Abstract
The effects of the beginning time of flooding on legume decomposition, N release, growth and yield of rice cultivated with white clover living mulch were investigated by field and pot experiments. The effects of the beginning timepoints of flooding were examined in the living mulch plot : the beginning of flooding at 10 days before transplanting (LMSTD) and at 10 and 30 days after transplanting of the rice (LM10DAT and LM30DAT, respectively). Peaks of NH4-N in the flood water were observed at 15, 4, and 10 days after flooding in LMSTD, LM10DAT and LM30DAT plots, respectively; this showed that flooding can stimulate the decomposition of the legumes and control the time of N release from the legumes. The height of the rice plant in the LM30DAT plot was higher than that in the LMSTD and LM10DAT plots in the field experiment. In the pot experiment, the tiller number in the LM30DAT plot was higher than that in the LMSTD and LM10DAT plots. In both the field and pot experiments the dry weights of the roots, stems leaves, and panicles were significantly or insignificantly heavier in the LM30DAT plot than in the LMSTD and LM10DAT plots. Moreover, the yield in the LM30DAT plot was higher than that in the LMSTD and LM10DAT plots. The dry weights of the weeds in the legume-treated soil were significantly lighter than that in the chemical fertilizer-treated. Thus, the growth and yield of rice with legume living mulch may be improved by delaying the flooding time.
