中文摘要：

在西北黄土高原丘陵沟壑区选择试验点。开展了苹果园水肥耦合试验，研究内容包括苹果园土壤农化性状测试分析；不同水肥耦合试验组合对土壤养分含量的影响；不同水肥耦合试验组合对苹果树的干周、产量、质量及效益的影响等。试验研究结果证明，实行平衡施肥后，土壤中的养分含量磷素提高到2～3级；氮素保持5级，钾素保持2级，有机质含量均有提高。提出了在苹果树不同树龄段，最适的水肥耦合量比例。按照该水肥耦合比例，能有效提高肥料利用率和土壤养分含量，基本达到了各树龄段的优质果园标准，经济效益显著。

英文摘要：

Water and fertilizer coupling experiment was carried out at the plot in the hilly and ravine region of north-west loess plateau, which include measurement and analysis on soil chemical features, influence of different combination of water and fertilizer coupling on soil nutrition content, on apple tree trunk, yield, quality, and efficiency. It is proved through study that with fertilizer balanceable application, the soil phosphorous content was raised to class 2 or 3, nitrogen content remained class 5, kalium content class 2 and all the organic contents improved. Based on the experiment results, the most adaptive percentage of water and fertilizer coupling was put forward for different tree ages. According to the percentage, fertilizer utilization efficiency and soil nutrition content could be obviously improved. The best standard of orchard quality for different tree ages and the best economic benefits have been realized.