Abstract:

To study the effect of phosphorus (P) deficiency to the nutrition efficiency of nitrogen (N) and potassium (K),the hydroponics culture experiments were carried out with the Clone RRIM600 (Hevea brasiliensis) seedlings under different P levels (P2O5: 0, 1, 5, 10, 31 mg/L). The results indicated that: the absorption efficiency of N and K of Hevea decreased significantly with the decrease of P level. The N utilization efficiency in stem significantly increased with the decrease of P level. The N utilization efficiency in root and leaf under 10 mg/L, 5 mg/L and 1 mg/L P treatments haven’t significantly difference with the normal level (31 mg/L, CK), but which under the 0 mg/L significantly higher than the CK. The K utilization efficiency in stem significantly increased with the decrease of P level, but which in the leaf and root haven’t significantly variety. Meanwhile, under P deficiency, the partition of N and K of the root were significantly increased to increase the growth of root, thus enhancing the absorption of N and K of Hevea. Furthermore, the P deficiency significantly increased the N/P and K/P, decreased the N/K. It indicated that the P not only the main limiting factor under P deficiency, but also lead to the N/K disorder, induced the relative N deficiency.