Tercer Congreso Internacional de Salicáceas en Argentina

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1 Evaluation of poplar and willow performances for biomass production in Northern Italy Facciotto G.; Bergante S. CRA- PLF Research unit for Intensive wood production, St. Frassineto Po 35, I Casale Monferrato (AL) Italy Tel: ; Fax: Abstract The Research Unit for Intensive Wood Production of Italian Agricultural Research Council (CRA-PLF) has contributed in the past to select poplars and willows for industrial uses particularly for plywood and paper production. The best results were obtained with the poplar clones. The Populus canadensis clones, like I-214, San Martino and others, selected for disease resistance, growth, stem shape and wood quality, became the most important clones cultivated in Italy for these purposes. Willow clones were not utilized by the farmers; but breeding, selection and conservation of these clones were carried out in the CRA-PLF. In the last fifteen years the researches on woody biomasses for energy purposes give more emphasis to willows, selected and widely utilized in Northern Europe for energy production. Few species are evaluated and improved for fast growth in Italy: Salix alba L., Salix babylonica L. and Salix matsudana Koidz. Currently in Italy poplar and willows for biomass production are cultivated in Short Rotation Coppice with high density of plantation ( trees ha -1 ) and harvested every two-three or five-six years. In order to find what are the clones more suitable for biomass production in Northern Italy, five experimental trials, three in Casale Monferrato (AL) one in Lombriasco (TO) and one in Gazzo (MN), were established comparing poplar and willow clones. Other objective of these trials is to collect information on the characteristics of the biomass and on the cultivation costs For each species from one to four clones have been used. A complete randomized block or a split-plot experimental design is utilized, with 3-4 replications for trial. Production results are very variables but sometimes willow are able to produce more biomass than poplars. Willow biomass production range from a minimum of 2,95 t ha -1 y -1 in sandy soil to 16,8 t ha -1 y -1 in suitable environmental conditions. In the same trials poplar range from 2 to 15,5 t ha -1 y -1. Rooting and survival results are very good for every clones with average of 90 %. The hybrids of S. matsudana named S78-003, Drago, Levante and S show the best results. They are also resistant to repeated coppices, producing a high quantity of sprouts and biomass also in second and third rotation and show less sensibility to diseases and insects than poplar clones currently utilized in Italy. Two of these Willow clones Drago and Levante in 2008 obtained the European Community Plant Variety Right, a Patent for commercialization in EU. Keywords: Poplar, Willow, Biomass, SRC

2 Introduction The Research Unit for Intensive Wood Production of Italian Agricultural Research Council (CRA-PLF) has contributed in the past to select new poplars and willows clones for industrial uses, particularly for plywood and paper production. Clones were selected for disease resistance, growth, stem shape and wood quality. The best results were obtained with the poplar species (Populus nigra, P. deltoides and their hybrids P. canadensis). The P. canadensis clones, like I-214, San Martino and others, became the most important clones cultivated in Italy for these purposes. Willow clones were not utilized by the farmers for quality wood productions, but breeding, selection and conservation of these clones were carried out in the CRA-PLF. The PLF maintain 590 genotypes from 30 species, a lot of which of European and Asian origin as Salix jessoensis Seemen and S. matsudana Koidz. The greater number of genotypes come from Salix alba: 423 clones of Salix alba are in propagation, 207 of these were obtained through controlled crossing (Vietto L. & Cagelli L., 2006). In the last fifteen years the researches on woody biomasses for energy purposes give more emphasis to willows, selected and widely utilized in Northern Europe (Sweden) for energy production in very high density plantations ( trees ha -1 ) (Ledin S. & Willebrand E., 1995) Among the great variety of available genotypes, few willow species are evaluated and improved for biomass production in Italy: Salix alba L., Salix babylonica L. and Salix matsudana Koidz.(Facciotto G. et al., 2006; Facciotto G. et al., 2008) Currently in Italy poplar and willows for biomass production are cultivated with two Short Rotation Coppice models: with high plantation density (1100 trees ha -1 ) and harvesting every five years, for biomass production and wood for industry (paper, pallets, particle boards), or with very high plantation density ( trees ha -1 ) and harvesting every two years for biomass production and/or particle boards (Bergante S. & Facciotto G., 2006). Materials and methods A total of five experimental plantations, with poplar and willow clones, located in Northern Italy were described in this paper. Turin Milan Rome Figure 1 Location of experimental trials in Northern Italy. 1, 2, 3: Casale Monferrato (AL), Mezzi farm; 4: Lombriasco (TO), Salesiani s farm; 5: Gazzo Bigarello (MN), ERSAF s farm

