共查询到18条相似文献，搜索用时 156 毫秒
1.
在实验室条件下 ,施用杀虫剂 (呋喃丹 )、杀菌剂 (多菌灵 )和除草剂 (丁草胺 )后 ,对黄松稻田土壤、紫色稻田土壤和红壤稻田土的硫酸盐还原细菌 (Sulfate reducingbacteria ,SRB)种群数量和硫酸盐还原活性的影响。结果表明 ,紫色稻田土壤、黄松稻田土壤和红壤稻田土的SRB种群数量和硫酸盐还原活性的范围分别为 (66 83～ 12 7 81)× 10 4 cfug- 1干土、(45 87～ 10 5 0 7)× 10 4 cfug- 1干土和 (3 81～ 61 62 )× 10 4 cfug- 1干土和S- 2 (7 14～ 11 57) μgg- 1d- 1干土、S- 2 (6 84～ 9 0 7) μgg- 1d- 1干土、S- 2 (1 91～ 6 67) μgg- 1d- 1干土 ,且稻田土SRB种群数量和土壤硫酸盐还原活性之间具有正相关性。每kg干土中加入 1mg的丁草胺或呋喃丹 ,能促进SRB的生长及其硫酸盐还原活性。 1kg干土中加入 5mg的多菌灵、50mg的丁草胺或呋喃丹 ,对SRB的生长和硫酸盐还原活性有明显的抑制作用。施用丁草胺和呋喃丹 7d时 ,多菌灵 14d时 ,对水稻田土壤的SRB种群数量和硫酸盐还原活性的抑制影响最大 ,然后逐渐减轻 ,最后显示出某种程度的促进作用 相似文献
2.
重金属污染对水稻田土壤硫酸盐还原菌种群数量及其活性的影响 总被引：4，自引：0，他引：4
在实验室条件下,采用重金属Cd2+、As5+、Cu2+、Pb2+和Cr3+处理黄松稻田土壤、紫色稻田土壤和红壤稻田土,28d后分析重金属污染对水稻田土壤的硫酸盐还原菌(SRB)种群数量和硫酸盐还原活性(SRA)的影响。结果表明,在每千克干土中加入200mgPb2+时,对稻田土壤的SRB种群数量和SRA有促进作用;当加入的Cd2+、As5+、Cu2+、Pb2+和Cr3+每千克干土分别超过1.0、30、500、400和200mg时,对稻田土壤SRB种群数量和SRA有明显抑制作用。随着加入量的增加,重金属对水稻田土壤的SRB种群数量和SRA的抑制作用越来越强,水稻田土壤通过自身来恢复SRB种群数量和SRA所需的时间也越长。同一种重金属元素对不同土壤的SRB种群数量和SRA抑制的污染临界值也有差异。 相似文献
3.
生物质炭对水稻土中脱氢酶活性和铁还原过程的影响 总被引：1，自引：0，他引：1
为探究添加生物质炭对淹水稻田体系脱氢酶活性及土水界面铁还原过程的影响,选择2种不同地区水稻土,采用土壤泥浆厌氧培养试验方法,分析添加不同粒径生物质炭后泥浆培养体系中脱氢酶活性、pH以及Fe(Ⅱ)浓度的变化。结果表明:生物质炭能够提高水稻土厌氧培养体系的脱氢酶活性,促进微生物铁还原进程。脱氢酶活性和铁还原能力随着生物质炭粒径的减小而增大。未添加生物质炭的处理中,2种水稻土脱氢酶活性最大分别为3.13,2.60μg/(ml·g·min),Fe(Ⅱ)累积量最高分别为8.07,7.44mg/g;通过添加生物质炭,2种水稻土培养体系脱氢酶活性最大分别达4.35,4.18μg/(ml·g·min)、Fe(Ⅱ)累积量最高分别为9.01,8.18mg/g。典范对应分析显示,水稻土初始pH与最大铁还原潜势及达到最大铁还原速率对应的时间呈极显著相关,表明生物质炭对铁还原过程的影响因土壤性质不同而存在差异;脱氢酶活性、Fe(Ⅱ)累积量之间呈现极显著的相关关系,两者在培养过程中相互促进。 相似文献
4.
