闽楠(Phoebe bournei)苗期适宜施肥量及DRIS营养诊断研究

Optimal Fertilization Amount and DRIS Nutritional Diagnosis at Seedling Stage of Phoebe bournei

开展闽楠苗期施肥及营养诊断研究对闽楠高效培育具有重要意义。采用三元二次通用旋转组合设计开展闽楠苗期施肥试验,通过建立方程得出最佳施肥量和最优解,依据诊断施肥综合法(DRIS)求得闽楠各营养元素的最适比值范围、需肥顺序及养分不平衡指数(Nil)。结果表明:当施氮4.76 g poL、磷2.12 g pot"、钾0.83 g pof1时存在最优闽楠生物量;DRIS图解法得出闽楠氮、磷、钾的最适比值范围分别为:磷/氮=0.089±0.009,磷/钾=0.411±0.045,钾/氮=0.219±0.019,低产组需肥顺序为氮〉磷=钾,高产组需肥顺序为氮=磷=钾;DRIS指数法得出低产组闽楠的NII值明显高于高产组,高、低产组需肥顺序均为氮>磷>钾。整体而言,闽楠对氮肥的需求最大,其次为磷肥和钾肥,诊断结果能够为闽楠平衡施肥提供参考依据。

Fertilization amount and nutritional diagnosis are of great significance for efficient cultivation of Phoebe boumei at the seedling stage.The optimal fertilization amounts were obtained from the established equation based on the quadratic general rotary design for the fertilization experiment of P.bournei seedlings.The diagnosis and recommendation integrated system(DRIS)was used to calculate the optimal ratio of nutrient elements,the order of nutrients requirement and nutrient imbalance index(Nil)of P.bournei.The results showed that the optimal biomass was obtained under nitrogen(N)fertilizer amount of 4.76 g pot-1,phosphorus(P)fertilizer amount of 2.12 g pot-,and potassium(K)fertilizer amount of 0.83 g pot-1.The DRIS graphic method showed that the optimal ratio of P to N was O.089±0.009,that of P to K was 0.411±0.045,and that of K to N was 0.219±0.019.The order of nutrients requirement in the low yield group was N>P=K,while that in the high yield group was N=P=K.The DRIS index method showed that the Nil value of P.bournei in the low yield group was significantly higher than that in the high yield group,and the order of nutrients requirement in both groups were N>P>K.On the whole,P.bournei has the largest demand for N,followed by P and K.The diagnosis results could provide a reference for balanced fertilization of P.bournei.