草原地区露天矿排土场土地复垦技术研究

露天矿排土场的严重水土流失 ,导致周边土壤盐渍化和草场退化 ,是草原露天矿区环境治理的关键和重点。因随机排土 ,大部分排土场的表层土壤为深层绿色泥岩土 ,不适于植物生长 ,治理难度很大。风蚀作用是限制排土场植被恢复的主要因素 ,而一定密度的人工灌丛可以减轻排土场平台的风蚀强度 ,形成地表凋落物覆盖层 ,改良土壤 ,加速植被的恢复。沙棘是草原露天矿排土场理想的复垦植物 ,可以在短时期内形成郁闭的人工沙棘灌丛 ,土壤培肥和水土保持效果显著 ,并明显减缓坡下草场盐渍化程度。因此 ,以沙棘为主的人工灌丛 ,应该成为草原露天矿排土场环境整治的主要模式。     

露天煤矿排土场不同植被土壤水分特征及其时间稳定性

选择晋陕蒙接壤区永利煤矿排土场沙打旺草地、紫花苜蓿草地、沙棘林地和原地貌草地土壤水分为对象,研究其蒸散、剖面分布、时间变化等特征,以期揭示土体重构及不同复垦植被模式对土壤水分及其时间稳定性影响。结果表明:排土场3种人工植被条件下土壤平均含水量同原地貌草地相比提高了50.7%~62.3%,另外,沙打旺复垦草地土壤含水量显著低于苜蓿复垦草地和沙棘复垦灌木林地(均降低了7.2%)。沙打旺和苜蓿会导致深层(120—260,120—220 cm)土壤水分亏缺,但有利于20—80 cm的土壤水分的保持;而沙棘易导致浅层(20—80 cm)土壤水分亏缺,但对深层(100—280 cm)土壤水分影响较小。上述结果说明,矿区排土场土体重构过程能够改善排土场土壤的水分条件,并且在进行植被重建的过程中,不同复垦植被对土壤水分的保持与利用形式有所不同,在本研究中,苜蓿和沙棘更有利于缓解土壤水分亏缺。     

天然地形和人工沙棘风障对排土场平台植被恢复的影响

以霍林河露天煤矿为例 ,通过对排土场不同地段植被的观察、野外小区实验和室内分析的方法 ,调查研究了天然地形风障以及人工沙棘风障对半干旱地区露天煤矿排土场平台植被恢复状况的影响。研究结果表明 ,地形与人工沙棘风障不仅起到防风作用 ,还可以改善土壤理化性质 ,促进其它植物的生长 ,防治水土流失 ,加速排土场的植被恢复与生态重建的进程。     

天然地形和人工沙棘风障对排土扬平台植被恢复的影响

以霍林河露天煤矿为例，通过对排土场不同地段植被的观察、野外小区实验和室内分析的方法，调查研究了天然地形风障以及人工沙棘风障对半干旱地区露天煤矿排土场平台植被恢复状况的影响。研究结果表明，地形与人工沙棘风障不仅起到防风作用，还可以改善土壤理化性质，促进其它植物的生长，防治水地，加速排土场的植被恢复与生态重建的进程。     

平朔安太堡露天矿排土场土壤种子库研究

采用萌发试验法研究了安太堡露天矿排土场土壤种子库特征,结果表明:排土场土壤中有活性种子存在,且以1年生植物为主,可为植被恢复提供物质基础;随着复垦时间的延长,土壤微环境改善,种子库的组成种类增加,数量增多,幼苗生长加快;复垦10年的沙棘、草地、刺槐林地,土壤种子库组成种类较新排土区明显增多,且优势种因复垦模式不同而异;未复垦的空旷区有利于种子传播,但土壤微环境差,不利于种子萌发,幼苗生长较差.     

