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果园土壤铜素分异特征及化学行为研究

Study of Variance Characters and Chemic Actions of Copper in Orchard Soils

【作者】 王正直

【导师】 刘春生;

【作者基本信息】 山东农业大学 , 植物营养学, 2003, 硕士

【摘要】 铜是作物生长发育必需的营养元素,也是污染环境的重金属元素。果园生产中由于大量施用波尔多液等含铜杀菌剂,造成铜在土壤中大量累积,破坏了土壤环境中的营养元素平衡,降低了果品的产量和质量,威胁着人、畜的健康。铜对土壤-植物环境的污染受到了广泛的重视。本文采用路线调查的方法对山东主要果园产区土壤含铜状况进行调查,采样分析了果园土壤铜的形态分级、剖面变异特性。深入研究了山东四种主要土壤类型的果园土壤对铜的吸附-解吸和缓冲性能特征,并用Langmuir等温吸附方程和非线性阻尼振动方程分别对其曲线进行了拟合,确定了土壤最大吸附量和对铜缓冲性能的大小。测定了果园土壤铜的空间变异特征,绘出等值线图,准确细致的反映了铜在土壤中的空间相关性。对解决果园土壤普遍存在的外源铜污染问题,及发展优质、高效农业都有积极的指导意义。1.果园土壤铜素状况供试果园土壤全铜和有效铜含量明显高于对照土壤。表层土壤全铜含量是对照土壤的1.53倍,6.7%的果园土壤超过国家二级标准(200mg·kg-1,6.5<pH<7.5)。表层和亚表层有效铜平均含量分别是对照土壤的6.92和3.80倍。有效铜及表层土壤的全铜含量与对照土壤的差异都达到极显著水平。2.果园土壤铜形态分级供试果园土壤中交换态铜的含量最低,占全铜的2%弱。各种形态的铜的含量都高于对照,以表层有机结合态铜最为明显,最高达68.79mg·kg-1,占全铜的22.07%。说明果园土壤铜的有效性明显提高。矿物残留态铜是土壤中铜的主要存在形态,占全铜的60%以上。3.果园土壤铜剖面分布随着剖面层次的加深,果园土壤中各形态的铜的含量都迅速下降,以全铜和有机结合态铜表现最为突出。与对照相比,果园表层和亚表层土壤各形态铜的含量明显升高,而60cm以下土层变化不大,说明外源铜主要影响果园表层和亚表层土壤中铜的含量和分布。4.土壤对铜的吸附-解吸特性<WP=6>用Langmuir等温吸附方程对供试土壤铜的等温吸附曲线进行拟合达到很好的相关性。供试果园土壤的按最大吸附量大小依次为:潮土>盐土>褐土>棕壤。解吸量远小于吸附量,其大小的顺序与吸附量的相反。解吸相对于吸附表现出明显的滞后效应,滞后圈的大小与土壤对铜的吸持作用大小成正相关。相对于对照,果园土壤最大吸附量明显降低,解吸量略有增加,对铜的吸持作用减弱。5.吸附-解吸的时间效应供试土壤对铜的吸附-解吸都是快反应,吸附和解吸过程都在约20 -30min内达到基本平衡。平衡时解吸的量远小于吸附量。果园土壤吸附达到平衡的时间略早于对照土壤,达到平衡时的吸附量小于对照土壤。6.土壤对铜的缓冲性能供试土壤对外源铜的缓冲能力随铜浓度的增大而逐渐减小,高浓度外源铜条件下缓冲能力降低明显。不同类型果园土壤对外源铜的缓冲能力大小依次为:潮土>盐土>褐土>棕壤,同种土壤类型上果园土壤缓冲能力小于对照。缓冲速率随时间变化的曲线符合非线性阻尼振动方程。有机肥能够明显的提高土壤对外源铜的缓冲能力,施用Ca肥也有一定的正效应。施加Fe肥降低了土壤对铜的缓冲能力。7.果园土壤铜的空间变异特性确定了供试果园土壤有效铜和全铜含量的变异大小及分布类型。供试果园土壤有效铜在东西向上表现出良好的自相关性,全铜为弱的自相关性。果园土壤铜的自相关性弱于对照。做半方差分析,确定岱岳区姜庄果园有效铜的空间相关域为9.64 m,红庙果园的为12.78 m,两者都小于对照的18.87 m,都属于中等空间相关性。红庙果园及对照土壤全铜的相关域分别为1.74m和22.22m,前者属于弱相关性,后者为中等相关性。果园土壤的铜素的空间相关性降低。采用Kriging插值法,并结合拟合的方程绘制了供试土壤有效铜和全铜的等值线图。果园土壤铜的空间变异明显的大于对照,等值线分布密集,有以多点同心圆形规则或散乱的分布特点。

