Search Results (4)

The major disadvantage of setting up a willow coppice is the low survival rate, which reduces economic efficiency and crop sustainability. The aim of this research was to test, under controlled conditions, the impact of water, gibberellic acid A3 (0.05%), and humic acid (0.2%) on the growth and development of two willow clones. Under humic acid treatment, 20 cm cuttings of the Tordis clone developed up to 15 roots, and 25 cm cuttings developed more than 23. In comparison, water stimulated more than 15 roots for both 20 and 25 cm cuttings. Gibberellins acted as an inhibitor, especially on the roots, and the cuttings dried out from the top to the middle, with weak development of shoots and callus formation. For both clones, the highest number of active buds was observed on 20 and 25 cm cuttings grown in water, with more than four for Inger and more than seven for Tordis. Root development of the Inger clone had a maximum of eight for 25 cm cuttings grown in water; it was three times lower in the same variant of Tordis and two times lower for the Tordis clone with humic acid treatment. In general, Inger cuttings of 15 and 25 cm highlighted a delayed root formation when humic acids and gibberellins were applied. In controlled condition experiments, the Tordis clone was more suitable owing to its higher development and increased growth stability. Full article

The paper presents some forestry aspects of using Inger and Tordis willow clones to obtain woody biomass and remedy degraded soils. The methodological aspects regarding the planting of willow seedlings, the evaluation of the survival rate, the evaluation of the biomass quantity and the enrichment of the soil are analyzed. The results of the experiments showed that the degraded soil decreased the viability rate of the cuttings by 16.6% for the Tordis clone and 35.8 for the Inger clone. The analysis of the soil samples showed that it was enriched in nutrients after 2 years of cultivation, by the decomposition of the fallen leaves on the soil and by the absorption of the substances from the soil. Regarding the amount of biomass, its mass per hectare after the first year of cultivation was 0.64 t/ha for the Inger clone and 0.66 t/ha for the Tordis clone, while the calorific values of 19,376 kJ/kg for Inger and 19,355 kJ/kg for Tordis were good values. The final conclusion of the paper highlights that Osier willow is a viable solution for obtaining energetic biomass and putting it back into the productive circuit of degraded soils. Full article

Energy plantations create new habitats in agricultural landscapes with species compositions different from those in forests or farmlands. The purpose of our nine-year research project (2010–2018) was to evaluate the dependence of weed-species richness and their selected ecological aspects on stands of energy-plant species, and varieties in energy-tree and -grass plantations in conditions of Central Europe, on the basis of a case study. The permanent research plots were established in plantations containing two varieties of willow (Tordis and Inger), one poplar variety (Pegaso), and one clone of Miscanthus × giganteus. This evaluation included the species composition of understory flora, habitat preferences of different species, life cycle, life forms, ecological demands, and the harmfulness of these weed-species. The ground flora of energy plantations is predominantly composed of synanthropic plants of a weedy character with differences in species composition among different energy-tree and -grass species and varieties. The total number of vascular plant species was 98. The highest number of species (58) was recorded in the Tordis and Inger willow varieties, and the lowest was observed in the Pegaso poplar variety (45). Perennial species prevailed by their share, 10 of which were found in all four research plots. Therophytes and hemicryptophytes prevailed. Most species have high light requirements and are typical for mild-to-warm suboceanic areas, demanding freshly moist alkalic soils that are medium-to-rich in mineral nitrogen. Fifty percent of all observed species are considered weeds in Slovakia. The “very dangerous” category represented 46.94% of weeds, the “less dangerous” category 51.02%, and the “nondangerous” category represented 2.04% out of 49 species. The biggest share of “very dangerous weeds” was found in the poplar stand (38.78%), less in willow (32.65% and 28.57%), and the least in miscanthus stands (26.53%). The weeds of the Tordis variety were relatively poorly influenced by specific environmental conditions, and the weeds of the Inger variety were mainly defined by the soil reaction. Weeds in the undergrowth of both Miscanthus × giganteus and poplar trees (Pegaso) had the greatest affinity to mineral nitrogen content and temperature requirements. Full article

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 m². 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. Full article