胶园土壤化学肥力演变及与橡胶树营养关系的研究

Evolution of Soil Fertility and Relationship with Rubber Tree Nutrition in Rubber Plantations

对海南橡胶园土壤化学肥力的演变及土壤养分含量与立地橡胶树叶片养分含量的相互关系进行研究。结果表明:我国胶园土壤植胶50多年后土壤肥力发生了较大的变化,其中有机质、全N、速效K含量有较大程度的下降,速效P含量则有降有增,总体土壤肥力下降。在植胶早期,植胶区土壤养分含量与叶片养分含量之间有极显著正相关性,而且土壤养分含量愈缺乏的地区,相关性愈明显。但随着时间的推移,土壤养分含量与立地胶树叶片养分含量的相关程度越来越小,目前近乎无显著相关性。由于橡胶树施肥以局部的穴施为主,加上有许多胶园修建梯田和环山行,较难采集有代表性的土壤,因此土壤分析结果只能作参考。

After more than 50 years of rubber planting, the soil fertility of tropical soil had had a great evolution. It showed that the contents of organic matter, total nitrogen, and available potassium in the plantation soils under consideration had been decreased greatly. ＂However, the contents of available phosphorus had been increased or decreased at different degrees. As a whole, the soil fertility was getting lower. There was a very significant correlationship between the nutrient contents in rubber tree leaves ＂and those in rubber plantation soils in the early years. Moreover, the correlationship was more significant in the barren regions. It was more important that, the correlationship became more and more insignificant as time going. Because of the localized fertilization （usually hole fertilization）and planted in terraces, representative soil samples in rubber plantation were difficult to be taken. Thus, it was suggested to apply the related leaf nutrients as the criterion of rubber tree nutrition status, and soil nutrients could be just used as reference indices.