Effects of Methods and Rates of Controlled Release Urea on Dry Matter Accumulation and Yield of Maize

No nitrogen as control，five nitrogen rates were designed to investigate the effects of methods and rates of controlled release urea（CRU）application on the dry matter accumulation and yield of maize in a randomized design.The results showed that the dry matter accumulation and leaf area index were getting more increase with increasing of N application rate，compared with normal urea，CRU has obvious superiority.It could increase them before male tetrad stage，while decrease them after anthesis in the range of 0～150 kg/hm2.In the experiment，the targets went up along with the increasing of N application rate.The results also indicated the grain yield of maize was getting more increase with increasing of N application rate in the range of 0～150 kg/hm2，and it was increased by 5.0%～21.4%.Compared with the normal urea，the 75 kg/hm2 treatment of the grain yield was improved by 6.7%，3.4% under bottom application and side dressing between the rows of CRU and the 150 kg/hm2 treatment of the grain yield was improved by 8.8%，1.9%，respectively.In conclusion，using CRU can coordinate the growth of shoot to get higher grain yield，and increase of bottom application is benefit to improve the effects of CRU on grain yield.