【Abstract】 Copper are both an essential nutrition element for crops and a heavy metallic element polluting the environment. Copper accumulated in orchards soils for long time used the bactericides containing copper, such as Bordeaux mixture, destroyed the balance of nutrition of soils, depressed the quality and quantity of fruits, and threatened the health of both human and domestic animals. It has been always attached to the pollutions of external copper on the soil-plant surroundings. Route inspection was used to investigate the copper contents in orchard soils of mainly fruit product areas of Shandong province. The form classification and section variance of copper in orchard soils were analyzed to conclude the characters of distribution and transform of external copper in soils. The ability of absorption-desorption and buffering of external copper in orchard soils were researched and respectively fit with the equations of Langmuir or nonlinear damped vibration equation. The geo-statistics was used to study the copper special variance characters in orchard soils and the isolines were painted to nicely reflect the content and special relativity of copper in the soils.1. Characters of copper in orchard soilsThe contents of T-Cu and DTPA-Cu in orchard soils are obviously higher than that of controls. The mean content of T-Cu in orchard top soils is 1.53 times as high as that of controls. And 6.7% of orchard soils are over the national second critical criterions. The contents of DTPA-Cu in top and second<WP=8>soils are 6.92 and 3.80 times as high as that of controls respectively. The content differences of DTPA-Cu and T-Cu in top soils between orchards and controls are notability.2. Forms classification of copper in orchard soilsThe content of EX-Cu is the lowest in orchard soils, and less than 2% of T-Cu. Contents of all forms copper are increased compared with controls, especially OC-Cu, which content is 68.79mg·kg-1, 22.07% of T-Cu. That indicates that the copper availabilities in orchard soils are higher than controls. The mainly form of copper in soils is RES-Cu, more than 60% of T-Cu. 3. The section distribution of copper in orchard soilWith the depth adding, the contents of all forms copper in orchard soils decreased, especially T-Cu and DTPA-Cu, which contents in all sections are notably higher than controls. The contents of copper under the second sections don’t change great as top soils, which shows that the external copper mainly affects the contents and distribution of copper in orchard surface soils. 4. Absorption-desorption of copper in soilsThe absorption curves of copper in orchard soils were notably fit for Langmuir equation. The ordinal max absorption of soils in test was: aquert >saline-alkali soil > drab soil >burozem. The desorptions were reverse and far smaller than absorption. The desorptions, compared with absorption, showed obvious lag phenomena. And the lag circles had positive correlation with the abilities of absorption. Compared with controls, the max absorption notably decreased, while the desorptions increased.5. The characters of absorption-desorption with timeBoth absorption and disorption were rapidness actions and would extend the balance within 20 min in orchard soils. The desorptions were far smaller than absorption. The time of extended the max in orchard soils was a little earlier than that of controls, and the adsorption in orchard soils was lower than controls.<WP=9>6. The buffering of copper in soilsThe buffering abilities of copper in tested soils were decreased with the content of external copper increased, especially under the condition of high copper content. The order of buffering abilities in tested soil was: aquert > saline soil>drab soil>burozem. The buffering abilities of copper in orchard soils were obviously decreased compared with controls for lots of buffering places were occupied by the copper which accumulated in the orchard soils. The curves of buffering rates changing with time were fit for nonlinear damped vibration eq

  • 【分类号】S153.6
  • 【被引频次】4
  • 【下载频次】222
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