Making organic effluent contributions
1. Presentation
Characterization of the technique
Description of the technique:
Applying organic effluent inputs. Two types of effluents are distinguished:
- Type 1 products (manure, compost…) with medium to high C/N ratio whose direct fertilizing effect will be limited (mineral fertilizer equivalence coefficient from 0.1 to 0.3) but which will have an indirect medium to long-term effect on the soil organic matter content and thus on the stock of organic nitrogen whose mineralization may occur within 2 to 3 years following the input.
- Type 2 products (slurry, poultry droppings...) with low C/N ratio and mainly presenting a direct fertilizing effect (mineral fertilizer equivalence coefficient from 0.6 to 0.7).
Effluents can be applied before crop establishment (maize, rapeseed...) or during crop growth (winter cereals, grasslands...), the objective being to coincide the application with periods of high nitrogen demand of the crop to limit nitrogen losses. Finally, it is preferable to incorporate/bury the effluent to limit nitrogen losses in ammoniacal form, by soil tillage for intercrop applications, or by injection for in-crop applications.
Implementation period
On established crop
Spatial scale of implementation
Plot
Application of the technique to...
All crops:
Easily generalizable
If a source of organic matter is locally available. The mineral fertilizer equivalence coefficient depends on the crop to which the effluent is applied.
All soil types:
Easily generalizable
This intervention should be carried out sufficiently early before sowing the crop, so as not to create "[[Understanding and avoiding a nitrogen deficiency| nitrogen deficiency]]" phenomena on the following crop. On some soils (which dry poorly after winter), this operation can be delicate before establishing a spring crop.
All climatic contexts:
Easily generalizable
Regulation
NEGATIVE
The application of organic effluents is regulated by the Nitrates Directive. Quantities may be limited in certain departments (implementation orders of this directive).
Nitrate Directive
2. Services provided by the technique
3. Effects on the sustainability of the cropping system
"Environmental" criteria
Effect on air quality:
Variable
acidification: VARIABLE
phytosanitary emissions: VARIABLE
GHG emissions: VARIABLE
particulate emissions: VARIABLE
Effect on water quality:
Variable
N.P.: VARIABLE
pesticides: VARIABLE
turbidity: VARIABLE
Effect on fossil resource consumption:
Decreasing
fossil energy consumption: DECREASE
Other:
No effect (neutral)
Pollutant transfer to water (N, P, phyto ...): variable
Improvement of soil structure limits runoff phenomena and thus direct transfer of pollutant products (P, phyto). The increase in OM content increases the retention of non-ionized molecules and thus (temporarily) reduces their transfer to air or water. The increase in OM increases microbial activity which participates in the degradation processes of chemical molecules (especially phytosanitary substances). This process is particularly interesting if it leads to total mineralization of the product. Otherwise, degradation can produce metabolites that themselves are sources of pollution. Finally, effluents also provide fertilizing elements (N, P, K) that must be managed carefully to avoid excesses and not cause transfer risks (e.g., nitrogen from effluents).
Pollutant transfer to air (N, P, phyto ...): variable
The increase in OM increases the retention of non-ionized molecules and thus (temporarily) reduces their transfer to air. OM inputs can generate nitrogen emissions by volatilization if not incorporated quickly.
Fossil energy consumption: Decrease
Even if these inputs require mechanical interventions (fuel consumption), they allow a reduction in the use of mineral nitrogen fertilizers, and thus the fossil energy consumption related to their production.
GHG emissions: variable
Contribution to carbon storage, but pH increase favors mineralization (CO2) and nitrogen volatilization (NH3 form).
"Agronomic" criteria
Productivity:
Increasing
In the long term, soil fertility improvement allows a significant yield increase: a trial conducted from 1984 to 2006 in Brittany shows a yield gap of about 1tDM/ha between a silage maize monoculture receiving mineral fertilization and a silage maize monoculture receiving 20t/ha of manure supplemented by mineral fertilization.
Soil fertility:
Increasing
Increase in the soil's mineral element storage capacities through improvement of the CEC. The application of organic effluents can also have a variable impact on pH: increase in pH for manure/droppings inputs (use of lime/carbonate in livestock buildings) or acidification for slurries.
Water stress:
Decreasing
Depends on soil type and initial water availability (OM allows better water retention in the soil: increase of 1% OM content = 15 to 20%, on average, increase in available water reserve; this increase seems significant only for shallow soils or crops with low rooting depth).
Functional biodiversity:
Increasing
Increase in soil micro/macro fauna (soil life)
Other agronomic criteria:
Variable
Weed risk : Increase
Organic effluent inputs may include seeds of weeds.
"Economic" criteria
Operational costs:
Variable
Expected return of fertilizing elements (N,P,K) allowing reduction of mineral fertilizer purchases. Possible purchase of organic product if not available on the farm (or as part of an exchange with a neighbor).
Mechanization costs:
Variable
If the farmer does not own a spreader adapted to this type of organic products (manure or compost spreader), this practice may result in investment in such equipment or a service for spreading the organic product.
Margin:
Variable
If organic amendments are purchased, costs increase. In the long term, an increase in soil supplies (N, P, K) can be expected, which may result in a reduction of mineral fertilizer doses.
Other economic criteria:
Variable
Fuel consumption:
variable
One pass for spreading the organic product (it can be considered that its incorporation is coupled with that of the previous crop residues). In the medium/long term, a decrease in fuel consumption can be expected if soil characteristic improvements lead to fewer soil tillage operations.
"Social" criteria
Working time:
Increasing
Spreading organic effluents is more time-consuming than spreading mineral fertilizers.
Effect on farmer health:
Variable
Relations with neighbors:
Decreasing
Spreading certain organic effluents can cause nuisances for neighbors (people near the fields) due to odors, ...
Observation time:
No effect (neutral)
4. Organisms favored or disfavored
Favored bioagressors
Disfavored bioagressors
Favored auxiliaries
Disfavored auxiliaries
Favored climatic and physiological accidents
Disfavored climatic and physiological accidents
5. For further information
- Municipal wastewater sludge
- Fertilizing with farm fertilizers
- -Bodet J.M. (Arvalis), Haccala S. (ITAVI), Aubert C. (ITPT), Texier C. (Institut de l'élevage) Book, 2001
- Manures and slurries: compositions and valorization on crops in Lorraine
- -Hance E. (Chamber of Agriculture of Lorraine) Technical brochure, 2003
- Guide to common analyses in pedology
- -Baize D. (INRA) Editions Quae, Book, 1998
- Guide to organic matters
- -Leclerc B. (ITAB) ITAB, Book, 2001
- Impact of carbon returns on silage maize yield and soil evolution
- -Cabaret M.M., Arzul J.P. (CRA Brittany), Morvan T. (INRA), Menasseri S. (Agrocampus Ouest). Website, 2007
- Liming, basics for rational use
- -Comifer Editions Comifer, Book
- Organic matters and soil sensitivity to crusting and compaction
- -Guerf J. Proceedings of the 4th Soil Analysis Days and 5th Forum on Rational Fertilization, Conference proceedings, 1993
- Making a good fertilization plan and a fertilization record
- -CRA Brittany Technical brochure link to the brochure
6. Keywords
Bioagressor control method:
Mode of action:
Type of strategy regarding pesticide use:
Annexes
Est complémentaire des leviers
- Growing species with interesting carbon storage capacity
- Growing legumes / fabaceae
- Applying compost inputs
- Returning and incorporating residues of the previous crop
- Returning and leaving residues of the previous crop on the surface
Contribue à
S'applique aux cultures suivantes
