Effects of microplastic polystyrene, simulated acid rain and arbuscular mycorrhizal fungi on Trifolium repens growth and soil microbial community composition

Microplastic pollution is a global and ubiquitous environmental problem in the oceans as well as in the terrestrial environment. We examined the fate of microplastic polystyrene (MPS) beads in experimental soil in the presence and absence of symbiotic arbuscular mycorrhizal fungi (AMF) and simulated acid rain (SAR) to determine whether the combinations of these three factors altered the growth of white clover Trifolium repens. We found that MPS, SAR, or AMF added singly to soil did not alter T. repens growth or yields. In contrast, MPS and AMF together significantly reduced shoot biomass, while SAR and MPS together significantly reduced soil available phosphorus independent of AMF presence. Microplastic polystyrene, AMF, and SAR together significantly reduced soil NO^-₃-N. Arbuscular mycorrhizal fungi added singly also enriched the beneficial soil bacteria (genus Solirubrobacter), while MPS combined with AMF significantly enriched the potential plant pathogenic fungus Spiromastix. Arbuscular mycorrhizal fungi inoculation with MPS increased the abundance of soil hydrocarbon degraders independent of the presence of SAR. In addition, the abundance of soil nitrate reducers was increased by MPS, especially in the presence of AMF and SAR. Moreover, SAR alone increased the abundance of soil pathogens within the fungal community including antibiotic producers. These findings indicate that the coexistence of MPS, SAR, and AMF may exacerbate the adverse effects of MPS on soil and plant health.     

Changing public interest in,and awareness of,acid deposition: Some evidence from the UK

It is fundamental that the general public have access to usable environmental information on which they can base their decisions. Since 1984 the Atmospheric Research and Information Centre (ARIC) has operated a public information programme for the UK on the subject of acid deposition. The objective of the programme is to disseminate information on acid deposition without advocacy. ARIC provides enquirers with a broad range of authoritative and accurate facts and opinions from a wide range of parties from all sides of the debate. These sources include pressure groups, governmental bodies and industrialists from the UK and overseas. By deconstructing complex technical material and reassembling it for dissemination in a user friendly form, ARIC assists those receiving information to obtain a balanced perspective. This enables personal decision making within the context of the fullest information resource ARIC is able to provide.     

Prolonged simulated acid rain treatment in the subarctic: Effect on the soil respiration rate and microbial biomass

Humus chemistry and respiration rate, ATP, ergosterol, and muramic acid concentration as measures of chemical properties, microbial activity, biomass, and indicators of fungal and bacterial biomass were studied in a long-term acid rain experiment in the far north of Finnish Lapland. The treatments used in this study were dry control, irrigated control (spring water, pH 6), and two levels of simulated acid rain (pH 4 and pH 3). Originally (1985–1988), simulated acid rain was prepared by adding both H₂SO₄ and HNO₃ (1.9:1 by weight). In 1989 the treatments were modified as follows. In subarea 1 the treatments continued unchanged (H₂SO₄+HNO₃ in rain to pH 4 and pH 3), but in subarea 2 only H₂SO₄ was applied. The plots were sampled in 1992. The acid application affected humus chemistry by lowering the pH, cation exchange capacity, and base saturation (due to a decrease in Ca and Mg) in the treatment with H₂SO₄+HNO₃ to pH 4 (total proton load over 8 years 2.92 kmol ha^-1), whereas the microbial variables were not affected at this proton load, and only the respiration rate decreased by 20% in the strongest simulated acid rain treatment (total proton load 14.9 kmol ha^-1). The different ratios of H₂SO₄+HNO₃ in subareas 1 and 2 did not affect the results.     

