氮磷配施对云南松实生苗生长的效应

为有效促进云南松实生苗生长，采用3×3回归设计，田间排列结合拉丁方和随机排列，对云南松实生苗进行氮、磷配合施用试验。结果表明：苗木生长量及生物量与氮、磷用量之间的关系符合抛物线方程，各生长指标均存在1个产量峰值。峰值以前，各生长量及生物量随氮、磷用量的增大而提高；峰值以后，各生长量及生物量随氮、磷用量的增大反而下降。根据肥料效应方程求得，苗高、地径生长量以及根、干和叶片生物量最大时的氮用量分别为0．17，0．16，0．20，O．15，0．19g／k土；以及磷用量分别为0．97，1．04，0．99，0．88，0．99g／kg土；最佳氮：磷分别为1：5．70，1：6．43，1：5．03，1：5．88和1：5．20。对应的最高理论产量分别为8．20，0．55em；1．374，0．177，2．295g。分别较对照提高了25．3％，29．1％以及151．6％，21．2％，175．2％。其中，施肥明显促进叶片生物量的积累，但各个生长指标对肥料用量和比例的响应规律不同，较高的氮肥比例有利于促进根系发育和叶片生物量的积累，较高的磷肥比例有利于促进树干的粗生长和高生长。

Fertilization Effect of Nitrogen Combination with Phosphorus on Seedling Growth of Pinus yunnanensis

In order to accelerate the seedling growth of Pinus yunnanensis, nitrogen in combination with phosphorus has been tested by using 3×3 regression design and drawing the characteristics of Latin square and random array. The results showed that the relationship between the growth increment, biomass and the amount of nitrogen, phosphorus can be described by quadratic parabola, and every growth index has a maximum value. The growth is improved as the increasing of amount of nitrogen and phosphorus in front of the maximum value, and the growth decreased as the increasing of amount of nitrogen and phosphorus in back of the maximum value. The optimum dosage and the optimum proportion of nitrogen and phosphorus under the highest growth indexes are calculated by the fertilization equations, and the highest growth indexes of height, basal diameter, root system, the biomass indexes of stem and leaves are 8.20, 0.55 cm; 1. 374, 0. 177,2. 295 g respectively. And the corresponding increments are 25.3%, 29.1%, 151.6%, 21.2% and 175.2% respectively more than that of the control, and the corresponding nitrogen dosage are 0. 17, 0. 16, 0. 20, 0. 15,0. 19 g per kilogram soil and the phosphorus are 0. 97,1.04, 0. 99, 0. 88 and 0. 99 g per kilogram soil, and the corresponding proportion of nitrogen to phosphorus are 1 ： 5.70,1 ： 6. 43, 1 ： 5.03, 1 ： 5.88 and 1 ： 5.20 respectively. In which the leaf biomass was obviously improved by fertilization, but there are different response rules by varied growth indexes to different dosages and proportions of fertilizers. For example, the higher amount of nitrogen is more beneficial to the development of root system and the accumulation of leaf biomass, the higher amount of phosphorus is more helpful to the diameter and the height growth of the stems.