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1.
硼、锌是植物正常生长必需的微量营养元素,植物缺硼或缺锌将会发生生理功能失调,生长发育受阻,从而影响农业产量与产品质量。土壤中硼、锌的有效供给情况与植物的硼、锌营养水平有着密切的关系。近年来,我们及郊区有关单位对水稻、小麦、油菜等作物进行硼、锌试验,反应不一。为了进一步明确硼、锌的有效性问题,我们对郊区几种主要的土壤作了调查研究。  相似文献   

2.
In low fertility tropical soils, boron (B) deficiency impairs fruit production. However, little information is available on the efficiency of nutrient application and use by trees. Therefore, this work verified the effects of soil and foliar applications of boron in a commercial citrus orchard. An experiment was conducted with fertigated 4-year-old ‘Valencia’ sweet orange trees on ‘Swingle’ citrumelo rootstock. Boron (isotopically-enriched 10B) was supplied to trees once or twice in the growing season, either dripped in the soil or sprayed on the leaves. Trees were sampled at different periods and separated into different parts for total B contents and 10B/11B isotope ratios analyses. Soil B applied via fertigation was more efficient than foliar application for the organs grown after the B fertilization. Recovery of labeled B by fruits was 21% for fertigation and 7% for foliar application. Residual effects of nutrient application in the grove were observed in the year after labeled fertilizer application, which greater proportions derived from the soil supply.  相似文献   

3.
This study aims to identify an alternative plant tissue to be used in the early diagnosis of boron (B) deficiency in chestnut (Castanea sativa Mill.). A B-deficient orchard was selected, and 16 trees were submitted to two levels of B fertilization. When flowers were in bloom, the following tissues were sampled: leaves, androgynous catkins and flowers. There was a significant increase in B content in plant tissues due to B application. In July, the highest B content was observed in flowers in B0, but leaves had the greatest content in B1. Boron content in the tissues collected in July was positively correlated with B contents in leaves sampled in September. Foliar B concentrations, irrespective of the sampling period, were correlated with chestnut productivity, while the other tissues did not. These results suggest that the leaves, sampled in bloom, were the most efficient tissue for the early diagnosis of B deficiency.  相似文献   

4.
镉铅锌污染对红壤中微生物生物量碳氮磷的影响   总被引:13,自引:2,他引:13  
用实验室培养法研究了不同镉、铅和锌化合物对红壤中微生物生物量碳、氮和磷的影响。引起微生物生物量碳显著减少的Cd、Pb和Zn(均为氯化物 )临界土壤含量水平分别为 30、4 50和 2 0 0mg/kg。以醋酸盐形式加入土壤中的Cd、Pb和Zn对土壤微生物生物量比氯化物有更大的毒性 ,可能与其较高的溶解度有关。不管施用何种化合物 ,Cd、Pb和Zn对微生物量的相对毒性依次为 :Cd Zn Pb。  相似文献   

5.
This nutrient solution experiment investigated the effects of zinc (Zn) and cadmium (Cd) on winter wheat growth and enzymatic activity. Twelve nutrient solution treatments were prepared of four zinc levels (0, 0.5, 5 and 50 mg L?1) and three cadmium levels (0, 5 and 50 mg L?1). Cadmium concentrations ≥5 mg L?1 decreased plant growth, superoxide dismutase activity, and leaf and stem zinc concentrations, but increased plant cadmium concentrations, proline content, and peroxidase and catalase activities. Root activity and zinc concentration were highest in the 5 mg L?1 treatment and lowest in the 50 mg L?1 treatment. Zinc concentrations ≥5 mg L?1 inhibited plant growth, but increased proline content and cadmium concentration in stems and leaves. Low levels of zinc (0.5 mg L?1) increased cadmium-induced toxicity in wheat plants but high levels of zinc (50 mg L?1) reduced. In conclusion, these results indicated that the addition of zinc alleviated cadmium toxicity if the zinc/cadmium ratio was >10/1. Additional study needs to be done to quantify zinc content before zinc is supplied to alleviate cadmium toxicity.  相似文献   