研究不同电子受体之间的竞争关系对揭示厌氧水稻土中微生物作用导致的氧化还原过程变化机理具有重要的理论意义。本研究采用土壤泥浆厌氧培养、人工合成氧化铁体系接种土壤浸提液厌氧培养及接种铁还原菌纯培养等试验方法,通过向培养体系中添加SO24-,探讨了硫酸盐作为竞争电子受体对不同铁还原体系中Fe（Ⅲ）还原的影响。结果表明,在2种水稻土的泥浆培养过程中,Fe（Ⅲ）还原速率均随着SO24-浓度增加而降低,但Fe（Ⅱ）的最终累积量却较对照处理有明显的增加。添加硫酸盐对Fe（Ⅲ）还原速率（k）的影响表现为：石灰性水稻土〉酸性水稻土;而最终Fe（Ⅱ）累积增加率则为：酸性水稻土〉石灰性水稻土。由接种不同水稻土浸提液的培养试验看出,添加SO24-后Fe（Ⅲ）还原受到显著的抑制,但随着培养时间延长Fe（Ⅲ）还原反应依然可以进行,并且Fe（Ⅱ）累积量最终达到与CK相同的水平。在接种铁还原菌的纯培养试验中,添加SO24-对供试的4株铁还原菌的Fe（Ⅲ）还原过程并未产生抑制效应,表明铁还原菌本身并不受硫酸盐的影响。 相似文献
5.
从内循环厌氧反应器颗粒污泥中分离、纯化得到一株硫酸盐还原菌命名为DSRBa,经形态和基于16SrDNA序列分析,该菌株归属于脱硫弧菌属（Desulfovibrio）。分别以甲酸钠、乙醇、乳酸钠、葡萄糖等为碳源,以硫酸盐、硫代硫酸盐、亚硫酸盐、单质硫为硫源,研究了不同温度、pH及不同硫酸根浓度对该菌株的影响。结果表明,菌株最适宜生长温度为30～35℃,最佳生长pH为7.0,无需绝对严格厌氧,当溶液中氧化还原电位（ORP）≤-40mV时,该菌株能较好生长,且生长4d后使溶液内氧化还原电位值达到-380mV,随后溶液内氧化还原电位基本保持不变。当系统内乳酸钠和酵母提取物浓度分别为3.5g·L-1和1g·L-1时,硫酸根浓度在1～4.5g·L-1范围对菌株生长无明显影响,且当SO24-浓度≤3g·L-1时,菌株生长4d对硫酸根的去除率达到90%以上。 相似文献
6.
硫酸盐还原细菌（SPBs）的筛选培养及在两相厌氧工艺中试验研究 总被引：1，自引：0，他引：1
通过硫酸盐还原细菌（ＳＰＢｓ）的筛选、培养条件优化及在两相厌氧工艺中产酸相应用硫酸盐还原细菌（ＳＰＢｓ）试验,选出了一株耐富含硫酸盐高浓度酵母生产废水的脱硫弧菌,并强化两相厌氧的工艺中产酸相硫酸盐还原细菌（ＳＰＢｓ）的活性。 相似文献
7.
为探讨光照和硫酸盐对微生物Fe（Ⅲ）还原的影响,在光照和光暗转换条件下,采用厌氧泥浆恒温培育方法分别在四川和天津2种石灰性水稻土中添加不同浓度硫酸盐溶液（20、50、800mmol·kg-1）,培养过程中定期测定土壤泥浆的Fe（Ⅱ）、叶绿素a含量和pH值。结果表明：光照条件下,添加20mmol·kg-1和50mmol·kg-1硫酸盐能减缓光照培养中因为蓝细菌光合作用放氧引起的Fe（Ⅱ）氧化反应,Fe（Ⅱ）氧化反应启动时间与对照处理相比延迟3～7d;蓝细菌在光照培养5d后开始迅速繁殖生长,叶绿素a增长速率表现为随硫酸盐浓度增大而增加,其最终含量在四川和天津水稻土中分别为20mg·kg-1和16mg·kg-1;800mmol·kg-1硫酸盐则完全抑制了Fe（Ⅱ）的重新氧化,且在整个培养周期中没有发现光合细菌存在。pH值变化呈现先微弱下降后升高的趋势,但始终维持在弱碱性范围内。当由光照转入避光培养后,Fe（Ⅱ）累积量又重新回升,增长速率表现为对照〉20mmol·kg-1S处理〉50mmol·kg-1S处理。表明光照并非直接影响铁还原微生物,而是通过光合微生物繁殖间接影响铁还原过程。 相似文献
8.
采用零价铁（ZVI,Fe^0）还原技术,修复被对硝基甲苯（PNT）污染的土壤,研究不同反应条件对还原效果的影响及随时间推移产物的变化,并对反应机理进行了初步探讨。结果表明,常温常压下,Fe^0可有效地将土壤中对硝基甲苯还原为苯胺化合物,反应过程中先生成对甲基亚硝基苯,最终生成对甲基苯胺。土壤含水量达到饱和时能显著提高PNT的还原率,土壤初始酸碱度控制在中性偏酸性有利于还原反应的进行,体系温度上升到25～35℃还原效果较好,当Fe^0加入量小于25mg·g-1时增加Fe^0用量能有效增大还原率。当2g土壤中PNT的初始浓度约为2．5×10^-6mol·g-1,Fe^0加入量是25mg·g-1,土壤水含量75％,土壤初始pH值6．8时,于25℃下反应5h后PNT的还原率可达95％以上。 相似文献
9.
