银杏苗期施P效应研究

采用盆栽试验,研究了不同施P水平对2年生银杏苗木各项生长、生理指标及叶片含P量的影响。结果表明:(1)施P(P2O5)量在0～3g·盆-1范围内,总的趋势是,银杏各项生长、生理指标均随施P量的增加而增加。当施P(P2O5)量超过3g·盆-1后,各项生长、生理指标均表现下降。(2)银杏苗木叶片全P含量在适量的供P范围内随施P量的增加而增加,含P(P2O5)量最高出现在3 0g·盆-1,超过此值后,随施P量的增加而逐渐下降。(3)银杏苗木各项生长指标与施P量之间存在二次函数关系,根据回归方程求得本试验条件下2年生银杏苗木的合理施P(P2O5)量为2 11～2 38g·盆-1。

A Study on Effects of Phosphorus Fertilization in Ginkgo Seedlings

Based on pot experiment, effects of phosphorus fertilization on growth and physiological indexes and phosphorus content in leaves of two year old ginkgo seedlings were studied. The results are as follows: (1)With increasing levels of phosphorus supply from 0.0 to 3.0 g P₂O₅ /pot, the growth and physiological indexes in ginkgo seedlings increased, while with increasing levels of phosphorus over 3.0 g P₂O₅/pot all of the indexes decreased. (2)The phosphorus content in leaves went up with increasing levels of phosphorus supply from 0.0 to 3.0 g P₂O₅/pot but went down gradually with further phosphorus supply from 3.0 to 4.0 g P₂O₅/pot. (3)There are quadric relationships between growth indexes and phosphorus supplies. Based on this, regression models were established and proper application amount of phosphorus from 2.11 to 2.38 g P₂O₅/pot for two year old ginkgo seedlings was calculated.