6.
利用地统计学和地理信息系统相结合的方法,从小尺度区域角度上研究了南京城郊土壤中铅(Pb)、锌(Zn)、铜(Cu)和镉(Cd)4 种重金属有效态含量的空间分布特征及其主要的影响因子。结果表明:(1) 研究区土壤中有效 Zn 变异程度相对较大,有效 Pb 的变异程度相对较小,而有效 Cu 和 Cd 为中等程度变异。(2) 研究区有效 Pb、Zn 含量空间分布具有中等程度的空间自相关性,而 Cu、Cd 空间分布具有强烈的空间自相关性;有效 Zn、Cd 的空间自相关尺度相对较大,而有效 Cu、Pb 相对较小。(3) 研究区土壤中有效 Pb 的空间分布主要受交通影响,交通量越大的道路附近土壤中有效 Pb 含量越高;有效 Zn 主要受城市生活废水的影响,城市生活污水灌溉和城市地表径流是土壤中有效 Zn 积累的主要原因;有效 Cu 主要与蔬菜种植过程中有机肥(主要是牛粪)施用关系密切,有机肥施用量越大,土壤中有效 Cu 含量越高;有效 Cd 受地形影响较大,地形低洼处土壤中有效 Cd 含量相对较高。  相似文献   

7.
Cu、Zn、Pb、Cd对鲫鱼(Carassius auratus)组织DNA毒性的研究   总被引:4,自引:0,他引:4  
用非程序DNA的合成作为毒性评价指标研究了混合重金属对鲫鱼 (carassiusauratus)组织DNA的毒性作用 ,结果表明 ,混合重金属的毒性作用靶标器官是鱼脑和鱼的肝脏 ;混合重金属中的主要毒性成分是Zn、Pb和Cd离子 ,混合重金属对鱼脑组织的毒性大小顺序是Pb>Cd >Zn ,对肝脏DNA的毒性顺序为Pb >Zn >Cd;Cu离子能够降低其它 3种离子的毒性作用 ,降低的机制在于竞争作用 ,导致了其它离子的吸收降低  相似文献   

8.
The adsorption of Zn2+, Pb2+, Cu2+, Co2+, and Cd2+ (M2+) by soils was measured at concentrations ranging from 10-7 to 10-2 M in 10-3 to 10-2 M CaCI2. Exchange between Ca2+ and M2+, and solubility products [M2+][OH?]2 indicate that M2+ is not precipitated as hydroxide but is adsorbed on cation-exchange sites. The proportion of selective adsorption sites with specified values of the selectivity coefficient calculated using Ca as reference ion, increased in the order montmorillonite < humus, kaolinite, < allophane. imogolite < halloysite, iron oxides. Raising the soil pH by Ca-saturation increased both the amount and affinity of adsorption. Selectivity of adsorption increased in the order Mg, Ca < Cd, Co < Zn < Cu, Pb, and the selectivity coefficient varied from < 1 to > 10 000. The formation of the coordination complexes of heavy metal with deprotonoted OH and COOH groups as ligands is suggested as a possible mechanism of selective adsorption.  相似文献   

9.
Plant analysis can be a useful tool in determining the general nutritional status of crops during the growing season. For this reason, a field experiment was conducted in the Fars province of Iran during 2008 season to evaluate the concentrations of nitrogen (N), phosphorus (P) and potassium (K) in maize leaf as affected by zinc sulfate and boric acid. Treatments were arranged in a randomized complete block design with two factors and three replications. Factor one included four levels of B (0, 3 and 6 kg ha?1 B added to the soil and B foliar spray with a 0.3% concentration); factor two consisted of five levels of zinc (Zn) (0, 8, 16 and 24 kg ha?1 Zn added to the soil and Zn foliar spray with a 0.5% concentration). The results of this work showed that the main effect of Zn and B levels and interaction of Zn–B on the leaf N and P concentrations was insignificant. A synergism was seen between Zn and K and also between B and K. The presence of a high amount of Zn or B in the soil prevented from increase of leaf K content, by B or Zn application, respectively.  相似文献   

