Effects of Nitrogen Addition on the Growth of Container Seedlings of Schima superba
Using 2-year-old Schima superba as the research object,four different nitrogen addition levels(A1-0 g·plant-1,A2-0.144 9 g·plant-1,A3-0.283 8 g·plant-1,A4-0.425 7 g·plant-1)were set up to study the effects of different nitrogen addition levels on the growth of large-sized container seedlings of Schima superba.(1)The effects of dif-ferent nitrogen additions on the ground diameter and seedling height of Schima superba showed an initial increase followed by a decrease,reaching the maximum in A2 treatment.The maximum height of the seedlings was 113.69 cm,and the max-imum ground diameter was 10.91 mm.(2)The leaf length reached the maximum(18.29 cm)in A4 treatment,and the total number of leaves reached the maximum(120 pieces)in A3 treatment.The maximum leaf width was in A1 treatment(4.46 cm).(3)With the increase of nitrogen addition,the dry weight of roots,stems,and leaves of Schima superba con-tainer seedlings showed the highest value in A3 treatment and the lowest value in A2 treatment.There was no significant difference in dry weight of stems and leaves among the four treatments(P>0.05),while the water content of roots,stems,and leaves of Schima superba container seedlings showed a trend of first increasing and then decreasing with the in-crease of nitrogen content.