Reuse potential of phosphorus-rich filter materials from subsurface flow wastewater treatment filters for forest soil amendment

The aim of this study was to test P-enriched filter materials from a wastewater treatment experiment regarding their fertilizing efficiency in pot experiments with silver birch (Betula pendula Roth.) seedlings. Tested materials included hydrated calcium-rich oil shale ash and well-mineralised peat. A mixture of peat and hydrated ash demonstrated the best results: seedlings grown on that mixture had the highest P concentration and an optimal N:P:K ratio in leaves. Hydrated ash has a low concentration of heavy metals and almost the same composition as common lime fertilizers. The hydrated ash sediment and its combination with well-mineralised peat enriched with phosphorus in wastewater treatment filters are promising materials for forest soil fertilization.     

锡金海棠子叶再生体系的建立

锡金海[Malussikkimensis（Wenz．）Koehne]是我国稀有植物和优良苹果砧木种质资源。本研究探讨了影响锡金海棠离体再生的条件,建立了锡金海棠子叶高效离体再生体系。结果表明,子叶再生体系的最佳诱导培养基SC＋0．1mg·L-1 NAA＋2．0mg·L-1 TDZ,最佳分化培养基SC＋0．1mg·L-1 NAA＋1．5mg·L-1 TDZ,最佳继代增殖培养基SC＋2．0mg·L-1 6-BA＋0．2mg·L-1 NAA,最佳生根培养基为1／2MS＋I．0mg·L-1 IBA。炼苗后,移入珍珠岩、花生壳与草炭（1：1：1）的基质中,20d移栽成活率高达90％。     

钻井废弃物配合外源有机物质对风沙土理化性质及菠菜生长的影响

采用室内盆栽试验研究水基废弃钻井泥浆、岩屑等钻井废弃物配合腐植酸、木本泥炭等外源有机物质在风沙土中的施用效果,并分析其对菠菜生长的影响,以期为钻井废弃物资源化利用和风沙土改良提供参考。共设3组室内盆栽试验:基础组共4个处理,以风沙土为对照(CK),将风沙土与岩屑按质量比1∶1混合后分别添加0、2%、4%含量水基废弃钻井泥浆(干基);基础组处理分别添加1%腐植酸、1%腐植酸+3%木本泥炭混合物,作为腐植酸组和木本泥炭组。结果表明: 基础组中,与CK相比,施用钻井废弃物显著增加了土壤有机质含量,pH和电导率上升,2%含量水基废弃钻井泥浆显著促进菠菜生长。腐植酸和木本泥炭使土壤pH降低,有机质含量显著增加,电导率上升,腐植酸组株高、总叶面积、鲜重、干重等植物生长指标均高于基础组中对应处理,混合添加腐植酸和木本泥炭后对植物生长促进效果不显著。最佳处理为腐植酸组添加2%含量水基废弃钻井泥浆,土壤有机质含量为13.1 g·kg^-1,播种40 d后菠菜株高、总叶面积、鲜重和干重分别比CK显著增加49.7%、93.4%、83.3%、34.6%。钻井废弃物配合有机物质施用可以显著增加土壤有机质含量,促进菠菜生长,风沙土+岩屑+水基废弃钻井泥浆(2%)+腐植酸(1%)是最佳组合模式。     

聚丙烯酰胺(PAM)防治土壤风蚀的研究进展

在我国西北地区,风蚀是造成土地退化的主要影响因素之一.聚丙烯酰胺(PAM)是一种高效的土壤结构改良剂.因其具有特殊的物理化学性质,可以与土壤作用而改善土壤表层结构,近年来一直受到人们的广泛关注.本文介绍了PAM的物理化学性质,详细论述了PAM对土壤风蚀量、起动风速的影响,及PAM在风蚀防治中的不同使用量、使用方法和效果,及其与其他材料的对比,并通过PAM对土壤物理性质的改善进一步分析PAM防治风蚀的机理.综合分析得出,虽然PAM在风蚀防治中存在一些问题,但作为一种固沙剂,它不仅能提高土壤抗风蚀的能力,而且也能改善土壤的物理性状,可为植物生长创造良好的水土条件;提出若在风蚀治理和改良城市环境中将PAM与植物种植相结合,将能大大提高植物的成活率、改善风蚀区的风蚀状况和生态环境工程建设的质量.因此,PAM在防治风蚀方面具有重要的现实意义和广阔的应用前景.     

