Effects Of Diatomite Organic Fertilizer On Some Physiological Metabolisms Of Chinese Cabbage Under Cd,Zn Compound Pollution

With the industrialization and urbanization intensifying and unreasonable use ofagricultural chemicals, heavy metals pollution is more and more serious in recentyears. Heavy metals pollution can threaten human being's health through the foodchain. Heavy metal pollution, particularly compound heavy metals pollution havebeen given much attention. In order to provide theoretical basis for remediation ofheavy metal pollution soil, indoor culture experiment and pot experiment were carriedout to study the effects of diatomite organic fertilizer on the forms,the bioavailabilityof Cd, Zn in soil and on some physiological metabolisms of Chinese Cabbage underCd, Zn compound pollution. The main results were as follows:1. Effects of diatomite organic fertilizer on soil Cd, Zn forms and bioavailability1.1Culture experiments showed soil pH increased and soil available Cd,Zn reducedafter diatomite organic fertilizer application in contaminated soil.1.2Diatomite organic fertilizer application decreased significantly the contents ofexchangeable form and Weaky-bound-to organic form of Cd and Zn, but increased thecontents of strongly-bound-to organic form and residual form of Cd and Zn incontaminated soil.1.3Comparing two diatomite organic fertilizer application rate of5%and10%, therewas no significant difference in soil pH, the contents of soil available Cd, Zn andforms of Cd, Zn.2. Effects of diatomite organic fertilizer on some physiological metabolisms ofChinese cabbage under Cd-Zn compound pollution2.1Pot experiment results showed that diatomite organic fertilizer applicationincreased soil pH and soil organic matter content, but decreased the contents of soilavailable Cd,Zn and the contents of Cd,Zn in Chinese cabbage. Diatomite organicfertilizer application increased the height, leaf number and fresh weight of Chinesecabbage significantly in contaminated soil.2.2Adding diatomite organic fertilizer increased CAT activity, while reducedSOD, POD activity, O2·-producing rate, the contents of H2O2, MDA and themembrane permeability of Chinese cabbage in contaminated soil.2.3Application of diatomite organic fertilizer significantly increased the contents ofChla, Chlb, Chla+b, stomatal conductance, leaf transpiration rate and photosynthesis rate of Chinese cabbage in contaminated soil.2.4Adding diatomite organic fertilizer increased Fv/Fm, electron transfer rate,performance index (PIABSand PICS) of reaction center significantly, but decreasedinactivation rate of PSⅡ reaction center significantly, indicating diatomite organicfertilizer could alleviate the damage of PSⅡ under Cd, Zn compound pollution.2.5Diatomite organic fertilizer application increased the contents of Mg, Ca, K, Fe, Pand Cu, but decreased the contents of Mn, B of Chinese cabbage in contaminatedsoil.