西双版纳橡胶林土壤氮的分布特征及与橡胶树生长的关系

Spatial Distribution of Soil Nitrogen of Rubber Tree Plantation and Its Relationship with Rubber Tree Growth in Xishuangbanna

【目的】研究不同品系橡胶树在西双版纳不同生态区种植对土壤氮的影响及其土壤氮变化与橡胶树生长的关系。【方法】分别采集了西双版纳州景洪、勐腊、勐海3个植胶区土壤、橡胶树叶片,并分析了不同割龄RRIM600、GT1、云研-774橡胶树土壤中不同形态氮和橡胶树叶片氮分布特征及关系。【结果】西双版纳州3个植胶地区中不同品系橡胶林土壤中氮的变化差异较大,景洪橡胶林土壤中全氮含量最高,勐腊、勐海相对较低;橡胶林土壤铵态氮和硝态氮较低,硝态氮变异最大;GT1品系橡胶林土壤中全氮含量较高,RRIM600、云研-774相对较低。土壤中全氮含量随割龄的增加而升高,碱解氮、铵态氮、硝态氮随割龄和品系不同而变化,并且土壤铵态氮和硝态氮以低割龄橡胶园相对较高,老割龄橡胶园相对较低;橡胶树叶全氮以景洪最高,勐腊、勐海相对较低,且随割龄的增加而降低。橡胶林保护带土壤全氮、碱解氮、铵态氮与橡胶树叶全氮含量呈显著正相关,而硝态氮与橡胶树叶全氮含量呈极显著正相关;种植带铵态氮和硝态氮与橡胶树叶片氮呈显著正相关。【结论】橡胶树及土壤氮含量随橡胶树品系、割龄、生长环境而变化,不同割龄、不同品系橡胶树对土壤氮具有显著的影响。

【Objective】The aim of this paper was to study the influence of rubber tree growth of different varieties on soil nitrogen in rubber tree plantation of different ecological regions in Xishuangbanna and understand the relationship between soil nitrogen and rubber growth.【Method】Soil and the leaves of different rubber tree varieties in rubber tree plantation with different rubber tapping years from different ecological areas(Jinghong, Mengla and Menghai) of Xishuangbanna were collected to analyze spatial variation characteristics and the relationship of soil nitrogen and rubber leaf nitrogen.【Result】Soil nitrogen of different varieties in rubber tree plantation had a big difference in three ecological regions of Xishuangbanna. Among the three sampling ecological regions, soil nitrogen content in Jinghong site was the highest. The contents of NH4-N and NO3-N were low, and NO3-N variation was high. Soil total nitrogen in GT1 rubber tree plantation was higher than that in RRIM600 and yunyan-774 rubber tree plantation. Soil total nitrogen content increased with the increase of rubber tapping ages. The contents of alkali-hydrolyzale nitrogen, NH4-N and NO3-N changed with rubber tapping ages, and the contents of soil NH4-N and NO3-N in young rubber tapping ages were lower than that in old rubber tapping ages. Total nitrogen content of rubber tree leaves in Jinghong site was the highest than that in Mengla and Menghai, and the content of total nitrogen in young rubber tapping ages was higher than that in old rubber tapping ages. Total nitrogen, alkali-hydrolyzale nitrogen and NH4-N in protection areas soil had significant positive correlation with the total nitrogen of rubber tree leaves, but NO3-N had extremely significant positive correlation with the total nitrogen of rubber tree leaves. Among different forms nitrogen in planting areas, only soil NH4-N and NO3-N had significant positive correlation with the total nitrogen of rubber tree leaves.【Conclusion】Nitrogen contents of soil and rubber tree varied with rubber tree varieties, rubber tapping ages and growth environment, and different rubber tree varieties and rubber tapping ages could have the significant impact on soil nitrogen content in rubber plantation.