Willow Cultivation Research Articles

Identification of Land and Potential Production of Willow Biomass Crops Using a Multi-Criteria Land Suitability Assessment

The New York State (NYS) Climate Act aims for net-zero emissions across all economic sectors by 2050, with renewable biofuels playing a key role in this transition. Approximately half of the biomass required for these biofuels is expected to come from purpose-grown sources like willow. To address this demand, we assessed land availability and biomass production potential for willow using a GIS-based fuzzy logic Land Suitability Assessment (LSA) model under three land scenarios: (1) including all cropland, (2) excluding conventional crops, and (3) excluding any cropland. Our findings show that NYS has the potential for between 1.07 and 1.59 million ha for willow cultivation, capable of producing 14.0 to 20.6 million dry Mg of biomass annually. Grassland/pasture accounts for 32–51%, and herbaceous cover for 32–48% of the potential areas. Between 33% and 53% of the area identified was in parcels that were 2–20 ha in size. These results highlight the considerable potential for purpose-grown biomass in NYS, supporting the state’s decarbonization goals and renewable energy transition.

Mine waste rock as a soil amendment for enhanced weathering, ecosystem services, and bioenergy production

Enhanced weathering of terrestrial rock material is a promising method for the removal of anthropogenic CO2 emissions from the atmosphere. Herein, we demonstrate that an ameliorated mining waste product can be effectively weathered in the soil environment when used as a soil amendment in conjunction with the cultivation of fast-growing willows (Salix matsudana Koidz. ⨯ S. alba L. “Austree”) in a pot study environment. Utilizing this locally sourced amendment minimizes emissions associated with grinding and transportation of enhanced weathering materials. Results showed that the willows were able to tolerate the relatively high metal concentrations of this amendment and sequester inorganic carbon (C) through the production of bicarbonate in soil solution. During the period of peak plant growth (10 weeks after planting), alkalinity measurements of soil solution from pots with willows and the addition of 25% by mass mine waste product indicated an additional 10 mg of inorganic C sequestration per liter of leached soil solution compared to unamended soils with willows. This represents 4.5 times the inorganic C sequestration rate of unamended soils. The addition of ameliorated mining waste also increased the pH of the soil solution by up to two units (pH of 6 in control vs. pH of 8 with the addition of 25% by mass mineral amendment). In addition to inorganic C sequestration, weathering of the ameliorated mining waste product may also provide base cations (such as calcium and magnesium) which could improve soil fertility. These results are encouraging for future investigation of ameliorated mine waste rock to sequester carbon and enhance the production of willows grown for ecosystem services and phytotechnologies.

A spatial analysis of the economic returns to land‐use change from agriculture to renewable energy production: Evidence from Ireland

AbstractCountries are looking to reduce their agricultural sector's carbon footprint while encouraging economic and environmental sustainability. One proposed method of making agriculture more sustainable while maintaining farm incomes is through the production of bioenergy feedstocks. We examine the spatial aspect of the production of renewable energy feedstocks in Ireland. Two feedstocks are looked at—grass silage and short‐rotation coppice (SRC) willow. Spatial microsimulation analysis is utilised to assess the spatial suitability for alternative land uses, simulating land‐use change to compare economic returns with the current agricultural use. A farm‐based carbon subsidy is modelled based on avoided agricultural emissions and carbon sequestered. We find that midlands counties, especially those in the north midlands, have the highest proportion of land where feedstocks would be more profitable than the current agricultural use. Counties on the western seaboard have the lowest proportion of land where feedstocks would give greater returns. The amount of land where feedstocks are more profitable increases as greater carbon subsidies are provided. Of the two feedstocks assessed, SRC willow cultivation is more profitable than grass silage production. The overwhelming majority of land where producing feedstocks would be more profitable has cattle farming as its current use.

