Study on the optimum nitrogen application rate and nitrogen application model on rice in coastal saline-alkaline regions
Field experiments in the coastal saline-alkaline rice area of the Liaohe River Delta were implemented to investigate the effects of different nitrogen fertilizer application rates(0-420 kg/hm2)and application methods(6∶3∶1 and 4∶3∶3 for basal fertilizer∶tiller fertilizer∶panicle fertilizer)on rice growth,as well as yield and quality.Dynamic investigations of rice tillering showed that the average number of tillers per hectare was positively correlated with nitrogen application rate under both 6∶3∶1 and 4∶3∶3 modes(r2 ≥ 0.90),and the effect of nitrogen fertilizer on the average number of tillers was greater under the 6∶3∶1 mode than under the 4∶3∶3 mode.By analyzing the relationship between different nitrogen application rates and yield,a linear-plus-plateau fertilizer response model was fitted for both modes.The optimal nitrogen application rates(EONR)under the 6∶3∶1 and 4∶3∶3 modes were determined to be 216 kg/hm2(range:210-235 kg/hm2)and 316 kg/hm2(range:300-332 kg/hm2),respectively,and the EONR under the 6∶3∶1 mode was 46.3％higher than that under the 4∶3∶3 mode.By comparing nitrogen use efficiency,it was found that nitrogen use efficiency was significantly higher under the 4∶3∶3 mode(37.2％-40.8％)than under the 6∶3∶1 mode(29.9％-34.2％)for all treatments.By analyzing rice nutrition and taste quality,while considering yield,it was further confirmed that the appropriate nitrogen application rates under the 6∶3∶1 and 4∶3∶3 modes were 300-332 and 210-235 kg/hm2,respectively.Considering the three indicators of rice yield,nitrogen use efficiency,and rice quality,this study recommends an appropriate nitrogen application rate of 210-235 kg/hm2 and the 4∶3∶3 mode in the coastal saline-alkali rice area of the Liaohe River Delta.These results provide practical technical guidance for rational fertilization and efficient use of nitrogen fertilizer for Liaohe River Delta,which can be helpful for green development of the rice industry in the region.
ricecoastal saline-alkaline regionyield and qualitythe optimum nitrogen application ratenitrogen application model
万方数据
维普
