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1.
During the study on the distribution of blue-green algae which was carried out to evaluate the practical significance of nitrogen fixation by blue-green algae in the nitrogen economy of paddy soils, some soils, in which the autochthonous algae could not grow vigorously, and as a matter of course, their nitrogen fixation was also Very poor notwithstanding every encouraging treatment such as fertilization by potassium phosphate, adjustment of soil reaction by calcium carbonate or inoculation of a nitrogen-fixing blue-green alga, were found. 相似文献
2.
The possible significance of blue-green algae in the nitrogen economy of paddy soil has been pointed out by many investigators. 相似文献
3.
红萍在稻田氮素平衡中的作用 总被引：2，自引：0，他引：2
应用１５Ｎ示踪法研究了红萍在稻田氮素平衡中的作用。红萍作基肥，当季水稻的１５Ｎ－红萍Ｎ素利用为２７．８％；第二季５．３８％；土壤残留３６．１％。红萍可排出体内１２％以上的氮素。红萍的排氮和吸氮有助于调节稻田的氮素平衡，稻田养萍抑制藻类生长，降低ｐＨ值和ＮＨ浓度，减少ＮＨ３挥发损失，以及减少蓝藻（颤藻）反硝化反应释放的Ｎ２Ｏ，提高化学肥料１５Ｎ的回收率：它比１５Ｎ－尿素不养萍处理１５Ｎ回收率增加４．２５％，比１５Ｎ－尿素追肥不养萍处理１５Ｎ回收率增加８．３５％～２５．１１％。 相似文献
4.
Summary Virgin alkali (sodic) soils have a high pH and high exchangeable Na and are often barren. Blue-green algae, however, tolerate excess Na and grow extensively on the soil surface in wet seasons. Experiments using a highly degraded alkali soil (silt loam, pH 10.3, electrical conductivity 3.5 dS m-1, 90% exchangeable Na) were conducted in soil columns, with or without gypsum, in order to study the influence of waterlogging on the growth of indigenous and inoculated blue-green algae and hence, soil reclamation. The growth of indigenous blue-green algae was initially slow in alkali soil, due to the high pH and exchangeable Na, and depressed in gypsum-amended soil, due to excess Ca. Inoculation hastened the establishment of blue-green algae in both the unamended alkali soil and the gypsum-amended soil, overcoming the adverse influence of excess Na in the former and excess Ca in the latter. Gypsum was effective in amelioration (pH 9.05, electrical conductivity 1.2 dS m-1, 41% exchangeable Na after 11 weeks) but blue-green algae were ineffective even after 17 weeks. In combination with gypsum, blue-green algae had no additional effect, and the C and N increases due to the growth of indigenous or inoculated blue-green algae were insignificant.Alkali soil reclamation by biological methods requires mobilization of Ca from native soil calcite and the exchange of Ca for Na in the exchange complex. The ineffectiveness of blue-green algae was ascribed to their inability to mobilize Ca. It is argued that current theories favouring blue-green algae as a biological amendment to bring about alkali soil reclamation are untenable and are not comparable with an effective chemical amendment such as gypsum. 相似文献
5.
《Soil biology & biochemistry》1973,5(1):91-95
Preliminary studies were made to evaluate the role of the blue-green algae in flooded rice soils in the Jogjakarta district of central Java. They included identification of the components of the blue-green algal populations and the effects of fertilizers. The main findings were: (1) members of the families Nostocaceae (7 genera and 12 species recognized) and Oscillatoriaceae (8 genera and 18 species) were generally more abundant than other families; (2) application of nitrogen and phosphorus fertilizers affected the composition (reduction in numbers of nitrogen-fixing blue-green algae) and total size of the populations (increase in algal biomass); (3) a major role for blue-green algae in the N-economy of flooded soils was indicated. 相似文献
6.