Economic potential of agricultural-riparian shrub willow: An evaluation of the biomass producing capabilities and costs of cultivating Salix viminalis downslope of potato cropping systems in PEI

Shrub willow (Salix spp.) is increasingly grown as a biomass crop and for a range of environmental applications. Merging the economic and environmental objectives of willow production may facilitate more widespread adoption by reducing production costs and justifying willow cultivation in traditional agricultural settings. Incorporating willow in agricultural-riparian transition areas, particularly in intensive or high-input agricultural systems, can enhance watercourse protection from diffuse pollutants, mitigate indirect agricultural N2O emissions, and sequester carbon. However, biomass accrual and economic feasibility needs quantification on localized scales.This study investigated the biomass accrual of 9 agricultural-riparian willow buffers in Prince Edward Island, Canada, receiving no direct fertilization. Carbon, nitrogen, and phosphorus assimilation was measured in stem and root biomass, limitations on growth assessed, and benefit-cost analysis was conducted to determine opportunities for bioenergy use and deployment. First rotation agricultural-riparian Salix viminalis displayed considerable site-to-site variation in biomass production, with water availability being the primary limiting factor on growth. Mean total plant biomass and annual yield ranged from 0.54 to 7.9 kg dry matter plant−1 and 0.25–16.59 Mg ha−1 yr−1 (mean 3.9), respectively. CO2 fixation was 0.67–46.64 Mg CO2 ha−1 yr−1, of which 0.23–15.7 Mg CO2 ha−1 yr−1 was root biomass, indicative of long-term sequestration. Nitrogen and phosphorus removal was 6.05–39.1 (mean 23.3) and 1.1–4.8 (mean 2.8) kg ha−1 yr−1. Benefit-cost analysis revealed that shrub willow production can be economically viable for on-farm heating when yields exceeding 5.6 Mg dry matter ha−1yr−1 are achieved, but off-farm sale is not currently economically justified.

Mapping Small-Scale Willow Crops and Their Health Status Using Sentinel-2 Images in Complex Agricultural Areas

The goal of this study was to estimate the areas under willow cultivation by farmers, as well as their growth and health status. Due to the extremely small patch size of land cover types in the study area, Sentinel-2 data were used to conduct supervised classification based on the random forest machine learning technique, and a large training dataset was produced from PlanetScope satellite imagery. The results of image classification using Google Earth Engine indicated that the Sentinel data were suitable for identifying willow-cultivated areas. It was found that these areas declined from 875.32 ha in 2017 to 288.41 ha in 2022. The analysis of the growth and health conditions of willow-cultivated plots also revealed that the temporal variations in the NDVI in these plots decreased significantly in 2022 as compared to previous years (p < 0.05). An in-depth analysis revealed a significant positive correlation between NDVI, precipitation, and temperature. It was found that the most efficient components explaining the process of browning the vegetation in the planted willow plots were the increasing temperature and decreasing precipitation. This research may be used to document the national and global monitoring efforts for climate change adaptation.

Reducing the time-dependent climate impact of intensive agriculture with strategically positioned short rotation coppice willow

In this study the implementation of a short rotation coppice willow system, planted as a riparian buffer in an intensive agricultural setting, to intercept and reduce nutrient losses, was investigated. The aim of the work was to assess how such a system could reduce the overall climate impact of an intensive agricultural setting. A life cycle assessment was carried out for a combined Irish dairy farm and willow buffer system considering the impact category, climate impact. The climate impact was considering using the time-dependent climate impact metric, with the results given in terms of the impact on the global surface temperature. The results were compared to an Irish dairy farm in which no willow was planted. Such a system has not previously been investigated in this way and this was the first time-dependent climate impact assessment of a willow plantation planted on pastureland. Geographic information systems software, was used to map areas particularly susceptible to agricultural run-off and suitable for willow planting, using the land bank of the Agri-Food and Biosciences Institute research farm in Hillsborough, Northern Ireland, for the case study. The harvested willow was assumed to be combusted in a combined heat and power plant. By implementing the willow system the time-dependent climate impact of an Irish dairy farm could be reduced by 8% with only 3.7% of the land used for willow cultivation over a 101-year study period. The results also found an immediate reduction in climate impact following the implementation of the willow system. Total GHG emissions were reduced by 131 Mg CO2eq ha−1 over the study timeframe. The results can be more broadly applied to other agricultural sectors, such as arable farming where the climate impact savings of the willow system could be even higher.

