Applications of polymer coated urea with different release time and conventional urea on summer maize growth

Field trials were carried out to study the effects of controlled-release coated urea products with different release durations(30 d, 60 d and 90 d marked with PCU30, PCU60 and PCU90 respectively)and conventional urea on summer maize grain yield, nitrogen recovery, accumulation and economic benefit. The results show that in condition of the same N-application rate, compared to traditional nitrogen application, yields, nitrogen recoveries, total nitrogen accumulations and economic benefits of summer maize are significantly increased under the basal applications 30% controlled-release coated urea(PCU30, PCU60, PCU90)and 70% conventional urea. For the 30% PCU60 and 70% conventional urea treatment, the summer maize yield is the highest, which is about 8778 kg/hm2, and compared to the traditional nitrogen application, the yield, nitrogen recovery, total nitrogen accumulation and economic benefit are increased by 12.0%, 11.02 percentage point, 18.9% and 10.7%, respectively.