|Nitrogen Use Efficiency Definitions|
World Nitrogen Use Efficiency for
Cereal Production is 33%
Agronomy Journal 91: 357-363
Importance of "YIELD" for estimating Nitrogen Use Efficiency
|Nitrogen use efficiency and/or fertilizer recovery in crop production systems can be computed using a wide range of methods. Those specifically designated for crop production systems follow. In addition, nitrogen use efficiency has been estimated using world N consumption and crop production, but on macro scales (Agron. J. 91:357-363). Other methods (Difference Method, Isotopic Method (Enriched and Depleted)) are delineated below. The components of Nitrogen Use Efficiency (NUE) are further discussed, as initially reported by Moll et al. (1982). Regardless of the method, almost all result in estimated NUE for cereal production that average between 30 and 35%. Topdress or sidedress N applications in the middle of the season can result in greater NUE's (>50%). Because the risk of N loss is greater when N is applied in the fall, N should be applied in the spring to minimize risk and optimize profitability regardless of tillage system (Vetsch and Randall, 2004).|
Keeney 1982 Justification, (reference used in AJ 91:357)
|1. Calculating N Use Efficiency using The Difference Method|
PFR = (NF)-(NC) / R
|2. Macro Calculation of World NUE (method defined)|
World Nitrogen Use Efficiency for
Cereal Production is 33%, |
Agronomy Journal 91:357
|3. Moll et al. (1982), components of NUE|
Moll, R.H., E.J. Kamprath, and W.A. Jackson. 1982. Analysis and interpretation of factors which contribute to efficiency to nitrogen utilization. Agron. J. 74:562-564.
1. Components of NUE (added discussion of Moll et al. (1982)
2. Text, Components of NUE (added discussion)
Consideration of additional parameters not discussed in Moll et al. (1982) *plant N loss
R.L., J.J. Patton, R.K. Teal, Y. Tang, M.T. Humphreys, J. Mosali, K. Girma,
J.W. Lawles, S.M. Moges, A. Malapati, J.Si, H. Zhang, S. Deng, G.V. Johnson,
R.W. Mullen, and W.R. Raun. 2003. Nitrogen balance in the Magruder Plots
following 109 years in continuous winter wheat.
J. Plant Nutr.
COMPONENTS of NUE (Moll et al., 1982), graphic illustration
|4. Nitrogen Use Efficiency (Recovery) Using Isotopic Methods|
Use of isotopic 14N
Studies involving residual soil nitrogen are not practical with depleted materials due to the high dilution factor
% plant N derived from the fertilizer =
|5. Fertilizer N Recovery (Varvel and Peterson, 1990)|
1. Difference method
PFR = (NF)-(NC) / R
2. Isotopic method (Depleted material)
PFR = ((NF) x (C-B)/D) / R
NF = total N uptake in corn from N fertilized
F = As-Ar/Af-Ar
Ef = F x total N uptake
d15N = atom % 15N (sample) - atom % 15N (standard) x 1000 / atom % 15 N (standard)
15N composition of the total N of grain and leaf samples of corn (Zea mays L.) decreased systematically as N fertilizer rates increased (Kohl et al., 1973). This result was considered to be consistent with increasing contributions of fertilizer N to plants as the rate of applied N increased.
Hauck and Bremner, 1976
percent nitrogen recovered (plant or soil) =
= 100P (c-b) / f(a-b)
P = total N in the plant part or soil in kg
unlabeled N uptake = (total N uptake in grain and straw) -
[N rate(% recovery of 15N in grain and straw)]
|6. Fertilizer N Recovery, Mass Balance (Davis et al., 2003)|
|Davis, R.L., J.J. Patton, R.K. Teal, Y. Tang, M.T. Humphreys, J. Mosali, K. Girma, J.W. Lawles, S.M. Moges, A. Malapati, J.Si, H. Zhang, S. Deng, G.V. Johnson, R.W. Mullen, and W.R. Raun. 2003. Nitrogen balance in the Magruder Plots following 109 years in continuous winter wheat. J. Plant Nutr. 26(8):1561-1580.|
The Magruder Plots are the oldest continuous soil fertility wheat research plots in the Great Plains region, and are one of the oldest continuous soil fertility wheat plots in the world.
