Willow Short Rotation Coppice Trial in a Former Mining Area in Northern Spain: Effects of Clone, Fertilization and Planting Density on Yield after Five Years

Abstract

Abstract:A willow short rotation coppice (SRC) trial was conducted on former mining land in northern Spain over a period of five years, with the purpose of evaluating the effects on yield of two planting densities (9876 and 14,815 cuttings ha −1 ), three treatments (control, two levels of nitrogen, phosphorus and potassium compound fertilizer (NPK) plus weed control) and three willow clones (Björn, Inger, Olof). The area was subsoiled, ploughed, harrowed and fertilized with NPK before trial establishment. A randomized block design was applied, with three replications of each treatment in a total of 54 plots, each of an area of 400 m 2 . The effects of the interactions between the various factors on yield and other growth parameters were also studied. The clone factor significantly affected the number of shoots per stool (greatest for the Inger clone) and the Olof clone, which showed the lowest mortality rate and produced the largest trees and largest quantity of biomass. The combined application of fertilizer and herbicide also significantly increased the values of all response variables considered, except the mortality rate. The planting density did not significantly affect the response variables. Clone × treatment interactions were significant for the shoots per stool, height, diameter and biomass variables, and the Olof clone displayed the highest height and diameter growth and yield. The results obtained in the first rotation indicate that the Olof clone adapted well to the trial conditions and therefore would be appropriate for producing biomass in abandoned mine land in Asturias. These findings will help in the development of strategies for the establishment and management of SRC on marginal land.

Effects of Site, Genotype and Subsequent Harvest Rotation on Willow Productivity

“…A similar number of shoots per stool (2.7) for seven willow genotypes in a three-year harvest rotation were found in another study [37]. An even smaller mean number of shoots per stool (1.4-2.3) were found in the willow harvested in the first five-year harvest rotation in Spain [39].…”

Productivity and Biometric Characteristics of 11 Varieties of Willow Cultivated on Marginal Soil

“…The presented results concerning biometric features of willow varieties are similar to those obtained by other researchers. They also confirm the thesis that parameters of those features are significantly different, depending on the variety [18,[28][29][30][31]. It should be emphasized that both the varieties included in the current research and those presented by other authors are characterized by more favorable values and relationships of biometric features compared to wild forms of willow growing in natural stands [32,33].…”

Poplar Short Rotation Coppice Plantations under Mediterranean Conditions: The Case of Spain

“…Other associated ecosystem benefits include an increased biodiversity (phytodiversity and zoological diversity) [32,331], erosion control and soil conservation [332], improvements in the water quality [333], and the role of the crop in phytoremediation [334][335][336]. In the case of Spain, the potential of the genus in the phytoremediation of soils has been evaluated through examples of the restoration of coal mining areas in northern Spain [131,337,338], or water phytodepuration [42,187,216,339]. Research has also focused on nutrient fluxes, evaluating the role of annual leaf litter in soil fertility throughout the rotation [340]; the quantification of accumulated carbon in both above-and below-ground fractions (reaching values of around 6.5 Mg C ha −1 year −1 in the above-ground woody biomass, around 1.0 Mg C ha −1 year −1 in the below-ground biomass [262], and around 2.5 Mg C ha −1 year −1 in the case of the litter [341]), as well as the economic implications of CO 2 capture [342].…”