3 Three experimental trials have been done in Casale Monferrato (AL), in Mezzi farm of CRA- PLF (1, 2, 3), one experimental trial in Lombriasco (4), near Torino, in the Salesiani Institute farm, and one in Gazzo Bigarello (5), near Mantova, in the E.R.S.A.F. (Lombardy Regional Agency for Services to Agriculture and Forestry) farm (Figure 1). Casale Monferrato (AL) trials In the Mezzi farm were planted three experimental trials of poplar and willow clones, with very high plantation density model, harvested every two years for biomass production. Soil texture is sandy. The trial 1 cover 5400 m 2 and was planted in 2002 utilizing Rotor machine and 20 cm long cuttings. Plantation density was 7500 trees ha -1 corresponding to a spacing of 1,90 m x 0,70 m. In this trial were compared a miscellaneous of two poplar clones I-214 and Neva (P. canadensis), and two willow clones Levante and S (S. matsudana hybrids). Soil preparation consist on ploughing (40 cm dept), harrowing and manure (50 t per hectare). Herbicides, Metholaclor and Pendimethalin, were utilized for pre-emergency weeds control; two disc harrowing were carried out during the first year after establishment and after each harvest. Two chemical spraying were applied to control insect: one during growing season to control Crysomela populi L. and one at the sprouting of the second year to control Cryptorrhynchus lapathi L. Five sprinkler irrigations, using rotors, were applied during summer period (35 mm for each irrigation). Plantation was harvested at the end of second and fourth year. After the first two year of growing the plantation was coppiced utilizing circular saw applied to the tractor and the trees were collected with a telescopic handler machine; subsequently the harvest was done with corn foragers equipped with a modified header (Baratto et alii, 2008). The trial 2 was planted in 2004 and cover 1600 m 2 ; as plantation material were utilized 20 cm long cuttings of the poplar clone Orion (P. canadensis) and of two willows clones Levante and S (S. matsudana hybrids). Plantation density was 8170 trees ha -1 corresponding to a spacing of 2,40 m x 0,51 m. Cultural management has been the same of the trial 1. Plantation was harvested at the end of second and fourth year utilizing respectively Class and Krone foragers with a modified header for biomass harvesting. The trial 3 was planted in 2004 and cover 2160 m 2. Plantation density was 8333 trees ha -1 corresponding to a spacing of 2,40 m x 0,50 m. Plantation was carried out with Rotor machine utilizing poplar clone I-214 and willow clone Levante cuttings, 20 cm long. Cultural management has been the same of the trial 1. Plantation was harvested at the end of second and fourth year utilizing respectively Class and Krone foragers. Lombriasco (TO) trial Plantation was made in spring Trial cover 5200 m 2. The experimental design is a randomized complete block with three replication of ten clones (six poplars and four willows): Orion, I-214 and Ballottino (P. canadensis), Baldo, and (P. deltoides), Drago, Levante, S and S (S. matsudana hybrids). Plantation density is 5747 trees ha -1 corresponding to a spacing of 2,90 m x 0,60 m. as plantation material were utilized 20 cm long cuttings, manually planted. Soil texture is sandy-silt with an increasing percentage of gravel toward the last part of the trial. Preparation consist of ploughing (40 cm dept), harrowing and P, K basic fertilization. Metholaclor and Pendimethalin were utilized for pre-emergency weeds control. Two mechanical weeds controls were carried out during the first year after establishment and after each coppice. No irrigation or pest treatments were applied. Trees were harvested at the end of third and fifth year utilizing John Deere forager with header modified for biomass harvesting. Gazzo Bigarello (MN) trial The Gazzo Bigarello trial has different plantation model: plantation density was of 1100 trees ha -1 corresponding to a spacing of 3 m x 3 m. It was planted in spring 2006, utilizing poplar and willow one year old poles, without root. The plantation will be harvested at the end of fifth year. Trial contains fifteen clones (10 of poplar and 5 of willow) compared in randomized complete blocks with three replications: Orion, Imola, , , , , (P. canadensis), Baldo, , (P. deltoides), Drago,

