| A plot experiment with four treatments: farmers′fertilization practice (T1), integrated nitrogen management (T2), normal high yield fertilization practice (T3) and high yield fertilization practice with integrated nitrogen management (T4) was conducted to study the effects of nutrient management on matter translocation, grain-filling properties and rice quality. Density of T1 and T2 was 25 holes·m-2, density of T3 and T4 was 28 holes·m-2. The dry matter weight, usable sugar of stem during heading stage, grain milling rate, yield, chalkiness, protein content, amylase content and parameters of grain-filling were analyzed. The main results are as follows:Under the same density, T1 and T3 increased dry matter accumulation during panicle initiation, because of excessive N application rate of basal-tillering fertilizer, at the same time, T2 and T4 increased dry matter accumulation after heading due to high N application rate of panicle and grain fertilizer. Compared to T1, T2 increased dry matter weight of plant by 11.71% (P<0.05) at mature stage, compared to T3, T4 increased dry matter weight by 8.29%; Compared to T1, T2 increased panicle dry weight 10.39% (P<0.05), compared to T3, T4 increased panicle dry matter 13.42% (P<0.05). T2 and T4 significantly decreased contribution of post-heading stored assimilate to grain yield (CTA) to T1 and T3. T2 increased CPA 5.74 percentage points to T1 (P<0.05), T4 increased CPA 5.46 percentage points to T3 (P<0.05). It showes that T2 and T4 increased post-heading stored assimilates accumulation, which is beneficial for increasing yield. Dry matter increased as density increased.T2 increased usable sugar accumulation by 25.71% to T1 (P<0.05), T4 increased usable sugar accumulation by 12.84% to T3. The sugar-spikele ratio of T2 was higher than others, they were not significantly different. T2 had higher soluble sugar content than others at heading stage. T1 had higher soluble sugar content than others at 20d after heading. T3 and T4 did not show significantly different both at heading and 20d after heading stage. T2 increased usable sugar translocation by 44.98% to T1 (P<0.05), T4 increased usable sugar translocation by 14.13% to T3. T2 increased usable sugar translocation ratio by 14.93% to T1 (P<0.05).The Richards equation described grain filling dynamics well. According paramters of Richards, cold area rice was belonged to asynchronous filling, the superior grains (SG) started filling quickly, and spended few days, but its final growth increment was big. The grain-filling characteristic parameters of SG were not significantly different in treatments. For T2 and T4 shorten SG grain-filling duration and increased its grain-filling rate, so their final growth increment were bigger, and the final growth increment of SG in T4 was biggest.Compared to T1, T2 improved the initial grain filling potential of the inferior grains (IG) by 10.56%, increased the mean grain filling rate of SG by 7.60%, and prolonged the active grain filling period of IG by 0.7 days, so the final growth increment of T2 were bigger.There were significantly positive correlations (P<0.05) between 1000-grains weight and usable sugar of stem translocation ratio, and significantly positive correlations (P<0.01) between stored matter assimilation post-heading and yield. T2 and T4 improved usable sugar of stem translocation ratio, and increased matter assimilation, so T4 increased 1000-grains weight by 0.21g to T3, and T2 increased 1000-grains weight by 0.69g to T1. T2 increased grains per panicle by 12.65% to T1, T4 increased yield by 7.21% to T3 (P<0.05), T2 increased yield by 11.58% to T1 (P<0.05). Productive panicle increased with density increased, and yield trended to increase.There were significantly curve correlations (P<0.05) between milling rate and dry matter translocation ratio of stem, and there was maximum milling rate, compared T1 and T3, T2 and T4 decreased dry matter translocation ratio of stem, and their milling rate were respective 74.28%, 73.45%.There were significantly negative correlations (P<0.05) between chalkiness and sugar-spikele rate, and T2 and T4 increased sugar-spikele rate, so T2 decreased chalkiness 6.62 percentage points to T1, T4 decreased chalkiness 3.97 percentage points to T3, both showed significantly different (P<0.01). There were not significantly different in protein cotent and anymose content during different nutrient managements.
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