Effects Of Urea Type And Fertilization Times On Growth And Yield Of Rice Under Sichuan Hills

The hybrid rice combination F You 498 grown under different urea type and different fertilization times,was used to clarify the effects of rice growth and development, transplanting methods on dry matter production, nitrogen accumulation and distribution, yield and its components in a field experiment, in 2014 and 2015. The results showed as follows:1. Rice dry matter accumulation and distribution were significant effected by different urea type and fertilization times. The increase of fertilization times can improve rice-jointing stage and heading stage and heading to mature period of accumulation of dry matter, thus higher biological yield is achieved. The increase of fertilization times can also improve leaf distribution ratio of dry matter in heading stage and spike distribution ratio of dry matter in maturity. Dry matter amount allocation after head and distribution of contribution were also increased by the increase of fertilization times. Dry matter's distribution ratio at each stage were not significant effected by different urea type, but PASP can inprove dry matter distribution of contribution after head by twice fertilizer and four times fertilizer.2. Both urea type and fertilization times had significant effect on nitrogen accumulation and distribution of rice. Rice stem and leaf's nitrogen accumulation were increased form jointing stage to heading stage,but decreased from heading stage to maturity. From heading stage to maturity, nitrogen distribution proportion of rice leaf and stem were also decreased, more nitrogen accumulated to panicle. With the rice growing process, plant nitrogen content gradually decreased, the lowest nitrogen content was maturity. With the increase of fertilizer times, the rice nitrogen accumulation of heading stage and mature stage were increased. As fertilizer inputs, mature spike won higher proportion distribution of nitrogen, nitrogen transport of rice leaves and stems also received a promotion. Rice nitrogen transport level with PASP was much higher than normal urea. The increase of fertilizer times can improve rice nitrogen uptake, N absorption per 100 kg seeds, also NCR, REN, AEN, and PFPN. AEN, PNUE and SNDR were decreased by increase of fertilizer times.3. Urea type and fertilization times had some impact on rice growth and development. Compared to normal urea, PASP can increased LAI and efficient LAI. The increase of fertilizer times can improve rice leaf area, high rate of leaf area, leaf SPAD value, LAI and efficient LAI in heading stage. Rice NCS amount was decreased by increase of fertilizer times, and compared to normal urea, PASP's NCS amount was decreased. Spikelet-promoting fertilizer inputs can improve the differentiation of rice secondary branch and spikelet number, and also improved the degradation rate of secondary branch and spikelet, spikelet-developing frtilizer's application can reduce the degradation rate of the spikelet.4. The two years' yield showed that:Four times fertilizer treatment can improved the effective panicle of rice, once fertilizer treatments got the highest seed setting rate, twice fertilizer treatment will reduce rice 1000-grain weight, the spikelet number was no significant influence under different treatment. Overall, the yield components in the four times fertilizer treatments were all at a higher level, and eventually won the highest yield. Compared with common urea, PASP can get a slightly higher yield at each fertilizer times treatment.5. Correlation analysis showed that there were very significant positive correlations between yield and dry matter amoumt in jointing stage, dry matter amount in heading stage, biomass, dry matter distribution ratio of leaf in mature period, heading stage and mature's stem leaf and panicle nitrogen content.And there were significant positive correlations between yield and dry matter translocation amount, dry matter amount allocation after head, nitrogen distribution proportion of leaf in heading stage, leaf's nitrogen translocation amount, leaf's nitrogen apparent transfer rate, leaf's nitrogen transshipment contribution. And there were very significant negative correlations between yield and soil NO3-N content in 0-30 cm soil layer at 7 days after transplanting. And there were significant negative correlations between yield and dry matter distribution proportion of stem in heading stage, nitrogen distribution proportion of spike in heading stage, soil NO3-N content in 0-30 cm soil layer at 16 days after transplanting.