Research on Biological Cycle of Nutrient Elements in Plantation of Rubber Intercropped with Amomum Longiligulare

In rubber(Hevea brasiliensis)plantation intercropped with Amomum longiligulare (RA) and pure rubber plantation(PP) of 30-year-old,biomass and nutrient elements(N、P、K、Ca、Mg)of each component of tree,intercrops and litters were detected.Net accumulation and biological cycle of nutrient elements of two plantations have been comparatively studied.The results showed that annual accumulative and uptake amount of 5 nutrient elements of RA was 3 447.07 and 1 083.43 kg/hm2,2.53 and 2.1 times of PP respectively.Annual return amount of RA was 363.26 kg/hm2,among which N、P、K、Ca、Mg was 1.9, 2.54, 1.42,1.05,1.16 times of PP respectively.With the comparison of 5 nutrient elements,the return amount of N was more in RA system,and P less for two plantations.Although the cycle coefficient of RA was lower than that of PP,the absorption coefficient was higher than that of PP,that means intercropping can improve rubber tree and A.longiligulare to uptake soil nutrients.