钾肥对小麦根际土壤镉的吸收及其植物毒性的影响

研究不同钾肥对Cd在根际土壤-植物系统中转移及植物有效性的影响可为农业生产提供依据。以潮褐土为供试土样,采用盆栽方法研究了氯化钾、硝酸钾、硫酸钾对小麦(Triticum aestivum L)根际环境镉的吸收转移及植物有效性的影响。结果表明,(1)KCl提高根际土中有效态Cd质量分数(wCd),K2SO4和KNO3降低根际土壤有效态wCd。(2)K2SO4处理下,小麦根wCd显著大于对照;随KNO3和KCl施入量的增加,小麦根中Cd含量逐渐升高。(3)相同处理三种钾肥比较小麦地上部干物重表现为:KNO3>KCL>K2SO4,根干物质量均低于对照。(4)钾肥的施入提高小麦体内CAT,POD酶活性。建议Cd污染土施用KNO3,尽量避免施用KCl和K2SO4。

Effect of potassium fertilizers on the absorption of cadmium in rhizosphere soils and its phytotoxicity

Soil contamination with Cd has been one of the focuses of environmental science,this study can give a good way to the agricultural production.The adsorption of Cd in wheat rhizosphere and its phytoavailability on wheat in meadow cinnamon soil that KNO3,K2SO4,KCl effect to them were studied.The results showed that(1) KCl application increased the content of Cd in the rhizosphere,while KNO3 and K2SO4 decreased Cd contents.(2) With the application of KNO3 and KCl,the absorption amount of Cd in the roots of the Triticum aestivum,L had a gradual increase,and K2SO4 made it obviously larger than the contrast.(3) The biomass of wheat above the ground descended in the order of KNO3,KCl,K2SO4,and the roots biomass was lower than that of contrast experiments.(4) The three kinds of potassium fertilizers all improved the activity of CAT and POD enzyme in wheat.So we suggest that we should use KNO3 in Cd polluted soils not KCl or K2SO4.