Improving Life-Cycle Nitrogen Use Efficiency And Environmental Performance Of Corn Production...
1
Overview Matching the timing and amount of N fertilizer with crop N demand has been identified as an effective measure for reducing reactive N loss. Increasingly wet springs in the main corn-growing areas of US have made N timing more crucial as early applications are subject to loss during wet weather. To make adoption choices, farmers need to understand the variability in performance and probability of undesirable outcomes. Our goal is to provide a detailed evaluation of the full life-cycle costs and benefits of N timing options within the context of a changing climate. This project combines long-term nitrogen rate field experiments with regional simulation under projected climate. Experimental data collection N timing and rate experiments are on-going at the Bradford Research Center near Columbia, Missouri. The soil is a Vertic Epiqaulf. Initiated in 2007, eight management systems with varying in N application timing, rate, and method used to determine rate are being tested in a randomized complete block experiment. A second experiment combines nitrogen and drainage management. Simulation We are using the DayCENT biogeochemical model to predict N 2 O emissions, nitrate loss, and yield with different nitrogen management under current and future climate. What we’ve learned so far • Soil type may be important in determining effect of N-timing on soil N 2 O flux. • In field experiments, N application at V7 has maintained yield, and reduced both N 2 O flux and nitrate loss in drainage water. • Amount and timing of rainfall result in large year-to-year variability in effect of N timing on N losses and grain yield. N 2 O emissions variation with timing, rate and soil type Yield and nitrate loss with N timing N 2 O emissions with timing of N fertilization Acknowledgements: This work is supported by the USDA National Institute of Food and Agriculture, Renewable Energy, Natural Resources and Environment program area, Grant Award No. 2015- 67019-23601, Accession No. 1005802. Special thanks to Laura Smith and Jordi Francis-Clar. Improving life-cycle nitrogen use efficiency and environmental performance of corn production through fertilizer timing and rate R.P. Anex 1 , P.C. Scharf 2 , B.D. Duval 3 , J.S. Evans 1 1 Department of Biological Systems Engineering, University of Wisconsin-Madison; 2 Plant Sciences, University of Missouri; 3 Department of Biology, New Mexico Tech. 4/29 5/7 5/15 5/23 5/31 6/8 6/16 6/24 7/2 7/10 7/18 7/26 8/3 8/11 8/19 8/27 9/4 9/12 9/20 -0.01 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 2015 Daily flux of Nitrous Oxide Pre-plant N Nitrous oxide, kg ha-1 day-1 Relative to preplant N, variable- rate sidedress N application reduced growing season N 2 O flux by 69% in 2015, from 2.4 to 0.7 kg N ha -1 . 2012 2013 2014 2015 4-Yr ave 0 0.5 1 1.5 2 2.5 3 sensor-based at V7 140 pre-plant N2O emissions, kg N ha-1 year-1 Average N 2 O flux is 61% lower with variable- rate sidedress N application relative to preplant N. Delaying N application to V6 in single or split application is predicted to generally reduce N 2 O flux, but effect varies with weather and soil type. N 2 O flux is measured weekly from all plots during the growing season. In drained experiments, drainage water sampled for nitrate weekly. The model is calibrated to field data and an extensive regional database of N-rate experimental data. Future climate predictions are from regional downscaling of Stars are plots that received N at V7 all others received preplant. Later N application improved N status in late August 2015, but not yield. Over three years (‘12-’14), average N application at V7 was 99% of preplant N amount. Average yield with application at V7 was 12% higher while nitrate in drainage water was 24% lower than with preplant N application. (Data not shown). Whether split or delayed N application reduces N 2 O emissions may depend on soil type. Simulation reproduces experimental data and predicts importance of both form of N fertilizer and soil type in modulating impact of N timing on N 2 O flux. On average, split or delayed N application maintains yield while reducing nitrate and N 2 O losses. But not everywhere or every year. P ercenteffectofsplitor delayed N fertilization -80 -60 -40 -20 0 20 40 60 80 100 N fertilization rate (kg N . ha -1 . yr -1 ) 100 120 140 160 180 200 220 240 MN TX IN W I-A W I-B IA clayloam IA sand CA preplant emissions O N preplant emissions O N - N delayed emissions O N size Effect 2 2 2 M easured C orn G rain Yield (gC . ha -1 +/-SD ) 0 2000 4000 6000 8000 M odeled Co . ha -1 ) 0 2000 4000 6000 8000 n = 20 sites; r = 0.59
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Transcript of Improving Life-Cycle Nitrogen Use Efficiency And Environmental Performance Of Corn Production...