4 Levante, S (S. matsudana hybrids), (S. babylonica x S. alba), SI (S. alba). In this farm texture soil is clay-loam, with pour drainage and oxygenation, difficult conditions for salicaceae. Soil preparation consist on ploughing (40 cm dept), harrowing and N, P, K basic fertilization. Two mechanical weeds control were carried out during the first three years. One chemical treatment against insects (Cryptorrhynchus lapathi L) was spayed each year at the sprouting. Two irrigation (flooding) during every growing season. Data collection At the end of the growing season in all the trials have been done the following measures: 1) rooting (%) at the end of the first year and survival (%) at the end of each year; 2) diameter (mm) at breast height (dbh) of stem on a sample of 30 trees/stumps; 3) number of sprouts per tree/stump On a sample of tree per each clone/density were measured dbh, wet and dry weight (after drying process 103 C in oven up to attainment of co nstant weight). Four different regression equations (power) were been calculated to evaluate trees weight (poplars and willows in very high plantation density, poplar and willow in high plantation density): equations correlate diameter with dry weight (in grams) of tree/shoot. Growth and production results of poplar and willow are reported in oven dry tons ha -1 (Odt ha -1, 0% moisture), at the end of each rotation, and in oven dry ton ha -1 per year (Odt ha -1 y -1, average) at the end of cycle of two-three rotations. Data were analyzed with ANOVA (p= 0,05) utilizing SPSS Statistic software. A Post hoc test was applied in case of significative results Results and Discussion Casale Monferrato, trial 1 Rooting was the same for poplar and willow genotypes (92 %). At the end of fourth year survival was lower, specially for poplar miscellaneous (63 %). Poplar clones utilized for this trial were selected for traditional cultivation and show a lower resistance to repeated harvesting. Willows show a better resistance to coppicing and a higher biomass production both in first and second rotation (table 1). Table 1- Casale Monferrato, trial 1. Average and ANOVA analysis of rooting (Root.) at the end of first year (S1R1), survival (Surv.) at the end of fourth year (S2R4) and total oven dry biomass (B) at the end of first (S2R2) and second (S2R4) biennial rotation. Root. (%) Surv. (%) B (Odt ha -1 ) B (Odt ha -1 ) Specie S1R1 S2R4 S2R2 S2R4 Poplar ,80 6,77 Willow ,55 23,69 Average 92,3 75,7 20,67 15,23 F values n.s. 26,1** n.s. 29,4** Casale Monferrato, trial 2 Rooting was, both for poplar and willow not so high, probably due to hot temperature in the first year and summer drought. Willow S gives the best result of rooting and survival (94% and 91%). The average value of dry biomass production of the trial at the end of first rotation was 12,69 Odt ha -1, without significant differences between clones. After harvesting, during second rotation, the differences between the clones become statistically significant (table 2): willow clones show the best productions, particularly S that produce 32,53 Odt ha -1 in two years (16,3 Odt ha -1 y -1 ).

5 Table 2- Casale Monferrato, trial 2. Average and ANOVA analysis of rooting (Root.) at the end of first year (S1R1), survival (Surv.) at the end of fourth year (S2R4) and total oven dry biomass (B) at the end of first (S2R2) and second (S2R4) biennial rotation Root. (%) Surv. (%) B (Odt ha -1 ) B (Odt ha -1 ) Clone S1R1 S2R4 S2R2 S2R4 Orion ,09 18,4 Levante ,89 28,09 S ,1 32,53 Average ,69 26,34 F values n.s n.s. n.s. 4,8 * Casale Monferrato, trial 3 Also in this trial both species/clones show rooting problems, maybe for hot temperatures in the first year and summer drought. Accordingly, the production in the first rotation is not so high, the willow clone Levante give the best result with 19,07 Odt ha -1. During second rotation the poplar clone maintain the same behavior and production, while the willow clone reach a very high yield (probably due to a production of great number of sprouts) of 38,34 Odt ha -1 in two years (19,2 Odt ha -1 y -1 ) (table 3). Table 3 - Casale Monferrato, trial 3. Average and ANOVA analysis of rooting (Root.) at the end of first year (S1R1), survival (Surv.) at the end of fourth year (S2R4) and total oven dry biomass (B) at the end of first (S2R2) and second (S2R4) biennial rotation Root. (%) Surv. (%) B (Odt ha -1 ) B (Odt ha -1 ) Clone S1R1 S2R4 S2R2 S2R4 I ,80 13,97 Levante ,07 38,34 Average 86,2 82,6 16,44 26,15 F values n.s n.s 29,8 * 68,4 * Lombriasco (TO) At Lombriasco rooting was good for all clones. The average was 94,4% and best rooting value was for Salix matsudana hybrid clone S (99%). Table 4 - Lombriasco. Average and ANOVA analysis of rooting (Root.) at the end of first year (S1R1), survival (Surv.) at the end of the first triennial rotation (S3R3) and at the end of second (S2R5) and third (S2R7) biennial rotation.