Comparative wood anatomy, composition and saccharification yields of wastewater irrigated willow cultivars at three plantations in Canada and Northern Ireland

Conventional wastewater treatment strategies can have high financial costs which often leads to discharge of undertreated wastewater into the ecosystem. In parallel, the cultivation of willows for bioenergy can be limited due to their high water demand. Despite the potential for treatment using willow plantations, the effect of wastewater irrigation on biomass development and biofuel potential has yet to be investigated across different cultivars and sites. Here, the effect of secondary treated wastewater irrigation on wood anatomy, biomass composition and enzymatic saccharification were investigated in one poplar and thirteen willow cultivars planted at one of three sites in either Canada or Northern Ireland. There was significant anatomical and compositional variation between cultivars at all three sites, but wastewater irrigation had little impact on biomass development. Vessel and fibre cell frequencies ranged between cultivars from 129 to 178 and 4322–7058 per mm2, with average transverse areas of 838–1278 and 120–190 μm2, respectively. Glucan and lignin content varied from 42.3 to 50.7% dry matter (DM) and 27.3–32.4% DM, respectively, whereas glucose release varied from 50 to 160 mg g−1 of glucan or 30–90 mg g−1 of DM. Glucan content and fibre cell frequency had significant positive correlations with glucose release yields, whereas average fibre cell area had an inverse correlation. These findings suggest both cell wall structure and tissue morphology could be important factors when considering biomass recalcitrance to deconstruction. Maintenance of biomass quality during irrigation provides evidence that integration of dedicated bioenergy production with environmental wastewater treatment using willow phytofiltration has potential as a promising clean biotechnology.

Effects of willow cultivation on chemical and biological properties in coastal saline soil

ABSTRACT The improvement effect of willow (Salix matsudana cv. zhuliu) cultivation on coastal saline soil and the main factors affecting soil properties were studied. Three treatments were designed: willow seeding site (SS), willow afforestation site (AS) and natural control site (CK). The results showed that soil pH and ECe decreased from 8.50 to 7.43 and from 6.8 dS/m to 0.8 dS/m at 0–20 cm layer, respectively. Willow cultivation significantly increased soil organic matter both in SS (3.64 g kg−1 – 4.05 g kg −1) and AS (2.82 g kg−1 – 3.92 g kg −1) treatments. The soil total nitrogen and available potassium of different treatments were increased with time and ranked AS > SS > CK. The AS16 treatment has a higher soil enzyme activity (soil urease, catalase, sucrase and phosphatase) and soil microbial population (bacteria, fungi and actinomycetes). Redundancy analysis suggested that soil pH and salinity were the key factors (85.4%) determining soil microbial quantities. Principal component analysis showed that the soil improvement by willow cultivation was significantly affected by soil enzyme activity, and AS16 had a better effect on costal saline soil especially in reducing soil salinity and improving microbial environment

