The effects of inoculation of earthworms and arbuscular mycorrhiza separately, and in combination, on Cd uptake and growth of ryegrass were studied in soils contaminated with 0.5, 10, 20 mg of Cd kg-1 soil. Both earthworms and mycorrhiza were able to survive in all the treatments with added Cd. Earthworm activity signicantly increased mycorrhizal infection rate of root and ryegrass shoot biomass. Earthworm activity decreased soil pH by about 0.2 units, and enhanced root Cd concentration and ryegrass Cd uptake. Mycorrhiza inoculation increased shoot and root Cd concentration substantially, and at the highest dosage of 20 mg Cd kgK1 decreased biomass of ryegrass. Inoculation of both earthworms and mycorrhiza increased ryegrass shoot Cd uptake at low Cd concentrations (5 and 10 mg Cd kgK1 soil), when compared with inoculation of earthworms or mycorrhiza alone. In conclusion, earthworm, mycorrhiza and their interaction may have a potential role in elevating phytoextraction efciency in low to medium level metal contaminated soil.

Laboratory incubation experiments were conducted to examine the effect of earthworm (Pheretimasp.) activity on soil pH, zinc (Zn) fractionation and Nmineralization in three soils. No Zn uptake by earthworms was observed. Zinc addition decreased pH of red soil (soil 1) and hydragric paddy soil (soil 3) by 0.5 and 0.2 unit, respectively, but had no effect on alluvial soil (soil 2). The effect of Zn on soil pH was possibly due to a specific adsorption mechanism between Zn and oxides. Earthworm activity significantly decreased the pH of the red soil, a key factor affecting Zn solubility, but not of the other two soils. Earthworm activity significantly increased DTPA-Zn (DTPA-extractable) and OxFe-Zn (NH2OH-HCl-extractable) in the red soil, but had little effect on other fractions. In the alluvial soil, earthworm activity significantly increased OxFe-Zn but decreased organic-Zn (organic-associated Zn). In the hydragric paddy soil, earthworm activity significantly increased MgCl2-Zn (MgCl2-extractable) and organic-Zn. The level of CaCl2-extractable Zn in all three soils was not affected by earthworm activity. Nitrogen mineralized as a result of earthworm activity was equivalent to 110, 120 and 30 kg N ha–1 in soils 1, 2 and 3, respectively. Zinc added at rates less than 400 mg Zn kg–1 did not seem to affect the activity of N-mineralizing microorganisms. The present results indicated the possibility of increasing the metal bioavailability of relatively low level metal contaminated soils, with a higher organic matter content, by earthworm inoculation.

以褐土（Cinnamon soil）、潮棕壤（Aquic brown soil）和酸性棕壤（Acid brown soil）为供试土壤, 通过培养实验, 研究了土壤中重金属Zn、Pb对赤子爱胜蚓（Eisenia foetida）生长率的影响, 赤子爱胜蚓（Eisenia foetida）对不同土壤中有效态Zn、Pb含量的影响, 并与野生环境中生长的灰暗异唇蚓（Allolobaphora caliginosa）进行比较。结果表明：重金属的污染明显抑制了赤子爱胜蚓的生长；赤子爱胜蚓可以显著提高潮棕壤中DTPA-Pb的含量, 对DTPA-Zn的含量影响不大；加赤子爱胜蚓, 褐土中DTPA-Zn和Pb的含量显著高于加灰暗异唇蚓, 潮棕壤中DTPA-Zn的含量和酸性棕壤中大DTPA-Pb的含量则相反。

以江苏省国营大沙河果园为代表, 查明淮北黄泛沉积区果园土壤肥力现状。结果表明:土壤

以江苏省吴县市农地为例, 研究了高强度经济开发下土壤环境中重金属元素的变化。结果表明, 除Zn接近背景值外, Cu、Pb全量已超过背景值;工业快速发展地区土壤中Pb已显著高于农业环境;它们的有效态含量已达到丰富或过多的供应水平, 且工业环境中显著高于农业环境中;重金属元素的活化率显示工业发展对土壤环境重金属元素的强烈污染冲击。这种20～30a尺度的土壤环境变化对水环境及食物安全和环境安全的潜在影响必须引起科学家和决策者的密切注意。

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

以灰化土（Aquods）为供试土壤, 分别加入４个浓度的Cd２＋(0、5、10、20mg·kg-1）模拟土壤污染, 设置每钵接种８条蚯蚓（Pheretimasp）、接种菌根（Inoculum Endorize-Mix2）和同时接种蚯蚓和菌根的处理, 以不加蚯蚓和菌根为对照, 并种植黑麦草（Lolium multiflorum）, 研究蚯蚓菌根相互作用对Cd污染土壤中速效养分和黑麦草生长的影响。结果表明, 在供试土壤上和设定的浓度范围内, 菌根浸染率不受添加Cd浓度的影响, 平均浸染率为22%, 加入蚯蚓能使菌根的侵染率提高9%。在Cd污染的土壤上, 引进蚯蚓显著增加了黑麦草地上部的生物量, 接种菌根对黑麦草地上部分产量没有明显影响, 同时接种蚯蚓和菌根与只接种蚯蚓相比没有显著差异。只接种蚯蚓或菌根均能显著提高土壤中速效N、P的含量, 而对速效Ｋ的含量无显著影响。菌根与蚯蚓并不存在着增加土壤中速效N、P、K的协同作用。蚯蚓、菌根均能增加黑麦草对Ｎ、Ｐ的吸收, 同时接种蚯蚓和菌根促进了黑麦草对Ｎ的吸收, 但没有促进对Ｐ的吸收。不论只接种蚯蚓或菌根, 还是同时接种蚯蚓和菌根均不能促进黑麦草对Ｋ的吸收。

以灰化土(Aquods soil)为供试土壤, 分别加入4种含量的Cd2+(0、5、10、20mg·kg-1)模拟土壤污染, 设置单独加8条蚯蚓（Pheretrnn sp.）、单独接种菌根(Inoculum Endorize-Mix2)、同时接种蚯蚓和菌根的3种处理, 以不加蚯蚓和菌根为对照, 各处理均种植黑麦草(Lolium multiflorum), 研究蚯蚓、菌根相互作用对土壤植物系统中Cd迁移转化的影响结果表明：(1)菌根对土壤pH无明显影响, 加蚯蚓可使土壤pH比对照约降低0.2, 蚯蚓和菌根同时作用对土壤pH降低没有协同作用(2)蚯蚓或菌根的加入均能显著增加土壤中可溶性有机碳(DOC)含量, 蚯蚓的影响大干菌根, 同时加入蚯蚓和接种菌根对土壤中DOC的增加有一定的拮抗作用(3)蚯蚓活动增加了黑麦草根部Cd的积累, 菌根则能促进Cd从黑麦草根部向地上部转移, 二者具有伲进Cd向地上部分转移的协同作用(4)蚓粪和土壤中DIPA提取态Cd含量与黑麦草吸收Cd量呈显著相关(p<0.01), 而蚓粪中DTPA提取态Cd含量均显著高于土壤中的含量(p0.05)因此, 蚓粪中有效态Cd是植物吸收Cd的重要供源。