Effects Of Planting Methods On Growth, Yield, And Quality Of Rice Under Different Ecological Conditions

The hybrid rice combination II You498grown under different ecological condition, was used to clarify the effects of seedling ages and transplanting methods on dry matter production, nitrogen accumulation and distribution, yield and its components, starch and nutrition quality of rice in a field experiment, in2010and2011. The results showed as follows:1. All rice dry matter and nitrogen accumulation and distribution, yield and its components, starch quality, contents of protein and mineral nutrition were significant effected by ecological conditions, seedling ages, transplanting methods, and there interactions.2. The dry matter accumulation and distribution of rice were clearly influenced by ecological condition, planting method and there interactions. The average daily sunshine hours was positively correlated with dry matter accumulation at sowing-tillering and heading-maturity periods and percentage of the matter exportation from stem-sheath (EPMSS). However, the accumulated temperature and average daily temperature mainly affected the distribution of dry matter after heading and the EPMSS and percentage of the matter transformation from stem-sheath (TPMSS). Moreover, different planting methods caused the changes of light and temperature conditions and plant spatial distribution, which finally result in the differences of dry matter accumulation and distribution.3. Both ecological condition and planting method had significant effect on nitrogen accumulation and distribution of rice. There were negative correlations between average daily sunshine hours with nitrogen uptake per100kg of grain (100kg-NU), plant nitrogen contents and nitrogen accumulation in most growth period, but the nitrogen harvest index (NHI) and nitrogen use efficiency (NUE) were positively corretated with average daily sunshine hours, significantly.50-day-old seedling transplanting treatment could improve the nitrogen accumulation during jointing-heading period, translocation of rice leaf and stem-sheath nitrogen after heading stage, NHI, partial factor productivity of applied nitrogen (PFPAN) and grain nitrogen use efficiency. Furthermore, it was found that the single seedling optimized-broadcasting treatment could enhance the nitrogen accumulation rate of rice during sowing-jointing and heading-maturity periods and thus improved the total nitrogen accumulation. And the single seedling hand-transplanted treatment could increase the NHI and PFPAN.4. The yield in2010and2011showed that:Renshou had the highest rice yield; Pixian had the intermediate level; while Ya’an had the lowest yield. Higher soil fertility was beneficial to the improvement of the effective panicle number per unit area, while adequate light conditions could increase the spikelet number per panicle, to ensure the rice production.50-day-old single seedling optimized-broadcasting treatment could improve the panicle number per unit area and keep a higher total spikelet number, which effectively increase rice yield in Renshou and Pixian. In Ya’ an,50-day-old single seedling hand-transplanted treatment could maintain an appropriate total spikelet number and promote grain filling to ensure rice stable yield.5. The changes of ecological condition and planting method could lead to the significant differences of rice quality. The amylose content was significantly affected by accumulated temperature, but the average daily sunshine hours, average daily temperature, and total sunshine hours mainly affected rice starch RVA profile characteristics.50-day-old seedling transplanting treatment could reduce the amylose content, while the single seedling optimized-broadcasting and single seedling hand-transplanted treatment enhanced rice starch RVA profile characteristics, whicn finally improved rice cooking and eating quality.6. In Renshou, the increase of the effective panicles per unit area was the main way to enhance the total spikelet number. The high yielding conditions with10.5t hm-2was as follows:(1) the panicle number per hectare was greater than173.5×104;(2) the spikelet number per panicle must be greater than249.1;(3) seed-setting rate and biomass should be above89.5%and17.0t hm-2. In Pixian, to reach grain yield above9.5t hm-2, total spikelet number per hectare and1000-grain weight should be greater than339.9×106and31.1g, while the dry matter and nitrogen accumulation after heading should reach above5.9t hm-2and11.2kg hm-2. In Ya’an, when total spikelet number per hectare, dry matter and nitrogen were greater than339.9X106,10.4t hm-2, and161.1kg hm-2, respectively, the rice yield would reach above9.0t hm-2.7. Both grain yield and rice quality would be improved with a reasonable planting method. In Renshou,50-day-old single seedling optimized-broadcasting treatment could significantly increase the dry matter and nitrogen accumulation before heading and promote leaf nitrogen tranformation after heading. Meanwhile, it also enhanced the peak viscosity (PKV) and breakdown viscosity (BDV), but reduced the setback viscosity (SBV), which finally improved rice yield and quality. In Pixian, using50-day-old single seedling optimized-broadcasting treatment could significantly increase the dry matter and nitrogen accumulation after heading to improve biomass and grian yield. By50-day-old single seedling hand-transplanted and50-day-old single seedling optimized-broadcasting treatment, the rice cooking and eating quality could be enhanced with the increasing of PKV and BDV. In Ya’an,50-day-old single seedling hand-transplanted treatment could promote the dry matter accumulation before heading and enhance EPMSS and TPMSS after heading. It could coordinate nitrogen accumulation during different periods to prevent the appearance of late-maturing phenomenon. Moreover, both PKV and BDV were increased, but SBV and pasting temperature (PaT) significantly reduced.