Effects of Mixed Urea Combined with Organic Fertilizer on Nitrogen Use Efficiency and Yield of Winter Wheat and Soil Nitrogen Supply Performance

Li Changying; An Jing; Dou Jinghai; Ding Meili; Du Jiaojiao

doi:10.14083/j.issn.1001-4942.2025.02.014

Abstract：A two-year field experiment was conducted with the wheat variety Tainong 18 as test material by setting 7 treatments including nitrogen-free control(CK),ordinary urea treatment(CU)and five treat-ments of mixed urea(M,ordinary urea and controlled-release urea at ratio of 7:3)combined with organic fer-tilizer(F).The proportion of organic fertilizer instead of mixed urea was designed as 0,25％,50％,75％and 100％,which were recorded as M100F0,M75F25,M50F50,M25F75 and M0F100,respectively.The effects of dif-ferent fertilization treatments on wheat nitrogen utilization,yield and soil nitrogen supply performance under e-qual nitrogen condition were studied.The results showed that the application of mixed urea combined with or-ganic fertilizer could significantly improve the transformation of soil humic acid components,affect the supply period of soil available nitrogen,promote the growth and nitrogen absorption of wheat,and then improve the nitrogen use efficiency(NUE)and yield of wheat.Under the CU treatment,the content of nitrate nitrogen and ammonium nitrogen in the surface(0～30 cm)soil increased and made wheat grow better at the early stage of winter wheat growth,but the higher leaching amount of nitrate nitrogen and ammonium nitrogen led to the soil available nitrogen content decreased rapidly after that,so the nitrogen use efficiency(NUE)and yield were lower.Compared with CU treatment,the treatments of mixed urea combined with organic fertilizer prolonged the supply period of soil nitrogen,reduced nitrogen leaching and increased soil enzyme activity,promoted the transformation of soil humic acid components,thereby improved wheat dry matter accumulation,NUE and yield.The average NUE of the two years was the highest under M50F50 treatment,and the NUE increased by 1.51％to 21.48％and 8.90％to 22.64％respectively compared with the other fertilization treatments in 2022 and 2023,respectively.In summary,the application of organic fertilizer instead of 50％mixed urea in the ex-periment conditions could improve soil nitrogen supply performance,increase winter wheat yield and NUE,so it was the best organic fertilizer replacement treatment.