基蘖肥氮量与寒地水稻产量和氮效率的关系

The relationship between N rate as basal and tillering fertilizer and rice yield,N uptake in Cold Area

在固定穗肥氮量(35 kg·hm^(-2))的条件下,研究基蘖肥氮量与寒地水稻产量和氮效率的关系。2011~2012年,设置基蘖肥氮量分别为30、65、85和115 kg·hm^(-2)的处理,并以不施氮为对照。测定了主要生育期水稻干物质、氮积累、产量和氮效率。结果表明:随着基蘖肥氮量的增加,水稻抽穗期前或拔节前的干物质积累量和氮积累量也相应增加,两者为显著的正相关;成熟期干物质积累量、氮积累与基蘖肥氮量呈显著的二次曲线关系,基蘖肥氮量太高反而不利于后期干物质和氮素积累;水稻产量和基蘖肥氮量呈二次曲线关系,收获指数亦随氮肥用量增加呈先增加后减小的趋势;氮素吸收效率、氮肥偏生产力和基蘖肥氮量呈显著负相关关系。2012年温度较高,因此产量和总氮积累均高于2011年。在试验的土壤条件下,平均基蘖肥氮量为64 kg·hm^(-2)较为适宜,基蘖肥用量增加虽没有造成减产,却使氮素大量损失,使氮效率降低,适宜的基蘖肥氮量是水稻高产和氮素高效利用的关键。

In 2011 and 2012,plot experiments with the same N rate as panicle（ 35 kg·hm^-2） were conducted to elucidate the effect of N rate as basal and tillering fertilizer（ NBT） on yield and N fertilizer use efficiency. N rates as basal and tillering fertilizer were 0,30,65,85 and 115 kg · hm^-2,respectively. Dry matter accumulation,N uptake,N fertilizer use efficiency and yield of rice were measured. The results showed that there were positive correlation between NBT and dry matter accumulation or N uptake before heading stage or jointing stage（ P 0. 05）; correlations between NBT and dry matter accumulation or nitrogen accumulation after heading or from heading to maturation were explained by quadratic curve significantly（ P 0. 05）,so too high NBT couldn＇t increase the dry matter accumulation and nitrogen uptake after heading. There were quadratic curve relationship between NBT and rice yield. The harvest index and N fertilizer agronomic efficiency firstly increased,then decreased with the increase of NBT. The NBT and nitrogen uptake efficiency or partial factor productivity of applied N showed an obviously negative correlation（ P 0. 05）. Yield and N uptake was higher in the 2012 than 2011 due to higher temperature. Appropriate NBT was about 64 kg·hm^-2in the soil with medium fertility. Although rice yield didn＇t decreased with increase of NBT,nitrogen use efficiency was reduced because of higher N loss. Appropriate NBT was the key of high yield combined with high nitrogen efficiency.