Effect Of Mg Ang Zn Fertilizers Topdressed At Different Fertilizing Stage On Yield And Accumulation Of Elements And Quality Of Japonica Rice With Good Eating Quality

Using field experiments,with high quality japonica soft rice,Nanjing 9108 and Nanjing 505 the materials in Suzhong region,experiment was conducted to study the effect of microelement fertilizer(Mg fertilizer,Zn fertilizer,and Mg-Zn mixed fertilizer)topdressed at different fertilizing stage(basic fertilizer stage,tillering stage,and panicle initiation stage)on the grain yield and its components and the quality.The main results were as follows:(1)With the delay of fertilization time,the panicles of topdressing Zn fertilizer treatments showed a downward trend,the treatments of topdressing Mg fertilizer in contrast,the treatments of topdressing Mg-Zn mixed fertilizer decreased first and increased later,The change trend of yield was same to the panicles,the yield had a obvious increase when topdressing Mg fertilizer and Mg-Zn mixed fertilizer at panicle initiation stage,the treatments of topdressing Mg-Zn mixed fertilizer reached the maximum,as topdressing Mg-Zn mixed fertilizer at panicle initiation stage,the spikelets per panicle and seed-seting rate reduced,the 1000-grain weight rised;Mg ang Zn fertilizers topdressed at different fertilizing stage,especially that Mg-Zn mixed fertilizer topdressed at panicle initiation stage,had the rational N content and accumulation at early stage,stronger N uptake ability and higher N accumulation,trans-portation with higher transportation ratio after heading,and high nitrogen agronomic efficiency,physiological efficiency,partial factor productivity,N requirement for 100 kg,nitrogen use efficiency for biomass production,nitrogen use efficiency for grain production and nitrogen harvest index.(2)Topdressing of Zn fertilizer at different fertilization period can improve the appearance of rice;When topdressing Mg fertilizer at panicle initiation stage,processing quality and appearance quality are improved,the protein content and setback was the lowest,the AC and breakdown reached the highest,the comprehensive was best;When topdressing Mg-Zn fertilizer at panicle initiation stage,the improve of processing quality was the most siginificant,the trend of the other guidelines of quality on rice was contrary to topdressing Mg fertilizer at panicle initiation stage,peak vidcosity and trough viscosity and breakdown were significantly lower,getting minimum,setback and pasting temperature was in contrast;Cool viscosity was negatively correlated with the rate of brown rice and significantly negatively correlated with head rice rate,excepe for peak viscosity and set back had no significant correlation with eating quality,the same law bettwen cool viscosity with GC,the main index of RVA had correlate or significant correlation with the appearance and the eating and the nutritional quality of rice.(3)Effects of Zn fertilizer applied at different fertilizing stage on rice yield were not observed.The content and accumulation of the test six elements in milled rice were significantly increased when the Zn fertilizer was top-dressed at basic fertilizer stage.With the delay of fertilizing period of Zn fertilizer,it showed a gradual downward trend;The use of Mg fertilizer simultaneously increased the rice yield and the accumulation and content of the six elements,rice yield reached the highest when the Mg fertilizer was top-dressed at panicle initiation stage.With the delay of fertilizing period of Mg fertilizer,it showed a gradually rising trend;Topdressing of Mg-Zn mixed fertilizer could also increase the rice yield and the accumulation and content of six element in milled rice.The rice yield and the accumulation and content of six element reached the highest when the Mg-Zn mixed fertilizer was top-dressed at panicle initiation stage,with the delay of fertilizing period of the Mg-Zn mixed fertilizer,they showed a descend first and then rise trend.In summary,effects of Zn fertilizer applied at different fertilizing stage on rice yield and qulity of rice were not observed,the content and accumulation of the test six elements in milled rice were significantly increased;Topdressing of Mg fertilizer at panicle initiation stage can improve the yield and quility and the content and accumulation of the test six elements of rice;Topdressing of Mg-Zn fertilizer at panicle initiation stage can improve the yield the content and accumulation of the test six elements of rice,it also could improed quility of rice,but the comprehensive was reduced.So,Topdressing of Mg fertilizer at panicle initiation stage was the best choice.