四川省江安县某硫铁矿区周边农田土壤重金属来源解析及污染评价

目的确定在云南兰坪铅锌矿周边污染农田种植万寿菊的最佳密度。方法种植万寿菊F1品种，研究不同种植密度(27 800、33 300、41 700 和55 600 株/hm²) 对万寿菊生长和镉铅累积特征的影响。结果 (1) 万寿菊生物量以茎部最大；镉含量在盛花期表现为茎>根>叶≈花，在成熟期表现为根≈茎>叶>花；铅含量在盛花期和成熟期表现为根≈叶>茎>花；镉铅主要累积在茎部。(2) 4个种植密度下，万寿菊单株生物量、单株镉铅含量以27 800和33 300 株/hm²种植密度最大，单位面积镉铅累积量以55 600 株/hm²最大。(3)土壤镉的化学形态以可氧化态和弱酸提取态为主；土壤铅的化学形态以可氧化态、可还原态和残渣态为主；万寿菊镉铅含量与土壤镉铅化学形态间的相关性不显著(P>0.05)。结论万寿菊可用于云南高原铅锌矿区污染农田的替代种植，为矿区污染农田的农业安全利用提供新方法。

Phytoremediation of heavy metal contaminated buriganga riverbed sediment by Indian mustard and marigold plants

PurposeTo determine the optimal density for planting marigold in a heavy metals polluted farmland around a lead-zinc mine, Lanping County, Yunnan Province.MethodA marigold variety F1 was planted to study the effects of different planting densities (27 800, 33 300, 41 700 and 55 600 plants/hm²) on the growth and the accumulation characteristics of cadmium and lead in marigold.Result (1) The stem biomass was the largest among marigold plant. The cadmium content in marigold was stem>root>leaf≈flower at the flowering stage, as well as root≈stem>leaf>flower at the maturity stage. The lead content in marigold was root≈leaf>stem>flower at the flowering and maturity stages. Cadmium and lead were mainly accumulated in the stem. (2) For the four planting densities, the biomass per plant and the cadmium and lead content per plant were the highest at 27 800 and 33 300 plants/hm², and the accumulation of cadmium and lead per unit area was 55 600 plants/hm². (3) The chemical forms of cadmium are mainly oxidizable and acid extractable, and the chemical forms of lead are mainly oxidizable, reducible and residual in soil. But there was no significant correlation between cadmium and lead content in marigold with chemical forms of cadmium and lead in soil.ConclusionMarigold can be used for alternative planting on the polluted farmland in the lead-zinc mining area of Yunnan Plateau, and providing a new method for agricultural safe use of polluted farmland in the mining area.