聚丙烯酰胺对坡地苹果园水土流失和土壤养分流失的影响

为了改善坡地苹果园的土壤环境,遏制水土流失和土壤养分流失,探寻聚丙烯酰胺适宜的干撒施用量,2010—2012年在陕北丘陵沟壑区的坡地苹果园,以不施聚丙烯酰胺为对照,分别撒施0.6、0.8、1.0、1.2、1.4和1.6 g·m^-2的聚丙烯酰胺,监测果园地表产流、土壤流失、养分流失和苹果植株生长状况.结果表明: 坡地果园的径流量和5—7月的产流次数均随聚丙烯酰胺撒施量的增加呈“V”型变化,其中撒施量为1.0 g·m^-2时最低,但果园侵蚀泥沙量则随聚丙烯酰胺撒施量的增加而降低.地表径流和侵蚀泥沙中的铵态氮、速效磷和速效钾的浓度均随聚丙烯酰胺撒施量的增加而降低;聚丙烯酰胺可显著降低地表径流中的硝态氮含量,对侵蚀泥沙中的硝态氮含量则无显著影响;侵蚀泥沙中的有机质、全氮、全磷和全钾含量均随聚丙烯酰胺撒施量的增加而降低.聚丙烯酰胺提高了苹果单果质量及产量,但对苹果植株生长及果实风味品质无显著影响.聚丙烯酰胺在坡地苹果园中的适宜撒施量应为1.0 g·m^-2.     

跨地带土壤置换实验研究

以温带针阔混交林暗棕壤地带内的白浆土、草甸土、泥炭土为原料,以长白山自然保护区内的寒温带山地棕色针叶林土为置换对象,完成了仿自然原型的土壤合成,进行了跨地带的土壤置换与植被生长实验研究。结果表明:①山地棕色针叶林土的腐殖质层厚度、酸度和速效氮含量为植被生长的限制性因子;②合成土壤理化指标必须以原生土壤限制因子拐点(值)指标为确定依据,作为合成土壤的关键性指标;③在长白山采用泥炭土与草甸土各占1/4,白浆土占1/2进行混合,土层厚度40cm,并使用石灰进行调酸达到中性后,植被恢复效果最好、造价最低。     

长期施肥对红壤旱地作物产量和土壤肥力的影响

历时14年的田间定位试验表明,红壤旱地磷素最为缺乏,施用磷肥对提高作物产量效果最好;施用石灰和微量元素对作物产量没有明显增产作用．施肥可以提高花生植株磷、钾的浓度,表明作物的养分含量受土壤养分供应水平的影响．土壤中赢余(亏损)的养分在养分库重建中的作用可以用速效养分库重建效率来表示．研究表明,当红壤旱地N、P2O5、K2O养分赢余1kg·hm^-2时,可分别使土壤中水解氮、有效磷、交换性钾含量提高0．6～6．26、0．20～0．28和1．1～8．5mg·kg^-1．红壤旱地氮和磷通过径流等损失较大,不同处理之间的变化幅度也较大．红壤每年可固定磷43．5kg·hm^-2,通过自身风化作用每年可提供氮48．1kg·hm^-2和钾40．5kg·hm^-2,以满足作物生长所需．     

Fatty acid composition of canola (Brassica napus L.), as affected by agronomical,genotypic and environmental parameters

