土壤侵蚀磁性示踪剂对土壤理化性质及小白菜生理特性的影响

Effects of Soil Erosion Magnetic Tracer on Physical and Chemical Properties of Soil and Physiological Characteristics of Pakchoi

用盆栽试验研究了不同浓度的土壤侵蚀磁性示踪剂对土壤理化性状、微生物量及小白菜生理特性、产量、品质的影响。结果表明,磁性示踪剂提高了土壤pH、电导率值以及速效钾含量,降低了小白菜对土壤碱解氮、速效磷的利用;显著提高了土壤微生物量碳、氮及碳氮比(p<0.05),改善了土壤微生物学性状。低浓度(5%)的磁性示踪剂提高了小白菜的叶绿素含量,有效改善了小白菜叶片的光合性能。磁性示踪剂还显著提高了小白菜SOD、POD活性及MDA含量(p<0.05),对CAT活性具有抑制作用。另外,磁性示踪剂降低了小白菜的产量,但低浓度(5%)处理改善了小白菜的品质,且Cu、Pb和Cd含量均在国家蔬菜食品卫生标准范围内,不会对食品安全构成威胁。

In order to determine the effects of the soil erosion magnetic tracer on soil and plants,pakchoi（Brassica chinensis） grown in the pots was exposed to different concentrations of magnetic tracer on basic physical and chemical properties,microbial biomass of soil and on physiological characteristics,yield and quality of pakchoi.The results showed that,compared with CK,the soil pH,EC and available K increased significantly with the application of magnetic tracer,but the applications of available N and P were stimulated.Magnetic tracer improved the soil microbial biological properties since microbial biomass C,N and C/N increased significantly（p0.05）.Compared with CK,plant biomass decreased significantly as magnetic concentrations increased（p0.05）.The chlorophyll（Chl） content increased significantly when applying lower concentration（5%） of magnetic tracer,and at the same time,the magnetic tracer promoted the photosynthesis.The activities of superoxide dismutase（SOD） and peroxidase（POD） and the content of malondialdehyde（MDA） of pakchoi increased significantly as magnetic concentrations increased（p0.05）,but the activity of catalase（CAT） decreased significantly（p0.05）.The quality of pakchoi was relatively improved by the lower（5%） magnetic tracer concentration treatment,and the pakchoi is safe for eating since the Cu,Pb and Cd contents of pakchoi were still lower than the national vegetable and food hygiene standards.