The Fuji, Ralls and Golden Delicious of apple varieties, 120 samples were collected from 20 orchards in Yanshan mountain area and the leaf N, P, K contents were analyzed.

• 摘要采集了燕山山区20个苹果园富士、国光和金冠等品种的120份叶样，对叶片中氮、磷和钾含量进行了分析。