氮肥运筹对优质杂交稻产量及氮素吸收利用的影响

为了探明施氮量及氮肥运筹对优质杂交水稻产量及氮素吸收利用的影响,以晶两优华占、锦两优华占和晶两优1212为试验材料,2017～2018年在湖南省浏阳市进行了不同施氮量(145～225 kg/hm^2)和不同氮肥运筹(基肥、蘖肥、穗肥施用比例)的大田小区试验。结果表明:(1)适当减少施氮量能显著提高杂交水稻氮素收获指数、籽粒氮利用效率及氮肥偏生产力。(2)杂交水稻产量存在显著的品种间差异和年间差异,其中2017年以晶两优华占产量最高(9. 56 t/hm^2),3品种平均为8. 75 t/hm^2; 2018年以锦两优华占最高(13. 45 t/hm^2),3品种平均为12. 87 t/hm^2。(3) 2018年高施氮量处理显著增产,而2017年则显著减产。可见,增加氮肥用量或改进氮肥施用模式是否增加杂交水稻产量,可能与种植期间的气候条件有关。

The Impact of Nitrogen Management on the Grain Yield and the Nitrogen Uptake and Utilization of High-quality Hybrid Rice

In order to ascertain the effect of nitrogen(N)management on grain yield and N absorption and utilization of high-quality hybrid rice,the field experiments with three varieties(Jing-liangyouhuazhan,Jin-liangyouhuazhan and Jing-lliangyou 1212)were conducted in Liuyang city,Hunan province in 2007 and 2008.Different N application rates(145-225 kg/hm^2)and ratios of basal fertilizer,tillering fertilizer and panicle fertilizer were taken as the treatments.Results showed that appropriately reduced N application rate could significantly improve N harvest index,grain N use efficiency and N partial productivity of high-quality hybrid rice.There were significantly yield differences between years and varieties.Of which,the highest yield was up to 9.56 t/hm^2 for Jing-liangyouhuazhan in 2017 and 13.45 t/hm^2 of Jin-liangyouhuazhan in 2018,and the average yield of three varieties was up to 8.75 t/hm^2 in 2017 and 12.87 t/hm^2 in 2018.High N treatment significantly increased grain yield in 2018 but reduced grain yield in 2017.Therefore,effects of increasing the amount of N fertilizer or improving the application mode of N fertilizer on the grain yield of high-quality hybrid rice may be related to the climatic conditions during the growing season.