6 Root. (%) Surv. (%) Surv. (%) Surv. (%) Clone S1R1 S3R3 S2R5 S2R D 91 BC 89 AB 87 AB D 91 BC 89 AB 82 BC Ballottino 91 D 90 C 89 AB 85 AB Orion 96 ABCD 95 ABC 93 AB 90 AB Baldo 93 BCD 93 BC 92 AB 92 AB I ABCD 97 ABC 95 AB 90 AB S AB 97 AB 70 C 49 D S A 99 A 97 A 97 AB Drago 97 ABC 97 ABC 81 BC 70 C Levante 92 CD 92 BC 92 AB 90 AB Average 94,4 94,2 88,8 83,2 F values 7,47** 4,40** 7,24** 16,9** The same clone maintain a high survival value until to end of first rotation (S3R3), and generally, for all clones, the survival has been unchanged in comparison to the rooting values (94,2%). After the first harvest, some stumps die; two willow clones, Drago and S show a high mortality, but generally the trial maintain a good survival values with an average around 89%. After second harvest the two willow clones show again high mortality, while generally the trial maintain a good values (83,2 %), (table 4). During first rotation differences in growth values (diameter, number of shoots per root) and biomass production between clones were significant: P. deltoides clones and at the end of third year have the greater diameter (over 50 mm) but generally the trees of this species produce only one shoot per root during first rotation, so better biomass production was reached by willow clones, particularly Drago and Levante that have a high growth in diameter and produce many shoots. During second rotation the two P. deltoides clones maintain a good diameter growth and produce many new shoots, so even if the differences between biomass values are not significant, the clone produce a higher quantity of dry matter (57,7 Odt ha -1 in two years). At the end of third rotation the best clone was the willow Levante that produce 59,60 Odt ha -1 in two years followed by S78-003, it has compensated the elevated mortality with a greater number of shoots per stump. Between poplar clones the best was Baldo that produce 53,58 Odt ha -1 in the last biennial rotation (table 5). Table 5 - Lombriasco. Average and ANOVA analysis of diameter (Diam), number of shoots per stump (sh/r) and total dry biomass (Odt ha -1 ) at the end of first triennial rotation (S3R3), second (S2R5) and third (S2R7) biennial rotation. S3R3 S2R5 S2R7 Clone Diam (mm) sh/s (n.) B (Odt ha -1 ) Diam (mm) sh/s (n.) B (Odt ha -1 ) Diam (mm) sh/s (n.) B (Odt ha -1 ) ,5 A 1,0 B 18,59 ABC 36,1 AB 5,0 C 42,56 39,3 A 4,2 D 44,29 abc ,0 A 1,0 B 19,86 ABC 36,6 A 6,3 ABC 57,70 33,3 ABC 5,8 CD 40,32 bc Ballottino 43,8 ABC 1,1 B 14,60 C 29,3 CDE 7,3 ABC 39,30 27,1 BC 8,2 ABCD 39,98 bc Orion 41,7 ABC 1,2 AB 15,79 BC 31,5 ABCD 5,6 ABC 37,82 28,2 BC 6,6 BCD 38,80 abc Baldo 48,3 AB 1,1 B 17,09 ABC 33,1 ABC 5,4 BC 37,46 35,7 AB 6,1 CD 53,58 abc I ,3 AB 1,1 B 17,77 ABC 27,4 CDE 7,3 ABC 36,58 24,5 C 7,9 ABCD 37,12 c S ,2 C 1,7 A 16,96 ABC 27,0 DE 8,9 A 42,45 23,8 C 10,7 A 54,90 ab S ,7 BC 1,5 AB 19,11 ABC 25,7 E 8,5 AB 55,89 21,6 C 10,0 ABC 52,45 abc Drago 43,6 ABC 1,4 AB 22,63 A 30,6 BCDE 6,7 ABC 48,83 24,9 C 10,6 AB 48,60 abc Levante 46,4 AB 1,2 B 21,32 ABC 26,8 DE 7,7 ABC 51,08 26,8 BC 8,1 ABCD 59,60 a Average 44,45 1,24 18,37 30,41 6,89 44,97 28,51 7,82 46,963 F values 5,30** 4,34** 3,60 ** 10,12** 3,63** n.s. 6,80** 5,82** 2,45* Table 6 - Lombriasco. Average and ANOVA of total dry biomass obtained in a cycle of 7 years (three rotation).

