Abstract: Field experiments were conducted to study the effects of different dosages coated controlled release urea (PCU60, 60 d release duration) combined with conventional urea (U) used as basal on the winter wheat grain yield, nitrogen (N) recovery rate, and soil NO₃^--N content, etc. Five treatments were installed, i.e., U (CK), 10% PCU60+90 %U (PU₁), 20% PCU60+80% U (PU₂), 30% PCU60+70% U (PU₃), and 40% PCU60+60% U (PU₄). In the meantime, a comparative analysis was also carried out on the PCU60 N release characteristics under field condition and in 25 ℃ static water. At the same N dosage, all the test indices in treatment PU₄ were significantly higher, with the grain yield, N recovery rate, total N accumulation amount, total tiller number and aboveground biomass at ripening stage, and economic benefit increased by 5.6%, 14.6%, 7.2%, 2.6%, 7.5%, and 984.3 yuan·hm^-2, respectively, compared with those in treatment U. The accumulation amount of NO₃^--N in 0-100 cm soil layer in all treatments ranged in 39.70-49.93 kg·hm^-2, and was the lowest (39.70 kg·hm^-2) in treatment PU₄. The N release pattern of PCU60 under field condition better fitted the N absorption characteristics of winter wheat.

Key words: winter wheat, coated controlled release urea, growth and development,  NO₃^--N