The Study Of Physiological Property Of The Rye In The Polluted Soil Of Hg And Cd And The Absorption Discipline To Hg And Cd

The soil is one of precious natural resources, and it is an essential condition for the human being to rely on for existence and development. However, various artificial and natural factors make the soil the human being rely on for existence be suffered from the pollution of different degree, and cause the soil which is originally possessed the physics and chemistry property degenerate and lose cultivation value, and threaten the safety of food chain and the health of human being. This thesis is based on the project of < Heavy metals pollution of soil and environment effect in Shuanghe bridge basin, little Qin Ling gold mine area>, it choose two kinds of heavy metals as research objects, which can pollute the peripheral soil most easily during mine exploitation, and choose the farmland soil in southern suburbs of Xi'an as experimental soil and simulate the polluted soil by adding the aqueous solution of HgCl₂. 3CdSO₄·8H₂O, and the root-beard which is planted in the simulated polluted soil is very flourishing and can use up various effective chemical element in the soil in a short time, and the rye which grow up quickly is a plant.In order to develop the experiment, it set the constitution density gradient followed by the standard of Environment Quality Standard for Soil (GB15618-1995), and designed several experiments, such as the soil absorption experiment, the urging bud of seed toxicity experiment and the potted plant experiment of rye growth, which mainly studied the alone and exchanged functions of the two kinds of heavy metals (mercury and cadmium) elements in the soil, some physiological characteristics of the growth of rye and absorption disciplines of rye to mercury and cadmium. Through the research of physiological characteristic of rye, it aims to explore and investigate the possibility on if the rye could be the monitor plant as for heavy metals pollution degree of the soil. Through the exploration of basic discipline of the rye absorption to mercury and cadmium, it is meaningful to reveal the heavy metals (mercury, cadmium) compound pollution and its ecosystem effect mechanism, evaluate the environmental quality and adopt pollution treatment measures.The results of above-mentioned experiments show:â‘ The absorption quantity of soil to mercury and cadmium is increasing with the corresponding density increment, while the adsorption rate represented the decreasing trend gradually. Under the conditions of the soil taken by this experiment and the density condition with adding mercury and cadmium, it is calculated that the theoretical maximum adsorbing quantities to mercury and cadmium are 588.2 mg/kg and the 156.26 mg/kg, respectively by the Langmuir equation; it means under this experimental soil condition, no matter how the density of mercury and cadmium changing, the theoretical maximum adsorbing quantity kept constant.â‘¡Mercury and cadmium and its exchanging functions have lowering, repressing or destruction function on the germination power, germination rate, average stem length and caulis of the rye seed , the content of chlorophyll, and the destruction condition of rye leaf slice quality film, therefore the external physiological characteristic (fresh heavy, stem length) and indirect physiological characteristic of rye (chlorophyll and electric conductivity rate) can be used to reflect the poisoned degree under the polluted soil in mercury and cadmium. When the rye grows into the polluted soil of mercury and cadmium, all the rate of emergence is more than 90%, which shows the rate of emergence can not reflect the poisoned degree under the polluted soil of mercury and cadmium although it is the physiological characteristic of rye.This thesis deeply discussed physiological quality indices of the rye and its absorption situation to mercury and cadmium under the alone and exchanging function of heavy metals (mercury and cadmium) through the potted plant experiments by adding the nourishment elements of N fertilizer and PK fertilizer, the fertilizing potted plant experiment show:â‘ The growing situation, fresh heavy of caulis and leaf, the content of chlorophyll and the injury degree of plasmolemma are better by fertilizing the P than fertilizing the N. In the soil of being rich in the heavy metals of mercury and cadmium, in order not to degrading the soil and to plant the high-quality of rye graze, it can alleviate the effects of heavy metals to the rye growth by employing the appropriate PK fertilizer.â‘¡If wanting to repair the pollution of heavy metals of mercury and cadmium, it can plant rye to absorb fixed amount of heavy metals of mercury and cadmium in the soil. The absorption quantity of mercury and cadmium by the root of the rye is more than by the caulis and leaf, which represents the rye can solidify the heavy metals of mercury and cadmium, and the effect is more obvious when adding fixed amount of N fertilizer.