覆盖栽培经营多年后,雷竹土壤会出现明显的酸化现象。土壤酸化会活化土壤中的铝,从而抑制雷竹的生长。因此,了解集约经营模式下雷竹林土壤铝的形态变化显得尤为重要。采用Tessier连续浸提法分析了不同种植年限下雷竹林土壤中各种形态的铝含量,结果表明:随着种植年限的增加,土壤pH值显著下降,表层土壤活性铝含量增加,雷竹栽种15年后,其在总铝中所占的比例由对照的6.15%增加至10.8%;醋酸铵提取的交换性铝由无到有,在种植15年后心土亦有显著增加;有机络合态铝含量随着种植年限的增加而增加,种植15年时表层土壤较对照增长42%,底层增长27%;其他各形态铝含量则随着种植年限的增加有下降的趋势。土壤pH值,有机质、全氮及交换性酸含量与交换态、铁锰氧化物结合态、有机络合态及残渣态的铝显著相关,而与碳酸盐结合态铝含量无关。
Adopted the mulching technique for several years, soils planted Lei bamboo will show a significant acidification. In the acidified soils, A1 will dissolve from minerals as active forms to influence the growth of bamboos. Therefore, it is important to understand the process of A1 form transformation during the bamboo growing stage with the intensive management. In this study, Tessier continuous extraction method was employed to analyze various A1 forms in bamboo soils in a chronosequence of cultivation. Results showed that soil pH dropped while active A1 contents increased with increasing cultivation time in the surface soil. After 15 years cultivation of Lei bamboo, the ratio of soil active A1 to total A1 increased from 6.15% to 10.8%, and the exchangeable A1 detected even in the sub-layer soil. The amount of organic complexed A1 increased with the cultivation time as well. In the soils with 15 years bamboo cultivation, it increased by 42% in the surface and 27% in the sub-layer soil. On the contrary, other forms of A1 decreased with cultivation time. Further relationship analysis showed that soil pH, organic matter, total nitrogen and exchangeable acid influenced the contents of exchangeable, Fe/Mn bound, organic complexation and residue forms of A1, except for carbonate bound A1.