Freshly-harvested blue-green algae (20 t ha?1) or Azolla (20 t ha?1) were incorporated into a waterlogged rice soil and changes of redox-potential and the availability of nitrogen and phosphorus were measured periodically. The soil progressively became reduced where blue-green algae or Azolla had been incorporated. The rate of N release from Azolla was more rapid than from blue-green algae and the amounts released after 7–35 days of flooding were between 41 and 76% and 12 and 35% respectively. Increased P availability was also recorded in soil following the incorporation of blue-green algae or Azolla and reached highest values after 21 days incubation. 相似文献
7.
The effect of surface growth of blue-green algae and bryophytes on some microbiological,biochemical, and physical soil properties 总被引：3，自引：0，他引：3
Summary The influence of surface growth of inoculated cyanobacteria (blue-green algae) on subsurface properties of a brown earth, silt loam soil was studied in reconstituted flooded soil columns. One blue-green algae species, Nostoc muscorum, become dominant within the first 7 days of inoculation. In light control columns (not inoculated) a bryophyte, Barbula recurvirostra, was dominant although significant growth of indigenous blue-green algae occurred. The blue-green algae counts were in the range of 1×106 g-1 dry soil in the surface layer (0–0.7 cm) in both columns. Any effect of surface phototrophic growth on soil properties was restricted to the surface layer. In inoculated columns there was a twofold increase in microbial biomass and an eightfold increase in bacterial numbers by week 13. However, bacterial numbers declined so that there was only a 2.8-fold increase by week 21. Dehydrogenase (x2.1), urease (x2.8) and phosphatase (x3.1) activities and polysaccharides (+69%) increased by week 21 as a result of the blue-green algae inoculation along with a significant improvement in soil aggregation. However, similar increases occurred in the light control columns, indicating that given appropriate conditions of light and moisture indigenous species may be ultimately as effective as introduced species in bringing about biochemical and microbiological changes to soil. 相似文献
8.
Misako Taniguchi Wilbur Ventura Koki Toyota Makoto Kimura 《Soil Science and Plant Nutrition》2013,59(3):757-766
Epibiotic microorganisms associated with micro crustaceans in the overlying water of Philippine paddy fields were examined by scanning electron microscopy, and their associations were compared with those observed in Japanese paddy fields (Soil Sci. Plant Nutr., 43, 633-641, 651-664, 1997). Various types of microorganisms, including bacteria, protozoa, and algae, colonized microcrustaceans and their kinds and colonizing patterns varied depending on the kinds of microcrustaceans. Common associations between epibionts and respective micro crustaceans were observed in the Philippines and in Japan: e.g., rodshaped bacteria on Cyclopidae and Cypridopsidae; no microorganisms on Simocephalus spp. 相似文献
9.
Tomio Yoshida Rosabel A. Roncal Ellen M. Bautista 《Soil Science and Plant Nutrition》2013,59(2):117-123
Photosynthetic nitrogen-fixing microorganisms help maintain the nitrogen level of soil in rice paddies when environmental factors favor the growth of microorganisms. Our studies showed that blue-green algae in particular have a significant role in nitrogen-fixation in light. The most active nitrogen-fixation by microorganisms occurred in the soil shortly after it had been submerged under light. The longer the submergence, the less nitrogen microorganisms were fixed. In a greenhouse experiment, the fixed nitrogen appeared not to be immediately available to the rice plant. The amount of nitrogen that can be fixed in the field by nitrogen-fixing microorganisms in paddy water was estimated using the acetylene reduction method during the rice-growing period. The amount of nitrogen fixation by these microorganisms is not sufficient to account for the amount of nitrogen uptake by rice during the rice-growing period. 相似文献
10.
S. Singh R. Prasad B. V. Singh S. K. Goyal S. N. Sharma 《Biology and Fertility of Soils》1990,9(3):235-238
Summary A field trial was set up to examine the effect of green manuring, blue-green algae, and neem-cake-coated urea on a rice crop. Summer green manuring using Sesbania aculeata increased the crop yield. Inoculation of blue-green algae increased the rice grain yield when 60 kg N ha-1 was applied as prilled urea, but the increase in grain yield was greater when 60 kg N ha-1 was applied as neem-cake-coated urea. The results of the present study show that applications of green manure, neem-cake-coated urea, and blue-green algae are complementary and that the three treatments can be used together in the rice ecosystem. The green manure and the fertilizer treatments had no effect on the algal flora of the soil. 相似文献
11.
