乾县苹果营养诊断和施肥研究

经调查，供试３４个果园的施肥量和产量变异很大。许多果园施氮肥过多，钾肥太少。经叶分析，Ｎ，Ｐ，Ｋ，Ｆｅ，Ｚｎ的平均含量依次是２２．８±２．５ｇ·ｋｇ－１，１．４±０．２ｇ·ｋｇ－１，１０．７±２．０ｇ·ｋｇ－１，２２５±５１ｍｇ·ｋｇ－１和１８．７４±１２．３６ｍｇ·ｋｇ－１．Ｋ和Ｚｎ的含量低于正常值的果园数分别占３５．３％和５８．９％．多数果园Ｎ，Ｐ，Ｋ营养不平衡，营养三要素的需要顺序多是Ｋ＞Ｐ＞Ｎ．根据目标产量、生产单位果品需要养分量和养分平衡指数，确定了各果园的最小养分因素及其需肥量，并按养分比例法推荐了其他肥料的施用量。

Nuitrient Diagnosis of Apple Trees and Fertilizer Recommendation in Qianxian County

Great variations of fertilizer amounts and apple yield exist among the 34 orchards investigated.The application of N fertilizer is excessive in many or chards while that of K fertilizer insufficient. The results of leaf analysis show that the average contents, in leaf, of N,P,K,Fe and Zn are 22. 8±2. 5 g·kg^-1, 1. 4±0. 2 g·kg^-1, 10. 7±2. 0 g·kg^-1, 225±51 mg·kg^-1, and 18. 74±12. 36 mg·kg^-1 respectively. The orchards with K and Zn contents in leaf lower than normal respectively amount to 35. 3% and 58. 9% of the total.There is animbalance among N,P and K in most orchards with the requirement order of K>P>N.According to the target yield, the required nutrient quality and the nutrient equilibrum indices of fruits, the amounts of minimum nutrient factors and the required fertilizer were determined.The application amounts of other fertilizers were recommondated with the method of nutrient ratio.