刺槐,国槐根际土壤生化成分及其对伴生杨树营养的影响

分析了杨树、刺槐和国槐的根面与根际土壤中的游离氨基酸及植物生长素ＩＡＡ，测定了不同处理小区中杨树叶片的营养状况（Ｎ、Ｐ、Ｋ和叶绿素含量）以及净光合速率和气孔阻力．结果表明，刺槐、国愧和杨树根面氨基酸组成和数量有很大差别；３个树种根际土壤中氨基酸含量显著低于根面．３个树种根面和根际土壤中ＩＡＡ含量为刺槐＞国槐＞杨树．混交豆科树种后，杨树叶片营养状况有所改善，净光合速率明显提高，气孔阻力有所降低．

Biochemical compositions in rhizospheric soil of Robinia pseudoacacia and Sophora japonica and their influence on nutrition or associated poplar

In this paper,the contents of free amino acid and phytohormone IAA in root suface rhizospheric and rhizoplane soils of Populus bejingensis, Robinia pseudoacacia and Sophora japonica are analysed, and the (contents of nitrogen,phosphorus, potassium and chlorophyll in poplar leaves and their net photosynthetic rate (NPR) and stomatal resistance (SR) under different treatments (pure poplar or mixed with leguminous trees) are measured. The results show that the total content and composition of free amino acids in rhizoplane soil of tree species tested are quite different, and the amino acid content rhizospheric soil is lower than that of rhizosplane soil. The IAA content in rhizoplane and rhizospheric soils of tree species tested is in order of Robinia pseudoacacia>Sophora japonica >Populus beijingensis. After mixed with leguminous trees, the nutritional condition of Populus beijingensis is improved, its NPR is greatly increased, and SR is decreased.