A commercial blue-green algae inoculant (Genesis II) for improving the N content of soils was applied to basalt and pumice soils in a greenhouse pot test with orchardgrass, pinegrass, Douglasfir, and ponderosa pine. Treatments were control (deionized water), live algae, killed algae, live algae plus P, K and S and P, K and S only. Plant biomass yields with live inoculant generally were significantly greater than with the control treatment but were the same as with killed inoculant. Live algae plus P, K and S further enhanced productivity. P, K and S alone produced no increase over the control treatment. Response to the inoculant compared to the control appears to be a result of addition of nutrients present in the inoculant stock solution. Further biomass increases with the P, K and S plus live algae treatment compared to live and dead algae treatments occurred because these nutrients became limiting as N was added. Total organic-N and total C in surface soils were similar in all treatments.When the stock solution was sampled via culture methods, the most prominent species found was Chlorella, a green alga. Anabaena, an N2 fixing blue-green alga, produced less than one colony per plate on the average. Phormidium, a blue-green alga not found in the inoculant, was dominant on the soil surface at the end of the test suggesting a soil origin for this species. Results indicate that Genesis II probably has very limited potential to enhance blue-green algal populations and, consequently, N of the forest soils used in this test. 相似文献
12.
13.
Shehata Salwa A. Lasheen Mohamed R. Ali Gamila H. Kobbia Imam A. 《Water, air, and soil pollution》1999,110(1-2):119-135
The toxic effect of multi metals mixture which exist simultaneously in aquatic ecosystem on natural phytoplankton assemblages (green algae, blue-green algae and diatoms) was studied. For this purpose a laboratory scale unit was designed to evaluate the effect of continuous flow metals mixture in forms if triple and penta metals in Nile water algae. Clear changes in algal biomass in terms of chlorophyll a (chl a) took place when subjected to metals combination. The rise or decline in chl a was in relation with other algal pigments (chl b, chl c, carotenoides and phenophytin), protein and carbohydrate content of algal cells. Substantial changes in phytoplankton community structure was detected and the most tolerant group was blue-green algae followed by green algae while diatoms was the most sensitive group. The most dominant species in all cases were blue-green alga Oscillatoria mougeotii and green alga Scenedesmus quadricauda. In addition clear changes in morphological shape was observed for tolerant species belonging to the three algal groups. Nile water algae has ability to remove and accumulate metals in the following order therefore Zn > Cd > Ni > Cu > Cr. In addition, phytoplankton has ability to recovered from the stress of metals when eliminated from the media and the recovered biomass was nearly equivalent to that before exposing to metals stress. The overall effect of metals mixture depending on the type and number of metals, the algal community structure and ratio between different morphological forms of algae (unicellular, colonial and filamentous). 相似文献
14.
重金属复合污染对水稻土微生物生物量和群落结构的影响 总被引：11，自引：1，他引：11
以浙江富阳小冶炼厂附近水稻土为例,采用氯仿熏蒸法、稀释平板培养法和磷脂脂肪酸(PLFA)技术研究了重金属复合污染对水稻土微生物生物量和群落结构的影响。结果表明,自然状态下铜、锌、镉、铅复合污染降低了土壤微生物量。土壤微生物群落结构对重金属复合污染产生了响应,约41.82%的土壤微生物群落结构的改变可由重金属污染来解释。污染程度高的土壤中,含脂肪酸12∶0,i15∶0,i17∶0,18∶0,i16∶0,19∶0相对较高的微生物占优势,而在污染程度低的土壤中,含脂肪酸20∶2ω6,9 c,20∶0,16∶1ω9 c,a15∶0,a16∶0,18∶1ω7,10M e16∶0,10M e19∶0的相对含量较高的微生物占优势。反映在具体类群上,随着污染程度的增加,微生物向着Cm ic/Nm ic低、真菌相对含量增加,放线菌与革兰氏阴性菌含量相对减少的趋势发展。 相似文献
15.
