Post on 07-May-2015
Alley Coppice : an innovative agroforestry system that combines
timber and energy wood production
Dupraz C., Tosi L., Paris P., Facciotto G., André J.,
Graves A., Lunny R., Morhart C., Nahm M.
Christian DUPRAZ, Jérémy ANDRE : Institut National de la Recherche Agronomique FranceLuca TOSI, Piero PARIS : Consiglio Nazionale delle Ricerche; ItalyGianni FACCIOTTO : CRA- PLF ItalyAnil R. GRAVES : Cranfield University United KingdomRory LUNNY : Teagasc –, IrelandChristopher MORHART : Albert-Ludwigs-University Freiburg, GermanyMichael NAHM : Forest Research Institute Baden-Württemberg, Germany
Two options available :
Competition : Short Rotation Coppice, Afforestation, Annual crops for energy (cereals, oilcrops..)
Complementarity :
Biomass from food crop residuesAgrivoltaismAF systems that produce energy from trees and food from crops (or the reverse)
Food versus Energy :
the « competition for land » issue in Europe
Agrivoltaïsm
Biomass for energy from trees in AF systems ?
Two ways :
● Energy from coppiced trees : SRC (Short Rotation Coppice)
● As the intercrop● On the tree line
● Energy from standard pollarded trees : dual purpose trees (timber-energy)
To mix or not to mix, that is always the question
Indicators of the productivity of mixtures
• Land Equivalent Ratio LER (Mead and Willey, 1980)
• LER = Sum (Relative Yields) = RYtree + RYcrop
Indicators of the productivity of mixtures
• Range of LER values :– 0.9 to 1.1 for mixtures of annual species– 1.0 to 1.2 for legumes/non legumes annual species–– ? in silvoarable agroforestry– ? in agrivoltaism–– Unknown for SRC-AF systems– Unknown for Pollarded trees – AF systems
»
1.36Measured LER
Poplars-winter cereals, 14 years rotation
Predicted modelled LER
Tree density Pruning height
Tree row orientation
1.2 to 1.6
Agrivoltaïc LERs
measured :
1.5 to 1.7
Indicators of the productivity of mixtures
• Range of LER values :0.9 to 1.1 for mixtures of annual species1.0 to 1.2 for legumes/non legumes species
1.2 to 1.6 in silvoarable agroforestry1.5 to 1.7 in agrivoltaism
Unknown for SRC-AF systemsUnknown for Pollarded trees – AF systems
»
Energy from AF systems :
1. The SRC intercrop option
Energy from AF systems :
1. The SRC intercrop option
The concern :
LERs for SRC-AF may be much lower...
than LERs for annual crops-AF
Simultaneous planting of timber trees
and SRC
France
Germany
Italy
Some results from our oldest experimentResults presented were obtained in a 7-year old experimental field, located in Northern Italy.
This has Pyrus and Sorbus as timber trees, and poplar SRC grown in a two-year rotation cycle.
Gianni Facciotto and colleagues
CNR, Casale-monferrato, ItalyCNR, IBAF, Porano, ItalyUniversita di Torino, Italy
Site of experimental trial: Casale Monferrato – AL
Lat: 45°08' N Long: 8°30’ E
Alt: 106 m a.s.l.
1
Timber trees
Pyrus and Sorbus clonespropagated in vitroculture (Univ. Milano)
Short Rotation Coppice
Poplar clones:Populus deltoides Lux
P. deltoides Oglio P. ×canadensis Triplo
Pure PearPure Sorbus
Near PearNear Sorbus
Between PearBetween Sorbus
0,0
10,0
20,0
30,0
40,0
50,0
60,0
Db
Hm
m Timber tree growth
Pure = Trees without SRC - Near = Trees with SRC only on one side Between = Trees with SRC on both sides
Short Rotation Coppice yields
Triplo Oglio Lux0
2
4
6
8
10
12
2008
2010
2012
Clones
Bio
mas
s (t
ha-
1)
Oven dry tons per hectare
Sensitivity to SRC competition varies between tree species
Reduction of timber trees growth by SRC competition not correlated to SRC productivity
Conclusions :
Improved and very productive SRC-AF possible
LERs of SRC-AF not yet available (modelling in progress)
Energy from AF systems :
2. The Pollarded trees option
31/03/2013
10/10/2013
Modelling pollarded trees AF systems with the Hi-sAFe model
Timber growth stopped
(but contradictory with field observations during the first year after pollarding)
Branches growth stimulated
Crop yield sustained
Time of first pollarding
RYs of AF systems with standard or pollarded trees
RYs Trunk Branches Crop
StandardPollarded
Pure forestryPure crops
0.620.18
10
1.11.84
10
0.680.81
01
Hi-sAFe model, André, Molto, Dupraz, in prep
Standard Pollarded
Crop & branches 1.78 2.65
Crop & timber 1.31 0.99
LERs of AF systems with standard or pollarded trees
Agroforestry systems with pollarded walnut trees
First evaluation by modeling and field monitoringJ. André, Q. Molto, G. Talbot, L. Dufour, J-F Bourdoncle, A. Sellier, C. Dupraz
Poster available.... please pay us a visit !
Take home Conclusions :
SRC-AF may have intermediate LERs (profitability to be assessed)
Pollarded trees-AF may have very high LERs
Farmers were wise....
Thank you for your attention