Vegetable oils with a high relative amount of unsaturated fatty acids are of great significance for human health. There is not any data on the effects of tillage practices on fatty acid composition of canola (Brassica napus L.). Hence, in a 2-year split plot experiment, the effects of different tillage systems (no (NT), minimum (MT) and conventional tillage (CT)), canola genotypes (Hyola 401 (V1) and PF (V2)) and sowing dates (including Sep. 8, 23 and Oct. 7) on the fatty acid composition of canola were evaluated. Tillage practices and the combination of canola genotypes and sowing dates were randomized to the main and sub-plots, respectively. The highest oleic acid content was the result of combining NT, V1 and Sep. 23, and the lowest was related to the combination of CT, V2 and Oct. 7. While the combination of NT, V1 and D1 resulted in the highest amount of unsaturated fatty acids, this amount was the lowest for the combination of CT, V2 and Sep. 23. For the selection of an appropriate canola producing strategy, all these parameters must be taken into account. The combination of NT, V1 and Sep. 23 may be the most favorable cropping strategy for canola production under a Mediterranean climate.     

Effect of silicate on phosphate availability for rice in a P-deficient soil

In a pot experiment the effect of silicate on P availability for rice grown in a P-deficient soil with and without flooding was analyzed. Treatments were designed as follows: C (control: Yakuno soil), SS (sodium silicate application, at 0.47 mg Si g^-1 soil) and SC (sodium carbonate application). In order to separate pH effect from Si effect, SC was adjusted to the same pH as SS.Soil pH of SS and SC increased by 1.0 unit. Shoot dry weight of SC plants, and more so of SS plants, increased under both nonflooded and flooded conditions. P concentrations in the shoots were not increased under either condition of SS and SC. With SS, Si concentration in the shoots significantly increased, Mn concentration significantly decreased, resulting in a higher P/Mn ratio in the shoot, but not with SC. Both SS and SC increased N concentration in the shoots nearly two times compared with control under both conditions.Adsorption experiments showed that neither SS nor SC decreased P adsorption by soil. SS also could not displace the adsorbed P in soil samples which had previously either received P or not.These results suggest that the beneficial effects of silicate on rice growth do not result from increasing P availability in soil. The Si effect may be attributed to decreasing Mn uptake, thus indirectly improving P utilization in the plant.     

生物质调理剂对川西北高寒草地沙化土壤养分和微生物群落特征的影响

将农牧废弃物进行资源化处置制成生物质调理剂,用于沙化土壤改良是目前川西北沙化草地生态治理的有效途径之一。为了阐明不同原料调理剂在川西北高寒沙化草地上的实际应用效果,本研究以不施用调理剂为对照(CK),设置施用量均为12 t·hm^-2的菌渣(JZ)、秸秆(JG)和生物炭(SWT) 3种调理剂,分析了调理剂施用对土壤养分和微生物群落特征及其相互关系的影响。结果表明: 与对照相比,各种生物质调理剂均显著增加了土壤速效养分和活性有机碳含量,增幅在23.0%～521.6%,其中施用秸秆调理剂(JG)的效果最佳,增幅为65.1%～521.6%。因生物质调理剂只在第一年施入,第二年的土壤速效养分和活性有机碳含量均较第一年整体下降了4.5%～92.3%,而土壤有机碳含量和微生物生物量碳均较第一年整体上升了5.6%～458.0%。生物质调理剂改变了微生物属水平优势菌属的相对丰度,其中,JG处理对细菌菌群的影响较大,JG和JZ处理对真菌菌群的影响较大。与CK相比,JG处理显著降低了土壤细菌和真菌的多样性,其中,Shannon指数显著降低了2.9%和31.8%,而Simpson指数显著提高了175.0%和320.9%。冗余分析显示,土壤速效养分和活性有机碳含量是影响微生物群落组成的重要因素,其中,土壤硝态氮含量和微生物生物量碳对细菌群落组成的影响较大,共解释了65.9%的群落变化,土壤速效钾含量和微生物生物量碳对真菌群落组成的影响较大,共解释了83.2%的群落变化。综合比较,秸秆调理剂能显著增加土壤速效养分和活性有机碳含量,有利于有益细菌和真菌微生物菌属的生长,可以作为提升川西北地区高寒草地沙化土壤质量的推广措施。     

Effect of phosphate rock,coal combustion by-product,lime, and cellulose on ryegrass in an acidic soil