Cluster analysis was used to group samples collected from ten stations in Moses Lake, Washington, according to the similarity of their contained algal species. During the period 1968 to 1970, nine recurring distinct sample groups, or algal populations, were identified. Of the nine, three were most distinct; they consistently recurred at the same stations, and were dominated by diatom, green, and blue-green algae, respectively. Of the six species of blue-greens that characterized that population, the recreationally nuisance forms,Aphanizomenon flos-aquae andMicrocystis aeruginosa, were dominant. The blue-green population was the most widespread in the lake and occurred in waters that were warmest and contained the lowest concentrations of inorganic nutrients: N, P, and C. Green algae dominated in waters that received treated sewage effluent and contained relatively high concentrations of nutrients. As the nutrient content declined when proceeding away from that area, blue-green algae became dominant. Temporal variation in biomass (chlorophyll content) of the blue-green population was inversely related to phosphate content, but not to the other nutrients. These results support the hypothesis that nuisance blue-green algae dominate in shallow eutrophic lakes during warm summer months when ambient nutrient content is low because, under these conditions, they apparently out-compete other forms for nutrients. In shallow unstable eutrophic lakes like Moses Lake, the nutrient supply rate from sediments may be considered great although ambient concentrations are low which allow the dominating blue-green population to reach a large biomass, e. g., maximums as high as 300 µg l?1 chlorophyll were observed. Because correlation analysis andin situ bioassays showed that biomass of blue-green algae was most closely related to inorganic phosphate even at times when nitrate was very low and invariable, we suggest that phosphorus availability is most critical to biomass formation. Control of ambient phosphorus content, therefore, would be most apt to result in a reduction in maximum biomass of the blue-greens. Phosphorus control would be unlikely to alter algal dominance in this shallow lake, however, since blue-greens seem to be generally favored over other populations by reduction in nutrient concentration during warm weather. 相似文献
16.
Means to control ostracods grazing on blue-green algae (cyanobacteria) important in fixing nitrogen in flooded rice soils were studied. The relative acute lethal toxicity (LC5048) to the ostracods Cyprinotus carolinensis and Heterocypris luzonensis grazing on Tolypothrix tenuis was 0.4 and 2.4 μg ml?1 for carbofuran and 4.5 and more than 56.0 μ g ml?1 for lindane. Complete inhibition of grazing was achieved with 1.0 and 25 μ g carbofuran ml?1 and 0.1 and 5.6μ g lindane ml?1 for C. carolinensis and H. luzonensis, respectively. Lindane at concentrations below 0.02 μ g ml?1 stimulated feeding by C. carolinensis on the alga. Breakdown of carbofuran markedly reduced its effectiveness as a measure to control grazing, but lindane did not rapidly lose its effectiveness. The toxicity of carbofuran to C. carolinensis feeding on T. tenuis was not affected by pH. The difference in ostracod responses to the pesticides, which may be associated with resistance acquired through previous exposure, is an important consideration in designing practical means to reduce grazing in paddy fields. 相似文献
17.
稻田CH4和N2O综合排放对控制灌溉的响应 总被引：4，自引：6，他引：4
为了揭示水稻控制灌溉对稻田CH4和N2O综合排放的影响,该文采用静态暗箱-气相色谱法对控制灌溉稻田CH4和N2O排放进行原位观测,分析稻田CH4和N2O综合排放对控制灌溉水分调控的动态响应。结果表明,控制灌溉稻田CH4排放通量多低于常规灌溉稻田,且主要集中在水稻分蘖前期,峰值出现在土壤脱水后第1～2d,排放总量较常规灌溉稻田减少81.2%～82.8%;N2O排放通量多高于常规灌溉稻田,峰值出现在肥后且土壤脱水后3～4d,排放总量较常规灌溉稻田增加了121.8%～144.3%。控制灌溉稻田CH4和N2O的综合全球增温潜势较常规灌溉稻田显著减少(p<0.05),减少幅度为15.0%～34.8%。控制灌溉显著降低了稻田CH4和N2O的综合温室效应。 相似文献
18.