不同人工植物配置对排土场边坡水土流失的影响

[目的]揭示人工植被配置对露天矿排土场边坡水土流失的影响,为半干旱地区露天矿区排土场边坡水土流失控制提供依据。[方法]以不同植物配置和对照(未治理)边坡为研究区,于2014年和2015年的5—10月,对边坡径流和土壤侵蚀量与降雨量的关系进行了统计学分析。[结果](1)控制坡面径流。乔灌草和灌草配置是较好选择,其坡面径流仅为对照的42.9%和52.6%,二者无显著性差异。(2)控制边坡土壤侵蚀。3种植物配置措施都与对照区存在显著性差异,其土壤侵蚀量仅为对照区的2.3%~6.7%。日降雨量与坡面径流和土壤侵蚀量之间都存在显著线性关系。[结论]不同植被配置对边坡侵蚀控制优于径流深,与对照区相比侵蚀量减少93%以上,而径流深仅减少了28%~57%。     

不同植被对晋陕蒙矿区排土场土壤养分16 a恢复程度的影响

为评价晋陕蒙矿区排土场土地复垦过程中不同植被措施对土壤肥力的恢复作用及程度,在内蒙古准格尔旗黑岱沟煤矿东排土场,分别选取已恢复16 a的7种不同人工植被(沙打旺、长芒草、紫穗槐+长芒草、刺槐林、沙棘林、杨树林、樟子松),并以周边原地貌条件下两种植被(退耕梯田长芒草、自然坡地沙棘林)为对照,分析了不同植被条件下0~10、10~20、20~40 cm土层土壤全氮、有机碳、硝态氮以及铵态氮的含量及其差异。结果表明:1)9种植被配置中除樟子松地和沙打旺草地外,土壤养分含量均随深度增加而递减。2)经过近16 a植被修复后,7种人工植被不同程度地改善了土壤肥力状况,其中刺槐纯林配置的恢复效果最佳,土壤肥力恢复程度接近或超过原地貌条件下植被的50%,沙棘次之。杨树和樟子松两种配置对土壤全氮、有机碳、硝态氮恢复效果相对较差,恢复程度均不超过40%。7种不同植被措施对土壤铵态氮的恢复程度相对较好,分别恢复到自然植被长芒草样地和自然植被沙棘样地的79.50%~93.77%,89.47%~105.70%。土壤全氮、有机碳、硝态氮恢复程度则相对较低,分别恢复到自然植被长芒草样地的24.70%~44.15%、25.09%~44.65%、47.25%~85.33%;分别恢复到自然植被沙棘样地的33.52%~56.85%、32.83%~54.82%、47.18%~84.66%。总之,尽管经过近16 a的复垦,7种人工植被下的土壤养分状况尚未完全恢复到该地区自然水平,但仍可认为该地区进行生态修复时可优先选择以刺槐为主的豆科乔木、以沙棘为主的灌木、以及长芒草等草本植物,并进行适当的套种、间种,以增强复垦效果。     

安太堡露天矿植被恢复过程中土壤生态肥力评价

平朔安太堡露天矿位于山西省西北部,地处黄土高原生态脆弱区,采煤造成了土地的严重损毁及植被的无存。自1989年以来,在平朔安太堡露天矿采煤废弃地开展土地复垦与生态重建工作已有20余年,现已形成2000 hm²不同复垦模式的人工生态林。对安太堡露天矿复垦地不同植被恢复模式土壤理化性质、酶活性和微生物区系进行分析和土壤生态肥力评价,为人工诱导和支持下的生态脆弱矿区采煤废弃地的生态恢复重建提供类比试验数据。结果表明:不同植被恢复模式中土壤理化性质、酶活性和微生物区系存在明显差异,通过主成分分析对各植被恢复模式的土壤肥力进行了综合评价,油松—刺槐混交林土壤肥力最高,人工植被恢复显著地改善了土壤生态环境,促进了土壤养分的提高。     

高寒矿区排土场不同坡向植被和土壤特征研究

针对高寒矿区排土场人工植被恢复问题,选取青海江仓矿区南北2个排土场的4个坡面(南坡、北坡、东南坡与东坡)为研究对象,进行了不同坡向立地条件下植被与土壤的调查分析。结果显示:除幼苗高度外,不同坡向植被高度、盖度、地上生物量、生殖枝数量具有显著差异(P<0.05),东南坡与南坡(阳坡)长势较好。土壤全氮、有效磷含量及pH在不同坡向差异不显著(P>0.05),土壤全磷、碱解氮、速效钾、有机质、含水量在不同坡向具有显著差异(P<0.05)。北坡土壤有机质含量比其他3个坡面平均高出127.95 g/kg(P<0.05),土壤含水量在北坡与东坡(阴坡)显著高于南坡与东南坡(P<0.05)。土壤细菌与放线菌数量在东南坡显著高于其他3个坡面(P<0.05)。利用随机森林方法得出,土壤细菌数量、含水量、碱解氮含量、全磷含量、有机质含量及植被高度是影响露天煤矿排土场不同坡向立地条件下植被与土壤特性的主要因子。因此,为减小矿区排土场复绿过程中坡向不同带来的影响,在人工建植初期应加大东坡与北坡(阴坡)的种子播量,适时追施氮肥,并选择加厚无纺布(>50 g/m^...     

