Variation of Soil Fertility in Eucalyptus Plantation and Its Soil Fertility Comprehensive Evaluation

The study was carried out in a Eucalyptus plantation and a contrast set up in Guangxi Paiyangshan State Forest Farm,and the soil chemical characteristics were analyzed.A grey correlation analysis was used to evaluate the soil fertility status before and after the planting Eucalyptus plantation.The results showed that except 4.0 years old contrast treatment with an increase of alkaline solution N and effective B in forest soil after afforestation,the rest of the nutrition indicators reduced after afforestation,and most of them were in a low or very low level.For Eucalyptus plantations at different ages and the contrast,the soil integrated fertility was significantly lower after afforestation,and was generallypoor.Among them,the soil integrated fertility was the highest before planting;3.5 years old Eucalyptus plantation decreased the most seriously;the soil fertility of 4.0 years old Eucalyptus plantation was lower than the same aged contrast.The research results could provide scientific and reasonable theories for formula fertilization of Eucalyptus plantation.