Cultivation Of Energy Crops Research Articles

Energy Quality of Corn Biomass from Gasoline-Contaminated Soils Remediated with Sorbents

Soil contaminated with petroleum-derived products should be used to cultivate energy crops. One such crop is Zea mays. Therefore, a study was performed to determine the suitability of Zea mays biomass obtained from gasoline-contaminated soil for energy purposes. The analysis included determining the heat of combustion and calorific value of the biomass, as well as the content of nitrogen, carbon, hydrogen, oxygen, sulfur, and ash in the biomass. Additionally, the suitability of vermiculite, dolomite, perlite, and agrobasalt for the phytostabilization of gasoline-contaminated soil was evaluated. It was found that the application of sorbents to gasoline-contaminated soil significantly reduced the severe negative effects of this petroleum product on the growth and development of Zea mays. Gasoline contamination of the soil caused a significant increase in ash, nitrogen, and sulfur, along with a decrease in carbon and oxygen content. However, it had no negative effect on the heat of combustion or calorific value of the biomass, although it did reduce the energy production from Zea mays biomass due to a reduction in yield. An important achievement of the study is the demonstration that all the applied sorbents have a positive effect on soil stabilization, which in turn enhances the amount of Zea mays biomass harvested and the energy produced from it. The best results were observed after the application of agrobasalt, dolomite, and vermiculite on gasoline-contaminated soil. Therefore, these sorbents can be recommended for the phytostabilization of gasoline-contaminated soil intended for the cultivation of energy crops.

Potential of Growing Energy Crops and Then Producing Liquid Fuels in Marginal Land: A China Scenario

To explore the potential of growing energy crops and then producing liquid fuels in marginal land in China, in this paper, the status quo of existing biomass resources and marginal land utilization in China have been first analyzed and the development process of biomass liquid fuels has then been reviewed. Secondly, using ethyl levulinate (EL) as our research subject, the production capacity of growing energy crops in marginal land and their potential to prepare liquid fuels have been explored. Finally, the problems in developing marginal land have been summarized, and proposed policy recommendations for marginal land development, energy crop cultivation, and liquid fuel development suitable for Chinese conditions. The results showed that the potential of sweet sorghum, cassava, jatropha curcas, and switchgrass cultivation in China in producing is 75.76 million tonnes, 1.52 million tonnes, 4.57 million tonnes, and 5.16 million tonnes, respectively. Among these crops, sweet sorghum and switch grass have a higher production capacity and are more suitable to be planted on marginal land and used to produce liquid fuels. The planting of these two crops has absorbed about a 111.11 million tonnes and 7.57 million tonnes of carbon dioxide (CO2), respectively, presenting significant carbon sequestration and oxygen-producing effects, which provides a theoretical basis for the analysis of land use change.

CURRENT STATE AND PROSPECTS FOR THE GROWING AND USE OF ENERGY CROPS IN UKRAINE

The purpose of the work is to analyze state of the art of Ukraine’s energy crops sector, as well as to develop recommendations for creating favorable conditions for the implementation of respective projects in the country. Energy crops are plants that are grown to obtain biomass as a fuel or feedstock for the further production of energy, biomass fuels or biofuels. Their advantage is the possibility of cultivation on marginal or low-quality lands, that is those that are unsuitable for the cultivation of common agricultural crops. Wood and grass energy crops have good fuel characteristics, which are close to those of forest wood. As for chlorine content and ash melting point, these indicators are much better than those of straw. In Ukraine, as in the EU, the potential for growing energy crops is determined mainly by the available area of unused agricultural and low-productivity land on which respective plantations can be created. Experts of the Institute of Engineering Thermophysics of the National Academy of Sciences of Ukraine estimate the current economic potential of energy crops for obtaining various types of biomass fuels in Ukraine as 5.44 Mtoe/yr (2021). By 2050, this potential may more than double, reaching 11.20 Mtoe/yr. In the current Ukraine’s biomass potential, the total share of energy crops is 21%, approximately equally divided between wood/grass crops (solid biomass biofuel) and corn silage (biogas). By 2050, this share may increase to 26%, the largest contribution being from wood/grass energy crops (16%) intended for solid biomass fuel production. Projects on the cultivation of energy crops are quite difficult for practical implementation as they are sensitive to many factors, which affects their economic performance. Usually, the payback period of such projects is 7...9 years, which is on the verge of profitability and economic feasibility. The Bioenergy Association of Ukraine has elaborated several tools to stimulate the development of this sector in the country. Implementation of the suggested support mechanisms will significantly increase the attractiveness of projects on energy crops cultivation for investment.