植被恢复对黑岱沟矿区排土场土壤性质的影响

[目的]以内蒙古准格尔旗黑岱沟露天煤矿北排土场为研究对象,为矿区的植被恢复和治理提供依据。[方法]通过野外土壤剖面调查和采集土壤样品,对9种植被恢复模式及对照区土壤理化性质进行测定和分析,并通过土壤质量指数计算,对不同植被恢复模式下土壤质量进行评价。[结果]各种植被类型均能有效地改良土壤。其中沙棘的容重最小,为1.35g/cm3;油松+沙棘+锦鸡儿的含水量最大,为13.32%;油松+杨树+柳有机质最高,为9.42g/kg;油松+沙棘+锦鸡儿土壤速效N和速效K含量均为最高,分别为21.32和90.21mg/kg;锦鸡儿土壤速效P含量最高,为6.47mg/kg;沙棘和锦鸡儿作为灌木的乔灌混交模式下土壤质量综合评价值最高,单一种植沙棘以及锦鸡儿的土壤质量综合评价值也较高。[结论]种植沙棘、锦鸡儿以及乔木、沙棘和锦鸡儿的乔灌混交类型对该地区土壤复垦有重要作用。     

Accumulation of copper in soils and leaves of tomato plants in greenhouses in Turkey

Copper (Cu)‐containing fertilizers, fungicides, and bactericides has been used extensively in the greenhouses in the Antalya province in recent decades with the use of such materials tending to increase year by year. The level of DTPA‐extractable Cu was determined in 210 soils (0–20 and 20–40 cm depth) and 105 leaf samples obtained from 105 tomato greenhouses. The DTPA‐extractable Cu contents of the soils taken from the 0–20 depth ranged between 0.76 and 88.03 mg kg^‐1 (mean 7.79 mg kg^‐1). The percentage of soils containing DTPA‐extractable Cu greater than the critical toxicity level (20 mg kg^‐1) was 8.1. The Cu content of tomato leaf samples ranged between 2.4 and 1,490 mg kg^‐1 (mean 166.5 mg kg^‐1). The Cu concentration in leaf samples was very high due to the intensive use of foliar applied Cu‐containing chemicals. As a consequence, 24.8% of the leaf tomato samples analyzed contained over 200 mg Cu kg^‐1, the maximum accepted tolerance level. Therefore, it may be necessary to reduce the use of Cu‐containing pesticides and fertilizers, or at least reduce the amount of Cu‐containing fertilizers being used in those greenhouses where Cu‐containing pesticides have been or are being used.     

Role of selenium in mitigation of cadmium toxicity in pepper grown in hydroponic condition

Selenium (Se) is an essential element for humans but is not considered as essential for plants. However, its beneficial role in improving plant growth and stress tolerances is well established. In order to study the role of Se in cadmium (Cd) toxicity in pepper (Capsicum frutescens cv. Suryankhi Cluster), this experiment was carried out in greenhouse conditions. Treatments comprised Cd [0, 0.25, and 0.5 mM cadmium chloride (CdCl₂)] and Se [0, 3, and 7 µM sodium selenite (Na₂SeO₃)] with three replications. The result showed that Cd decreased chlorophyll a, chlorophyll b, and carotenoids, whereas Se supplementation diminished Cd toxicity on photosynthetic pigment. Selenium at 7 µM significantly increased the leaf area in the plants grown at 0.25 mM Cd. The application of Se at 3 µM with 0.25 mM Cd and Se at 3 µM and Se at 7 µM with 0.5 mM Cd increased the activity of catalase (CAT). Selenium at 7 µM decreased the proline content of pepper leaves exposed to Cd at 0.5 mM (30%). Selenium significantly enhanced the antioxidant activity of leaves, which was diminished by Cd toxicity. In general, Se has a beneficial effect on plant growth and is an antioxidant enzyme of pepper cv. Suryankhi Cluster under Cd stress and non-stress conditions.     