They were initiated in 1892 by Alexander C. Magruder who was interested in the productivity of native prairie soils when sown continuously to winter wheat.
Simple estimate of nitrogen (N) balance
1. account for N applied,
2. account for N removed in the grain
3. account for estimated plant N loss, denitrification, nitrate leaching
4. account for non-symbiotic N fixation, N applied in the rainfall,
5. have an estimate of total soil N (0-30 cm) at the beginning of the experiment
6. have an estimate of total soil N (0-30 cm) at the end of the experiment
Manure plots: total soil N decreased from 6890 kg N ha-1 in the surface 0-30 cm in 1892, to 3198 kg N ha-1 in 2002.
Check plots (no nutrients applied for 109 years) only 2411 kg N ha-1 or 35% of the original total soil organic N remains.
Nitrogen removed in the grain averaged 38.4 kg N ha-1yr-1
N additions (manure, N in rainfall, N via symbiotic N fixation) averaged 44.5 kg N ha-1 yr-1 in the Manure plots.
Following 109 years, unaccounted N ranged from 229 to 1395 kg N ha-1.
By year basis, translates into 2 to 13 kg N ha-1yr-1 that were unaccounted
Manure plots, estimate of nitrogen use efficiency (NUE) (N removed in the grain, minus N removed in the grain of the check plots, divided by the rate of N applied) was 32.8%
Similar to the 33% NUE for world cereal production reported in 1999.
World Nitrogen Use Efficiency for Cereal Production is 33%
Agronomy Journal, 91:357-363
Davis, R.L., J.J. Patton, R.K. Teal, Y. Tang, M.T. Humphreys, J. Mosali, K. Girma, J.W. Lawles, S.M. Moges, A. Malapati, J.Si, H. Zhang, S. Deng, G.V. Johnson, R.W. Mullen, and W.R. Raun. 2003. Nitrogen balance in the Magruder Plots following 109 years in continuous winter wheat. J. Plant Nutr. 26(8):1561-1580.
Raun, W.R., Solie, J.B., Johnson, G.V., Stone, M.L., Mullen, R.W., Freeman, K.W., Thomason, W.E., and Lukina, E.V. (2002) Improving nitrogen use efficiency in cereal grain production with optical sensing and variable rate application. Agronomy Journal, 94: 815 to 820.
Edmonds, Daniel E., Silvano L. Abreu, Adelheid West, Donna R. Caasi, Travis O. Conley, Michael C. Daft, Birehane Desta, Brandon B. England, Chelsea D. Farris, Tia J. Nobles, Nehaben K. Patel, Elliott W. Rounds, Brennan H. Sanders, Samar S. Shawaqfeh, Lakmini, Lokuralalage, Roji Manandhar, and W. R. Raun. 2009. Cereal nitrogen use efficiency in Sub Saharan Africa. J. Plant Nutr. 32:2107-2122.
NUE: > 100%
Vetsch, Jeff, and Gyles Randall. 2004. Corn production as affected by
nitrogen application timing and tillage. Agron. J. 96:502-509.
Improve, and/or measure NUE
Plant Nitrogen Loss as NH3
1. Increased plant N loss with increasing nitrogen applied in winter wheat observed with 15N. J. Plant Nutr. 23:219-230. (Lees et al., 2000)
2. Post-anthesis nitrogen loss from corn. Agron. J. 85:659-663. (Francis et al., 1981)
3. Effect of nitrogen rate on plant nitrogen loss in winter wheat varieties. Desta et al. (1997). J. of Plant Nutr. 20:389-404. (pdf)
4. Gaseous Nitrogen Loss from Soybean Foliage
|NEW N Management Strategy for Corn and Wheat|
|PDF version from Agronomy Journal (91:357-363)|
of Nitrogen Use Efficiency
(added discussion of the Moll et al.
Nitrogen Cycle Page