Irrigating Crops
1. Presentation
Characterization of the technique
Description of the technique:
| Rémy Ballot | INRA | remy.ballot(at)grignon.inra.fr | Grignon (78) |
The water supply by irrigation aims to lift, partially or totally, the limiting factor of water supply to crops. Irrigation also has an effect, favorable or unfavorable, on certain pests.
Implementation period On established crop
Spatial scale of implementation Farm
Application of the technique to...
All crops: Easily generalizable
Irrigation can potentially be applied to all crops, but its interest varies from one crop to another. It depends on (1) the crop's sensitivity to water stress, (2) the timing of the crop cycle relative to water availability, and (3) the positive or negative effect of irrigation on pests affecting the crops.
All soil types: Easily generalizable
Irrigation can potentially be applied to all soil types, but its interest strongly depends on the soil available water capacity.
All climatic contexts: Easily generalizable
Irrigation can potentially be applied to all climatic contexts, but its interest depends on the frequency of dry climatic episodes.
Regulation
Depending on territories and climatic factors, water restrictions may be decreed and limit or even prohibit the use of irrigation.
2. Services provided by the technique
3. Effects on the sustainability of the cropping system
"Environmental" criteria
Effect on air quality: Decreasing
pesticide emissions: NEUTRAL
GHG emissions: INCREASING
Effect on water quality: Variable
pesticides: VARIABLE
Effect on fossil resource consumption: Increasing
fossil energy consumption: INCREASING
Other: No effect (neutral)
Irrigation has a variable impact on the risks of pollutant transfer to water. It promotes the uptake by the crop of nitrogen fertilization and soil nitrogen supplies and thus helps minimize nitrogen residues at the start of the drainage period. However, excessive water supply generates drainage and runoff and causes transfers of nitrogen, phosphorus, or pesticide residues to water.
Irrigation leads to an increase in greenhouse gas emissions linked to the energy consumed for pumping (if thermal engine) or moving the reels. Moreover, irrigation can cause anoxic conditions at the soil surface favorable to nitrous oxide emissions by denitrification.
Fossil energy consumption also increases due to pumping, and possibly moving the reels.
"Agronomic" criteria
Productivity: Increasing
Irrigation primarily prevents or reduces losses due to water stress, but it also prevents losses due to pests for which no chemical control solution is available (example: green stink bug on soybean).
Soil fertility: No effect (neutral)
Water stress: Decreasing
Irrigation aims to compensate for water deficits related to insufficient rainfall.
Other agronomic criteria: Variable
Pressure from diseases:
Some pathogens are favored by irrigation: fusarium head blight on soft wheat if irrigated at flowering, downy mildew and sclerotinia of the head on sunflower, corn smut…
"Economic" criteria
Operational costs: Increasing
Operational costs increase due to water consumption and powering pumping devices. It also requires revising the entire technical itinerary coherently: seeding density, nitrogen dose, etc.
Mechanization costs: Increasing
Irrigation involves additional mechanization costs for equipment depreciation, pumping, moving reels, etc.
Margin: Variable
The impact of irrigation on profitability depends on (1) additional costs and (2) yield gains allowed.
"Social" criteria
Working time: Increasing
Irrigation involves additional workload for its implementation and management.
4. Organisms favored or disfavored
Favored pests
| Organism | Impact of the technique | Type | Details |
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Disfavored pests
| Organism | Impact of the technique | Type | Details |
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Favored Natural enemies
| Organism | Impact of the technique | Type | Details |
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Disfavored natural enemies
| 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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Disfavored climatic and physiological accidents
| Organism | Impact of the technique | Details |
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5. For further information
6. Keywords
Pest control method: Cultural control
Mode of action: Mitigation
Type of strategy regarding pesticide use: Redesign
