Pedosphere 16(4): 435--443, 2006
ISSN 1002-0160/CN 32-1315/P
©2006 Soil Science Society of China
Published by Elsevier B.V. and Science Press
Phosphorus transfer and distribution in a soybean-citrus intercropping system |
ZHOU Wei-Jun1,2, WANG Kai-Rong1, ZHANG Yang-Zhu1, YIN Li-Chu1 and LI He-Song1 |
1 College of Resources and Environment, Hunan Agricultural University, Changsha 410128 (China). E-mail: wjzh0108@163.com; 2 Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China) |
ABSTRACT |
A mini-plot field experiment was conducted on a loamy clay Oxisol to compare and evaluate P absorption and transfer in plant organs and P movement in soil profile at three P application depths under the soybean-citrus intercropping versus the monoculture using a 32P tracer technique. Total P absorption (Pt) by soybean and P accumulation (Pa) in soybean organs decreased significantly (P < 0.05) under the intercropping in contrast to the monoculture. With intercropping, when 32P was applied in topsoil (15 cm soil layer), total 32P absorption (32Pt) in soybeans was significantly lower (P < 0.05), but when 32P was applied to deeper soil layers (35 or 55 cm soil layer), 32Pt in soybeans was significantly greater (P < 0.05). The percentage of P in leaves to total P (Pa/Pt) and 32P in leaves to total 32P (32Pa/32Pt) for soybean were ≥ 25% and those of root ≥ 12%. When P was applied in topsoil and 55 cm soil layer, no significant differences were found between intercropping and monoculture for Pt of citrus. The P absorbed by citrus was transferred rapidly to the growing organs of aboveground during the experiment, and the speed of transferring to the growing organs slowed when P was applied to the deeper soil layers. In intercropping, P mobility was heightened in the soil profile, and P in deeper soil layers moved up to topsoil more rapidly. |
Key Words: agroforestry ecosystem, citrus, monoculture, 32P fate, soybean |
Citation: Zhou, W. J., Wang, K. R., Zhang, Y. Z., Yin, L. C. and Li, H. S. 2006. Phosphorus transfer and distribution in a soybean-citrus intercropping system. Pedosphere. 16(4): 435-443. |
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