施用氮肥对温州蜜柑产量和品质的影响

红壤丘岗坡地桔园，在施用有机肥和磷钾肥的基础上，施用不同量的氮肥后，土壤ｐＨ值随着施氮量的增加而下降，呈线性负相关。不同施氮量对柑桔产量的影响具有极显著的差异。施氮后，土壤速效氮，磷，钾和叶片氮，磷，钾含量与产量呈显著或极显著线性相关。

INFLUENCE OF N APPLICATION ON YIELD AND QUALITY OF WENZHOU MANDARIN

The experiment results showed that pH of the red earth in hilly orangery was decreased with increasing amount of N applied (r=-0.905) on the basis of the application of organic manure, P and K fertilizers. The mandarin yields varied greatly with the amounts of N applied (y=33.02+12.94x+5.07x²-6.04x³).After application of N the mandarin yield had a significant or correlation with the contents of available N, P and K in the soil and leaves. The invert sugar, reducing sugar and V. C contents were linearly correlated with the amount of N applied but the total acidity was negatively correlated with the of N applied (r=-0.918).So N application could raise the quality of mandarin.