Julien Toillon Context and objectives Material and methods Emilie Kartner Intensive tree plantations for bioenergy (short rotation coppice, SRC) are A network of collaborations and plantations has been Bénédicte Rollin often synonymous with soil depletion. To maintain productivity in the long established in in order to answer practical term while reducing inputs (water, fertilizer), an optimized matching between: questions about SRC itineraries through the study of Erwin Dallé Nouveaux concepts de cultures ligneuses durables eight factors on productivity and water and nitrogen use pour la production de biomasse à des fins énergétiques Laurent Roux 1. plant material characteristics (genera, species, genotypes, mixed or not) particularly in terms of efficiencies of resource use (especially water and efficiencies (WUE* and NUE, respectively), e.g. planting Laureline Besdeberc nitrogen), density, fertilization, N fixing species introduction, etc. INTENS&FIX This network is part of three research projects: Romain Leray 2. cultural practices (spraying, densities, pruning, etc.), Nicolas Marron - CREFF: Cost reduction and efficiency improvement of SRC (ERA- And, 3. soil and climate conditions is to find. Net Bioenergy project funded by ADEME and FNR, 2009-2012), The approach taken to meet this objective is to study the effects of the three - SYLVABIOM: New concepts of sustainable energy crops with woody species (ANR Bioenergy project, 2009-2012), categories of above factors on productivity and its determinants through the UMR INRA – Nancy University, Forest study of carbon, nitrogen and water cycles in a network of plantations spread - Intens&Fix: Ecological intensification of plantation forest Ecology and Ecophysiology (EEF), ecosystems (ANR Systerra project, 2011-2014) 54280 Champenoux, France throughout northern France. u When should we harvest, v Is it relevant to fertilize SRC plantations? w What is the best spring vs. fall? Situation: Bioenergy crops are fertilized, but is it useful to fertilize SRC plantations? cultural antecedent? Situation: When harvest is only possible during Objectives: Effect of chemical fertilization on biomass production, WUE and NUE, Situation: To avoid concurrence with food the leafy period, leaf exportations are likely to alter and comparison with fertilized and unfertilized miscanthus plots. agriculture, SRC plantations will be preferably soil fertility. installed on marginal, less fertile sites. Protocol: Biomass, WUE and NUE estimations in a poplar plantation (4 Objective: Effect of harvest period during the year clones) in Estrées-Mons (80) where some of the blocks were fertilized. Objective: Effect of the cultural antecedent (rich vs.

on re-growth, WUE and NUE. 22 4.7 0.5 Wood carbon isotope discrimination (‰) Wood nitrogen content (‰) * poor) on biomass production and WUE and NUE. 21.8 0.45 4.6 0.4 21.6 Protocol: Biomass, resprouting, WUE and NUE 4.5 0.35 21.4 Protocol: Biomass, WUE and NUE estimations 0.3 21.2 4.4 estimations in a willow plantation in Kerguéhennec (56) 0.25 in four willow plantations in French (8) differing 21 4.3 0.2 20.8 in fall 2009 and 2010, and spring 2010 and 2011. 4.2 0.15 by their antecedent, grassland vs. maize cultivation 20.6 0.1 4.1 7 19.6 0.35 20.4 0.05 900 20.5 Clump dry mass (kg) Wood carbon isotope discrimination (‰) Wood nitrogen content (%) C B B A B C C A Tree height (cm) Carbon isotope discrimination (‰) 20.2 4 0 6 19.4 0.3 800 Unfertilized Fertilized Unfertilized Unfertilized Unfertilized Fertilized Unfertilized Fertilized Unfertilized Unfertilized Unfertilized Fertilized 20 700 5 19.2 0.25 Dorskamp I214 Koster Miscanthus Dorskamp I214 Koster Miscanthus 600 19.5 4 0.2 19 500 2.5 Clump dry mass (kg) 19 3 18.8 0.15 Answer: No. There is no 400 2 300 18.5 2 18.6 0.1 significant yield and N 200 1 18.4 0.05 ACBB 18 AABB 1.5 100 A A B C A B A A A B BC C 0 18.2 0 content increases 0 17.5 Fall 2009 Spring 2010 Fall 2010 Spring 2011 Fall 2009 Spring 2010 Fall 2010 Spring 2011 Fall 2009 Spring 2010 Fall 2010 Spring 2011 (grassland) (grassland) Ambly-Fleury (maize) (maize) Amagne (grassland) Asfeld (grassland) Ambly-Fleury (maize) Semuy (maize) in the poplar 1 Answer: Despite a constant decrease in N wood content harvest 0.5 Answer: Yield was not linked to the cultural antecedent. fertilized plots. A A B after harvest, there is no clear trend concerning yield and WUE. 0 However, willow trees showed a better efficiency to use water Unfertilized Fertilized Unfertilized Unfertilized Re-growth has to be monitored for a longer period. Dorskamp I214 Koster on the poorer sites (grassland antecedent).

