不同施肥处理下橡胶苗对土壤养分吸收和分配的化学计量特征

Stoichiometric characteristics of soil nutrient absorption and distribution in young rubber plants under fertilizer treatment

为了揭示橡胶苗对施肥变化的响应和适应性,为海南橡胶经济林的土壤和施肥管理提供参考,以大田1年生橡胶(Hevea brasiliensis)苗为对象,设置不同的施肥处理,分析了不同器官的氮、磷、钾含量及其生态化学计量特征,探讨橡胶苗在施肥影响下对土壤养分分配和利用的特点。结果表明:随着施肥量的增加,除了磷含量在叶片中,钾含量在树干中略有下降外,氮、磷、钾含量在橡胶苗其他器官中的含量都在增加,氮、磷、钾养分的分配比例主要集中在叶片,超过30%。影响橡胶苗生长的第1限制因素是氮,在橡胶生产实践中,可在本研究施肥配方的基础上适当增施氮肥、减施磷和钾肥,同时加强有机肥施用,以提高土壤有机氮含量。

Research and analysis of the plant nitrogen,phosphorus,and potassium ecological stoichiometry can reflect the distribution status and mutual correlation of the nutrients in different organs of the plant,and determine the nutrient-limiting factors of the plant in the different environments.Young rubber plants transplanted were treated with fertilizer at four different rates in an experiment with random complete block design and three replicates each treatment and then sampled,and the contents of nitrogen,phosphorus and potassium and their ecological stoichiometric characteristics in different organs of the young rubber plants collected were determined and analyzed to explore the characteristics of the distribution and utilization of soil nutrients in the young rubber plants under fertilizer treatment.The results showed that with the increase of fertilizer application rate the contents of nitrogen,phosphorus and potassium in all the organs of the young rubber plants increased except phosphorus content in the leaves and potassium content in the trunk that decreased slightly,and that the nitrogen,phosphorus and potassium were mainly distributed in the leaves,accounting for more than 30%.The first limiting factor affecting the growth of the young rubber plants is nitrogen.In normal rubber production young rubber plants can be applied with formula fertilizer formulated with nitrogen at an appropriately higher ratio and phosphorus and potassium at a lower ratio on the basis of the existing fertilizer formula,and at the same time organic fertilizer should be applied to improve the soil organic nitrogen content.