A review of Willow (Salix spp.) as an integrated biorefinery feedstock

Throughout history, the genus Salix (willow) has been an incredibly useful temperate plant for humans, with widespread global distribution and species indigenous to all continents except Antarctica. Estimations of the number of species range from 450 to 520 worldwide, and there are still more natural hybrids and multi-hybrid combinations. Several biomass willow breeding programmes have been established across the globe. All of these attempt to produce fast-growing, high-yielding stems with a straight habit and minimal side branching that are highly adaptable to different sites and are also disease and pest resistant. Short rotation coppice (SRC) cultivation involves growing willow at close spacings with a stocking rate of around 15,000 per hectare with harvests every 2–4 years. The crop is mechanically harvested, typically using a forager, and material has recently been used for bioenergy applications. Trial plots have achieved yields of up to 20 odt/ha/yr, whilst well-tended commercial crops have yielded up to 14 odt/ha/yr. Global willow breeding programmes have produced a wide variety of commercial genotypes that have suitable properties for easy planting and harvesting and have the added benefit of elevated levels of bioactive compounds , including salicin , present in the bark, which can be used in medical and veterinary applications. These high-yielding willow varieties grow well in the wetter regions of the globe, including NW Europe, and afford multiple harvests before re-planting. Salix's versatility and adaptability and the SRC cultivation process make them an ideal candidate feedstock for use in an integrated biorefinery to produce a range of biobased materials, including pharmaceuticals, and biocomposites , fuels, energy and fertiliser. • Willow is a pioneer species and grows well in the wetter regions of the world. • Willow plantation can yield 8–9 harvests collected every three years over 25 years before re-planting. • Commercial willow varieties cultivated over the last 20 years were developed for bioenergy. • Cultivation of willow in flood-prone areas offers the potential for flood risk mitigation. • Willow has high potential as an integrated biorefinery feedstock for the manufacture of biobased products.

Different color regulation mechanism in willow barks determined using integrated metabolomics and transcriptomics analyses

BackgroundThe rich yellow-orange to vividly deep red bark of willow (Salix spp.) branches have high ornamental and economic value. However, the mechanism underlying the regulation of willow branch color remains unknown. Therefore, we performed metabolomics and transcriptomics analyses of purple, green, and red willow barks to elucidating the mechanisms regulating color development.ResultsSeven anthocyanins were isolated; pelargonidin, petunidin 3-O-rutinoside, and cyanin chloride were the most abundant in red bark, whereas pelargonin chloride was most abundant in purple bark. The green bark contained the highest level of malvidin; however, the malvidin level was not significantly higher than in the red bark. The purple bark contained the largest amount of canthaxanthin, a carotenoid pigment. The integrated pathways of flavonoid biosynthesis, carotenoid biosynthesis, and porphyrin and chlorophyll metabolism were constructed for the willow barks. Among the three barks, the expression of the structural genes ANS, ANR, and BZ1, which are involved in anthocyanin synthesis, was the highest in red bark, likely causing anthocyanin accumulation. The expression of CrtZ, which participates in the carotenoid pathway, was the highest in purple bark, likely leading to canthaxanthin accumulation. The high expression of DVR, POR, and CRD1 may be associated with green pigment synthesis in the chlorophyll biosynthesis pathway.ConclusionsPurple bark color is co-regulated by anthocyanins and carotenoids, whereas red bark is characterized by anthocyanin accumulation and chlorophyll degradation. The green pigment is regulated by maintaining chlorophyll synthesis. BZ1 and CrtZ are candidate genes regulating anthocyanin and canthaxanthin accumulation in red and purple barks respectively. Collectively, our results may facilitate the genetic breeding and cultivation of colorful willows with improved color and luster.

Unweaving the population structure and genetic diversity of Canadian shrub willow

Perennial shrub willow are increasingly being promoted in short-rotation coppice systems as biomass feedstocks, for phytoremediation applications, and for the diverse ecosystem services that can accrue. This renewed interest has led to widespread willow cultivation, particularly of non-native varieties. However, Canadian willow species have not been widely adopted and their inherent diversity has not yet been thoroughly investigated. In this study, 324 genotypes of Salix famelica and Salix eriocephala collected from 33 sites of origin were analyzed using 26,016 single nucleotide polymorphisms to reveal patterns of population structure and genetic diversity. Analyses by Bayesian methods and principal component analysis detected five main clusters that appeared to be largely shaped by geoclimatic variables including mean annual precipitation and the number of frost-free days. The overall observed (HO) and expected (HE) heterozygosity were 0.126 and 0.179, respectively. An analysis of molecular variance revealed that the highest genetic variation occurred within genotypes (69%), while 8% of the variation existed among clusters and 23% between genotypes within clusters. These findings provide new insights into the extent of genetic variation that exists within native shrub willow species which could be leveraged in pan-Canadian willow breeding programs.