酸雨对土壤有机碳氮潜在矿化的影响

Acid rain is a serious environmental problem worldwide. In this study, a pot experiment using forest soils planted with the seedlings of four woody species was performed with weekly treatments of pH 4.40, 4.00, 3.52, and 3.05 simulated acid rain （SAR） for 42 months compared to a control ofpH 5.00 lake water. The cumulative amounts of C and N mineralization in the five treated soils were determined after incubation at 25 ℃ for 65 d to examine the effects of SAR treatments. For all five treatments, cumulative CO2-C production ranged from 20.24 to 27.81 mg kg^-1 dry soil, net production of available N from 17.37 to 48.95 mg kg^-1 dry soil, and net production of NO3-N from 9.09 to 46.23 mg kg^-1 dry soil. SAR treatments generally enhanced the emission of CO2-C from the soils; however, SAR with pH 3.05 inhibited the emission. SAR treatments decreased the net production of available N and NO3-N. The cumulative CH4 and N2O productions from the soils increased with increasing amount of simulated acid rain. The cumulative CO2-C production and the net production of available N of the soil under Acmena acuminatissima were significantly higher （P 〈 0.05） than those under Schima superba and Cryptocarya concinna. The mineralization of soil organic C was related to the contents of soil organic C and N, but was not related to soil pH. However, the overall effect of acid rain on the storage of soil organic matter and the cycling of important nutrients depended on the amount of acid deposition and the types of forests.     

Effect of anion composition of simulated acid rain on nutrient behavior in reclaimed saline soils

Abstract

Field experiments with the “Taikichi” taro cultivar were conducted in volcanic ash soil of Kagoshima Prefecture, Japan, in order to determine the effects of potassium applied with fertilizers and manures on the growth and yield of taro. The experimental design was accord ing to the L27 (3¹³) orthogonal factorial experiment, the three factors selected being the manures, nitrogen fertilizers and amount of potassium application.

“Metsubure” corm formation was infrequent in hog manured plots without potassium application, but was significantly increased by the application of potassium fertilizer. Furthermore, the occurrence of “Metsubure” corms was significantly lower in fields prepared with hog manure than in those prepared with plant residue and cattle manure.

Chemical analysis of the taro plants and manures revealed that the plants absorbed much more calcium when planted in hog manure than in other manures. The CaO/K₂O ratio was also higher. The main reason for this was assumed to be the lower content of potassium in the hog manure (0.37% K₂O on a dry basis).

The analytic results suggest that potassium disturbs the calcium uptake ability of the taro plant causing “Metsubure” corm formation.

The authors also attempted to determine the effects of several kinds of nitrogen fertilizers on “Metsubure” corm formation, but no clear results were obtained in this experiment.     

小麦与油菜种子萌发对酸雨胁迫的反应研究

用pH2.0、2.5、3.0、3.5、4.0、5.0模拟酸雨处理小麦和油菜种子试验结果表明,pH2.0时小麦和油菜种子不发芽,pH2.5时只有小麦异状发芽,pH≥3.0时小麦和油菜种子发芽率、发芽势、发芽指数、活力指数均与pH值显著正相关,小麦异状发芽率则随pH值上升而降低。小麦和油菜的吸水值、呼吸速率、贮藏物质运转效率也与pH值显著正相关,小麦贮藏物质消耗率与pH值显著正相关,而油菜与pH值显著负相关;小麦和油菜的根、芽长抑制指数均与pH值显著负相关,且小麦抗酸雨胁迫能力强于油菜。     

紫色土增施单质硫对大蒜生长发育和硫素营养的影响

对紫色土施用单质硫条件下大蒜生长发育及硫素营养吸收和代谢进行了研究。结果表明,大蒜株高、叶面积、经济产量(蒜头)和经济系数以中等供硫水平最高,而茎粗和生物产量则以高硫水平最大。大蒜能耐高浓度的硫素供应,在0～120kghm-2供硫情况下,其全硫(TS)、水溶性硫(SS)和无机硫(Io-S)含量均随供硫量的增加而上升,小分子水溶性含硫氨基酸含量(Ws-S)以低硫水平最高,而大分子蛋白质硫含量(Wis-S)以中等供硫水平时最高,与大蒜素含量的变化一致。大蒜素含量与不同硫组分比率的关系分析发现,大蒜素含量与Ws-S/TS呈极显著的正相关(r=0.752 ),与Io-S/SS呈显著的正相关(r=0.702 )。全氮含量与全硫含量变化趋势一致,全磷含量以低硫水平时最高,全钾含量以中等供硫水平时最高。     