红壤区不同肥力水稻土根际硝化作用特征

通过根际培养箱(三室)——速冻切片技术研究了红壤地区高、低两种肥力下水稻苗期根表、根际和土体土壤矿质态氮含量和硝化强度,以及水稻生长、氮素积累的差异。结果表明,肥力水平对水稻根表和根际土壤铵态氮(NH4+-N)含量无显著影响,但高肥力显著提高土体土壤NH4+-N含量,以及根表、根际和土体土壤硝态氮(NO3--N)含量及硝化强度。两种肥力水稻土硝化强度最大值均出现在距根表2 mm处,分别为0.20和0.31μmol kg-1 h-1。土体土壤硝化强度随距根表距离增加而降低,低肥力土壤在距根表10～40mm处时硝化强度接近本底值,而高肥力土壤在距根表20～40 mm处时接近本底值。与不种水稻的CK相比,种植水稻显著提高根际土壤硝化强度。高肥力能显著改善水稻生长,增加植株氮素积累量,尤其显著促进根系生长及通气组织发育。由于红壤稻田肥力水平的差异造成水稻根际硝化强度以及水稻吸收NO3-的差异,导致高肥条件下水稻显示出更强的生长势和氮素吸收利用能力。因此,合理提高红壤稻田肥力水平对改善红壤区水稻根际土壤硝化作用及水稻氮素营养具有重要意义。     

自由基在鸡肾病发生中的作用研究

肾病即急性肾小管坏死.鸡肾病在养鸡生产中极为常见,尤其近年来,鸡肾病的发生日益增多,由于其发生机制不清楚,临床治疗鸡肾病的依据不足,致使治疗效果不佳,为此,提出本研究以探讨鸡肾病的发生机制,为本病防治提供理论依据.     

Occurrence of Sexual Hormones in Sediments of Mangrove in Brazil

The presence of sexual hormones (female estrogens) was assessed in sediments of a mangrove located in the urban region of southern Brazil. The estrogens are involved in human sexual reproduction. They act as the chemical messengers, and they are classified as natural and synthetic. The estrogens inputs in the environment are from treated and untreated sewage. The presence of estrogens in sewage is excretion from the female due to natural production and use of contraceptives (synthetic estrogens). With the indiscriminate release of sewage into the environment, estrogens can be found in rivers, lakes, and even in oceans. In this work, the presence of estrone (E1), 17-??-estradiol (E2), and 17-??-ethynilestradiol (EE2) in eight sedimentary stations in Itacorubi mangrove located on Santa Catarina Island, south Brazil, was investigated. Historically, the Itacorubi mangrove has been impacted by anthropogenic activities because the mangrove is inserted in the urban area of the Florianopolis. The estrogen EE2, used as contraceptive, had the highest concentration in mangrove sediment, 129.75?±?3.89 ng/g. E2 was also found, with its concentration ranging from 0.90?±?0.03 to 39.77?±?1.19 ng/g. Following the mechanism, under aerobic or anaerobic conditions, E2 will first be oxidized to E1, which is further oxidized to unknown metabolites and finally to CO₂ and water (mineralized). EE2 is oxidized to unknown metabolites and also finally mineralized. Theoretically, under anaerobic conditions, EE2 can be reduced to E1 even in environments such as mangrove which is essentially anaerobic.     

