| This study mainly studied the soil organic matter and nitrogen contents of four different land use types in typical small watershed of Jianshan river, Fuxian Lake. The results showed that, on the slopes of different land use types,the contents of soil organic matter and nitrogen were the highest on the lower slopes and the lowest on the upper slopes,and it爷s placed in the middle on the mid-slopes. Soil organic matter and nitrogen contents decreased with soil depth increasing, shouing 0-20 cm higher than 20-40 cm and 20-40 cm higher than 40-60 cm. With the increase of soil depth,the gap between contents decreased. The content of soil organic matter in sequence was secondary forest, planted forest, shrub-grassland and farmland. The content of total nitrogen in sequence was shrub-grassland, farmland, planted forest and secondary forest. The content of available nitrogen in sequence was farmland, secondary forest, shrub-grassland and shrubgrassland. Through regression analysis, we obtained that there was significant linear correlation among the contents of soil organic matter, total nitrogen and available nitrogen. The content of soil organic matter is an important index for soil nitrogen supplying capacity. Through correlation analysis, we got that there was significant negative correlation between soil depth and the contents of soil organic matter and nitrogen. The conversion coefficients between soil organic matter and total
nitrogen were different in different land use types, the sequence was farmland, shrub -grassland, planted forest and secondary forest. |
