氮、磷叶面施肥对云南松苗木萌蘖的影响

Response of sprouting ability of Pinus yunnanensis seedlings to different rates of nitrogen and phosphorus foliar fertilizer

[目的]通过对1年生云南松苗木平茬后不同氮、磷肥的叶面喷施,分析其对云南松苗木萌蘖量、萌条生长的影响。[方法]本次试验以1年生云南松苗木为研究对象,采用氮、磷二因素三水平的3×3回归设计,研究氮、磷叶面施肥对平茬后云南松苗木萌蘖能力的影响。[结果](1)不同施肥处理下,云南松苗木萌蘖初期,施用氮、磷肥能够促进云南松苗木萌蘖,提高苗木净萌蘖量和萌蘖累计量,净萌蘖量单施效果比配施效果好且单施磷肥的效果较好,萌蘖累计量氮、磷配施的效果比较理想。(2)云南松苗木萌蘖累计量对氮、磷叶面施肥的响应符合二元二次回归方程及钟形曲面。通过交互效应表明,氮用量为0.37 g·株^(-1)、磷用量为1.11 g·株^(-1)时,萌蘖累计量达到最高值。从等产线图看,单施氮的适宜用量范围在0~0.15 g·株^(-1),单施磷肥的适宜用量范围在0~0.75 g·株^(-1)。(3)氮、磷叶面施肥促进云南松苗木萌条的生长,萌条长度与萌条基径生长存在极显著正相关关系。[结论]叶面喷施氮、磷肥明显提高云南松苗木萌蘖量,促进萌条的生长。整体来看,氮、磷配施比单施氮肥、磷肥更利于萌蘖能力的提高。

[Objective]The effects of different application rates and methods of nitrogen and phosphorus fertilizers on the sprouting and growth rate of one-year-old Pinus yunnanensis seedlings were analyzed through foliar fertilization after plant stumping.[Methods]In this study,one-year-old P.yunnanensis seedlings were selected as the research object,and the effects of foliar fertilization of nitrogen and phosphorus on sprouting ability of P.yunnanensis seedlings after stumping were studied using a 3×3 regression design with three levels of each of two factors of nitrogen and phosphorus.[Results]The results showed that:(1)Under different fertilization treatments,the application of nitrogen and phosphorus fertilizer promoted the sprouting of P.yunnanensis seedlings at the early stage of sprouting,and improved both the net and cumulative sprouting numbers.The effects of single application on the net sprouting number was better than that of combined application,and the effects of single application of phosphorus fertilizer was better than that of N fertilizer.The effect of combined application of nitrogen and phosphorus was ideal for the cumulative sprouting amount.(2)The response of the cumulative amount of sprouting and tillering of P.yunnanensis seedlings to N and P fertilization conformed to the binary quadratic regression equation and the bell-shaped surface.The interaction effect showed that the cumulative sprouting amount reached the pick when the nitrogen rate was 0.37 g·plant^(-1) and the phosphorus rate was 1.11 g·plant^(-1).The results showed that the suitable application rate of nitrogen and phosphorus fertilizer was between 0~0.15 g·plant^(-1) and 0~0.75 g·plant^(-1),respectively.(3)The foliar fertilization of nitrogen and phosphorus promoted the growth of sprouts of P.yunnanensis seedlings,and there was a significant positive correlation between shoot length and sprouting basal diameter.[Conclusion]Foliar application of nitrogen and phosphorus fertilizer significantly increased the number of sprouts and promoted the growth of sprouts of P.yunnanensis.As the whole,the combined application of nitrogen and phosphorus was more conducive to the improvement of sprouting ability than the single application of nitrogen and phosphorus.The optimal fertilization range was 0.37 g·plant^(-1) for nitrogen and 1.11 g·plant^(-1) for phosphorus,and the cumulative sprouting amount reached the highest value.