在大规模植胶背景下,为了探究胶树整个生命过程土壤养分的变化以及分布规律,以海南广坝农场为例,采用空间换时间的方法,对同一农场8个不同龄段的胶园土壤养分进行了分析研究,结果表明1)胶林土壤表层(0～20cm)有机质平均含量明显高于20～40cm土层,且随着树龄增加有机质含量呈现出先递减后增加的趋势。不同树龄的土壤有机质含量从大到小为次生林(CK)>5a>10a>35a>20a>40a>25a>30a>15a。统计分析结果显示,有机质在0～20cm土层与全氮呈显著相关(R=0.781 30),在20～40cm土层,与全氮呈极显著正相关(R=0.918 11),与全磷呈显著相关(R=0.772 49)。2)胶林土壤的全氮含量表层(0～20cm)显著高于下层,表层土壤的全氮含量随着树龄缓慢增加,20～40cm土层随着树龄先递减后增加。土壤全氮含量高低顺序为次生林(CK)>5a>10a>35a>40a>30a>25a>20a>15a。3)胶林土壤中的全磷含量随着土层深度下降,且随树龄变化与有机质相吻合(先减后增)。各个龄段全磷含量高低顺序为5a>10a>次生林(CK)>35a(40a)>20a>25a>15a(30a)。4)全钾含量在土壤剖面上无明显变化,但却随着树龄的增加逐渐减少。土壤中全钾平均含量大小顺序为35a>10a>5a>25a>30a>次生林(CK)>20a>40a>15a。上述结果主要是因胶树生长发育特点、土壤质地类型以及人为施肥管理上的差异等综合影响所致。通过本次试验,期望能够了解橡胶树在不同树龄对各养分的需求以及土壤中各营养元素的动态变化,为指导胶农科学生产和施肥管理提供理论参考。

In the background of large scale rubber planting,in order to probe into the changes of rubber trees across the life course and distribution of soil nutrients,the method of space for time was used for the analysis and research on 8 different segments of the rubber plantation soil nutrients in the farm.The results show that(1)The organic matter content of the surface soil(0～20cm)was significantly higher than that in 20～40cm soil layer.With the age increasing,organic matter content showed a trend that decreased at first and then increased.The organic matter content of the soil at different ages from high to low in order of the secondary forest(CK)>5a>10a> 35a>20a>40a>25a>30a>15a.Statistical analysis showed that the organic matter in the soil layer of 0～20cm and total nitrogen was significantly correlated(R=0.78130),In the 20～40cm soil layer,there was a very significant positive correlation with the total nitrogen(R=0.91811),and significantly with the total phosphorus(R=0.77249).(2)The total nitrogen content of the surface soil(0～20cm)was significantly higher than that of the lower,the content of total nitrogen in surface soil increased slowly with the increase of age,20～40cm soil layer decreased at first and then increased with the increase of age.The total nitrogen content of soil is in the order of the secondary forest(CK)>5a>10a>35a>40a>30a>25a>20a>15a.(3)The total phosphorus content in the soil decreased with soil depth.With the change of tree ages the trend of total phosphorus content in the soil was the same as organic matter content.The total phosphorus contents in soil at different ages showed such a from-high-to-low ordes as 5a>10a>secondary forest>35a(40a)>20a>25a>15a(30a).(4)The content of total potassium had no significant change in the soil profile, but gradually decreases with increase of age. The average content of total potassium in the soil was in the order of 35a>10a>5a>25a>30a>secondary forest (CK)>20a>40a>15a. This is mainly due to the growth characteristics of rubber tree, soil texture and the difference of artificial fertilization management and so on. Through the experiment, expect to be able to understand the demand on nutrient of rubber tree at different ages, and the dynamic changes of nutrient elements in the soil, to provide a theoretical reference for the guidance of scientific production and fertilization management of plastic agricultural.