x Do we have to coppice y Is it interesting to variegate

at the end of the first year? UUU plantations with N fixing species? Estrées-Mons Situation: First year coppicing can stimulate the re-growth Amagne Situation: Mixture of poplar, willow or eucalyptus with N during the next year, but it can also affect weak plants when Asfeld UUUUUU UUU UUU Ambly-Fleury Semuy Moyenvic fixing species (black locust, acacia, alder) can be a way to the first year growth has been poor. UUU La brosse UUU Pleyber-Christ improve or to maintain soil fertility in intensive plantations. Montceaux Champenoux Objective: Effect of a first year coppicing on biomass UUU UUU Lamballe UUU UUU UUU Saint-Gilles DarnieullesUUU Padoux UUU UUU La prénessaye UUU Saint-Ségal Le Chesnoy U Sélestat Objective: Effect of mixture production, re-growth and WUE and NUE. UUU UUU Gennes sur Seiche AttignyUU Kerlavic UUU UUU UUU Kerguéhennec Les Cormiers La ferme du Bouchet of poplar with black locust Blois Saint-Cyr-en-Val Nouzilly U UUU Guémené-PenfaoUUU UUU UU UUU on biomass production, Protocol: Biomass, resprouting, WUE and NUE estimations Saint-Sulpice UUU Brinon-sur-Sauldre -des-Landes WUE and NUE. in a willow plantation (3 clones) in Saint-Sulpice-des-Landes (44) UUU UUU where a part only has been coppiced at the end of the first year. Vatan Echigey Protocol: Biomass production, 450 Height time course (cm) Carbon isotope discrimination (‰) 400 29.0 Clone *** WUE and NUE estimations 350 Inger Coppicing ns 300 28.0 in a poplar / black locust Tora ns Association d’Initiatives Locales 250 CxC Uncoppiced Tordis pour l’Energie et l’Environnement 200 27.0 plantation in Saint-Cyr-en-Val (45) with pure and mixed 150 Institut National de la Recherche 100 26.0 Agronomique blocks (alternating rows) of the two species. Coppiced 50 Forêt, Cellulose, Bois-construction, 0 25.0 Ameublement Uncoppiced Coppiced Uncoppiced Coppiced Uncoppiced Coppiced Answer: The mixture of eucalyptus with acacia in Brazil or in 6-Jul 7-Apr 6-Jun 4-Oct 5-Aug 7-May 3-Nov 21-Jul 4-Sep 22-Apr 21-Jun 19-Oct 23-Mar 18-Nov 20-Aug 22-May TORA TORHILD INGER 19-Sep Chambres d’Agriculture Congo has not shown a clear effect on biomass production. In Answer: Yes, but the relevance of a 1st year coppicing depends on the 1st Europe, the experiments are in progress. year growth. Here, coppiced trees were almost as big as uncoppiced trees Institut pour le Développement INTENS&FIX Forestier after 2 years. Laboratoire des Interactions Microorganismes Minéraux Matière Organique dans les Sols

z { | Do we have to use monoclonal Is sludge spreading Is there an optimal planting density? 600 23 1500 plants/ha 1500 plants/ha 7500 plants/ha blocks or mixtures of clones? a relevant practice? 7500 plants/ha 22 500

Situation: Mixture of clones and varieties is a way to limit 21 Situation: Sludge spreading in SRC could be pathogen development, but what is the effect on biomass 400 20

a way to valorize these wastes, but do the trees production due to more intense competition? 300 need this additional fertilization? 19 Objective: Effect of a clonal mixing on biomass production, (cm) height Stem 18 Objective: Effect of different quantities of sludge on 200 WUE and NUE. Clone *** - System *** - CxS *** Bulkleaf carbondiscriminationisotope (‰) Clone *** - System *** - CxS *** biomass production, WUE and NUE. 0 0 Protocol: Biomass, resprouting, WUE and NUE estimations 110 132 154 176 198 220 242 264 Date (day of the year 2010) in a poplar plantation in Vatan (36) with pure and mixed Protocol: Biomass production, resprouting, WUE and NUE Situation: How does competition blocks of different clones. estimations in a willow plantation in Brinon-sur-Sauldre (18) among plants in dense plantations Clone *** - Mixing ns - CxM ** Clone *** - Mixing ns - CxM ns 180 20.0 with sludge inputs or not. Tree fresh weight (kg) Carbon isotope discrimination (‰) affect biomass production? 160 19.8

19.6 140 19.4 120 Objective: Effect of planting density 19.2 Answer: The experiment is still in 100 19.0 80 progress. Results are likely to be (SRC, 1500 vs. very SRC, 7500 trees 18.8 60 18.6 / ha) on productivity, WUE and NUE. 40 dependent on soil fertility: SRC on rich 18.4

20 Pure

18.2 Mixture Pure

Mixture soils does not need additional nutrient 0 18.0 Beaupré Bolaere Hunnegen Raspalje Cima Luisa Avanzo Triplo Beaupré Bolaere Hunnegen Raspalje Cima Luisa Avanzo Triplo inputs and elements will probably not be Protocol: Biomass, WUE and NUE Answer: Clonal mixture has no significant effect assimilated by plants and remain on the soil. estimations in a 2-year old poplar on biomass production, but it is recommended plantation in Echigey (21) with to prevent pathogen development. different planting densities.

Answer: After two years, trees were higher in the denser plantation.

Nouveaux concepts de cultures ligneuses durables However, they were more pour la production de biomasse à des fins énergétiques

Nouveaux concepts de cultures ligneuses durables pour la production de biomasse à des fins énergétiques water-use efficient in the less dense plantation.

Plantation network partners: Conclusion * In the different experiments, intrinsic water- use efficiency (WUEi, assimilated carbon per Most experiments are still running and conclusions are only preliminary. unit of transpired water) is estimated through However, it appears that it is difficult to generalize because results are its well-known surrogate (Farquhar and Richards 1984): carbon isotope discrimination highly dependent on initial soil fertility. Soil richness is indeed a key factor 13 (δδδ C, ‰), estimated from wood (panels 1, 2, 3 and SRC technical itineraries as well as plant material have to be adapted and 6) or leaves (panels 4 and 8). to soil quality in order to maximize the growth potential while avoiding Farquhar GD, Richards RA. 1984. Aust. J. Plant Physiol. rapid soil depletion and loss of fertility. 11:539-52.