Abstract: To explore the effects of nitrification inhibitor along with nitrogen fertilizer application in the growing season of wheat, a field experiment was conducted to investigate the wheat yield formation and nitrogen use efficiency using twofactor splitplot design. There were five levels of nitrogen fertilizer applications (0, 210, 240, 270, 300 kg·hm^-2). The wheat cultivar of Yangmai 16 was fieldgrown. The results showed that the wheat yield was the highest under 240 kg·hm^-2 of nitrogen fertilizer application accompanied by nitrification inhibitor, reaching 7260 kg·hm^-2 due to higher panicle number per unit area, grain number per panicle, and 1000grain weight. The wheat biomass yield was the highest under 240 kg·hm^-2 of nitrogen fertilizer application together with nitrification inhibitor. Nitrification inhibitor had no significant effect on economic coefficient of wheat. Nitrification inhibitor effectively increased soil available nitrogen concentration and decreased the magnitude of such enhancement with the increases of nitrogen fertilizer. Nitrification inhibitor significantly improved nitrogen accumulation in wheat plant, but decreased nitrogen use efficiency for wheat grain yield. Combined with nitrification inhibitor application, the lower nitrogen fertilizer application such as 210 and 240 kg·hm^-2 treatments increased wheat agronomic efficiency, average recovery efficiency, physiological efficiency and partial factor productivity of nitrogen fertilizer by 16.1 kg·kg^-1, 69.9%, 23.1 kg·kg^-1 and 31.4 kg·kg^-1,  respectively. In conclusion, application of nitrification inhibitor plus 240 kg·hm^-2 of nitrogen fertilizer could ensure high wheat yield and improve nitrogen use efficiency.

Key words: Trichogramma dendrolimi, Antherea pernyi, Life table, Fecundity, Survival rate