Effects of controlled-release fertilizer on nitrous oxide and nitric oxide emissions during wheat-growing season: field and pot experiments

Outdoor pot and field experiments were conducted to study the effect of controlled-release fertilizer (CRF) on nitrous oxide (N2O) and nitric oxide (NO) emissions and wheat yields during the 2011-2013. Three treatments, namely conventional N fertilizer (CF; urea and compound fertilizer, 300 kg N ha(-1)), CRF (210 kg N ha(-1), which is 70% of the N applied in the CF treatment), and check (CK, 0 N), were applied in three replicates. The soil temperature, soil moisture, N uptake by wheat, wheat yield, and variations in NO3-N, NH4-N, N2O, and NO emissions were measured. Results showed that the average total N2O and NO emissions in the CRF treatment in the pot and field experiments decreased by 26.5 and 19.4%, respectively. The average N2O and NO emission factors decreased by 32.1 and 24.8%, respectively, compared with the CF treatment. However, the CRF wheat yields were insignificantly lower than those from the CF treatment. Results indicated that CRF could improve the efficiency of fertilizer N use, reduce labor cost, and increase economic benefit without sacrificing the yield.