海南农垦橡胶树叶片氮磷钾含量年际变化分析

对15 a来海南农垦橡胶树叶片氮磷钾养分含量年际变化进行分析,发现在所采集的叶片样本中氮素养分含量整体偏低,约有50%的样本低于正常指标值下限;磷素养分含量大部分属于正常指标范围内,但近两年有下降的趋势;钾素养分含量虽然大部分超过正常指标值上限,但仍未达到丰产指标值。研究结果表明,氮素仍是海南农垦橡胶树正常生长的主要养分限制因子,目前的海南农垦橡胶树钾素营养诊断指标有偏低的现象。

Annual Variation of N,P,K Content of Rubber Tree Leaves in Hainan

The annual variation of N, P, K content of rubber tree leaves in the main rubber producing areas of Hainan state farms from 1997 to 2011 was studied. The results showed that: (1)the nitrogen content of the leaves was low, with half of the samples lower to the minimal normal nitrogen diagnostic index; (2)the phosphorous content of the leaves was in the range of the normal phosphorous diagnostic index, but reducing in the last two years;(3)the potassium content of the leaves was almost beyond the maximum of the normal potassium diagnostic index, but not reaching the high yield potassium diagnostic index. The main results showed that nitrogen was the main limiting nutrient factor of the rubber tree in the Hainan state farms and the potassium diagnostic index being used in the Hainan State farm should be upgraded.