以太湖地区三种典型的水稻土(黄泥土、白土、乌泥土)为例, 利用模拟—培养试验, 着重研究模拟酸雨对土壤的铜吸附解吸能力的影响。研究结果表明:与未淋溶土壤相比, 经模拟酸雨淋溶的三种土壤对铜的吸附量有所增加, 随着淋溶液pH的降低, 增幅减小:易解吸态铜的解吸量则随淋溶液pH的降低而增大, 模拟酸雨降低了土壤对重金属污染的缓冲能力;虽然黄泥土、乌泥土对铜的吸附量远大于白土, 但模拟酸雨对黄泥土和乌泥土的吸附—解吸能力的影响程度也大于白土。

以太湖地区两种典型的水稻土(乌泥土和白土)为供试土壤, 在盆栽条件下种植多年生黑麦草, 并配制不同pH值的模拟酸雨浇灌。通过多次刈割鲜草, 研究模拟酸雨对土壤2植物系统中铜的化学行为的影响。结果表明:对植物体内铜含量的影响是模拟酸雨和“稀释效应”两种影响综合作用的结果。试验初期, 表现为处理黑麦草体内铜含量低于对照;随收割茬次的增加, 表现出随处理pH的降低, 黑麦草体内铜含量增加, 且对缓冲能力弱的白土影响强度大于缓冲能力较强的乌泥土;对土壤pH有明显影响, 随模拟酸雨作用时间增长, 土壤pH下降, 其降幅随处理pH的降低而增大;模拟酸雨主要影响交换态铜, 表现为随处理pH的降低交换态铜的分配系数增高, 在处理pH=3.0时影响到碳酸盐结合态铜, 只有强酸化条件下(处理pH=2.0)才影响到铁锰氧化物结合态铜, 对有机物结合态及残渣态铜几乎无影响。

The objective of this study was to investigate the effect of earthworms and arbuscular mycorrhiza (AM) on the Cd transfer from soil to plant The Aquods soil, obtained from Laitiao Village, Hong Kong, was amended with Cd which Concentration is 5, 10 and 20 mg•kg-1 respectively. After two months amendment, the soil was inoculated with eight earthworms (Pheretina sp.) and arbuscular mycorrhiza (Inoculum Endorize-Mix2) separately, and in combiantions Both blank and inoculated samplepotswere received 15 pre germinated ryegrass seeds (Lolium multiflonwn).The results showed that(1) the soil pH decreased by about 0.2 units with earthworms inoculation, while no soil pH change was observed with mycorrhiza inoculation The combination of earthworms and mycorrhiza inoculation was not able to reduce the soil pH to the same level as earthworms alone (2) the concentration of dissolved organic carbon (DOC) in soil was significantly increased with earthworms and mycorrhiza inoculation, with the effect of earthworm outweighed that of mycorrhiza The combination of earthworms and mycorrhiza inoculation did not significantly increase the DOC compared with earthworms alone (3) mycorrhiza inoculation significantly increased Cd concentration in shoot and root, however earthworm alone only significantly increased Cd concentration in root Earthworms mycorrhiza combination increased the Cd transfer from ryegrass root to shoot (4) The concentration of DTPA extractable Cd in earthworm castor in soil was positively correlatedwith iyegrass uptake of Cd (p <0.01) , and the concentration of DTPA-extractable Cd in earthworm castwas higher than that in soil (p <0.05).Therefore, the available Cd in earthworm cast was the important source of Cd uptake by plant

本文采集了太湖地区典型水稻土土种(黄泥土、白土、乌泥土), 实验室分析了土壤酸碱缓冲能力、土壤中重金属的形态分布特性以及吸附解吸动态与缓冲速率, 指出不同土种间土壤对重金属污染的缓冲能力差异较大, 肥力较高的爽水型水稻土黄泥土的缓冲能力最强。