Abstract:

The results of soil monitoring in the fourth year of plantation indicate that afforestation with Chinese fir leads to the decrease in contents of organic matter, rapidly available phosphorus, rapidly available potassium, hydrolytic acid, exchangeable Mg²⁺, moreover leads to the decrease of pH value, so that, the soil fertility of forest land tends to degeneration, however fertilization can avoid soil degeneration and improve soil fertility of the forest land. When calcium magnesium phosphate is used as base fertilizer, soil fertility indexes, such as organic matter, rapidly available nitrogen, rapidly available phosphorus, rapidly available potassium, exchangeable Ca²⁺, exchangeable Mg²⁺ and the pH value can be increased. The results also show that the increase of soil fertility indexes is related with the amount of calcium magneaium phosphate applied. The contents of the 5 main nutrients in leaves of Chinese fir sapling are related with the season and the stand age. The contents of all the nutrients in winter are higher than those in summer, as the age of stand increases, the content of total nitrogen decreases while that of total phosphorus, total potassium, total calcium, total magnesium increases.

Key words: Chinese fir, Soil fertility, Nutrient of leaves