Towards just transition of coal regions - Cultivation of short rotation copies and dedicated energy crops for biomass co-firing vs photo voltaic power plants

• Abandoned coal mine areas to continue sustainable use now in the green energy business. • Options proposed include forming biomass plantations vs construction of solar power plants. • Sustainability criteria such as economic, environmental and social aspect need to be considered. • Decision can be made using both aggregated economic analysis and multi criteria sustainability assessment. In developing countries, which dominantly produce electricity by burning coal, energy transition represents a significant challenge. Short rotation coppice and dedicated energy crops could be a promising raw material for production of biofuel and its further usage for electricity and heat generation. This work assesses possibilities and elaborates on the sustainability of cultivation of short rotation coppice type willow and dedicated energy crop Miscanthus on former areas of coalmines belonging to the largest power utility in Bosnia and Herzegovina, namely JP Elektroprivreda BiH d.d. – Sarajevo. Abandoned coal mine areas were mapped and, by settled criteria, dedicated either to future photovoltaic power plants integration or the cultivation of energy crops and their further use in the considered generation portfolio mix. In order to assess the contribution of both photovoltaic power plants and biomass in the upcoming energy transition process, an adequate method has been developed in this article and specific sustainability indicator groups determined to further calculate the sustainability ratio. The paper focuses on economic, environmental and social indicator groups, which were used to perform the aggregated economic analysis and the multi criteria analysis. Performed aggregated economic analysis lightly favours the construction of photovoltaic power plants over the use of willow as fuel. In this analysis, Mischantus is lagging far behind due to its lower yield compared to willow. The multi criteria analysis on the other hand, valorises the social indicator adequately and the sustainability ratio results are much closer for both considered renewable sources types. This shows the importance of a comprehensive approach and definition of appropriate methods to enable decision-makers to draw appropriate conclusions.

A financial and environmental sustainability of circular bioeconomy: A case study of short rotation coppice, biochar and greenhouse production in southern Finland

Business opportunities of circular bioeconomy have been proposed to lessen the socio-economic challenges of rural areas and to conserve diminishing natural resources. Recently, the financial and environmental sustainability of circular bioeconomy has gained considerable research interest. This study examines three promising operational models for circular bioeconomy development in southern Finland: willow cultivation on marginal lands, wood-based biochar production and wood chip heated greenhouse production. The feasibility of these models is assessed by analysing their financial and environmental sustainability using a multi-methodological approach. Financial sustainability is analysed using net present value and internal rate of return indicators via cash flow analysis. Environmental sustainability is examined using carbon footprint indicator in a life cycle assessment and a closed loop analysis. The results reveal correlations between both types of indicators, suggesting that a circular bioeconomy may lead to win–win situations. Potential closed loops are identified, and a circular bioeconomy model is suggested for improving security of supply and the flexibility of raw materials. Imbalanced revenue allocations between primary and secondary production are recognised as a potential threat to financial feasibility. Understanding financial and environmental sustainability of divergent operational models supports decision making and the legitimacy of change.