Remediation of soil acidity is crucial for increasing crop production and improving environmental quality of acid infertile soils. Soil incubation and greenhouse pot experiments were carried out to examine the interactions between phosphate rock (PR), coal combustion by-product (BP), dolomitic lime (L), and cellulose (C) in an acidic soil and their effects on ryegrass (Lolium perenne L. cv Linn) growth. BP and PR application increased plant P content and dry matter yield (DMY) of shoots and roots by improving soil Ca availability and reducing Al toxicity. Application of BP at low rates (5 to 10 g BP kg^-1) with PR appeared to decrease both plant P content and DMY compared to PR application alone. The reduced DMY is due to an increased Al concentration in soil solution as a result of displacement of sorbed Al by Ca of BP. Increases in DMY were obtained by addition of lime along with PR and BP at low rates or by increasing BP application rates above 15 g kg^-1. This improved plant response was likely related to alleviation of Al toxicity by CaCO₃ contained in the BP. In addition to raising the pH to an acceptable level for plant growth, the dolomitic lime supplied needed Mg for plants, thereby maintaining a good balance between available Ca and Mg for plants in the BP- and PR-amended soils. The addition of cellulose to the BP- and PR-amended soils reduced water-soluble Al and increased DMY. Plant growth increased PR dissolution by 2.4 to 243% in a soil with low available P. Use of BP at moderate rates with PR and dolomitic lime appears to be the best combination in increasing crop yields on infertile acidic soils.     

Effect of amendments on phytoavailability and fractionation of copper and zinc in a contaminated soil

The ability of amendments to modify the soil properties and influence plants to immobilise Cu and Zn was studied in a naturally contaminated, additionally spiked podzolic soil. Lolium perenne L (perennial rye grass), Festuca rubra L (creeping red fescue) and Poa pratensis L (Kentucky blue grass) were tested in a pot study in the presence of soil amendments (lime, phosphate, and compost, individually and in combination) to assess the effect of soil-plant-amendment interaction on phytostabilisation. The ability of treatments to stabilize metals was assessed on the basis of metal fractionation in soil, partitioning of metals in plants, and metal uptake by the plants. Significant partitioning of Cu into immobile forms occurred as a result of the growth of Festuca rubra, and of Zn by the growth of Poa pratensis. Application of lime significantly reduced the exchangeable fraction of Zn, whereas phosphate application had an accelerating effect on exchangeable Cu. With combined application of amendments, the plant metal concentration decreased by more than 40% for Cu and 70% for Zn, compared to soils receiving no amendments. Combined application of amendments, in conjunction with growth of Festuca and Poa, can be recommended for phytostabilising of Cu and Zn in moderately contaminated acid soils of southwest British Columbia.     

不同物料配比对城市绿地土壤渗透性及污染物净化效果的影响

绿地土壤是城市的重要载体。为探讨不同物料配比对西咸新区土壤渗透性改良及污染物净化效果的影响,本试验将生物质炭、蛭石、珍珠岩、堆肥、聚丙烯酰胺(PAM)、椰糠等6种物料分别与体积比为4∶4的土沙混匀,室内培养30 d,分析了介质容重、饱和导水率、饱和含水量及污染物总氮(TN)、总磷(TP)、化学需氧量(COD)、铜(Cu)、锌(Zn)、镉(Cd)浓度。结果表明: 体积比分别为0.5∶1.5(Ⅰ)和1∶1(Ⅱ)的生物质炭∶堆肥添加1%PAM配比对介质渗透性(包括容重、饱和导水率、饱和含水量)的改良效果最好;I添加0.5%PAM配比对TN、COD的净化效果优于添加1%PAM处理,但后者对Zn、Cd、Cu的吸附率分别达99.9%、99.7%、97.2%。综合考虑,体积比为0.5∶1.5的生物质炭∶堆肥添加1%PAM可作为西咸新区城市绿地土壤换填介质。     

