不同肥料配比对富士苹果产量及品质的影响

为了探讨不同氮磷钾配合施肥对渭北旱塬富士苹果产量及品质的影响，为富士苹果的优质、高产提供理论依据，本文通过连续5年（2004～2008）氮磷钾不同配比施肥定位试验，研究了不同配比施肥对苹果产量及品质的影响。结果表明:施用化肥能使苹果产量提高12.62%～48.57%；NPK配合施肥处理5年中平均产量为34.8 t/hm2，较对照增加了48.57%；PK，NK和NP处理的苹果平均产量较对照 （CK）分别增加了12.62%，21.50%和21.16%。当地化肥对苹果产量的贡献顺序为:氮肥＞钾肥≥磷肥。NPK配合施肥，苹果商品率不断提高，果径大于75 mm的果实个数所占比例逐年增加，由2004年的53.7%增至2008年的81.2%，增长率达51.2%；苹果的糖酸比由2004年的37.1逐年提高到2008年的39.9，提高了7.5%；Vc含量及硬度同样有逐年递增趋势。PK、NK、NP处理，果径小于75 mm的果实个数所占比例逐年增加，糖酸比及Vc含量逐年降低，尤其是NP处理，糖酸比由2004年的32.7降至2008年的20.8，降低了36.3%。PK、NK、NP处理苹果Vc含量5年降低了15.6%，硬度也随试验时间的推移出现逐年下降趋势。NPK配合施肥提高了苹果产量，促进了苹果品质的改善。

Effect of different fertilization on yield and quality of Fuji apple

To study effects of different N, P and K fertilization on quality and yield of Fuji apple in order to provide the theoretical foundation for high yield and quality of apple production in the Weibei tableland. A 5 year field experiment from 2004 to 2008 was conducted. The results showed that the apple yields are increased by 12.62% to 48.57% under the different fertilization, and the order of increase rates by the elements is N＞K≥P. The effect of application of N fertilizer combined with P and K fertilizers is the best, the ratio of apple diameters which are bigger than 75 mm is increased from 53.7% in 2004 to 81.2% in 2008, and the ratio of sugar/acid is increased from 37.1 to 39.9. However, for the NP, PK and NK treatments, the ratio of sugar/acid, Vc and hardness are all decreased, especially for the NP treatment, the ratio of sugar/acid and Vc are decreased by 36.3% and 15.6% respectively. Application of N, P combined with K fertilizer can improve the apple yield and quality.