酸性土壤上缺磷和铝毒对大豆生长的交互作用

Interactive effects of P deficiency and Al toxicity on soybean growth:A pot experiment with acid soil

以7个磷效率不同的大豆基因型为材料,通过土壤盆栽试验进行石灰和磷肥处理,研究酸性土壤上缺磷和铝毒对大豆生长的交互影响及其基因型差异.结果表明:缺磷和铝毒是酸性土壤上同时存在的影响大豆生长的主要障碍因子,其中铝毒对大豆生长的限制更为严重;缺磷和铝毒对酸性土壤上大豆生长的影响具有显著的交互作用.同时施用石灰(降低铝毒)和磷肥(提高磷有效性)比单施石灰或单施磷肥处理对大豆生长的促进效果更显著;缺磷和铝毒对大豆磷吸收的影响远大于对氮、钾吸收的影响.合理种植大豆对酸性土壤具有较好的改良作用.同时施用石灰[1.103gCa(OH)2.kg-1土]和磷肥(2.018gKH2PO4.kg-1土)可使酸性土壤pH值平均提高38.4%,交换性铝含量降低96.3%,有效磷含量提高3223.8%.种植磷高效大豆基因型比磷低效大豆基因型对酸性土壤的改良效果更好.

Taking seven soybean genotypes differing in P efficiency as test materials,a pot experiment with acid soil was conducted to study the interactive effects of P deficiency and Al toxicity on the growth of the genotypes under liming and P fertilization. The results showed that P deficiency and Al toxicity were the limiting factors for the soybean growth on acid soil,and the impact of Al toxicity was more severe. There existed interactive effects between P deficiency and Al toxicity. Comparing with liming or P fertilization alone,their combination could greatly promote soybean growth. The impact of P deficiency and Al toxicity on the P uptake by soybean was far greater than that on N and K uptake. A reasonable planting system for soybean would be helpful for the amelioration of acid soil. The combined application of 1.103 g Ca（OH）2·kg-1soil and 2.018 g KH2PO4·kg-1 soil） could increase the acid soil pH by 38.4% and the available P content by 3223.8%,and decreased the soil exchangeable Al content by 96.3%. Planting P-efficient soybean genotypes rather than P in-efficient soybean genotypes had better effect in acid soil amelioration.