Liposomes enhance bioremediation of oil-contaminated soil

Liposomes (composed of soy phosphatides) in the form of small unilamellar vesicles (SUV), when added to soil contaminated by crude oil, accelerate bioremediation. After three weeks incubation at 30 degrees C, using soil experimentally contaminated (with 10,000 ppm crude oil), level of bioremediation increased from 40% without SUV to 75% with SUV (0.1 wt% phospholipids per dry weight soil). Similarly, for accidentally contaminated soil (with approximately 17,000 ppm crude oil), addition of 0.1 wt% SUV to the soil increased the bioremediation level from 55 to 80%. The enhancing effect of liposomes is explained by two interrelated phenomena: a large increase both in total bacteria number and in diversity of bacterial species in the soil. Comparison after four weeks revealed 21 bacterial species in the presence of liposomes (many being oil-degrading bacterial species) and only nine species in the absence of liposomes. Both effects may be related to the physical effects of liposome phospholipids, which modify the crude oil by wetting it, thereby making it more accessible to the microorganisms. In addition, liposome phospholipids serve as phosphate and nitrogen sources for the bacteria.     

施用泥炭对风沙土改良及蔬菜生长的影响

通过盆栽试验比较了施用不同剂量的泥炭(0％、2％、5％、8％及10％)对风沙土改良的效果和对白菜生长及产量的影响。结果表明,泥炭能增强风沙土的持水能力,降低土壤的pH值,增加土壤中有机质、全氮、速效氮和速效磷等的含量;白菜根系长度、生物量、高生长和地上部分的生物量均有增加,其中8％泥炭处理为最佳,其根系长度、根鲜重、干重、高生长、地上部分鲜重、干重依次比对照增加71％、402％、464％、107％、847％和1001％;同时施用泥炭还有利于提高白菜干物质的积累及其品质。     

长期施用化肥及秸秆还田对砂姜黑土细菌群落的影响

【目的】在施用化肥的基础上进行秸秆还田是提高砂姜黑土肥力的有效措施,以往的研究只注重秸秆还田对土壤结构、肥力等物理化学性状方面的研究,缺少施肥对砂姜黑土微生物群落影响的研究。本研究以安徽蒙城典型的砂姜黑土为研究对象,以期揭示长期施用化肥和秸秆还田对砂姜黑土细菌群落的影响。【方法】采用454高通量测序对砂姜黑土不同农业施肥措施下的细菌群落进行分析研究,并通过生物信息学的分析方法揭示影响砂姜黑土细菌群落的主要因素。【结果】通过对454高通量测序数据的分析,发现砂姜黑土主要的细菌门类为放线菌、变形菌、酸杆菌、绿弯菌和拟杆菌。长期施用化肥显著提高了砂姜黑土肥力和作物产量,但导致了细菌群落结构的显著变化和多样性的显著降低。秸秆还田有利于土壤肥力的进一步提高,但是并没有缓解长期施用化肥对土壤细菌群落产生的不利影响。分析发现土壤pH的变化是导致土壤细菌群落变异的主要因素。【结论】在施用化肥的基础上进行秸秆还田有利于砂姜黑土肥力的提升,然而并没有缓解由施肥导致的土壤酸化对土壤细菌群落组成和多样性产生的不利影响。这暗示秸秆还田可能并未对砂姜黑土微生物生态产生根本性的有益影响,对于秸秆农田的利用方式还需要进一步研究,以达到农业生产效益和生态效益的并重。     

Removal of dimethyl disulfide by the peat seeded with night soil sludge

The removal characteristics of dimethyl disulfide (DMDS) with a fibrous peat biofilter were studied. The peat itself did not remove DMDS. The peat inoculated with aerobically-digested night soil sludge as a source of microorganisms showed an efficient removal of DMDS with the maximum removal rate, 0.68 g-S·kg-dry peat⁻¹·d⁻¹ and the saturation constant, 1 ppm. The removal rate of DMDS by the biofilter decreased when pH was below 5.5. The number of microorganisms isolated on thiosulfate-agar plates (pH 7) remarkably increased in DMDS-acclimated peat. Similar removal characteristics and the change in microflora were observed in methanethiol (MT)- and dimethyl sulfide (DMS)-acclimated peat. These results indicated that some chemolithotrophic and non-acidophilic sulfur-oxidizing microorganisms such as Thiobacilli, originating from night soil sludge, were responsible for degradation of these organosulfur compounds in the peat biofilter.     

