尿素硝酸铵溶液替代尿素对冬小麦'新冬55号'生长及氮素利用的影响OACHSSCD

To determine the optimal application rate of urea ammonium nitrate(UAN)solution as a substitute for urea in the winter wheat cultivar'Xindong 55',a single-factor randomized block field plot experiment was conducted.The experimental design consisted of five treatments:no nitrogen fertilization(CK),100%urea(T1),UAN substituting 100%of urea-based pure nutrient content(T2),UAN substituting 85%of urea-based pure nutrient content(T3),and UAN substituting 70%of urea-based pure nutrient con-tent(T4).The nitrogen application rate for the 100%urea treatment(T1)was set at 450.00 kg·hm-2 of N,with phosphorus fertilizer(as P2 O5)applied at 191.25 kg·hm-2 and potassium fertilizer(as K2 O)at 195.00 kg·hm-2.All treatments received consistent types and amounts of phosphorus and potassium fertilizers.The results indicated that among the UAN substitution treatments,T2 demonstra-ted the most pronounced improvement in winter wheat growth and yield compared to T1,with increases of 12.10%in effective tillers per plant and 10.80%in yield at maturity.Treatments T3 and T4 achieved yield maintenance with reduced fertilizer input.Compared to T1,T2 also significantly enhanced total nitrogen content in winter wheat plants across growth stages.Plant nitrogen content increased with higher UAN application rates,and nitrogen use efficiency was effectively improved,with T2 exhibiting the highest nitrogen use ef-ficiency 21.96%higher than T1.Both T3 and T4 also showed higher nitrogen use efficiency than T1.In conclusion,under drip irriga-tion conditions,the T2 treatment(UAN substituting 100%of urea-based pure nutrient content)significantly promotes winter wheat growth and enhances nitrogen utilization,providing a scientific basis for rational fertilization practices in winter wheat cultivation.