Water Needs of Willow (Salix L.) in Western Poland

Willows are one of the plants which can be used to produce biomass for energy purposes. Biomass production is classified as a renewable energy source. Increasing the share of renewable sources is one of the priority actions for European Union countries due to the need to reduce greenhouse gas emissions. To achieve the best possible growth of the willow and increase its biomass for fuel, it is crucial to provide optimal water conditions for its growth. The aim of the study was to determine the water requirements of willows under the conditions of the western Polish climate and to verify whether this area is potentially favourable for willow cultivation. The novelty of this paper lies in its multi-year climatic analysis in the context of willow water needs for the area of three voivodships: Lubusz, Lower Silesian, and West Pomeranian. This is one of the few willow water-needs analyses for this region which considers the potential for widespread willow cultivation and biomass production in western Poland. Reference evapotranspiration (ETo) was determined by the Blaney-Criddle equation and then, using plant coefficients, water needs for willow were determined. Calculations were carried out for the growing season lasting from 21 May to 31 October. The estimated water needs during the vegetation season amounted on average to 408 mm for the West Pomeranian Voivodeship, 405 mm for the Lubusz Voivodeship, and 402 mm for the Lower Silesian Voivodeship. The conducted analysis of variance (ANOVA) showed that these needs do not differ significantly between the voivodeships. Therefore, it can be concluded that the water requirements of willows in western Poland do not differ significantly, and the whole region shows similar water conditions for willow cultivation. Furthermore, it was found that water needs are increasing from decade to decade, making rational water management necessary. This is particularly important in countries with limited water resources, such as Poland. Correctly determining the water requirements of willow and applying them to the cultivation of this plant should increase the biomass obtained. With appropriate management, willow cultivation in Poland can provide an alternative energy source to coal.

ВИРОЩУВАННЯ ЕНЕРГЕТИЧНОЇ ВЕРБИ В УМОВАХ ЗАХІДНОГО ПОЛІССЯ

The research results of influence of the planting density, fertilization and soil type on the productivity of the energy willow in the conditions of Western Polissia are presented. On average over five years of research in the cultivation of energy willow it was found that the highest yield of dry biomass 102.9 t/ha was obtained on dark gray light loamy soil with a planting density of 20 thousand pcs/ha and fertilizer application at the rate of N60 P200 K200. The lowest yield of dry biomass was at planting density of energy willow of 10 thousand pcs/ha in the variant without fertilizers on dark gray light loamy soil and sod-podzolic cohesive sandy soil – 49.1 and 26.9 t/ha, respectively. The mineral fertilizer application with rate of N60 P100 K100 ensured an increase in the yield of dry biomass by 13.5 and 7.5 t/ha depending on the type of soil. The increase of phosphorus and potash fertilizers rate to 200 kg a.i./ha contributed to an increase in dry mass up to 23.6 and 13.0 t/ha compared to the variant without fertilizers. A similar result was obtained on sod-podzolic cohesive-sandy soil. The lowest indicators were in the variant without fertilizers at the planting density of 10 thousand pcs/ha – 26.9 t/ha, 15 thousand pcs/ha – 30.2 t/ha and 20 thousand рcs/ha – 35.6 t/ha dry biomass. The application of mineral fertilizers with rate of N60P100K100 for all planting densities increased the dry biomass yield to 34.4; 38.5; 45.3 t/ha, respectively. Increase of phosphorus and potash fertilizers rate up to 200 kg a.i./ha against the background of N60 contributed to an increase of energy willow yield up to 39.9 t/ha (with a planting density of 10 thousand pcs/ha), 44.1 t/ha (15 thousand pcs/ha) and 52.3 t/ha (20 thousand pcs/ha) of dry biomass. On average for five years, the application of fertilizer with N60P200K200 rate on dark gray light loamy soil, and at planting density of 20 thousand pcs/ha provided the highest yield of solid biofuel from energy willow of 22.7 t/ha and energy of 363 GJ/ha, while on sod-podzolic cohesive-sandy soil under the same growing conditions the yield of solid biofuel from willow was less by 11.1 t/ha and energy of 178 GJ/ha. Keywords: energy willow, dry biomass, solid biofuels, energy, soil.