Effect of Gypsum and Polyacrylamide Application on Erodibility of an Acid Kunigami Mahji Soil

Calcium carbonates and gypsum are often used to improve the chemical status of acid soils. This study discusses the effects of gypsum and polyacrylamide (PAM) application on infiltration and erodibility of a Japanese acid soil. Acid Kunigami mahji soil (sedimentary rock derived, Typic Hapludult) from Okinawa was packed into an acrylic plastic box, and simulated rainfall of 40 mm h⁻¹ was applied. Prior to the rainfall, 2.5 t ha⁻¹ of gypsum and/or 15 kg ha⁻¹ of non-ionic or anionic PAM were applied onto soil surface. During a rainfall, surface runoff was collected periodically, and sediment concentration, pH, and electric conductivity of the runoff were measured. Gypsum application enhanced surface runoff. During the rainfall, EC of the runoff was greater than the critical coagulation concentration of the clays of the mahji soil, however the soil became dispersive with gypsum application. PAM application could improve infiltration of gypsum amended mahji soil and reduce sediment loss.     

The individual and combined effects of ozone and simulated acid rain on chlorophyll contents,carbon allocation and biomass accumulation of armand pine seedlings

The seedlings of armand pine (Pinus armand Franch.) were applied to exposure, alone or in combination, to charcoal filtered air (CF) or ozone (O₃) at 300±15 nl/l(ppb) for 8 h a day, 6 days a week, and simulated rain of pH 6.8, 3.0 or 2.3, six times a week, alone and in combination, for 14 weeks from June 15 to September 20, 1993. No significant interactive effects of O₃ and simulated acid rain were observed on chlorophyll contents, carbon allocation and biomass accumulation of the seedlings in the present study. The O₃ caused reductions in biomass accumulation of whole-plant and below-ground parts, but not that of above-ground parts without an acute visible foliar injury. At the same time, the O₃ reduced R/S ratio, but raised F/C ratio. Therefore, O₃ also altered carbon allocation pattern. On the other hand, chlorophyll contents were increased by simulated acid rain, but other determined parameters were not altered.     

Effect of humic acid and fulvic acid based liquid and foliar fertilizers on the yield of wheat crop

Abstract

An organic-mineral liquid fertigation fertilizer containing humic acid, nitrogen (N)–phosphorus (P)–potassium (K), zinc (Zn), sulfur (S), manganese (Mn) and a liquid foliar fertilizer consisting of fulvic acid and gibberellic acids were formulated and applied to wheat. The purpose of this study was to develop an efficient and cost effective liquid and foliar fertilizer and compare their potential with commercially available urea and DAP. The fulvic acid and humic acids were obtained by alkaline extraction of lignite coal. All the treatments were significant over the control. The application of the liquid fertigation fertilizer and liquid foliar fertilizer along with 50?kg of urea per acre showed the best results biological yield (grain plus straw yield). It was found that the highest yield was obtained in T₆ treatment and the second best results were obtained with T₂ treatment, but has a high cost, while treatment T₆ was the most significant economical and yielded a high income when compared to other treatments.     

An integrated analysis of sulfur emissions,acid deposition and climate change

This paper presents one of the first integrated analyses of acidification and climate change on a geographically-detailed basis, and the first linkage of integrated models for acid deposition (RAINS) and for climate change (IMAGE 2). Emphasis in this paper is on Europe. Trends in driving forces of emissions are used to compute anthropogenic SO₂ emissions in 13 world regions. These emissions are translated into regional patterns of sulfur deposition in Europe and global patterns of sulfate aerosols using source-receptor matrices. Changes in climate are then computed based on changes in sulfate and greenhouse gases. Finally, we compute ecosystem areas affected by acid deposition and climate change based on exceedances of critical loads and changes in potential vegetation. Using this framework, information from global and regional integrated models can be used to link sulfur emissions with both their global and regional consequences. Preliminary calculations indicate that the size of European area affected by climate change in 2100 (58%) will be about the same as that affected by acid deposition in 1990. By the mid 21st century, about 14% of Europe's area may be affected by both acid deposition and climate change. Also, reducing sulfur emissions in Europe will have both the desirable impact of reducing the area affected by acid deposition, and the undesirable impact of enhancing climate warming in Europe and thus increasing the area affected by climate change. However, for the scenarios in this paper, the desirable impact of reducing sulfur emissions greatly outweighs its undesirable impact.     

