关键词: 梨, 果园, 叶片, 矿质营养元素, DRIS, 环渤海湾地区

Abstract: he pear tree nutrition diagnosis is based on mineral nutrition element contents in its leaves. This study investigated the nutrient status of pear leaves and soils in main orchards around the Bohai Bay region. The results showed that：（1）In 81%–97% orchards，the P，Ca，Mg and Fe contents in leaves were at optimal level，while in 26%–40% orchards，N and Zn contents were at the lower level.（2）Except for Mg and Zn，the other mineral nutrients content in leaves varied significantly in different cultivars. Pingguoli pear had higher N and P contents，but lower K content，Laiyang Chili pear had lower N，but higer P and K contents，and Dangshan Suli pear had lower contents of N，P and K.（3）N/P，Mg/P，Zn/P，K/Mg，Ca/Mg，Zn/Mg were screened for the DRIS parameters，and the sequence of the elements，necessary for improvement of the low-yield pear trees，was approxinately Mg > P > Ca > K > Zn > N > Fe. （4）The soil pH is positively correlated to leaf Ca，Mg content，but negatively correlated to leaf Zn content. There was a significant positive correlation between organic matter in soil and the leaf N，Mg content. Anyway，between the leaf content of N，K，Ca，Mg，Zn and soil available nutrients，there is a significant positive correlation.

Key words: pear, orchards, leaf, mineral nutrients, DRIS, Bohai Bay region