Ecological aspects of peat, straw, and wood ash application for energy willow cultivation

The utilization of ash obtained as a result of the combustion of fossil fuels (coal, peat) or biomass (straw, wood, solid waste) is an environmental problem that should be optimally solved. The chemical characteristics of ash depend on several factors, mostly on sources of fuel. According to characteristics, ash can be used in agriculture, forestry, or utilized for other purposes. The content of heavy metals (Cd, Ni, Pb, Cr) in peat ash is several times higher than in willow wood ash and straw ash. It means that peat ash application is limited to agricultural crops and its optimal application is one year before planting SRC trees, especially on poor and acid soils. The application of peat ash at a dose of 10 mg dry mass ha-1 in willow plantations on post-mining peaty soils changed soil acidity from 5.2 pH to 5.88 pH and stimulated tree growth. Wood and straw ash was applied to wil?low plantations on arable loam-sandy soils in doses 0.5, 1.0, and 1.5 t dry mass ha-1. The positive effect of ash application in doses 1.0 and 1.5 t dry mass ha-1 showed in the second year after the application both for soil and for willow growth.

ECONOMIC AND ECOLOGICAL PERSPECTIVES OF ENERGY WILLOW CULTIVATION BY THE YALTUSHKIVSKA EXPERIMENTAL BREEDING STATION OF THE INSTITUTE OF BIOENERGY CROPS AND SUGAR BEETS OF THE NATIONAL ACADEMY OF AGRARIAN SCIENCES OF UKRAINE

The article analyzes the peculiarities of energy consumption in Ukraine, and it is established that among the main consumers of fuel and energy resources, the largest share belongs to the agricultural sector, which is also characterized by the significant potential of biomass suitable for biofuel production. It was determined that the most promising source of thermal energy should be solid biofuel, the production of which in Ukraine is accompanied by a shortage of quality raw materials. Analysis of the problem allowed generating its solution in the form of cultivation of energy plantations of plants of short rotation, in particular energy fast-growing willow on the lands, withdrawn from the agricultural rotation. It is established that in the perspective of realization of the described solution, the priority tasks for scientific institutions of agrarian profile are selection of productive varieties and hybrids of short-rotation energy plants suitable for processing into rigid biofuels and development of technologies of their cultivation and processing. Among such organizations, the object of research was selected Yaltushkovo experimental breeding station of the Institute of bioenergy crops and sugar beet NAAS of Ukraine, that is engaged in breeding and elite seed production of agricultural and bioenergy crops, including energy willow. In scientific activities of Yaltushkivska experimental breeding station were carried out and analyzed experiments on the technology of growing energy willow for the production of solid biofuel from various aspects of the production cycle, including the introduction of nutrients, alternative treatment practices, the use of cover crops, planting patterns, biomass growth features, as well as collection systems and logistics. Prospects for the practical use of energy willow based on economic calculations made for the efficiency of a 10-hectare plantation were disclosed. EcoWillow 2.0 program was chosen as the methodological basis - the most complete tool for financial analysis of willow plantations. It was determined that special attention should be paid to reforming the provision of heat energy to the rural population through the creation of energy cooperatives on the use and cultivation of energy willow on the basis of intersectoral scientific and production integration at the local level, involving as a scientific partner of the existing USEC «All-Ukrainian scientific- educational consortium» to ensure coordination of communication between science, public, government and business.

Ethylenediurea (EDU) spray effects on willows (Salix sachalinensis F. Schmid) grown in ambient or ozone-enriched air: implications for renewable biomass production