PHYTOPARASITIC NEMATODES OF THREE ENEGRY CROPS FOR BIOFUEL PRODUCTION

The literature review focuses on a comprehensive analysis of scientific research aimed at studying the interaction of phytoparasitic nematodes with energy crops such as Miscanthus, Jerusalem artichoke, and paulownia, as well as examining the factors influencing the spread of these nematodes in cultivation systems of three biofuel crops: giant Miscanthus, velvetleaf, and Jerusalem artichoke. The research is grounded in analyzing the interaction between nematodes and the yield of these crops, along with the potential positive impact of nematode communities from different trophic groups on soil quality and phytoremediation. Special attention is given to phytoparasitic nematodes, which are among the most widespread soil pests of plants. Considering the interaction between nematodes and energy crops is crucial for developing resilient and efficient cultivation systems that ensure high yields and preserve the biodiversity of soil ecosystems.The research concludes that phytoparasitic nematodes have a significant negative impact on the cultivation of energy crops, particularly giant miscanthus. However, certain climatic, chemical, and physical conditions are conducive to the formation of nematode communities that can positively affect soil quality and maintain its fertility. The review provides an overview of three energy crops for biofuel production (giant Miscanthus, velvetleaf, and Jerusalem artichoke), highlighting the nematode pests associated with each of these crops, which have been found in the rhizosphere of plants over many years of published research. Attention is also given to the negative impact of phytoparasitic nematodes on the cultivation of energy crops, especially Miscanthus. However, it has been observed that certain climatic, chemical, and physical conditions favor the formation of nematode communities that can positively influence soil quality and maintain its fertility. This work is significant for the development of strategies to manage the population levels of various trophic levels of nematodes, especially phytoparasitic ones, particularly in the context of cultivating promising energy crops for biofuel production. Additionally, the review describes the important influence of phytoremediation on the population of nematode communities in the soil. The obtained results can serve as a basis for further research in this field and the implementation of effective methods to preserve soil fertility and increase the productivity of energy crops. Furthermore, the findings of this literature review can contribute to the development of environmentally sustainable methods for cultivating energy crops, thereby aiding in the conservation of natural resources and reducing the impact of agricultural activities on the environment.

Energy crops in Brazil: challenges and perspectives for climate change mitigation

This article explores Brazil's current energy crop cultivation scenario, emphasizing strategies to increase diversity and sustainability in biofuel production. The study underscores the importance of investments in research and development, focusing on the identification of new plant species adaptable to various climatic conditions. It highlights the need for integrated approaches, including agricultural zoning based on soil and climate information, to support crop diversification and sustainable agricultural practices such as crop rotation, species consortium, and agroecological methods to maximize resource utilization and minimize environmental impact. Moreover, it emphasizes the need for integrated approaches, including agricultural zoning based on soil and climate information, to support crop diversification. Sustainable agricultural practices, such as crop rotation, species consortium, and agroecological methods, are underscored to maximize resource utilization and minimize environmental impact. The article also discusses the pivotal role of tax incentives and subsidies in encouraging the adoption of energy crops, particularly within the context of family farming. Additionally, it underscores the potential of utilizing residual biomass from agricultural, industrial, and residential activities to further reduce reliance on specific energy crops. The article delves into the significance of scientific knowledge in policy formulation, particularly addressing biodiversity concerns and ensuring a sustainable approach to biofuel production. Furthermore, it highlights that collaborative efforts are essential among governments, private sectors, and research institutions to forge a resilient, equitable, and sustainable future for bioenergy, thereby promoting a diversified and independent energy matrix of Brazil.

The factors determining uptake of energy crop cultivation and woodland creation in England: Insights from farmers and landowners

Perennial energy crops (PECs) and trees have key roles to play in delivering the negative emissions needed for the UK to reduce greenhouse gas emissions to net zero by 2050. Significant changes to land use are needed and the decision to make changes will lie with individual landowners. Using in-depth, semi-structured interviews, this research explores the attitudes of farmers and landowners in England to replacing traditional arable and livestock farming with growing annual or perennial energy crops or planting trees. It was concluded that considerable government policy intervention will be needed to overcome the many economic and social barriers in place including lack of markets and attractive contracts for growers, high establishment costs, loss of annual income, high prices available for cereal crops and the cultural division between farming and forestry. Although energy crops and woodland creation are generally researched and regulated separately, this research suggests that annual energy crops, PECs and woodland creation form a spectrum of land use options for a landowner, with the propensity to adopt these crops being determined predominantly by crop attributes including the risk of planting and the term of commitment.

Complex aspects of climate change impacts on the cultivation of perennial energy crops in the Czech Republic

Perennial energy crops, called also second-generation energy crops, can make a significant contribution to the renewable energy balance in Central European, land locked regions, in the future. When estimating the biomass potential of energy crops, possible impacts of ongoing climate change must be considered. Climate change in Central European conditions will result in an increase in average temperatures and especially in the amount and distribution of precipitation. This will be reflected in a change in the type of climate region assigned to each land plot. Climate change leads to a change in growing conditions, a change in yields of conventional and energy crops and to a change in the allocation of energy crops to land in the region. Analysis of production data from long-term field experiments shows that the varieties of second-generation energy crops are and will be capable of adapting to the current effects of climate change over the next two decades. Modelling of biomass potential in a GIS environment shows that climate change will result in a change in land allocation between short rotation coppice and Miscanthus. The manner in which land is selected for energy crops has a significant impact on biomass potential from second generation energy crop. The paper presents a methodology for estimating the impact of climate change on the biomass potential of perennial energy crops using the Czech Republic as an example.