Effect of litter removal on species richness and acidification of a mixed oak-pine woodland

Eutrophication of woodland ecosystems and disappearance of acidophilous species have often been observed in central and western Europe over recent decades. Considerable increase in air-borne nitrogen and sulphur has been invoked as responsible for these processes in most studies. Historic data indicate that for hundreds of years man removed litter and fodder from many woodlands in these areas. As a result, woodland soils became poorer and more acid than they were originally. Cessation of the removal of materials may resulted in soil enrichment and eutrophication of many woods. This hypothesis was tested in a 16-year litter removal experiment in an acidophilous mixed oak-pine wood in southern Poland. It was found that litter removal resulted in substantial impoverishment of soil. After 16 years soil of the litter removal plots contained significantly less P, Mg and Ca, and had a lower cation exchange capacity (CEC) in the epihumus subhorizon, and less Ca and a lower CEC in the humus and lessivage horizons than soil in the control plots. Vascular plant species and bryophytes colonized the litter removal plots much more frequently. Within 16 years species richness increased in the field layer of these plots, but abundance of dominant species and character of vegetation remained unchanged, while vegetation of the control plots changed from acidophilous to neutrophilous. Disappearance in the control plots of vascular plants species and mosses common in mixed woodlands was caused by thick litter layer which impeded seed germination and seedling development, and by competition of dominant species. The results obtained suggest that acidophilous vegetation in the field layer of the study wood was associated with material removal by man over a long time, and its eutrophication largely resulted from the cessation of traditional methods of management.     

钐-甘氨酸-维生素B6对酸雨胁迫下大豆幼苗的影响

试验研究钐-甘氨酸-维生素B_6(Sm-Gly-VB_6)对模拟酸雨伤害大豆幼苗的防护作用结果表明,在pH2.5酸雨胁迫下大豆幼苗叶绿素含量减少,叶绿素a/b值下降,细胞质膜透性增加,过氧化氢酶(CAT)活性下降。而同一强度酸雨胁迫下经50mg/kg Sm-Gly-VB_6预处理的大豆幼苗叶片叶绿素含量、细胞质膜透性与过氧化氢酶活性损伤较轻,对酸雨伤害大豆幼苗有一定缓解效应。     

The effect of simulated acid rain on feather mosses and lichens of the boreal forest

Permanent field plots containing a dominant ground cover of feather moss (Pleurozium schreberi) and the forage lichen, (Cladina), were established in mature, boreal forest jack pine stands to monitor the effects of simulated acid precipitation. For a five-year period commencing in 1981, bimonthly sprays (pH range 2.5 to 5.6) were given throughout the growing season. The feather moss wefts were extremely sensitive to simulated rains of pH 2.5 and 3.0; but loss of cover and frond blackening were also observed at pH 3.5. The pH 2.5 treatment killed almost all of thePleurozium, while the cover remaining in the pH 3.0 treatment after 5 years was reduced by 44%. In laboratory studies designed to compare the effects of H₂S0₄, HN03 and a 2:1 mixture of both, microcosms sprayed with H₂S0₄ alone (pH 3.0) were more significantly affected than fronds treated with HN0₃ alone or pH 5.6 sprays of any ratio. Although less sensitive thanPleurozium, field-sprayed lichens were also visibly damaged. At pHs less than 3.5,C. stellaris andC. rangiferina had reduced podetial height and dry weight; whileC. mitis was affected by a combination of the acid rain treatment and other associated factors. While ambient rains of pH 4.2 may not in themselves be harmful to the boreal ground flora, it is apparent that the feather mosses and lichens, lacking a cuticle and true roots, are very sensitive to occasional, extremely acidic rain events.     

