| In study, to investigate the effects of phosphorus on grain yield and quality of double cropping rice, early rice variety “Ganxin203” and late rice variety “Wufengyou T025”were used as test materials. Double cropping rice stem tillers dynamics, yield and its composition, chlorophyll content, the utilization rate of phosphate fertilizer, soil physical and chemical properties were studyed by phosphorus and five different treatments(basal fertilizer: tillering fertilizer: earing fertilizer = 10:0:0, 7:3:0, 5:5:0, 5:3:2, 4:4:2).This studies indicated the correlation different ratios of base P to dressing P with the yield of double cropping rice to seek for the optimal ratio of base P to dressing P and phosphate fertilizer to provide theoretical basis and technical support.The main results of this word were as follows:(1) Phosphorus application can promote stem tillers development of double cropping rice, but under the condition of equal amounts of phosphoric, there were no obvious effect of stem tillers development of double cropping rice with different ratios of base P to dressing P.(2) The influence of P application to leaf chlorophyll content in the early and late rice on were performance in the mature period; There were no obvious effect of leaf chlorophyll content of early rice and late rice tillering stage with different ratios of base P to dressing P. In the period of beginning period and mature period, chlorophyll contents were highest in P4 method, which had obvious effect of other treatment.(3) Compared with P-deficiency treatment, the yield of double cropping had obvious effect of P application. Moreover, There were no obvious effect of early yield in different ratios of base P to dressing P. In the late rice, the P4 treatment had obvious effect of P3 and P1 treatment. There was a positive correlation between rice yield with the yield component in double cropping rice. The total spikelet number(grain x number of spikelets per panicle)were very significant positive with rice yield. The amount of total grain number per panicle of new effect and the total amount of new bigger effect on the final production, the rule is basically identical in early, late rice. Yield increased by P-applied in early rice was mainly through raising effective panicles, number of grain per panicle. But there is relatively small effect of seed setting rate and 1000-grain weight. In the different ratios of base P to dressing P of double cropping rice, the grain yield were highest under the ratio of basalpotassium: tiller potassium: paniclepotassium was 5:3:2.(4) The partial factor productivity of applied P and agronomic efficiency of applied P were highest under the ratio of basal potassium: tiller potassium: panicle potassium was5:3:2. This indicated that Phosphorus application promote apparent efficiency of fertilizer P and the optimal ratio of base P to dressing P can obtain maximum apparent efficiency of fertilizer P.(5) Phosphorus application can make the decline of the pH value, strength acidic soil and available phosphate in rice field. But the content of rapidly-available potassium, alkali solution nitrogen, organic matter were no significant changes. |
