Prefer low heavy metal content inputs
1. Presentation
Characterization of the technique
Description of the technique:
| Anne Schaub | ARAA | a.schaub(at)bas-rhin.chambagri.fr | Schiltigheim (67) |
|---|---|---|---|
| Isabelle Feix | ADEME | iseballe.feix(at)ademe.fr | Angers (49) |
Some inputs are likely to contain more heavy metals or trace elements (TE) than others: cadmium in phosphate fertilizers, copper and zinc in pig slurry, various TEs, notably cadmium, copper, zinc and lead, in organic fertilizers and amendments (waste or product types). For these inputs and/or in the case of acidic soils and/or crops that accumulate TEs (leafy vegetables such as spinach and lettuce), ask your supplier for the TE composition of possible inputs in order to choose the one that provides the lowest TE flux, for example per unit of fertilizer sought.
Example of implementation: Particular vigilance is required in the case of vegetable crops (leafy vegetables accumulators) grown in organic farming, a system using only fertilizers of natural origin, many of which are rich in TEs: in this case, avoid natural phosphates from mines in Russia or the Northwestern USA for example, which have high cadmium content and also contain chromium, zinc, nickel, manganese and cobalt, especially if the soil is acidic, because these TEs are then more available to the crops.
Details on the technique:
TEs are also part of the composition of some plant protection products (copper, aluminum, zinc in fungicides). It is recommended to sum all the TEs brought by inputs (fertilizing materials of course, including livestock effluents and organic residual products, but also other inputs: plant protection products, even irrigation water when relevant) on each plot and compare to regulatory limit fluxes.
Implementation period During the intercrop period
On established crops
The technique is interesting to apply at the time of planning the fertilization plan, when possible.
Spatial scale of implementation Plot
Application of the technique to...
All crops: Easily generalizable
The technique is particularly useful when the crop is highly accumulative.
All soil types: Easily generalizable
In acid soil, the technique is more useful than in alkaline soil because TEs are more available to crops in acid soil.
All climatic contexts: Easily generalizable
Regulation
POSITIVE influence
Numerous regulatory texts for the spreading of organic residual products (under waste or product status) with limit contents in spread ORPs and limit fluxes over 10 years. Regulatory texts concerning the approval of fertilizing materials
2. Services provided by the technique
3. Effects on the sustainability of the cropping system
"Environmental" criteria
Effect on fossil resource consumption: Variable
fossil energy consumption: VARIABLE
Other: No effect (neutral)
In general, fossil energy consumption is unchanged… but in some cases it may be necessary to treat fertilizing materials and this has an energy cost (e.g., phosphate fertilizers requiring decadmiumization) or it may be necessary to change the origin of raw materials which can impact energy costs related to transport (more or less) (e.g., change of origin of natural phosphates used).
Soil and water contamination by TEs:
Ecotoxicity and accumulation of TEs in trophic chains:
"Agronomic" criteria
Productivity: Variable
TE fluxes brought by inputs are rarely sufficient to cause a decrease in crop yield, except in the very long term with repeated inputs of particularly contaminated inputs (very low probability). Conversely, in case of soil deficiency in trace element(s), TE inputs by inputs can have a positive effect on the yield of crops demanding these trace elements.
Production quality: Increasing
Soil fertility: Variable
For a soil well supplied with trace elements, limiting TE inputs is neutral. For a deficient soil, limiting TE inputs by inputs decreases its fertility.
Functional Biodiversity: Variable
For a soil well supplied with trace elements, limiting TE inputs is neutral. For a deficient soil, limiting TE inputs by inputs has a rather negative impact on soil organisms.
"Economic" criteria
Operating costs: Variable
Inputs chosen for their low TE content may be more expensive. If they are free organic residual products, the impact is neutral. For a mixed crop-livestock farmer there may also be costs for analyzing spread livestock effluents and for some who irrigate, costs for analyzing irrigation water.
Mechanization costs: No effect (neutral)
Margin: Variable
"Social" criteria
Observation time: Increasing
In the sense that it takes time to inquire about TE contents from the supplier. For organic wastes, the supplier automatically provides analysis reports. For fertilizer-type products, the information can be difficult to obtain. It also takes time to analyze livestock effluents or water used for irrigation.
4. Favored or disadvantaged organisms
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 Auxiliaries
| Organism | Impact of the technique | Type | Details |
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Disadvantaged Auxiliaries
| 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. For further information
- Soil contamination - Transfers from soils to plants
- -Anne Tremel-Schaub and Isabelle Feix
EDP Sciences and ADEME, Book, 2005
6. Keywords
Bioaggressor control method:
Mode of action:
Type of strategy regarding pesticide use:
Annexes
S'applique aux cultures suivantes
