介质泄漏影响下生物粘泥中的微生物进行微观分析,利用扫描电子显微镜（SEM）观察生物粘泥内部的空间结构、紧密度等．利用聚合酶健式反应一变性梯度凝胶电泳（PCR-DGGE）技术．分析不同生物粘泥中的内部优势菌种、微生物多样性及相似性。SEM分析表明,与未投油的生物粘泥比较。投加0．3g·L^-1柴油时的生物粘泥内部结构复杂、紧密度好．而投加0．9g·L^-1柴油时的生物粘泥内部结构简单、紧密度差。PCR-DGGE分析表明,与投加0．9g·L^-1柴油的生物污泥相比,投加0．3g·L^-1柴油的生物粘泥的细菌数量和种类更多,微生物多样性更大,优势茵种更多。     

Effects of Organic and N Fertilizers on Methane Production Potential in a Chinese Rice Soil and its Microbiological Aspect

An incubation experiment to determine the effects of organic and chemical N fertilizers on methane (CH₄) production potential in a Chinese flooded rice soil was conducted. Organic matter, added as rice straw and organic manure, increased CH₄ production rate significantly. Chemical N fertilizers such as ammonium bicarbonate (AB), modified ammonium bicarbonate (MAB), and urea (U) did not show a clear effect when they were applied with rice straw. Field results may be very different because of the involvement of rice plants. Organic manure showed different promoting effects on CH₄ production rate. Pig manure stimulated the production rate most, followed by chicken and cattle manure. This difference in organic manure was not related to either total C added to the system or to C/N. The study on bacteria groups related to CH₄ production indicated that the different effects of organic matter may be closely related to content of easily decomposable organic matter. A significant linear relationship between CH₄ production and the logarithm of the number of zymogenic bacteria was found with an r value of 0.96. This finding suggests that the number of zymogenic bacteria may be used as an index to predict CH₄ production potential in flooded rice fields and other wetlands.     

微生物除草剂开发的限制因素和对策

综述了限制微生物除草剂开发的因素,并就这些问题提出了相应的解决对策。     

镁铵造纸废液生产固沙保土有机肥

利用镁铵代替钠碱蒸煮麦草、制浆造纸和副产的环保型造纸黑液中大量木质素的粘结性,经蒸发浓缩、改性处理、制作成环保型固沙保土有机肥.在中科院沙漠实验室进行了室内与野外全面试验,结果表明:固沙效果明显、抗风蚀性能很好,由于其有机质含量近40%(质量分数),能增加沙漠和沙地养分,所以又利于沙漠植物生长而长期固沙.推广应用该成套创新技术成果,既能根除造纸废液的污染,又能解决固沙治沙的技术难题;既有显明的环境效益和社会效益,又有很好的经济效益.     

Impact of Faba Bean-Seed Rhizobial Inoculation on Microbial Activity in the Rhizosphere Soil during Growing Season

Inoculation of legume seeds with Rhizobium affects soil microbial community and processes, especially in the rhizosphere. This study aimed at assessing the effect of Rhizobium inoculation on microbial activity in the faba bean rhizosphere during the growing season in a field experiment on a Haplic Luvisol derived from loess. Faba bean (Vicia faba L.) seeds were non-inoculated (NI) or inoculated (I) with Rhizobium leguminosarum bv. viciae and sown. The rhizosphere soil was analyzed for the enzymatic activities of dehydrogenases, urease, protease and acid phosphomonoesterase, and functional diversity (catabolic potential) using the Average Well Color Development, Shannon-Weaver, and Richness indices following the community level physiological profiling from Biolog EcoPlate™. The analyses were done on three occasions corresponding to the growth stages of: 5–6 leaf, flowering, and pod formation. The enzymatic activities were higher in I than NI (p < 0.05) throughout the growing season. However, none of the functional diversity indices differed significantly under both treatments, regardless of the growth stage. This work showed that the functional diversity of the microbial communities was a less sensitive tool than enzyme activities in assessment of rhizobial inoculation effects on rhizosphere microbial activity.     

Effects of Some Soil Management Systems on Soil Physical Properties,Microbial Biomass and Nutrient Distribution Under Rainfed Maize Production in a Humid Rainforest Alfisol

The inter ac tion of land use and sea sonal mi cro cli mat ic events could explain the dif fer ences in soil qual ity char ac ter is tics which medi ate bio log i cal and phys i cal pro cesses of the soil under low input land use sys tems (plough plus har row, strip/heap till age, man ual clear ing/no till). It is hy poth es ised that in a humid trop i cal Alf isol, low input sys tem involv ing reduced till age meth ods, and min eral fer til izer and/or live stock manure use, would sup port a higher den sity of micro bial bio mass, soil aggre ga tion, organic C and total N and hence improve ment in soil qual ity. The dynam ics of biotic and abi otic soil prop er ties as affected by meth ods of seed bed prep a ra tion char ac ter ised by man ur al input and mi cro cli mat ic tran si tions from wet to dry sea son was stud ied in a maize field in a trop i cal rain for est Alf isol in Ak ure, a humid rain for est zone of Nige ria. Each year, tri als were car ried out dur ing the rainy (April–July) and late (September–December) sea sons of 2001 and 2002. Meth ods of seed bed prep a ra tion involv ing plough plus har row, strip/heap till age and no till age, and addi tion of dif fer ent gra di ents of manures (mineral N and/or plant debris and live stock litter) were imposed on the soil at the site of the exper i ment (of com pa ra ble phys i cal prop er ties of bulk den sity and texture). Among the treat ments, there were sig nif i cant dif fer ences in the val ues of water hold ing capac ity, aggre gate sta bil ity (macro-aggre ga tion), con cen tra tions of micro bial bio mass, organic C, total and min eral N and CEC. In the rainy and late sea son tri als, the strip/heap till age and the no till treat ments improved aggre gate sta bil ity (as mea sured by the per cent ages of aggre gates between 2 and 10 mm of soil) and water hold ing capac ity over plough + har row. For exam ple, in the rainy sea son trial, under treat ments involv ing strip/heap till age and the no till alone and in com bi na tion with live stock manur ing and res i due reten tion, the val ues of aggre gates between 2 and 10 mm range from (110–116; 113–119 g/kg) and water hold ing capac ity (0.11–0.14; 0.12–0.15 g/g) over plough + har row (107.3 g/kg; 0.11 g/g). Sim i lar trends were found in the val ues of soil micro bial bio mass C (377, 353; 547, 490 μg/g dry soil), soil organic C (3.8, 4.3; 5.2,5.5 g/g) and total N (2.9, 2.3; 2.9, 3.0 mg/g) for strip/heap and no till treat ments com pared to plough + har row (327.6 μg/g dry soil; 3.4 g/g; 2.8 mg/g). Although the %C micro bial to C organic ratio (an indicator of the utilisation of organic carbon by the microbes in terms of organic matter turn over rate) was sta ble for all treatments, its magnitude was not con stant but increased with increases in soil C concentration. The values of microbial bio mass carbon to organic carbon (Cmic: Corg) ratio were higher under plough ing and heap till age com bined with min eral N (0.096, 0.099) than in no-till treat ment (0.083) in the rainy sea son trial. Similar trends were obtained in the magnitudes of this param eter in the late sea son trial. Microbial bio mass correlated positively with both soil organic C (y = 0.393c − 6.7; r² = 0.99; P< 0.05) and water hold ing capacity (y = 0.87c^0.39; r² = 0.94; P<0.05) and neg a tively with bulk density (y=−0.3c+1.9; r² = 0.90; P<0.05), strong positive lin ear cor re la tion were also found between soil macro aggre gates and other soil prop er ties: micro bial bio mass C (y=0.41c−18.4; r²=0.95; P<0.05), organic C (y=0.61c−14.3; r² = 0.97; P<0.05) and total N (y = 0.063c−10.8; r² = 0.98; P<0.05). Huge responses of soil characteristics were obtained from low input land use systems (plough plus har row, strip/heap till age, manual clear ing/no till). These proper ties mediate many biological and physical processes of soil carbon, N mineralisation, soil aggregation and water hold ing capacity and microbial bio mass, and led to improvement in soil quality. The emerged trend was that the interaction of land use, clay content of the soil and seasonal micro climatic events could explain the heteroge neity of soil components among treatments.     

腐植酸肥对土壤养分与微生物活性的影响

本试验进行了腐植酸肥对土壤微生物活性与土壤速效养分影响的研究。试验在温室条件下,采用盆栽饲草高粱法,设腐植酸肥、化肥和对照（CK）3个处理。试验表明：抽穗期,腐植酸肥处理的土壤细菌数比化肥处理高4558％;拔节期和抽穗期,腐植酸肥处理的土壤放线菌数比化肥处理高2857％和4358％,土壤真菌数比化肥处理高弱26％－20...     

Differences in Soil Properties and Bacterial Communities between the Rhizosphere and Bulk Soil and among Different Production Areas of the Medicinal Plant Fritillaria thunbergii

To explore rhizosphere effects, geographical differences and their effects on the bacterial community associated with the geoherb Fritillaria thunbergii, some physicochemical properties of soil samples (3 sampling sites × 2 habitats (rhizosphere and bulk soil)) were measured and the soil bacterial community detected by PCR-denaturing gradient gel electrophoresis (DGGE). Among the three regions, soil pH varied between 4.48 and 7.73 indicating that F. thunbergii could grow both in acid and slightly alkaline soil. As the authentic Dao-di producing area, Ningbo showed the highest soil quality with the highest content of organic matter (OM) (2.46%), phosphatase (268 mg kg(-1) 24 h(-1)) and urease activity (1481 mg kg(-1) 24 h(-1)). In comparison with the bulk soil, pH, organic carbon content, and phosphatase and urease activities were all lower in the rhizosphere, suggesting that the roots may secrete some unique metabolites in root exudates. Statistical analyses showed that soil properties of Ningbo and Panan in Zhejiang province were more similar to each other than those in Nantong in Jiangsu province. In addition, PCR-DGGE analysis showed that main bacterial population identified in F. thunbergii was proteobacteria (18 bands, 55%), acidobacteria (4, 12%), actinobacteria (4, 12%) and bacterioidetes (6, 18%). Overall, soil properties and microbial communities varied not only between the rhizosphere and bulk soil but also among the three regions. We suggest that the plant, together with the soil properties, cooperatively shape the structure of the rhizosphere bacteria, and that the soil properties have a close relationship with the geoherbalism of F. thunbergii.     

水厂水质的腐蚀性及防蚀处理

调查研究了我国南方六省40座水厂水质的腐蚀性及其防蚀工艺。腐蚀性水损坏水厂的铁质设施,并使管网水呈黄色。饱和指数I_L小于-0.6、稳定指数I_R大于8以及含有高浓度侵蚀性二氧化碳的水,一般都有腐蚀性。这种水的腐蚀性,可用投加石灰、氢氧化钠或苏打的方法控制;微生物导致的腐蚀可用加氯法防止。     

食用菌产生微生物絮凝剂最佳培养条件的研究

从食用菌中筛选出一种絮凝效果较佳、环保、安全的微生物絮凝剂,开拓废渣再利用的新途径,特开展了该研究。试验采用6种食用菌,经培养后进行培养条件和絮凝条件的优选实验。实验表明,鸡腿菇是最佳的微生物絮凝剂产生菌。在培养过程中确定小麦粉培养基为最佳培养基,最佳的培养基配方组合为小麦粉20mg·L^-1,蔗糖20mg·L^-1,酵母粉6mg·L^-1。实验剩用鸡腿菇对高岭土水样进行絮凝实验,絮凝率为69.39％。