Meta-analysis in the Selection of Groups in Varieties of Citrus

Brazil is the largest producer of oranges (Citrus sinensis) in the world. The nutrient management of tree orchards is designed from experiments with a limited number of varieties. This knowledge is transferred to other varieties by diagnosing tissue nutrient composition and tree demand. Compositional data analysis has been first applied to tissue analysis of agricultural crops using centered log ratios with compositional nutrient diagnosis (CND-clr). The isometric log ratio (ilr) transformation is a new approach based on binary nutrient ratios and the principle of orthogonality (CND-ilr). We analyzed eleven nutrients: nitrogen (N), sulfur (S), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), boron (B), copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe) in leaf tissue samples across 108 commercial plots (thirty-one grow Valencia, twenty-two Hamlim, twenty Pera, and thirty-five Natal). Nutrients were partitioned between macro- and micronutrients as well as anionic and cationic species. The effect size of varieties over Valencia was quantified by the mean and standard deviation of ilr values across ilr coordinates. Specific varietal nutrient profiles and ilr norms were defined. The nutrient profile of orange varieties could be classified into homogeneous groups to take advantage of fertilizer trials conducted on varieties of the same group. The Aitchison distance and a perturbation vector could be instrumental for diagnostic purposes and nutrient management.     

Effect of iron-quercetin complex on reduction of nitrite in in vitro and in vivo systems

This study investigated whether reducing agents such as quercetin and iron(II) facilitate formation of nitric oxide (NO) gas from orally ingested nitrite in an vivo study. When 3 mg/kg Na (15)NO2 was orally administered to rats with or without iron(II) or quercetin, Hb (15)NO, which is indicative of systemic (15)NO, was detected in the blood, with the maximum blood concentration of Hb (15)NO at 15 min after nitrite or nitrite plus quercetin treatment, whereas after administration of nitrite plus iron(II) or nitrite plus iron(II) and quercetin, the time was shortened to 10 min. Interestingly, iron(II), quercetin, or iron(II) plus quercetin did not affect the total amount of Hb (15)NO generated from orally administered Na (15)NO2. However, the systemic nitrite concentration was significantly decreased in the presence of iron(II) or iron(II) plus quercetin. These results may indicate that iron(II) is critical to the generation of NO gas from nitrite, whereas quercetin contributed little under the in vivo experimental conditions.     

旱地果园水肥管理模式研究进展

分析了旱地果园水肥管理模式的研究进展和存在问题,指出水肥胁迫尤其是水钾已成为旱区果树高产稳产优质化的主要限制因子。在系统探讨旱地果园水分管理、养分管理、综合管理以及果树叶营养综合诊断施肥标准的基础上,提出了旱地果园的高效水肥管理模式。     

Role of aldehyde oxidase in the hepatic in vitro metabolism of 3-methylindole in pigs

The metabolism of 3-hydroxy-3-methylindolenine (HMI), a recently discovered metabolite of 3-methylindole (3MI, skatole) produced by porcine liver microsomes, was investigated in vitro using porcine liver cytosol. HMI was rapidly metabolized to a single product, 3-hydroxy-3-methyloxindole (HMOI), by porcine cytosol. By the use of the selective inhibitors menadione and quinacrine, it was shown that the enzyme responsible for the oxidation of HMI into HMOI was aldehyde oxidase (AO; aldehyde:oxygen oxidoreductase, EC 1.2.3.1). The activity of AO in the conversion of HMI to HMOI was measured in a population of pigs (n = 30) with a wide range of 3MI levels in back fat (0.07-0.30 mg/kg). AO activity was found to be negatively correlated (r = -0.70; P < 0.001) with the level of 3MI in fat. The results of the present study suggest that AO plays an important role in the metabolism of 3MI in the pig and that its catalytic activity is related to an adequate 3MI clearance.     

东北黑土土壤磷的纬向分异

以中国东北的中纬度黑土区为样带,研究了有机磷浓度与有机质、全氮浓度的关系;全磷、有机磷、无机磷及有机磷和无机磷的比率与纬度分布的关系。结果表明,有机磷和有机质、全氮浓度具有良好的相关性,它们之间的相关系数分别为0.90和0.92,呈极显著正相关(P<0.01)。全磷、有机磷、无机磷、P_o/P_i在纬度上都存在不同程度的分异规律,即随着纬度的升高,其浓度或比率均有逐渐升高的趋势;其相关系数分别为0.68、0.77、0.26和0.60,相关分析表明,这些纬向分异规律都达极显著水平(P<0.01)。除了无机磷的纬向分异原因尚不明确之外,其他纬向分异的原因可能是由于黑土南北样带气候热量上的差异和人类活动的影响所致,从而造成南北样带之间有机质的矿化程度和速率产生差异。