Study on the Application Effect of Slow-release Nitrogen Fertilizer in Tea Garden

[Objective] The study aimed to know the application effect of slow-release N fertilizer in tea garden. [Method] 4 treatments of urea (CK), coated fertilizer, coated fertilizer with N content being reduced 20 %, coated fertilizer + dicyandiamide (DCD) were set up and the yield, N content and quality of tea and N content in soil were analyzed and compared. [Result] The tea yield in urea treatment was highest, reaching 14 599.5 kg/hm2. Compared with CK, the yields in the treatments of coated fertilizer, coated fertilizer reduced N content and coated fertilizer + DCD reduced 2.6 %, 4.3 % and 8.1 % resp. The N content in functional leaves of tea tree was comparatively steady, in 3.08 %～3.94 %. Different treatments caused no obvious effect on tea quality. Both ammonium-N and nitrate-N contents in soil treated with urea related to application time and times, that in soil treated with coated fertilizer were higher during spring tea period and then decreased gradually and that in soil treated with coated fertilizer reduced N content were less. After adding DCD into coated fertilizer, the nitrification was obviously inhibited, the nitrate-N content decreased obviously and the ammonium-N content had some increase in soil comparatively. [Conclusion] The research provided basis for further developing and applying new kinds of fertilizers.