Supplementary Table S1 Average yields for each fertilizer type, application time, Year, and their interactions.

Yield (kg ha-1)

Trial Fertilizer Application time Year 1 Year 2 Both

1 C NO APP 2872.2 2206.9 2539.6urea 100P 3705.4 3703.2 3704.3urea 30P:70LF 4207.3 3270.2 3738.8urea 30P:70GS4 3260.7 2879.2 3070.0PCU 100P 3944.2 3154.1 3549.2PCU 30P:70LF 3440.4 2911.1 3175.7PCU 30P:70GS4 3448.7 2864.7 3156.7NI+UI 100P 3956.5 3478.3 3717.4NI+UI 30P:70LF 3039.2 2984.8 3012.0NI+UI 30P:70GS4 3426.1 3007.3 3216.7NI 100P 3620.6 3250.6 3435.6NI 30P:70LF 3745.8 3314.8 3530.3NI 30P:70GS4 2947.3 3019.6 2983.4

All All 3508.8 3080.4 3294.6

C All 2872.2 2206.9 2539.6urea All 3724.5 3284.2 3504.3PCU All 3611.1 2976.6 3293.9NI+UI All 3474.0 3156.8 3315.4NI All 3437.9 3195.0 3316.4

All NO APP 2872.2 2206.9 2539.6All 100P 3806.7 3396.5 3601.6All 30P:70LF 3270.7 2942.7 3106.7All 30P:70GS4 3608.2 3120.2 3364.2

2 C NO APP 3985.2 1925.0 2955.1urea 50P:50GS4 4684.1 3382.5 4033.3PCU 50P:50GS4 4483.4 3192.9 3838.1UAN 50P:50GS4 4805.9 3056.0 3931.0NI+UI 50P:50GS4 4580.7 3184.5 3882.6NI 50P:50GS4 4642.0 2910.0 3776.0UI 50P:50GS4 4405.5 3394.5 3900.0

All All 4512.4 3006.5 3759.4

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All NO APP 3985.2 1925.0 2955.1All 50P:50GS4 4600.3 3186.7 3893.5

“NI” is nitrification inhibitor, “UI” is urea inhibitor, “NI+UI” is nitrification and urease inhibitors and “PCU” is polymer coated urea. “NO APP” is no fertilizer application, 100P is 100% of the fertilizer applied at planting, 30P:70LF is 30% of the fertilizer applied at planting and 70% applied in late fall, 30P:70GS4 is 30% of the fertilizer applied at planting and 70% applied at Feekes growth stage four, and 50P:50GS4 is 50% of the fertilizer applied at planting and 50% applied at Feekes growth stage four.

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Supplementary Figure S1 The yield, cumulative N2O emissions and yield scaled N2O emissions for Year 1, Year 2 and an average of both years for trial 1.Scatter plots show the relationships between yield-scaled N2O emissions and cumulative N2O emissions, and between yield-scaled N2O emissions and yield.

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Supplementary Figure S2 The yield, cumulative N2O emissions and yield scaled N2O emissions for Year 1, Year 2 and an average of both years for trial 2. Scatter plots show the relationships between yield-scaled N2O emissions and cumulative N2O emissions, and between yield-scaled N2O emissions and yield.

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