Effect of Control Release Urea on Spring Maize Yield, N Use Efficiency and SoilNitrogen
控释尿素对玉米产量、氮肥利用率及土壤氮素的影响

The experiments were conducted to investigate the effects of single basal application of control release urea with kieselguhr as the carrier on rate of yield of maize,shoot dry weight and N uptake of maize in different growth stages,NH4+-N and NO3——N of soil.The results show that control release urea application could increase shoot dry weight and N use efficiency of maize,inhibit urease activity of soil and maintain soil NH4+-N and NO3——N during the late growth stage.The treatments of twice fertilization and control release urea could increase yield by 23.48% and 17.70%,improve N use efficiency by 17.33% and 17.58%,respectively.Therefore,the control release urea in this study can be used by single basal application to maize production system,and help to change twice fertilization(basal and dressing) to once fertilization(basal),and thus benefit to labor-saving and improve nitrogen utilization efficiency.