提高氮肥利用效率.pdf

1、Dept.of Soil Science,Univ.of Sask.Enhancing the Efficiency of Nitrogen FertilizersJ.Schoenau,S.Malhi,C.Grant,H.Asgedom,R.Lemke,S.LamichhaneDept.of Soil Science,Univ.of Sask.IntroductionTop Crop Summit 2025:Dr.Rich Farrells presentation“Achieving GHG Emissions Reduction Targets Using EEF Fertilizers”

2、-EEF fertilizers are effective in reducing nitrous oxide emissions.My presentation today emphasizes agronomic impacts:-Yield,fertilizer N recovery by crop.Dept.of Soil Science,Univ.of Sask.Why enhanced efficiency N fertilizers?Typically,recovery of N fertilizer by crop in year of application is 70%,

3、in part due to losses before plant use.Losses occur due to volatilization of ammonia gas,leaching and denitrification of nitrate.Production of ammonium and nitrate well in advance of crop demand can contribute to accelerated losses.Reduce N losses,increase fertilizer N recovery,increase agronomic ef

4、ficiency(yield increase per unit N applied)by matching supply of available N closely to crop uptake.Dept.of Soil Science,Univ.of Sask.4 R Nitrogen ManagementSourceTimePlaceRateNitrogen fertilizer source is important consideration,and how it interacts with timing,placement and rate.Dept.of Soil Scien

5、ce,Univ.of Sask.Ammonia gas susceptible to loss to atmosphere:volatile gassing off from surface.Nitrate susceptible to loss through leaching and denitrification to N2O and N2 gases.STOP,SLOW DOWN THESE PROCESSES FOR A WHILE!Dept.of Soil Science,Univ.of Sask.Dept.of Soil Science,Univ.of Sask.Urease I

6、nhibitorsUrease inhibitors:NBPT and NPPT containing products stop urea hydrolysis to ammonia gas for a period of time by inhibiting urease enzyme.Urea urease ammonia(NH3 gas)Reduces ammonia gas and ammonium present in soil,therefore reducing volatile ammonia losses following application of urea on s