Effects of Cutting Length, Orientation and Planting Depth on Early Willow Shoot Establishment Stina Edelfeldt & Anneli Lundkvist & Johannes Forkman & Theo Verwijst # Springer Science+Business Media New York 2014 Abstract To assess the effects of different planting systems on early performance (survival, shoot emergence time, num- ber of shoots, maximum shoot height and biomass shoot production) of willow, cuttings of varying lengths were planted horizontally at different depths and compared with vertically planted cuttings. Cutting lengths of (i) 25–200 cm and (ii) 7–21 cm were studied in a field experiment and in a box experiment, respectively. Shorter cuttings planted deeper had a lower survival rate and emerged a few days later compared to longer cuttings planted shallower. The perfor- mance was considerably higher at the apical part of the cut- tings, regardless of cutting length. Longer cuttings planted shallow had a higher performance. Vertically planted cuttings produced more biomass and shoots per length unit than hor- izontally planted cuttings. We conclude that planting systems based on the use of longer horizontally planted cuttings would probably lead to an uneven establishment and gaps in the stand caused by apical dominance. Also, to achieve the same performance, the need of planting material would be consid- erably higher compared to systems with vertically planted cuttings. To obtain a fast and more even early establishment of willows, we recommend the use of vertically planted cut- tings with a length of at least 20 cm. If cuttings are planted horizontally, they should not be planted deeper than 5 cm. Keywords Billets . Horizontal planting . Lay-flat . Salix . Short rotation coppice . Vertical planting Introduction Establishment of willow stands, particularly during the first few months, has a large impact on their future biomass pro- duction. In this context, a good establishment is characterized by large shoots, a high number of shoots and a low variability in shoot size per unit area. Large shoots have higher survival expectancy and a higher expected biomass production capac- ity [1]. Weeds may have strong negative effects on survival and early biomass production [2], and a high abundance of weeds is an important explanation for disappointment among the crop among farmers [3]. An early coverage of the ground by producing many and large shoots reduces the competition from weeds. Early variation in plant size, either caused by small-scale differences in the environment or by differences in cutting quality, enlarges over time and leads to size hierar- chies, mortality and gaps in the stand [4, 5], which are pre- served during consecutive harvests [6]. Commercial willow planting is commonly performed by specialized planting machines, producing about 20 cm long cuttings, using long 1-year old shoots (rods) that are pushed vertically in the soil and cut just above the soil surface [7]. Another alternative is using billets, i.e. cuttings chopped into short lengths and planted by dropping them into the bottom of a shallow trench [8, 9]. Billets could potentially be planted with a sugar cane planter [9]. A third option is using a lay-flat system in which longer cuttings or rods are placed horizon- tally into prepared furrows of different depths [9, 10]. This could reduce the risk of dehydration, especially if cuttings longer than the normal commercial standard are used. Fur- thermore, the rods in the lay-flat system are not subjected to the mechanized cutting process, which in traditional commer- cial planting may cause damage to the cuttings, decreasing their performance [11]. On the other hand, a possible S. Edelfeldt (*) : A. Lundkvist : J. Forkman : T. Verwijst Department of Crop Production Ecology, Swedish University of Agricultural Sciences, P.O. Box 7043, SE-750 07 Uppsala, Sweden e-mail: Stina.Edelfeldt@slu.se Bioenerg. Res. DOI 10.1007/s12155-014-9560-3