Splitting the total nitrogen dose applied to the crop
1. Presentation
Characterization of the technique
Description of the technique:
| Philippe Eveillard | UNIFA | peveillard(at)unifa.fr | Paris (75) |
|---|---|---|---|
| François Dumoulin | CA 60 | françois.dumoulin(at)agri60.fr | Fresnoy le Luat (60) |
| Anne Schaub | ARAA | a.schaub(at)bas-rhin.chambagri.fr | Schiltigheim (67) |
| Rémy Ballot | INRA | remy.ballot(at)grignon.inra.fr | Grignon (78) |
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Split the total nitrogen dose into several applications at dates and doses matching the crop's needs to maximize the actual nitrogen use efficiency. By favoring applications during periods of active canopy growth or crop sensitivity to nitrogen deficiency, splitting allows (i) better utilization of soil nitrogen supplies, (ii) limiting temporary losses by reorganization or permanent losses by volatilization or leaching, and (iii) for certain crops, promoting nitrogen transfer to harvested organs (protein content of grain for some cereals with straw). The recommended number of applications is a compromise between (i) the agronomic interest of multiple applications and (ii) technical feasibility (possibility to pass through a developed canopy).
Example of implementation:
For winter wheat, the total nitrogen dose is typically split into 3 applications: a first application at the end of winter, the second at stem elongation - early booting, and the last at late booting - flag leaf.
For maize, the total dose is split between a first application at sowing and a second between the 6 and 10 leaf stages; for very permeable soils, 3 applications are necessary: sowing, 4-6 leaves, 10-12 leaves.
Implementation period On established crop
Spatial scale of implementation Plot
Application of the technique to...
All crops: Sometimes difficult to generalize
For some crops, making applications beyond a certain stage at which nitrogen is still utilized is limited by equipment access. For maize, for example, nitrogen applications are utilized up to flowering stage but equipment access is no longer possible from the 12-leaf stage (except fertigation under pivot). Moreover, splitting must also consider quality criteria required by the targeted market (no late applications on brewing barley or biscuit wheat for which a low protein content is required).
All soil types: Easily generalizable
In soils with good water reserves, splitting mainly limits temporary losses by reorganization and permanent losses by leaching in permeable or karstic soils.
All climatic contexts: Sometimes difficult to generalize
The effectiveness of nitrogen applications is also conditioned by the climatic context: 15-20 mm of rain within 2 weeks following an application is necessary for it to be utilized by the crop. In the absence of irrigation, an application coinciding with a stage where crop needs are high but without rainfall will not be better or may be less well utilized than an application shifted to coincide with favorable climatic conditions.
Regulation
Regulatory influence: Positive - Negative
2. Services provided by the technique
3. Effects on the sustainability of the cropping system
"Environmental" criteria
Effect on air quality: Increasing
Phytosanitary emissions: DECREASE
GHG emissions: DECREASE
Effect on water quality: Increasing
N.P.: DECREASE
Effect on fossil resource consumption: Decreasing
Fossil energy consumption: DECREASE
Other: No effect (neutral)
Pollutant transfer to water (N, P, phytosanitary ...): Decrease
Reduction of nitrogen losses by leaching.
Pollutant transfer to air (N, P, phytosanitary ...): Decrease
Reduction of losses by volatilization.
Fossil energy consumption: Decrease
Reduction in fossil energy consumption linked to the manufacture of mineral fertilizers. This decrease is greater than the increased consumption due to the additional fertilizer spreader passes.
GHG emissions: Decrease
Reduction in carbon dioxide emissions linked to the manufacture of mineral fertilizers and reduction in nitrous oxide emissions linked to mineral fertilizer spreading. This decrease is greater than the increase due to the additional fertilizer spreader passes.
"Agronomic" criteria
Productivity: Variable
Increase in yield or protein content (cereals with straw) of the crop if splitting is done without changing the total dose.
Production quality: Variable
Soil fertility: No effect (neutral)
Water stress: No effect (neutral)
Functional Biodiversity: No effect (neutral)
"Economic" criteria
Operating costs: Decreasing
Reduction in costs related to the purchase of mineral fertilizers not utilized by the crop.
Mechanization costs: Increasing
Splitting the total dose implies an increase in the number of passes.
Margin: Increasing
The increase in mechanization costs linked to the number of passes is offset by the increase in yield and/or the reduction in fertilization costs enabled by splitting. The margin is thus improved, variably depending on the crops. If splitting allows a better protein content in wheat and the buyer pays a better price for wheat with high protein content, the margin is even higher.
Other economic criteria: Increasing
Fuel consumption: Increase
Splitting the total dose implies an increase in the number of passes.
"Social" criteria
Working time: Increasing
Overall workload: Increase
Splitting the total dose implies an increase in the number of passes.
Observation time: Variable
Splitting on some crops involves the use of Decision Support Tools with additional observations (wheat: double density, N-Tester…). Not on other crops (maize).
4. Organisms favored or disadvantaged
Favored Pests
| Organism | Impact of the technique | Type | Details |
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Disadvantaged pests
| Organism | Impact of the technique | Type | Details |
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Favored Beneficials
| Organism | Impact of the technique | Type | Details |
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Disadvantaged Beneficials
| Organism | Impact of the technique | Type | Details |
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Favored climatic and physiological accidents
| Organism | Impact of the technique | Details |
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Disadvantaged climatic and physiological accidents
| Organism | Impact of the technique | Details |
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5. To learn more
- Nitrogen and proteins - Betting on splitting
- -Perspectives agricoles n°307, p30-33, Press article, 2004
- Nitrogen fertilization calculation - Methodological guide for establishing local prescriptions
- -COMIFER
Technical brochure, 2011
- Nitrogen fertilization - Splitting: A winning strategy!
- -Plovie A.
Cultivar n°626, p42-44, Press article, 2009
- Nitrogen fertilization - Optimizing the efficiency of applications in crop
- -Cohan J.P. (Arvalis)
Perspectives agricoles n°352, p24-27, Press article, 2008
- Split and adjust
- -UNIFA
Website
- Nitrogen management on wheat: A matter for specialists
- -Agreste
Agreste primeur n°159, Press article, 2005
6. Keywords
Pest control method:
Mode of action:
Type of strategy regarding pesticide use:
