Abstract:Monitoring of soil fertility in Eucalyptus 12ABL plantation was based on the fertilization test, which continued for five years. The tseatment 1 (N1P1K1),8 (N3P3K1) and 9 (N3P3K2) were selected as the monitoring sites from 9 different fertilizer plots. The investigation results were as follows: The pH value in the soil reduced from 5.17 before planting to about 4.6, and the organic matter content of soil changed slightly, which was lower in the treatment 1 than in others. The total N contents of the soil were lower than before planting in all treatments. The total P contents of the soil were similar to the background, and the K contents of the soil in the treatment 8,9 were higher than before planting, but which was lower in treatment 1. The available N contents of the soil were lower after planting than before planting, especially in the treatment 1. The available P content of soil decreased after planting in the treatment 1, which was similar to background in other treatments. The available K contents of soil were higher after planting than before planting in all treatments, which was more obvious in the treatment 9. The exchangeable Ca contents of the soil in the treatment 8,9 were lower after planting than before planting, especially in the treatment 9. The highest current increment in height growth occurred in the second year after planting for the treatment 9, which was in the third year after planting for the treatment 8, and treatment 1. The litter was positively correlated to the tree increment. The pulpwood produced per hectare was 2073.55 kg, 4807.88kg, and 5054.52kg in the treatment 1, treatment 8, and treatment 9 respectively. The monitoring result showed that Eucalyptus growth was related to the environment, especially it was closely related to the soil habitat.