Ground-level ozone (O3) is a widespread air pollutant causing extensive injuries in plants. However, its effects on perennial energy crops remain poorly understood due to technical difficulties in cultivating fast-growing shrubs for biomass production under O3 treatment on the field. Here we present the results of a two-year evaluation in the framework of which willow (Salix sachalinensis F. Schmid) shrubs were exposed to ambient (AOZ) or elevated (EOZ) O3 in two successive growing seasons (2014, 2015) and treated with 0 (EDU0) or 400 mg L−1 (EDU400) ethylenediurea spray in the second growing season. In 2014, EOZ altered the chemical composition of both top young and fallen leaves, and a novel mechanism of decreasing Mg in fallen leaves while highly enriching it in young top leaves was revealed in shrubs exposed to EOZ. In 2015, EDU400 alleviated EOZ-induced decreases in leaf fresh mass to dry mass ratio (FM/DM) and leaf mass per area (LMA). While EDU400 protected against EOZ-induced suppression of the maximum rate at which leaves can fix carbon (Amax) in O3-asymptomatic leaves, it did not alleviate EOZ-induced suppression of the maximum rates of carboxylation (VCmax) and electron transport (Jmax) and chlorophylls a, b, and a + b in the same type of leaves. In O3-symptomatic leaves, however, EDU400 alleviated EOZ-induced suppression of chlorophylls a and a + b, indicating different mode of action of EDU between O3-asymptomatic and O3-symptomatic leaves. Extensive herbivory occurred only in AOZ-exposed plants, leading to suppressed biomass production, while EOZ also led to a similar suppression of biomass production (EDU0 × EOZ vs. EDU400 × EOZ). In 2016, carry-over effects were also evaluated following cropping and transplantation into new ambient plots. Effects of EOZ in the preceding growing seasons extended to the third growing season in the form of suppressed ratoon biomass production, indicating carry-over effect of EOZ. Although EDU400 protected against EOZ-induced suppression of biomass production when applied in 2015, there was no carry-over effect of EDU in the absence of EDU treatment in 2016. The results of this study provide novel mechanistic understandings of O3 and EDU modes of action and can enlighten cultivation of willow as energy crop.

Resource potential and properties of cellulose obtained from tree willow wood

Willow trees occupy an important place in the dendroflora of the middle zone of the European part of Russia due to their extensive species diversity and large intrapopulation variability. In the Arkhangelsk Region and other regions in the North-East of Russia, abandoned agricultural land (post-agrogenic land) can serve as places for the creation of willow plantations. Currently, such lands are actively overgrown with various tree species, usually of low quality and not of significant commercial interest. The creation of plantations will allows by a short logging turnover to obtain stable wood yields and organize a highly profitable economy on unused land. There is no any information on the willow cultivation in Russia. Willows of the Salix genus grow everywhere and there are more than 130 species. About 30 of these species are found in the Arkhangelsk region. Based on the data of the State forest register of the North Taiga forest region, the tree willow occupies an area of 5.3 thousand hectares. Land with strong moisture is widespread in the Arkhangelsk region. Willow grows well in these areas. Due to this, as well as the good strength of the pulpwillow wood can be widely used in pulp and paper production.

Willow bark and wood as a source of bioactive compounds and bioenergy feedstock

Willow (Salix) is one of the available sources of renewable raw materials, which can be used in various branches of the medical, chemical and energy industry. However, its biomass should be used primarily for the production of high added-value substances. Therefore, the aim of this study was to assess the production potential of biomass (bark and wood), bioactive substance concentration and energy features of 10 willow genotypes cultivated in annual cycles. Our research found that the highest total biomass yield (13 Mg ha−1 y−1 d.m.) was obtained from the S. purpurea × S. daphnoides UWM 029 hybrid but the highest bark yield from S. americana UWM 094 (3.9 Mg ha−1 y−1 d.m.). The significantly highest salicin concentration was found in the bark of S. purpurea × S. daphnoides (approx. 29 mg g−1); the salicylic acid level was about ten times lower. The potential bioactive substance yield was affected by the bark yield per hectare. The highest salicin yield (over 92 kg ha−1) was obtained from both S. purpurea × S. daphnoides hybrids. The highest yield energy value of wood (191 GJ ha−1 y−1) was found for S. purpurea × S. daphnoides UWM 029. In conclusion two interspecies hybrids of S. purpurea × S. daphnoides UWM 029 and UWM 193 were found to be the most promising in terms of the analysed features. However, a full assessment of the practical use of the hybrids requires further research into the economic and environmental effects of willow cultivation and bioactive substances production.