Application of silicon sources increases silicon accumulation in perennial ryegrass turf on two soil types

This study investigated the ability of perennial ryegrass to accumulate silicon and the factors that may influence plant silicon accumulation. Plants were grown in the greenhouse in two soil types, peat:sand mix and Hagerstown-silt-loam, amended with two commercially available sources of silicon, calcium silicate slag and wollastonite at 0, 0.5, 1, 2, 5 and 10 t/ha. Shoot tissue of nine-week-old perennial ryegrass plants was analyzed for silicon content (%) and found to reach a dry matter concentration of up to 4% in this study. Silicon accumulation in perennial ryegrass was influenced by the soil type and source, and was higher in plants grown in low-silicon peat:sand mix compared to Hagerstown-silt-loam. Silicon content (%) in the plants consistently increased with increasing rates of silicon in all four soil and source combinations. Acetic acid (HAc) extractable silicon and Ca increased in both soil types when amended with either of the silicon sources. Effects of silicon sources on soil pH varied with soil type. This study indicates that soil type, source of silicon, and rate of silicon application are important factors influencing the uptake of silicon by perennial ryegrass which is a widely used turfgrass species in golf courses, sports fields, and residential lawns in the United States.     

油茶良种‘华硕’的组织培养及高效生根

以油茶‘华硕’带芽茎段为外植体,研究植物生长调节剂、珍珠岩对其快速繁殖及试管苗生根的影响。结果表明：茎段腋芽萌发的最佳培养基为：MS＋2.0 mg·L^-1 6-BA＋0.1 mg·L^-1 IAA,萌发率达88.68%;最佳继代增殖培养基为：WPM＋3.0 mg·L^-1 6-BA＋0.01 mg·L^-1 IBA＋6.0 mg·L^-1 GA3,增殖系数可达11.27;最佳壮苗伸长培养基为：WPM＋0.05 mg·L^-1 IAA＋6.0 mg·L-1GA3;最佳生根培养基为：1/2MS＋1.0 mg·L^-1 IBA＋50 g·L^-1珍珠岩,生根率95.83%。炼苗后移栽到泥炭土、珍珠岩、黄土（1：1：1,V/V/V）混合基质中,成活率达85%以上。     

Seasonal Changes in the Rhizosphere Microbial Communities Associated with Field-Grown Genetically Modified Canola (Brassica napus)

The introduction of transgenic plants into agricultural ecosystems has raised the question of the ecological impact of these plants on nontarget organisms, such as soil bacteria. Although differences in both the genetic structure and the metabolic function of the microbial communities associated with some transgenic plant lines have been established, it remains to be seen whether these differences have an ecological impact on the soil microbial communities. We conducted a 2-year, multiple-site field study in which rhizosphere samples associated with a transgenic canola variety and a conventional canola variety were sampled at six times throughout the growing season. The objectives of this study were to identify differences between the rhizosphere microbial community associated with the transgenic plants and the rhizosphere microbial community associated with the conventional canola plants and to determine whether the differences were permanent or depended on the presence of the plant. Community-level physiological profiles, fatty acid methyl ester profiles, and terminal amplified ribosomal DNA restriction analysis profiles of rhizosphere microbial communities were compared to the profiles of the microbial community associated with an unplanted, fallow field plot. Principal-component analysis showed that there was variation in the microbial community associated with both canola variety and growth season. Importantly, while differences between the microbial communities associated with the transgenic plant variety were observed at several times throughout the growing season, all analyses indicated that when the microbial communities were assessed after winter, there were no differences between microbial communities from field plots that contained harvested transgenic canola plants and microbial communities from field plots that did not contain plants during the field season. Hence, the changes in the microbial community structure associated with genetically modified plants were temporary and did not persist into the next field season.