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Willow biomass produced in short rotation coppice systems can potentially be used as biomass feedstock in Europe, the United States and Canada. However, most researchers focus on data from the first harvest rotation only, whereas multiple rotations have been rarely investigated. The aim of this study was to evaluate the effect of cultivar (5), planting density (12,000–96,000 cuttings/ha) and harvest rotation (annual, biennial, triennial) on willow biomass yields during 12 consecutive years in northern Poland. Every experimental factor and the interactions between factors significantly impacted willow yields. Biomass yield was highest in the triennial harvest rotation (13.3 Mg ha−1 year−1), 15.9% lower in the biennial rotation and 26.9% lower in the annual rotation. The highest average yield (14.6 Mg ha−1 year−1) was noted at a planting density of 24,000 cuttings/ha, and yields were 9.3%–46.0% lower at the remaining densities. Cultivar UWM 095 had the highest average yield (13.0 Mg ha−1 year−1), whereas the yield of the remaining cultivars was 4.6%–32.4% lower. During the 12‐year period, yields were higher after the first harvest in annual, biennial and triennial harvest rotations. This above implies that high biomass yields can be obtained after the first harvest rotation if willows are cultivated on fertile soils at higher planting density, well managed and coppiced after the first year. However, yields are unlikely to be higher in successive harvest rotations, and they can even be lower, but more stable than in the first harvest rotation. Research on willow production focuses on data from the first harvest rotation only, whereas multiple rotations have been rarely investigated. We evaluate the effect of cultivar (5), planting density (4) and harvest rotation (3) on willow yields during twelve consecutive years. The results show that high yields can be obtained after the first harvest rotation if willows are cultivated on fertile soils at higher planting density, well managed and coppiced after the first year. However, yields are unlikely to be higher in successive harvest rotations, and they can even be lower, but more stable than in the first harvest rotation. [ABSTRACT FROM AUTHOR]

Willow biomass can be collected in the form of entire or chipped shoots. The method depends on the harvest cycle of the plants, availability of necessary machines and the expected use of harvested raw material. Methods of harvesting influence on biomass quality during its acquisition and further in the storage period. Therefore, the aim of the research was to characterize the harvest of willow plantation with the use of a biobaler WB 55 and to assess the quality of the obtained biomass during the 9-month period of its storage. Willow was harvested with biobaler WB 55 in January 2010 on a commercial plantation. The 3.5 ha plantation was situated in the north-east of Poland, in the village of Dorotowo (53°42'9.88" N 20°25'11.02" E). An analysis of the biomass quality in terms of its thermophysical and chemical properties was carried out at the laboratory of the Department of Plant Breeding and Seed Production of the UWM in Olsztyn. Willow harvesting with a unit consisting of a 129 kW tractor and biobaler WB 55 was conducted efficiently. The average harvesting efficiency was about 18 bales per hour of the unit operation (8.75 Mg h-1 FM). The fresh matter density in the bales averaged 358.10 kg m-3 FM, whereas in dry matter it was 166.16 kg m-3 DM. With extended duration of storage, the quality of willow biomass as an energy raw material improved. The biomass in the bales steadily lost its moisture, from 53.06% in January to 17.48% in September. On the other hand, the lower heating value increased during that same period from 7.75 MJ kg-1 to 15.65 MJ kg-1. It has been found based on the observations made during the study period that the advantages of a biobaler WB 55 are the easy and efficient harvesting of plants on a plantation and bales can be used for energy production as needed. [ABSTRACT FROM AUTHOR]

The subject of the studies was to determine some parameters of pellets produced from waste materials generated during production of the certified seed materials of barley, wheat, red fescue as well as mixed cereal grains wastes, produced from sunflower husk and from short-rotation willow biomass. As a control pellets produced using dry oak or pine woodchips were applied. The following parameters were taken into account: water content, ash content, calorific value and elemental composition (C, N, H and S). Pellets produced from mixed cereal wastes showed the highest moisture content while pellets from other studied wastes manifested moisture content close to oak woodchips pellets. Crude ash content in pellets produced from waste substances was several times higher than in woodchips pellets and considerably exceeded the standard value. Analyses of caloric and heating values showed that pellets from mixed cereal wastes had the lowest values of those parameters. Any of pellets produced from waste materials met demands of first class wood pellet given in German standard DIN 51731 for pellets heating value between 17.5 and 19.5 MJ·kg[sup -1]. Sulphur content in waste pellets was sometimes higher by factor of twenty than maximal value for first class pellets (amounting to 0.154% in sunflower husk pellets when allowable level is 0.08% S). Quality parameters of pellets made of short-rotation willow biomass were higher then determined in cereal wastes pellets because of its higher caloric values and lower ash, sulfur and nitrogen concentrations. [ABSTRACT FROM AUTHOR]

Short rotation woody crops are grown to be used as feedstock for energy and industrial purposes in many countries of Europe, and in the USA and Canada. Wood biomass is acquired from forests, the wood industry, and as a by-product of trimming trees and bushes. In future, considerable amounts of wood biomass should be supplied by dedicated energy crops (willow, poplar, black locust). The aim of this study was to determine the morphological features, yield and energy value of the yield of three species of plants grown at a site with poor soil quality and low usability for edible crops. The study has shown that the species of willow and poplar can be grown on poor quality agricultural land because they provide high yield, high energy, and high coal equivalent. However, the biomass of black locust may fail to provide sufficient yield to justify setting up a plantation using this species. [ABSTRACT FROM AUTHOR]

In order to ensure consistent supplies of agriculture-derived lignocellulosic biomass for the emerging biomass market, dedicated plantations of short rotation woody crops (SRWC) need to be developed. Our research aimed at defining the yield, survivability, and morphological features of three plant species (SRWC) cultivated under the conditions of northeastern Poland, on poor soil unsuitable for food or fodder crops. The first factor for the experiment was provided by three plant species: willow (Salix viminalis L. UWM 006), poplar (Populus nigra x P. Maximowiczii Henry cv. Max-5), and black locust (Robinia pseudoacacia L.). The second factor consisted of seven soil enrichment regimes, referred to as "fertilization," and a control. Willow grew significantly the highest. Poplar grew to a similar height and the diameter of its shoots was significantly the biggest. The yield varied significantly depending on plant species and soil enrichment regime. During a two-year rotation cycle of the crops, poplar and willow produced notably higher yields than black locust, despite growing on poor soil. The soil enrichment regimes, in turn, significantly improved the crop yields. [ABSTRACT FROM AUTHOR]