Overview Matching the timing and amount of N fertilizer with crop N demand has been identified as an effective measure for reducing reactive N loss. Increasingly wet springs in the main corn-growing areas of US have made N timing more crucial as early applications are subject to loss during wet weather. To make adoption choices, farmers need to understand the variability in performance and probability of undesirable outcomes. Our goal is to provide a detailed evaluation of the full life-cycle costs and benefits of N timing options within the context of a changing climate.This project combines long-term nitrogen rate field experiments with regional simulation under projected climate.
Experimental data collectionN timing and rate experiments are on-going at the Bradford Research Center near Columbia, Missouri. The soil is a Vertic Epiqaulf. Initiated in 2007, eight management systems with varying in N application timing, rate, and method used to determine rate are being tested in a randomized complete block experiment. A second experiment combines nitrogen and drainage management.
SimulationWe are using the DayCENT biogeochemical model to predict N2O emissions, nitrate loss, and yield with different nitrogen management under current and future climate.
What we’ve learned so far• Soil type may be important in determining effect of N-timing on soil N2O flux.
• In field experiments, N application at V7 has maintained yield, and reduced both N2O flux and nitrate loss in drainage water.
• Amount and timing of rainfall result in large year-to-year variability in effect of N timing on N losses and grain yield.
N2O emissions variation with timing, rate and soil type
Yield and nitrate loss with N timing
N2O emissions with timing of N fertilization
Acknowledgements: This work is supported by the USDA National Institute of Food and Agriculture, Renewable Energy, Natural Resources and Environment program area, Grant Award No. 2015-67019-23601, Accession No. 1005802.Special thanks to Laura Smith and Jordi Francis-Clar.
Improving life-cycle nitrogen use efficiency and environmental performance of corn production through fertilizer timing and rate
R.P. Anex1, P.C. Scharf2, B.D. Duval3, J.S. Evans1
1Department of Biological Systems Engineering, University of Wisconsin-Madison; 2Plant Sciences, University of Missouri; 3Department of Biology, New Mexico Tech.
4/295/05
5/115/17
5/235/29
6/046/10
6/166/22
6/287/04
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7/227/28
8/038/09
8/158/21
8/279/02
9/089/14
9/20-0.01
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2015 Daily flux of Nitrous Oxide
Pre-plant N Sidedress at V7
Nitr
ous o
xide
, kg
ha-1
day
-1
Percent effect of split or delayed N fertilization
-80 -60 -40 -20 0 20 40 60 80 100
N fertilization rate (kg N . ha
-1 . yr
-1)
100
120
140
160
180
200
220
240
MNTXINWI-AWI-BIA clay loamIA sandCA
preplantemissionsON
preplantemissionsON-N delayed emissionsONsizeEffect2
22
Relative to preplant N, variable-rate sidedress N application reduced growing season N2O flux by 69% in 2015, from 2.4 to 0.7 kg N ha-1.
2012
2013
2014
2015
4-Yr ave
0 0.5 1 1.5 2 2.5 3
sensor-based at V7140 pre-plant
N2O emissions, kg N ha-1 year-1
Average N2O flux is 61% lower with variable-rate sidedress N application relative to preplant N.
Delaying N application to V6 in single or split application is predicted to generally reduce N2O flux, but effect varies with weather and soil type.
N2O flux is measured weekly from all plots during the growing season. In drained experiments, drainage water sampled for nitrate weekly.
Measured Corn Grain Yield (gC . ha-1 +/- SD)
0 2000 4000 6000 8000
Modeled C
orn Grain Yield (gC
. ha
-1)
0
2000
4000
6000
8000n = 20 sites; r = 0.59
The model is calibrated to field data and an extensive regional database of N-rate experimental data. Future climate predictions are from regional downscaling of five global climate models.
Stars are plots that received N at V7 all others received preplant. Later N application improved N status in late August 2015, but not yield.
Over three years (‘12-’14), average N application at V7 was 99% of preplant N amount. Average yield with application at V7 was 12% higher while nitrate in drainage water was 24% lower than with preplant N application. (Data not shown).
Whether split or delayed N application reduces N2O emissions may depend on soil type.
Simulation reproduces experimental data and predicts importance of both form of N fertilizer and soil type in modulating impact of N timing on N2O flux.
On average, split or delayed N application maintains yield while reducing nitrate and N2O losses. But not everywhere or every year.
