Studies Of Changing Trend On The Nutrients Of Rubber Plantation Ecosystem In Main Rubber Planting Area Of China

Nutrients balance of rubber plantation is very importation to maintain high yield for rubber trees. In 2003, a relatively full investigation was done according to the different kinds of soil,clones and tapping system in the main rubber planting areas in Guangdong, Hainan and Yunnan provinces. The contents of organic matter(OM), total nitrogen(TN), available phosphorus(AP), available potassium(AK) in soil and the contents of nitrogen(N), phosphorus(P), potassium (K), calcium(Ca) and magnesium(Mg) in leaves were tested. Then the analysis between the tested results and the past nutrients contents of these areas was done. Which included the nutrients changing trend of rubber plantation before and after the stimulated tapping system(STS), the relationship between yield and nutrients contents and the short degree of rubber tree nutrients in different planting areas, so as to advise some subjects for setting up a nutrient diagnosis standard and using this standard to ensure the sustainable development of rubber industry.The analysis of nutrients changing trend in soil before and after the STS showed that the nutrients contents in every planting area were decreasing after STS, but there was still some differences. In Guangdong, all kinds of soil were decreasing in OM,TN,AK. In Hainan, the contents of all nutrients were decreasing, including AP. And in Yunnan, the nutrients condition was not bad, only the AP was very short.The analysis of nutrients changing in leaves showed that the nutrients contents of rubber trees in all the three planting areas were decreasing after the STS. The Mg was very short in all the three kinds of soil in Guangdong, and some were short in P and K. The N and P of leaves were under the level, and some samples were short in K. In Yunnan, only the leaf N was short obviously.Relationship between the yield of different clones and the contents of nutrients was analyzed. The result showed that the nutrients of rubber ecosystem were very important for the trees yield. But it also showed the yield didn't depend mostly on single element. In fact, the yield of rubber trees depended on the integration of different nutrient elements and...