Effects of Different Ratios of NH+4 -N/NO-3 -N on Growth of Larix gmelinii Seedings
An experiment was conducted to study the effects of NH+4 -N, NO-3 -N and their different supply ratios on the growth of Larix gmelinii seedlings by water culture system in greenhouse. Results showed that L. gmelinii seedlings grew better at higher NH+4 -N concentration. The growth of seedlings declined with increasing ratio of NO-3 -N. Excessive NO-3 -N inhibited root growth and the root/shoot ratio of the seedlings significantly decreased as the NH+4 -N/NO-3-N ratio was over 75％. Increasing NH+4 -N ratio in nutrient solution led to the increase of phosphorus content and the decrease of potassium content in plant tissues. The pH value of the culture medium was affected markedly by the ratio of NH+4 -N to NO-3 -N, which decreased with increasing NH+4 -N and increased with increasing NO-3 -N.
Larix gmelinii seedlingsNH+4 -NNO-3 -NNutrientspH value of medium
NETL
NSTL
万方数据
维普