采用DTPA溶液浸提-邻菲罗啉比色法测定土壤中有效铁的含量,探讨了此方法的最佳实验条件.结果表明,以邻菲罗啉为显色剂,可在510nm处测定土壤中有效铁的含量;最适试剂用量为:每5ml待测液加入100 g/L的盐酸羟胺l ml,100 g/L的醋酸胺8 ml,100 g/L的邻菲罗啉显色剂10ml;待测液显色最适条件为温度在60℃下显色30 min;优化后的测定方法相对标准偏差RSD＜2.0％,回收率98.6％～ 100.2％.此法操作简便、灵敏度高、显色稳定、回收率高,适用于测定微碱性或碱性土壤中有效铁的含量. 相似文献
10.
11.
管理措施对水稻土中电子传输体系活性的影响 总被引：4，自引：0，他引：4
Electron transport system(ETS)/dehydrogenase activity in a paddy field soil was measured under a variety of incubation conditions using the reduction of 2-(p-iodophenyl-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride(INT) to iodonitrotetrazolium formazan(INTF).The results exhibited a high positive correlation between the ETS activity and the incubation temperature and soil moisture,Dehydrogenase/ETS activity displayed a negative correlation with insecticide concentrations,and the activity affected adversely as the concentration of the insecticide increased.The hiher doses,5 and 10 field rates(1 field rate=1500mL ha^-1),of insecticide significantly inhibited ETS activity,while lower rates failed to produce any significant reducing effect,Inorganic N( as urea) of concentrations from 0 to 100ug N g^-1 soil showed a positive response to ETS activity,However,at concentrations of 200 and 400ug N g^-1,the activity was reduced significantly. 相似文献
12.
聚丙烯酰胺(PAM)对扰动红壤侵蚀产沙过程的影响 总被引：1，自引：0，他引：1
为了研究聚丙烯酰胺(PAM)对防治扰动红壤水土流失的影响,采用室内人工模拟降雨试验,探讨了不同坡度、雨强与土壤处理下扰动红壤坡面产流与产沙变化过程.试验结果表明,630T型PAM减流效果好于630S型PAM效果,其减流效益在雨强越大的情况下效益越显著;630S型PAM2 g/m~2减沙效益最显著,平均含沙量比对照减少93.22%～99.65%,侵蚀总量减少93.83%～99.96%;但从经济角度来看,630T型PAMI g/m~2最佳,其平均含沙量比对照减少83.59%～99.69%,侵蚀总量减少89.23%～99.78%. 相似文献
13.
从广西钦州市钦北区的富硒土壤中筛选出一株可高效还原亚硒酸盐的细菌QZB-1。16S rDNA基因序列分析确定菌株为粘质沙雷氏菌(Serratia marcescens)。研究发现菌株QZB-1可耐高达180 mmol/L的亚硒酸盐。进一步研究发现菌株QZB-1在36 h之内对1 mmol/L亚硒酸盐的还原率为95%，随着硒浓度升高还原率有所下降。正交实验表明，对菌株还原亚硒酸盐的影响程度依次是初始亚硒酸盐浓度>培养时间>接种量，最佳还原条件是初始亚硒酸盐浓度为1 mmol/L，接种量为10%，培养时间为36 h，此时菌株QZB-1对亚硒酸盐的还原率大于98.55%。研究结果表明新型亚硒酸盐还原菌粘质沙雷氏菌QZB-1可高效还原亚硒酸盐为单质纳米硒，可高效应用于亚硒酸盐污染水体和土壤的治理。 相似文献
14.
《Communications in Soil Science and Plant Analysis》2012,43(12):1479-1500
Abstract Laboratory and greenhouse experiments were conducted to determine the effects of rate of nitrapyrin and soil pH on nitrification of NH4 + fertilizer in soil, and growth and chemical composition of burley tobacco (Nicotiana tabacum L. cv. ‘KY ‐14'). Such experiments were needed to develop information for increasing efficiency of N fertilizer use and to lessen the fertilizer‐induced soil acidity and salt effects on tobacco plants. Results for laboratory and greenhouse incubations indicated that nitrification proceeeded slowly below pH 5.0 and the nitrapyrin necessary to delay nitrification increased with both increasing soil pH and length of incubation time. Generally, nitrification could be delayed 30 days by nitrapyrin rates of 0.25 or 0.5 μg g‐1 regardless of soil pH. but rates of 1 μg g‐1 nitrapyrin or higher were required for 60 days and longer incubation times, particularly at higher soil pH. Growth and morphology of tobacco plants were either unaffected, or affected positively, by low rates of nitrapyrin (up to 2 μg g‐1). However, rates of 4 μg g‐1 and above reduced total plant dry weight, reducing sugars and contents of mineral elements. Concentrations and content of plant NO3 ‐ N and Mn were greatly decreased by application of nitrapyrin. Values for most parameters measured increased with increasing soil pH. The data show that low rates of nitrapyrin may be used to alter the ratio of NO3 ‐ to NH4 + N absorbed by tobacco and possibly improve growth and safety of tobacco. 相似文献
15.