10.
Citrus, especially K innow (Citrus deliciosa × Citrus nobilis), fruit yield and quality in Pakistan is not competitive with that of other countries which could be mainly attributed to the lack of good nutrient management for citrus orchards. The yield losses in this fruit crop occur mainly due to heavy fruit dropping. Experiments to overcome these problems were conducted at four different sites one each in Faisalabad, Toba Tek Singh, Jhang and Sargodha districts of Punjab, Pakistan. The soil and leaf chemical analysis showed severe deficiency of Zn and our pervious results have shown that soil amendment with potassium (K) at 75 K2O kg ha?1 improved the citrus fruit yield and quality at all selected sites. In the present experiments, effect of foliar application of Zn and K alone or in combination was studied on nutrient uptake, fruit yield, fruit dropping and juice quality. The fruit trees were pretreated with a selected K level of sulfate of potash (SOP) or muriate of potash (MOP), i.e., 75 kg K2O ha?1 along with recommended nitrogen (N) and phosphorus (P) doses. Zinc [Zn, 1% zinc sulfate (ZnSO4) solution], K [1% potassium sulfate (K2SO4) solution] and Zn + K (solution containing 0.5% each of ZnSO4 and K2SO4) were sprayed at the onset of spring and flush of leaves or flowers, fruit formation and at color initiation on fruit. Overall, application of Zn, K or Zn + K was effective in improving the nutrient uptake, yield and quality parameters of citrus fruit at all sites. Fruit dropping was also reduced by the foliar spray of Zn, K or Zn + K but the most promising results were recorded with foliar spray containing both Zn and K.  相似文献   

11.
In this study, we used once-plowed lands that have returned to forest for over 50 years to study the vertical distribution of meteorologically-deposited lead. These mineral soils were an essentially homogeneous 20 cm-thick layer when last plowed. As such, they were effectively a “clean slate” upon which pollutants deposited since the last plowing can be measured without the confounding aspects of well-developed natural soil horizons and the spatial heterogeneity of native forest soils. The concentration and amount of lead as well as copper and zinc, biologically active metals, were measured at five sites in New England. In the mineral soil, copper content ranged from 25 mg cm depth-1 m-2 at 0–2 cm depth to 37 mg cm depth-1 m-2 at 6–8 cm depth, but showed no consistent pattern with depth at all sites. Zinc concentrations and amounts increased with depth in the mineral soil to 14 μg g-1 and 167 mg cm depth-1 m-2, respectively. In contrast, lead showed a decrease with depth from 350 mg cm depth-1 m-2 at 0–2 cm depth to 102–108 mg cm depth-1 m-2 between 10 and 20 cm depth. At all five sites, decreases in lead concentration with depth were correlated with decreases in the amount of organic mater. Amounts of total lead deposited since the abandonment from plowing have been estimated at 1.4 g m-2 in rural sites. Thirty-five percent of this presumably anthropogenically-derived lead was in the forest floor; the remaining 65% was in the upper mineral soil.  相似文献   

12.
NOGALES  R.  GALLARDO-LARA  F.  BENITEZ  E.  SOTO  J.  HERVAS  D.  POLO  A. 《Water, air, and soil pollution》1997,94(1-2):33-44
Water, Air, &; Soil Pollution - A greenhouse experiment using soil was conducted to investigate the effects of the addition of different forms of either nickel or lead, together with an...  相似文献   

13.
The quantities of lead, zinc, and calcium dissolved by various extraction techniques from soil, earthworm faeces, and decayed earthworm (Dendrobuena rubida, Savigny) corpses have been studied. A small proportion of the total metals was water soluble and the amount of lead in faeces was significantly higher than in soil. Putrefied earthworm extracts gave by far the highest concentrations of all three metals. Acetic acid extractable lead was higher in soil than faeces but putrified earthworm extracts gave the highest concentration of lead. The quantities of zinc and calcium extracted were lowest in soil, higher in faeces, and much higher in decomposed earthworms. This particular species of earthworm can therefore be considered as a possible source of lead and zinc contamination in heavy metal polluted, acid soil.  相似文献   

14.
硼在土壤中的吸附-解吸及其对植物吸收硼的影响   总被引:11,自引:4,他引:11       下载免费PDF全文
本文对湖北省几种主要旱地土壤进行了硼的吸附-解吸实验,同时对这些土壤上油菜幼苗吸收硼进行了试验,并用Freundlich和Langmuir等温吸附方程对实验结果进行了拟合。从中发现,一些土壤硼的解吸存在着明显的滞后解吸现象,这种现象可用滞后系数来定性描述。  相似文献   

