Effect Of Nitrogen And Potassium Fertilizer Application Amount On The Population Quality And The Yield Of Cropping Medium Rice

The experiment was carried in Fengtai County Rice Original Seed Farm of Anhui Province from 2007 to 2008. The effects of different nitrogen and potassium level on group quality and yield formation of different technical measures in medium japonica Rice by using"Wandao 68".The results show that :1,When the amount of nitrogen applied was 262.5kg/hm², the maximal of tillers PTP was 76.10% averagely; When the amount of nitrogen applied were187.5 kg/hm² and 112.5 kg/hm², stem tillers and effective ears decreased , tillers PTP were 72.71% and 70.86% respectively; The maximum of stem tiller of time put off when nitrogen applied was 337.5 kg/hm², tillers PTP was 66.30%. The effects of potassium on stem tiller development were not big , the average stem tillers increased a little and effective ears were identical with increasing potassium fertilizer when nitrogen fertilizer was identical.2.,When amount of nitrogen fertilizer applied was 262.5kg/hm²(A₃), the maximum of percentage of effective LAI was 94.7% 95.5%, exceptA₂B₃, others were very different from 87% to 95.5%; The difference of percentage of high effective LAI treatment is obvious in 62.43% 81.08%, The treatment of A₃ was also the highest. Percentage of high effective LAI and yield were being related to assuming extremely notable rectifying(R=0.813**) , percentage of effective LAI and yield were being related to assuming notable rectifying(R=0.652*)by the correlation analysis.3,When amount of nitrogen fertilizer applied was 262.5kg/hm²(A₃),the treatment of the dry matter accumulation quantity to account for the dry weight proportion was higher than others. Dry matter accumulation increased with amount of potassium fertilizer increasing.4,The plant height increase with amount of nitrogen fertilizer increasing, The best treatments of percentage of the toppest joint and panicle lengh to plant height were A₂ and A₃. The correlation analysis indicated that the toppest joint height and the output closely related, the longer the toppest joint height was, the more yield was. At the same of nitrogen level, increasing potassium fertilizer, the plant height will reduce, however percentage of the toppest joint and panicle lengh to plant height will go up.5,The total spikelets and max LAI of A₃ are more than other treatments, the ratio of spikelets to leaf area were 0.604,0.584,0.585,which were higher than others. It shows that When amount of nitrogen fertilizer applied was 262.5kg/hm² , it was advantageous to the growth and coordination of source and sink; the tendency of different potassium level indicated that the total spikelets,max LAI and the ratio of spikelets to leaf area increased with potassium fertilizer increasing. 6,The variance analysis indicated that nitrogen fertilizer is major factor to affect the yield, the effect of potassium fertilizer is not notable for the yield. When the amount of nitrogen applied was 262.5kg/hm², the yield reached maximum. When the amount of potassium applied was 375.0kg/hm², the yield reached maximum.