集约经营对雷竹林土壤与植株铝含量的影响

Influence of Intensive Management on Soil Extractable Al and Phyllostachys praecox Al Content

选择不同种植年限的雷竹林及对照水稻田,分析土壤酸度、土壤提取态铝及植株铝含量。结果表明:在水稻田改种雷竹后,雷竹林地表层土壤酸化严重;集约经营增加了土壤有机质含量,最高为64.2 g·kg-1,较对照提高50%;土壤中提取态铝含量随着种植年限增加而显著增加,8-羟基喹啉提取态铝的含量最高为108.0mg·kg-1,是对照的10倍,乙酸提取态铝含量最高为235.4 mg·kg-1,是对照的4倍多;竹根中铝的含量随着种植年限增加而显著增加,而竹鞭、竹秆及竹叶则相反。可见,在覆盖栽培的集约经营模式下,雷竹林土壤酸化显著,生物毒性铝和生物可利用铝含量剧增,雷竹根部铝大量积聚,养分转运受阻,从而危害雷竹正常生长。

Phyllostachys praecox plantations with various ages and the neighboring paddy field （served as control） were selected for analysis of soil acidity,the soil extractable Al content and the bamboo Al content.Results showed that the soil was severely acidified in P.praecox stands after shifted from the paddy field.The intensive management increased soil organic matter content up to 64.2 g · kg-1 that was 50% higher than in the control.Soil extractable Al content increased significantly with the cultivation duration of bamboo.The highest content of 8-hydroxyquinoline extractable Al was 108.0 mg · kg-1 that was 10 times as the control and acetic acid extractable Al content was 235.4 mg · kg-1 that was 4 times as the control.The Al content in the bamboo roots increased with the cultivation duration.However,Al contents in the bamboo rhizomes,stems and leaves were the opposite,suggesting there was a damage of nutrient transport in bamboo due to the Al toxicity.Accordingly,the increased soil phytotoxic and bioavailable Al content along with the severe soil acidification did harm to the bamboo growth under the intensive management.