15.
《Journal of plant nutrition》2013,36(12):1965-1973
In this study, changes in cell wall uronic acid concentrations of boron (B)-tolerant and B-sensitive cultivars of wheat and barley were analyzed in control (plants that were grown on water and received no B) and B-treated plants. Ten-day-old seedlings of wheat (Triticum aestivum L. ‘Atay’ (B-sensitive) and ‘Bolal’ (B-tolerant)) and barley (Hordeum vulgare L. ‘Hamidiye’ (B-sensitive) and ‘Anadolu’ (B-tolerant)) were grown in H3BO3 solution (10 mM final concentration) or water for 3, 5, or 7 days. For determination of changes in cell wall uronic acid concentrations of wheat and barley cultivars, cell walls were extracted from root and leaf tissues of control and B-treated plants. Cell wall uronic acid concentrations of root and leaf tissues of each cultivar were statistically analyzed. Various reciprocal analyses were performed. These analyses were high-B-tolerant versus B-sensitive cultivars and control versus B-treated plants. In all reciprocal analyses, no significant changes were observed. These data, thus, suggest that cell wall uronic acid content does not contribute to detoxification of excess B in wheat and barley.  相似文献   

16.
17.
土壤中硼的含量和分布的规律性   总被引:10,自引:0,他引:10  
刘铮  朱其清  唐丽华 《土壤学报》1989,26(4):353-361
  相似文献   

18.
大巴山区土壤中的硒和氟   总被引:19,自引:1,他引:19       下载免费PDF全文
以大巴山区典型早古生代地层上发育的自然土壤为对象 ,研究了大巴山区土壤中Se、F等生命元素的含量及分布规律。结果表明 :大巴山区土壤中硒、氟的平均含量分别为 6 65± 14 2 5μgg- 1和 670±451μgg- 1,远高于对照和中国土壤背景值 ;富Zn贫Fe的土壤环境有利于Se、F的富集 ;土壤中硒、氟的含量受地层分布、母岩岩性等因素的控制 ,同时 ,表生地球化学作用、生物作用以及山地剥蚀地貌也影响它们在土壤中的重新分配。  相似文献   

19.
山西土壤氟含量分布及影响因素研究   总被引:22,自引:1,他引:22       下载免费PDF全文
张乃明 《土壤学报》2001,38(2):284-287
氟(Fluorine)是一种与人体健康密切相关的微量元素,人体摄入氟元素不足或过量均会对健康产生危害。从1886年H. Moissan第一次成功地利用电解法把氟元素单独分离出来至今,对自然环境中氟及其化合物的研究报道越来越多,研究的深度和广度都有很大发展。  相似文献   

20.
几个典型华南人工林土壤的养分状况和微生物特性研究   总被引:37,自引:1,他引:37  
薛立  吴敏  徐燕  李燕  屈明 《土壤学报》2005,42(6):1017-1023
为了了解华南主要树种对土壤肥力的影响,分别用土壤化学分析方法、稀释平板法和酶分析法对相似立地条件的杉木林、马尾松林、湿地松林、马占相思林和尾叶桉林的凋落物养分、土壤养分、微生物数量及酶活性进行了研究。结果表明,5种林分中,杉木林的凋落物储量最大,凋落物的养分储量较大,为94.08kg hm-2。5种林地均呈强酸性。杉木林的土壤肥力较高,有机质、全氮、全磷、全钾、碱解氮、速效磷和速效钾含量分别为25.54 g kg-10、.96 g kg-1、0.37 g kg-11、2.04 mg kg-1、64.42 mg kg-1、1.87 mg kg-1、41.88 mg kg-1,但是土壤微生物数量小;马尾松林、湿地松林凋落物的养分储量小,土壤养分含量较低,土壤肥力低;马占相思林有效地改善了土壤化学性质,凋落物的养分储量在5种林分中最大,达106.2 kg hm-2,土壤肥力高,有机质、全氮、全磷、全钾、碱解氮、速效磷和速效钾含量分别为23.42 g kg-1、0.93 g kg-1、1.28 g kg-1、15.29 mg kg-1、69.32 mg kg-1、1.98 mg kg-1、76.88 mg kg-1,微生物数量大,酶活性强;尾叶桉林的土壤有机质、N和P含量低,K含量高,微生物数量小和酶的活性较低,土壤肥力低。  相似文献   

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