EFFECTS OF SUPPRESSION OF HERBICIDES ON VINEYARD NITROGEN STATUS, AND SOIL MICROBIAL AND CHEMICAL INDICATORS
Background
• Cover cropping in vineyards can bring many ecosystem services but can induce competition for nitrogen and water with grapevine (Celette et al., 2009).
• Cover cropping is widespread in Northern Eastern of France but chemical weeding under vine rows is still widely used to limit competition (Wilmes, 2014).
• Grapevine nitrogen nutrition, depends on N availability in soil and microbial activity, which can be affected by cultural practices (Steenwerth and Belina, 2008).
• Since 2014, the project « soil management in viticulture » aims to study the impact of suppression of herbicides on nitrogen dynamics in grapevine and in soil.
Experimental design
Financial partners
ResultsNitrogen Balance Index (NBI) of grapevine
Conclusion and perspectives
Technical partners
DUROCHER E.1, LANGENFELD, A.2, LEY L3., KLEIN C.1, THIOLLET-SCHOLTUS M.4, NASSR, N.2
1 EPLEFPA les Sillons de Haute Alsace, France ; 2 RITTMO Agroenvironnement, France ; 3 INRA SEAV, France ; 4 INRA UR-0055 ASTER, France
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Experimental plot
March April May June July August Sept Oct Nov
Budbreak Veraison Leaf-fall
- Bacterial/fungal biomass (16S & 18S rDNA)- Metabolic diversity (Biolog ®) : Average Well Color Development
(AWCD) + Functional Richness (FR)- N mineralization + N mineral concentration (NO3
-, NH4+)
Tillage Cover cropping
Chemical weeding
Cover croppingTillage
Classical system (CS) : chemical weeding under row
Innovative system (IS) : cover cropping + tillage under row
YieldWood weight
Nitrogen Balance Index - NBI (Chlorophyll
fluorescence of leaves)
Yeast Available Nitrogen in
must
Grapevine :nitrogen indices
Soil : microbial and chemical indices0-30 cm under rows
Site : Domaine de l’EcoleRouffach city
Grape variety : RieslingSurface : 0.30 haSoil : silty clayey
calcareousPlantation : 1998
Measurements (2014-2016)
2014
2016
NBI values
Classical
Innovative
Classical
Grapevine Nitrogen yield and Nitrogen indices
Low nitrogen status
• 2014 and 2015 (not shown) : Nitrogen deficiency in IS
effect of competition with cover crop at veraison
• 2016 : N deficiency less pronounced in IS
Effect of fertilization applied in May 2016
• N deficiency in center of CS lack of fertilization
Microbial and chemical indices
Fig. 4 : Principal Component Analysis of microbial and chemical indices
3 stages
• 2014: drop of Nitrogen indices of IS (NBI, Wood weight and Yeast available nitrogen)
• 2015 : stronger drop of yield and Nitrogen indices IS grapevine is more impacted the 2nd year
Decision : addition of an organic fertilization in 2016• 2016 : recover of N indices following organic fertilization but
yield still low• Presence of weed induces a competition for nitrogen
References : Celette F., Findeling A., Gary C., 2009. Competition for nitrogen in an unfertilized intercropping system: The case of an association of grapevine and grass cover in a Mediterranean climate. European Journal of Agronomy, 30, 41-51.Steenwerth K., Belina K.M., 2008. Cover crops and cultivation: Impacts on soil N dynamics and microbiological function in a Mediterranean vineyard agroecosystem. Applied Soil Ecology, 40, 370-380. Wilmes C., 2014. Un désherbage mécanique sur vigne qui progresse au delà des producteurs bio. Agreste, SRISE Alsace.
Fig.2 : Yield and nitrogen status indices of grapevine of innovative system, as a percentage of classical system from 2014 to 2016.
Fig 1 : Nitrogen Balance Index maps of Classical and Innovative Systems in 2014 and 2016
Innovative
• Transition towards non chemical soil management can induce significant drop of grapevine’s yield and others indices due to an competition for nitrogen, but organic fertilization can counteract these effects.
• However, at the soil microbial level, year effect is more noticeable than soil cover cropping under row.• At this stage, further analyses in next years are needed in order to determine which parameter is more sensitive to soil management
practices.
Effects of innovative soil management : - At grapevine level : induces N drop visible in leaves,
grapes and wood, with a yield decrease.Fertilization enhances N availability but effect on yield is
delayed.- At soil level : no significant effects on microbial
parameters and on N availability in soil.
Acknowledgements : the Authors would like to thank the Domaine de l’Ecole, Agence de l’Eau Rhin-Meuse and ComitéInterprofessionnel des Vins d’Alsace
• N mineralization rate and other microbial indices taken separately don’t show significant differences
between the 2 systems• PCA : Year effect stronger than
system effect • NO3
- concentration correlates with 16S and 18S DNA
Microbial communities more sensitive to climatic conditions than
soil management practices
0
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40
60
80
100
120
0 50 100 150
N m
ine
ralis
atio
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(mg
/kg
of
soil)
Days of incubation at 28°C
ClassicalInnovative
0 50 100 150Days of incubation at 28°C
0 50 100 150Days of incubation at 28°C
Fig. 3 : Nitrogen mineralization rates in soil at budburst
201620152014
High nitrogen status
0%
50%
100%
Yield (t.ha-1)
Yeast Availablenitrogen (mg.l-1)
Wood weight(kg.vine-1)
Nitrogen BalanceIndex (NBI_R)
Classical system
Innovative system 2014
Innovative system 2015
Innovative system 2016
