长期石油污水灌溉对东北旱田土壤微生物生物量及土壤酶活性的影响

以土壤微生物生物量和土壤酶活性等为土壤微生物变化指标,研究了含油污水长期灌溉对东北沈抚灌区农田土壤微生物的影响.结果表明:土壤微生物生物量碳和生物量氮随着污灌有机物污染程度的增加而增加,与土壤石油烃(TPH)含量极显著正相关,相关系数分别为0.955和0.962(P<0.01);与土壤多环芳烃(PAHs)含量也极显著正相关,相关系数为0.941和0.946(P<0.01).土壤酶活性分析表明,土壤脱氢酶和多酚氧化酶与土壤TPH含量极显著正相关,相关系数分别为0.977和0.958(P<0.01);与PAHs含量也极显著正相关,相关系数分别为0.997和0.977(P<0.01).土壤中的脲酶受污水灌溉中含N物质的影响与TPH含量显著相关,相关系数为0.713(P<0.05),与PAHs污染无明显相关性.而纤维素酶与土壤有机物污染无明显相关关系.土壤微生物生物量和土壤脱氢酶、多酚氧化酶可以作为污灌土壤TPH和PAHs污染敏感的生物学和生物化学指标.     

黑土环境中乙草胺的微生物降解特征研究

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。     

Enhancement of revegetation on construction fill by fertilizer and topsoil application: Effect on mycorrhizal infection

The influence of topsoil and fertilizer application on denuded road construction sites was evaluated to assess its contribution to improvement of vegetation re-establishment. the study sites were within a mixed hardwood and conifer forest on crushed, unweathered subsurface material with low fertility and low biological activity. Topsoils were removed from the site, stockpiled and reapplied to the site after construction. the effect of topsoil amendment on plant growth, soil fertility, mycorrhizal infection and an index of microbial biomass were measured in field and greenhouse experiments. Plant growth on the topsoil amended field plots were greatly increased relative to treatments with fertilizer but no topsoil. Three years after establishment, dry weight production on the plots without topsoil treatment was about 40 per cent of the plots treated with topsoil. Greenhouse experiments were designed to compare fresh, dried and stockpiled topsoil. These experiments indicated that storage of the harvested topsoil for five months in a stockpile had minor effects on plant growth, soil fertility, mycorrhizal infection and microbial biomass. Topsoil volumes had to exceed 20 per cent of the total soil volume to achieve statistically significant benefits and higher ratios showed greater benefit. the percentage of mycorrhizal infection was greatest in topsoil treatments without fertilizer. the addition of fertilizer increased growth but reduced the percentage of roots forming mycorrhizae. When the total weight of infected roots was calculated, however, infection was found to be greatest with a moderate level of fertilizer (equivalent to approximately 27 kg N ha⁻¹ and 39 kg P ha⁻¹), and was less in both higher fertilizer treatments and in unfertilized treatments. Topsoil amendment increased microbial biomass nitrogen but fertilizer treatment did not.     

长期少免耕对中国东北玉米农田土壤呼吸及碳氮变化的影响

在黑土区37年不同耕作模式定位试验田,采用原位法比较常规旋耕灭茬起垄（CT）、旋耕留高茬行间深松-少耕（RT）、免耕（NT）和深翻（PT）4种耕作模式土壤呼吸速率及其与土壤温度和湿度的关系,测定土壤总碳氮、无机氮,微生物碳氮的变化。结果表明,玉米生育期间土壤呼吸呈单峰变化,开花期达最大值,生长季平均呼吸速率依次为RT > NT > CT > PT。4个处理土壤温度与土壤呼吸速率间存在显著指数关系。不同耕作模式0~10 cm土壤温度可解释土壤呼吸速率变异的38.3%~67.9%,温度敏感性系数Q10范围为2.1~5.3;RT和NT处理显著提高0~20 cm土壤碳氮含量;RT处理在0~20 cm土壤中微生物碳含量均高于CT、NT和PT处理。RT处理土壤呼吸对温度响应提高,RT和NT处理显著增加上层土壤总碳氮含量,利于土壤质量提升。     

黄河故道区域不同种植模式及秸秆还田方式对土壤的改良效果

由于长期受到流水冲击,黄河故道区域农田以中低产田为主,因此本区域农田质量提升成为黄河中下游平原绿色发展的重要研究课题。在河南濮阳清丰地区秸秆还田方式的基础上,选取黄河故道区域广泛种植的小麦、玉米和花生三大主要农作物,于2009年进行4种种植模式长期定位试验：小麦-玉米、小麦-花生、小麦-玉米-小麦-花生和单季花生,其中小麦和玉米秸秆全部还田,花生秸秆不还田,探究不同种植模式对土壤理化性质和微生物群落结构的影响。结果表明,秸秆还田量越多,土壤有机质含量提高越多,小麦-花生、小麦-玉米-小麦-花生种植模式下土壤有机质含量最高,且其土壤含水量也显著高于其他处理,上层土壤容重有所降低,显著改善了土壤砂质化,提升了土壤的蓄水能力;秸秆还田量较大的种植模式的养分保持能力明显提高,养分含量显著增加;微生物群落结构对不同种植模式响应结果为,花生可以显著提升微生物丰度,微生物群落多样性随种植作物类型的增加而增加。因此,小麦-玉米-小麦-花生种植模式较为适宜濮阳清丰黄河故道区域,有利于土壤改良和区域农业的可持续发展。     

宜春市生态农业与农业可持续发展模式

通过对宜春市红壤丘陵区生态农业建设的现状和制约因素的研究,提出宜春市生态农业建设模式。通过发展特色立体农业体系,突显微生物农业,发展绿色食品产业,以达到合理利用资源,实现农业生态系统良性生态循环和经济循环协调发展。     

农药污染对微生物多样性的影响

介绍了土壤农药污染对微生物多样性的影响,并简单探讨了研究的发展方向。     

人工接种堆肥和自然堆肥微生物区系变化的比较

[目的]为了明确堆肥过程中微生物菌群的组成与变化,为堆肥工艺的优化和人工接种腐熟菌群的应用提供理论依据。[方法]采用传统的平板培养技术研究了人工接种堆肥、自然堆肥微生物群落演变过程。[结果]传统培养方法显示两种堆肥过程中微生物群落演变均呈"升高-降低-升高-降低"变化,堆肥整个过程中细菌数量占优势;人工接种NMF菌群增加了堆肥中微生物总体数量,丰富了微生物种群多样性,促进了堆肥菌群演替,堆肥腐熟时间缩短;接种NMF菌群能够提高堆肥纤维素分解菌、放线菌、氨化细菌、硝化细菌数量,减少堆肥反硝化作用,有利于纤维素、木质素等难降解物质的分解、转化为腐殖质,同时能够减少堆肥过程中氮素损失。[结论]研究堆肥过程中微生物区系的演变对于了解堆肥进程、优化堆肥工艺具有重要的意义。     

秸秆微贮饲料养羊效果研究

在饲草资源极度缺乏的宁南偏旱区,利用当地农作物秸秆微贮后喂羊,试期66 d.结果表明,试验组每只羊平均日增重204.55 g,对照组92 .42 g,试验组比对照提高121.33%,差异极显著(P＜0.01),平均每只羊试验组比对照组多收益59.79元,不但解决了当地饲草的紧缺问题,而且提高了养羊业的经济效益.