不同产量水平苹果园氮磷钾营养特点研究

【目的】获得不同产量水平苹果园土壤与植株叶片、果实氮磷钾营养特点。【方法】将10年生红富士/平邑甜茶苹果园按产量水平分为4类，1997～2000年连续4年定期采集土壤与植株样品进行测定分析，并从2001年开始对4类果园进行不同施肥量试验。【结果】随产量水平提高，土壤碱解氮、有效磷、速效钾均呈增高趋势，反映了增加土壤养分供应能力对提高产量水平具有重要作用，但在同一产量水平上，这3项指标测定值变化幅度大，且与产量的相关系数较低。高产园植株叶片一般表现出较高的全氮、全磷含量，较低的全钾含量，果实则表现为较高的全氮含量，较低的全磷含量，全钾含量变化不大，其中高产园叶片全钾含量下降最显著，在土壤有效钾含量较高的条件下，高产园叶片全钾含量并不高，并且叶钾与土壤速效钾的相关性较差，此时叶钾主要受产量的影响，随产量的上升而下降。不同产量水平果园施肥反应存在差异，各类果园增施磷肥均未表现出增产效果，增施钾肥均有增产效果，仅中低产园对增施氮肥表现出增产效果。【结论】根据目标产量确定施肥量时，要根据土壤有效养分含量对施肥量进行调整；根据叶分析结果判断植株钾素营养状况时应考虑产量对钾素吸收分配的影响。

Characteristics of N, P, and K Nutrition in Different Yield Level Apple Orchards

【Objective】In order to get the information about the characteristics of N, P, K nutrition in different yield level apple orchards. 【Method】 The orchards with ten-year-old apple trees (M. domestica Borkh. cv. Red Fuji/M. hupenensis Rhed) were divided into four types, soil and plant samples were collected and determined at certain time from 1997 to 2000, fertilizer treatments were also conducted in different type orchards. 【Result】The results showed that soil alkaline hydrolyzable N, available P and K concentration had an increasing tendency as yield level increased, indicating the important effect of soil fertility on yield. But the three index value changed much and had low correlation index with yield at the same yield level. At high yield level orchards leaf total N and P, fruit total N were relatively high but leaf total K and fruit total P were relatively low, leaf total K was mostly influenced by yield, and decreased with yield increased. The effect of fertilizer on yield was changed with the change of yield level. Application of P did not increase yield at all four yield level orchards, but as K was concerned, and it was contrary. Application of N increased yield at middle and low yield level orchard. 【Conclusion】Fertilizer application amounts to apple trees should base on not only the yield but also the soil available nutrients. The estimation of K level in apple trees should base on not only the leaf K concentration but also the effect of yield on K absorption and distribution.