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...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 ia 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.展开更多
基金Project supported by the Knowledge Innovation Programme of the Chinese Academy of Sciences (No. KZCX2-407).
文摘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 ia 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.
