贵州典型土壤-辣椒系统中镉的迁移富集特征

Transport and Enrichment Characteristics of Cd in Typical Guizhou Soil-pepper System

为筛选出低富集Cd的辣椒品种在生产上应用,通过设置不同Cd浓度,采用黄壤和石灰土作为盆栽供试土壤,研究贵州典型土壤-辣椒系统中镉的迁移富集特征。结果表明：1Cd处理浓度为0～5 mg/kg时,辣椒同部位的Cd含量均随处理浓度的增加而增加;黄壤种植的辣椒中Cd含量比石灰土种植的低6.11%～11.84%,其根、地上部分Cd含量的增加量均较石灰土高,分别为4.1和1.4倍。22种类型土壤中,Cd从辣椒根部向果实的转运系数分别为0.04～0.25和0.21～0.50,并且黄壤种植辣椒根部Cd向果实转运速度比石灰土低3倍。3辣椒对Cd的富集系数分别为0.93～1.65和1.02～3.04,且石灰土种植辣椒对Cd的富集系数比黄壤的高1.10～1.84倍。辣椒种植在石灰土中的转运富集能力比黄壤高,试验品种属于易富集Cd品种。

To screen pepper varieties of Cd low concentration to apply in the production, pot experiments were conducted to study the trans- port and enrichment characteristics of Cd in typical Guizhou soil-pepper system by setting different Cd concentration. Results： （i） After har- vest of pepper, Cd content was 6.11% - 11.84 % lower in yellow soil than in calcareous soil. When Cd content ranged from 0mg/kg to 5mg/kg, increasing trends of Cd content of pepper root and overground part were 4.1 and 1.4 times faster under the planting condition of yellow soil than calcareous soil condition respectively. （ii） In yellow soil-pepper and calcareous soil-pepper system, Cd transfer coefficients were respectively 0.04 - 0.25 and 0.21 - 0.50 farm pepper root to pepper fruit. And the transfer speed was 3 times faster under the planting condition of calcareous soll than yellow soil condition. In addition, Cd enrichment characteristics were respectively 0.93 - 1.65 and 1.02 - 3.04, and the characteristics were 1.84 - 1.10 times higher under the planting condition of calcareous soil than yellow soil condition. In short, the transfer speed and enrichment capacity of Cd from pepper root to pepper fruit in calcareous soil was quicker than in yellow soil. Moreover, the used pepper breed initially belong to the enrichment of Cd varieties.