Net mineralization of sulfur and nitrogen was studied in three Canadian Prairie soils using two commonly used incubation methods. In the open system technique, where the soils were leached periodically II.3–11.8 μ g SO2?4 -S g?1 soil was mineralized in 17 weeks. Little mineralization or a net immobilization of sulfur (from 1.4 to 1.3 μ g SO2?4-S g?1 soil) was observed in a closed system where the soils were left undisturbed throughout incubation. Changes in the specific activity of 35S-labelled soil solution sulfate during the closed incubation indicated that mineralization-immobilization processes were occurring simultaneously resulting in minimal net changes in CaCl2-extractable SO2?4 concentrations. The amounts of mineralized nitrogen (32.6–57.8 μg N g?1 soil) were found to be independent of the incubation method employed. 相似文献
16.
Influence of long-term fertilizing with different forms of nitrogen fertilizer on pH, humic fractions, biological activity and dynamics of nitrogen of an arable brown earth The evaluation of soil characteristics in a 53 years field trial (arable brown earth, sandy silty loam, eff. field cap. 160mm, pH 5,9, total C 0,9 %, total N 0,1 %, CEC 15 meq/100 g soil) gave the following results: Fertilizing with ammonium sulfate decreased pH in topsoil down to 4.9. The acidification reached a depth of 50cm. Liming in addition to ammonium sulfate could not keep pH on the same level as calcium cyanamide did. The other treatments showed pH-values between 5.8 and 6.0. Total carbon and nitrogen in treatments with farm manure, calcium cyanamide and ammonium sulfate were 0.91 to 0.98 % C, in the treatments without N and with nitrate 0.81 resp. 0.87 % C. Farm manure and calcium cyanamide produced a higher content of humic acids in organic matter than ammonium and nitrate fertilization did. Ammonium fertilization increased the content of fulvic acids. Biological activity of soils, measured as activity of 5 enzymes and 02-consumption depends mainly on pH. Highest activity is found in the soil of treatment calcium cyanamide (except catalase). The proportion of hydrolysable and non-hydrolysable nitrogen (12 % non-hydrolysable N) was not changed by fertilizing (except in the plot with farm manure which increased non-hydrolysable N to 14%). Nitrogen mineralisation in laboratory incubation trials were closely correlated with total N (r = 0.94). Lower correlation was found in plant experiments (r = 0.72 to 0.79). Other factors influencing nitrogen mineralisation are discussed. 相似文献
17.
长江中游水稻土潜育作用的特点 总被引：5，自引：0，他引：5
PAN Shu-Zheng 《土壤圈》1996,6(2):111-119
The gleyization of representative paddy soils in the middle reaches of the Yangtze River was characterized, taking oxidation-reduction potential(Eh), the amount of active reducing substances and the forms of iron and manganese as the parameters. The Eh value was linearly related with the logarithm of the amount of active reducing substances, which was contributed by ferrous iron by 83% on an average. The degree of gleyization of different horizons was graded as ungleyed, slightly gleyed, mildly gleyed and gleyed. The Eh of the four grades was > 500, 300-500, 100-300 and < 100 mV, respectively, and the corresponding amount of active reducing substances was < 1, 1-7, 7-30 and > 30 mmolc kg-1, respectively. The amount of ferrous iron of the four grades was < 0.5, 0.5-5, 5-25 and > 25 mmol kg-1, respectively. The extent of gleyization of a soil was classified as upper-gleyed, middle-gleyed and lower-gleyed, depending on whether the depth of the gley horizon was less than 30 cm, 30-60 cm or more than 60 cm. 相似文献
18.
通过室内恒温(25℃)避光培养试验,研究了黑土环境中乙草胺的微生物降解特征。在适宜水分条件下,将土壤样品分别进行常规、灭菌、选择性抑菌剂加入等处理后培养并测定土壤乙草胺含量和土壤微生物量。结果显示:在灭菌土壤中乙草胺的残留量较未灭菌土壤显著增加,未灭菌土壤中乙草胺残留数量与微生物量变化密切相关,表明微生物活性是影响乙草胺降解的主要因素。适当的水分有益于土壤中微生物生长,从而促进了土壤中乙草胺的降解。加入青链霉素后乙草胺残留量远大于放线菌酮和常规培养,表明细菌比真菌具有更强的降解乙草胺的能力。随着乙草胺的施药量增加,初期微生物量显著降低,是导致乙草胺总降解率下降的主要原因。 相似文献