Yongsheng Song Wensheng Shu Aidong Wang Weiqiu Liu 《Journal of Soils and Sediments》2014,14(3):577-583
Purpose
Algae play an important role in degraded areas during the initial stages of soil formation by improving its physico-chemical properties, reducing the erosion of soil, and thus favoring the settlement of vascular plants. This study investigates the characters of soil algal communities on copper tailing dumps and discusses the contribution of soil algae to the primary succession progress of young mine tailings ecosystems.Materials and methods
Five representative potential successional series (bare land, algae crust, mixed algal–moss crust, moss crust, and vegetated site) on copper tailing dumps and a nearby reference site were selected. The soil algae were identified using growth slide method, dilution plate method, and by direct microscopic observation of the soil suspensions. All experiments were carried in an incubation chamber at a temperature of 25 °C and with a 16 h/8 h light–dark cycle at a light intensity of 3,000 lux.Results and discussion
A total of 120 algal species were recorded. Cyanophyta (blue-green algae) were the most diverse taxonomic group, followed by Bacillariophyta (diatoms) and Chlorophyta (green algae), although diatoms were absolutely absent in bare sites. Diversity of soil algae was highest in vegetated site, whereas it was lowest in bare sites. Total algal abundance ranged between 0.15?×?103 cells/g to 46.8?×?103 cells/g dry soil, with the lowest abundance in the youngest site and the highest abundance in the mixed algal–moss crust site. Correlation analysis showed that the growth of soil algae was inhibited by high Cu, Zn, and Fe concentrations and low nutrient content and that the green algae were more sensitive to nutrient content than blue-green algae.Conclusions
Our results suggest that blue-green algae were most diverse, followed by diatoms and green algae. Species and abundance of soil algae in the tailings increased with the early succession process because of the decrease in heavy metal content and the improvement of nutrient conditions. The growth of soil algae created conditions for the settlement and growth of higher plants, but the appearance of moss and vascular plants inhibited the growth of soil algae. 相似文献19.
蓝藻厌氧发酵产沼气机械搅拌工艺优化及中试验证 总被引：2，自引：1，他引：1
在蓝藻厌氧发酵过程中,由于蓝藻密度较小,容易在反应器中上浮而结壳,从而降低反应器产气效率。该文以蓝藻为原料,研究机械搅拌对其厌氧发酵产沼气的影响。分别选取不同的搅拌周期、搅拌持续时间及搅拌强度3个因素,在试验的基础上采用响应曲面法确定蓝藻厌氧发酵产气的最佳搅拌因素,为蓝藻厌氧发酵产沼气技术应用提供技术参数。以模拟得到的二次多项式回归方程,从而预测得到蓝藻最佳搅拌条件为:搅拌周期6 h、搅拌持续时间20 min/次、搅拌强度56 r/min。中试中,在最佳搅拌条件下,蓝藻的比产气速率、比产甲烷速率最大,分别为0.39、0.236 L/(L·g)。研究发现:搅拌强度对蓝藻厌氧发酵产沼气影响最大,搅拌周期其次,搅拌持续时间最小;搅拌强度过大、搅拌频繁将会破坏适于特定厌氧微生物生长的微环境,使系统中不同种属厌氧微生物的协同作用受到局部破坏,反应器中污泥的蛋白酶、脱氢酶及辅酶活性下降,产气率降低;搅拌强度小、搅拌周期长,蓝藻容易上浮,与污泥中微生物接触有效接触减少,蓝藻转换效率低,微生物活性降低。适当的搅拌混合可以破坏蓝藻上浮结壳,同时提高蓝藻与微生物之间接触效果及产气效率。 相似文献
20.
P. Roychoudhury G.R. Pillai S.L. Pandey G.S.R. Krishna Murti G.S. Venkataraman 《Soil & Tillage Research》1983,3(1):61-65
The application of blue-green algae improved the aggregation status of rice field soils under different levels of irrigation and nitrogen fertilizer (urea) and increased the grain yield of rice significantly. 相似文献