粉煤灰复田立地欧美杨营养诊断研究

Study on Nutritional Diagnosis of Populus×euramericana in Reclaimed Area by Coal Ash

（１）叶片营养诊断表明，粉煤灰复田立地上欧美杨处于Ｎ素和Ｐ素营养亏缺状态，而Ｋ素较为充足，但施Ｋ有利于林木对Ｐ素的吸收，效应仍很显著。（２）相关分析表明，叶片Ｎ、Ｋ素浓度与生长呈正相关关系，而Ｐ则呈负相关关系，说明叶片Ｐ素含量与生长的关系实质上是一种“稀释效应”。

The nutritional diagnosis of the leaves shows that in the reclaimed area bycoal ash, the trees of P.× euramericana are in a state of nutrition deficiency,so the applica-tion of N not only raised the N concentration of the leaves,but promoted bothe tree growthand its absorption of K,Ca,Mg etc.nutritional elements.The application of P mainly raisedthe P concentration of the leaves and solved the problem of P deficiency.(2) The correlationanalvsis shows that the application of K helps to promote the absorption of P. From the re-sult of K application,it shows that the appropriate K value of 1.5%proposed by J. Garbayeis obviously on the low side,which is not suitable for the poplar clone we're dealing with.(3)The application of green manure can raised the Mg and P concentration of P.×eurameri-cana's leaves,but its mechanism of significant effect has to be studied further.(4)The N,Kconcentration of the leaves has a positive correlation with the growth of P.×euramericana,which shows that the higher the leaf concentration,the bigger the tree increment.On thecontrary,the P concentration of the leaves has a negative correlation with the tree growth,which shows that in face,the relationship between P concentration and tree growth is a kindof“diluted effect”.