Effects and methods of urea application combined with urease or nitrification inhibitors under drip irrigation on maize

In order to evaluate the feasibility of addition of urease inhibitor (hydroquinone,HQ) and nitrification inhibitors(DCD) into urea solution applied in drip fertigation,a pot experiment with maize as a test crop was conducted under greenhouse condition.HQ and DCD were supplied through drip fertigation and soil application before sowing,and the dosages were 0.3%,0.5% and 1.0% of urea application rate for HQ and 2.5%,5.0% and 10.0% of urea rate for DCD.The results indicated that,under drip fertigation with urea solution,0.3%HQ,0.5%HQ and 5.0%DCD could significantly increase N use efficiency(NUE) as compared to fertigation with urea alone,and the NUE were 74.8%,75.8%,75.3% respectively;When HQ and DCD were applied to soil under drip irrigation,HQ showed no positive effect on NUE.However,DCD increased significantly the NUE of urea with data as 61.9%,54.6% and 58.4%,respectively.The NUE of urea with HQ and DCD application in drip fertigation system were higher than that with HQ and DCD applied into soil before sowing under drip irrigation.