7 Tot. B Tot. B/7 Clone Odt ha -1-1 Odt ha -1 y ,30 11,90 ABC ,72 13,96 ABC Ballottino 73,89 10,56 BC Orion 73,01 10,43 C Baldo 81,34 11,62 ABC I ,91 10,42 C S ,86 12,41 ABC S ,22 14,46 AB Drago 95,76 13,68 ABC Levante 102,20 14,60 A Average 86,820 12,403 F values 3,81** To compare clones the productivity of a cycle of seven year, the yields of the first, second and third rotation are been added for each clone to obtain an average of annual biomass production (Table 6). The differences among the clones are statistically significant; the S. matsudana hybrid clone Levante shows best production with a mean of 14,6 Odt ha -1 y -1. Between poplar -1 clones the best is that produce 13,96 Odt ha -1 y Generally in Lombriasco the productions resulted low during first triennial rotation, and specially during first and second year. This was due probably to summer drought. After the first rotation biomass productions (Odt ha -1 y -1 ) increased of 3,7 times and became very good both for willows and poplars. Gazzo Bigarello (MN) In this trial rooting was lower than in the other trials. This was probably due to soil texture, too clay. Differences in biomass production was not significant. Plantation reach in four years of growth 39,2 Odt ha -1, corresponding to a annual production of 9,80 Odt ha -1 y -1. The best -1 production was reached by P. canadensis clone Imola that produce 10,8 Odt ha -1 y Table 7- Gazzo Bigarello. Total average and ANOVA of rooting (Root.) in the first year (S1R1), survival (Surv.) in the fourth year (S4R4), and dry biomass, total and average annual. S1 R1 S4R4 S4R4 Root. (%) Surv. (%) B (Odt ha -1 ) B (Odt ha -1 y -1 ) ,1 9, ,7 1 0,9 Baldo ,0 1 1, ,4 8,3 Imola ,1 1 0, ,4 1 0, ,5 1 0, ,0 1 0, ,3 7, ,8 9, ,5 9,9 Drago ,2 9,1 Levante ,7 8,9 SI ,1 8,8 S ,0 9,7 Average 87,3 86,7 39,2 9,80 F values n.s n.s n.s n.s

8 Conclusion The biomass production and rooting/survival of clones tested are very variable. Generally new willow clones, hybrids of S. matsudana, give good results, accordingly with others ones described in literature (Facciotto G. et al., 2006; Facciotto G. et al., 2008; Cerrillo T. et al., 2008). Rooting and survival can reach 94%. in very high density plantations, stump mortality after harvest is counterbalanced by production of a great number of shoots per stump. In Casale Monferrato willow clones give in all the trials best production, specially during the second rotation. In Lombriasco the best production was reached by a P. deltoides clone but, in average, willow clones maintain a production 17% higher than poplar ones. In Gazzo Bigarello willow production is more less the same of poplar one, and this results is probably due to cultivation model of this plantation. Biomass production of willow is generally correlated with the presence of many shoots, but utilizing poles without roots at the establishment, at the end of fourth year the productions of willow clones are lower than poplar ones. Between poplars the P. deltoides clones show good productions but generally P. canadensis clones have better rooting and survival values during all the cycle length. High biomass productions can be obtained using the very high density model ; but in this case the higher costs for planting, for weed and pest control and for the site restoration must be considered. The high density model gives more flexibility and opportunities for diversification of the biomass production (pulp & paper, packaging and particle board); anyway some disadvantages must be taken into consideration also in this case: a greater surface area covered and a longer rotation period is necessary. References - Baratto G., Bergante S., Facciotto G., Annunziati M. (2008) - Studies of poplar and willow short rotation coppice establishment. IPC 23rd Sess. 'Poplars, Willows and People's Wellbeing'. Beijing, China, October pp. url: - Bergante S., Facciotto G. (2006) Impianti annuali, biennali, quinquennali. Produttività e costi in alcune realtà del Nord Italia. SHERWOOD - Foreste ed Alberi Oggi n Cerrillo T., Facciotto G., Bergante S. (2008) - Biomass production of different willow s combinations preliminary results. Proceedings of '16 European Conference & Exhibition, from Research to Industry and Markets. 2-7 June Valencia. Spain Facciotto G., Bergante S., Lioia C., Rosso L., Mughini G., Zenone T., Nervo G. (2006) - Produttività di cloni di pioppo e salice in piantagioni a turno breve. Forest@. 3: Facciotto G., Di Candilo M., Bergante S., Baratto G., Diozzi M. (2008) - Willow clones for biomass production in SRC plantations. Proceedings of '16 European Conference & Exhibition, from Research to Industry and Markets. 2-7 June Valencia. Spain Ledin S., Willebrand E. (1995) Handbook on how to grow short rotation forests. IEA Bioenergy. Swedish University of Agricultural Sciences. Department of Short Rotation forestry. - Vietto L., Cagelli L. (2006) Raccolta, conservazione e gestione del germoplasma delle Salicaceae. Manuale per la raccolta, studio, conservazione e gestione del germoplasma. APAT