硫、硼、锌对黄籽油菜营养特性的影响

采用盆栽试验与化学分析的方法,对甘蓝型黄籽油菜———"渝黄一号"进行了分析。结果表明:(1)增施S或Zn肥和土壤差异对苗期油菜生物量影响达显著性水平;(2)增施S、B或Zn肥,油菜苗期和苔期叶片S、B、Zn含量也相应地增加,对苗期叶片N、P和苔期叶片硫影响达极显著水平;(3)土壤差异,对叶片苗期吸收P和苔期吸收K、S的影响达显著性水平。     

Effect op foliar sprays of sulphuric acid with and without elemental sulphur in the prevention of chlorosis In Peanut (Arachis hypogaea. L.)

Abstract

A field experiment was conducted on an alkaline calcareous soil of Agronomy farm of the College of Agriculture, University of Udaipur to study the effect of sulphur on crop yield, leaf elemental composition, chlorophyll synthesis and activities of haematin enzymes. Application of elemental sulphur 21 days before planting with and without 0.1 per cent foliar sprays of H₂SO₄. increased crop yield by 137 to 197 per cent. Application of all these treatnents had no effect on nitrogen, phosphorus and potassium content of leaves but sulphur content was signficantly increased. Iron content of green leaves was decreased significantly 4 to 5 times together with an increase in the activity of catalase and peroxidase enzymes. Chlorosis in these soils appears to be on account of a reduced physiological availability of iron after absorption.     

Effect of acid deposition on forested catchment in the western Tokyo,Japan

Acid deposition and its effect on Andisols were investigated in the forest experimental station, the Rolling Land Laboratory (RLL), located in the Tama Hill region of Central Japan. The annual volume-weighted mean pH value of open bulk precipitation was 4.8 in the period 1990 to 1992. Nitrate deposition at RLL was larger than for sulfate, which was obviously different from results in Japan Environment Agency (JEA) stations or in study areas of Europe and North America. Abundant nitrate deposition was ascribed to the high emissions from a non-point source, mainly cars. Although sulfate concentration in throughfall fluctuated, its concentration in soil solution was kept at a low level. This was attributed to the high sulfate adsorption capacity of the Andisols.     

Effect of simulated acid rain on nitrogenase activity in the lichen genus peltigera under field and laboratory conditions

Lichens of the genus Peltigera were exposed to simulated acid rain in the laboratory and at a field site in Southwestern Alaska. Exposure to simulated rainfall of pH 4.4 had no effect upon acetylene reduction in P. rufescens after experiments of 28 and 60 days duration, although in the former experiment there was some evidence of a transient effect after 14 days. Simulated acid rain of pH 3.4 or 4.4 also had no effect upon nitrogenase activity in P. aphthosa during a 21-day field study, indicating that nitrogenase activity in Peltigera is not sensitive to precipitation in this range of acidity.     

砒砂岩沟坡沙棘根系分布特征及其对林下土壤的改良作用

沙棘是砒砂岩地区植被恢复的先锋树种,沙棘根系形态不但影响植物本身的生长,还影响其保土效果及改土效果。采用根系追踪法,研究砒砂岩地区同一坡面不同坡位、不同林龄沙棘根系的分布形态,测定沙棘林下土壤的理化性质,以裸坡地作为对照,分析沙棘林对土壤的改良作用。结果表明:1)砒砂岩沟坡沙棘根系在垂直方向上集中分布在0～40 cm深的土壤中,在水平方向分布可达137 cm。2)沙棘一级侧根的数量与小环境有密切关系,土壤水分条件越好,侧根数量越多,根长越短;沙棘根系的径粗与埋深呈反比,并且与距植株中心距离也呈反比。3)人工沙棘林在砒砂岩沟坡上,其根系分布表现为坡顶根系由于土层薄受到砒砂岩的限制,水平分布较发达,在坡底由于土壤厚度及肥力的充足,沙棘在垂直分布上明显深于坡顶。4)种植沙棘可增加土壤含水量和土壤孔隙度,同时还可以提高土壤中的速效N、P、K及有机质质量含量。