Preliminary Study on Fertilization Effectiveness of Azadirachta indica Young Plantation in Yuanmou Dry-hot Valley

Twenty-two months' test in Yuanmou dry-hot valley showed there was high significant increase effect for Azadirachta indica young plantation's fertilization. The most effective treatment was N150P150K50 according to the growth response of N,P and K on young plantation, whose height growth increment was 1.9 times that of non-fertilizer treatment. The growth increment of basal diameter was 2.7 times that of CK. The index of fertilizing effect of these treatments reached 2.86～14.17. The growth of height, and basal diameter of Azadirachta indica young plantation were sensitive to P and N. The result of partial correlation analysis showed there existed positive correlation between young plantation's growth and N,P and K. However, only N and P had significant effect on the growth of Azadirachta indica young plantation.