The efficiency and stability of soil organic carbon sequestration by perennial energy crops cultivation on marginal land depended on root traits

The sustainability of bioenergy cropping systems hinges on the dynamics of soil organic carbon (SOC). Switchgrass and Miscanthus, as the two leading perennial energy crops, have been extensively cultivated on marginal land for bioenergy production. However, the effects of their cultivation on SOC sequestration and its underlying mechanisms remain unclear. Herein, we quantified the contributions of plant– and microbial–derived C to SOC accumulation by tracing 13C natural abundance and amino sugars on switchgrass- and Miscanthus-planted lands (i.e. belongs to poor acidic red soil) experienced 10 years of C3–C4 vegetation conversion. The results showed Miscanthus cultivation induced an approximately 6.3 times greater improvement in SOC compared to switchgrass. However, the organic C stability in Miscanthus-planted soil was comparatively lower than that of switchgrass. This was consistent with our global meta-analysis, whereby Miscanthus and switchgrass cultivation were observed to increase SOC by 16.0% and 7.1%, respectively. Miscanthus–cultivated soil was more replenished by plant–derived C stored in particulate organic C, owing to the greater biomass and lower root quality (reflected by the high ratio of lignin to nitrogen). In contrast, switchgrass–cultivated soil was enriched with more microbial–derived C, as its greater root quality induced a more efficient C utilization by the microbes. This was preferentially associated with the soil minerals. In conclusion, perennial energy crops cultivation on marginal land substantially enhances SOC sequestration, whereas the stability of SOC is dependent on the root traits.

Methodology for strengthening energy resilience with SMART solution approach of rural areas: Local production of alternative biomass fuel within renewable energy community

The article presents a proposal for a comprehensive methodology for the design of the process of local production of alternative energy fuel. The goal of the methodology is to ensure a local source of renewable fuel (biomass) for the needs of covering the supply of thermal energy to citizens in rural areas. In the first part, the methodology deals with the issue of sustainable cultivation of energy crops, namely short rotation coppice and its appropriate placement on soil blocks which are threatened by erosion or degraded by intensive agriculture. Subsequently, the local energy community independently produces alternative pellet biofuel, from the initial cultivation of young woody plants to the final production of ecological wood-based fuel with a calorific value of 16 MJ/ kg. The proposed innovative method of heat production leads to environmental benefits, energy savings, reduced payments for energy supply, and overall modernization of the technologies used.

Deployment of hydrogen in hard-to-abate transport sectors under limited carbon dioxide removal (CDR): Implications on global energy-land-water system

The decarbonization of hard-to-abate transport sectors presents a significant barrier to climate mitigation necessitating the deployment of hydrogen and carbon dioxide removal (CDR) methods. Existing studies are yet to look at the combined implications of these two carbon mitigation solutions on global climate-energy-land-water system. Using an integrated assessment model, several hydrogen transition scenarios for hard-to-abate transport sectors have been developed in the current study against a pathway with just fossil and biofuels. All pathways have been modelled to achieve below 1.5 and 2 °C global mean temperature by 2100. Results show that the transition of hard-to-abate transport sectors to hydrogen would lead to reduction in emissions from the transport sector but resulting emissions from other sectors such as buildings, industry, and power would increase compared to a pathway with just fossil and biofuels. Considering the amount of energy required to transition the hard-to-abate transport sectors to hydrogen, the transition would cause an increase in land use for cultivating energy crops while reducing land allocated for food crops and pastures. Water and fertilizer demand for hydrogen production and energy crop cultivation is another issue to expect from the transition. Transitioning the hard-to-abate transport sectors to hydrogen under limited reliance on CDRs (1.8–2 GtCO2yr−1 until mid-century) could lead to a reduction in primary energy consumption, CO2 emissions, CDR deployment, land expansion for bioenergy crops, water (for bioenergy crops, CDR, and hydrogen production), and fertilizer consumption by 3%, 13%, 14%, 22%, 23%, and 2%, respectively compared to a transition under an unlimited availability of CDRs.

Nematode abundances and community diversity under energy crop (maize and sainfoin) cultivation in annual and perennial cropping systems

Despite conservation efforts and increased awareness, the loss of soil biodiversity goes on across a wide range of ecosystems. Since soil function and structure depend mainly on the state of the biological communities, the soil quality assessment and disturbance in annual vs. perennial cropping systems is done with the help of indicators such as nematodes. Agricultural practices like mix cropping causes variations in the taxonomic abundance of soil nematode communities. This field experiment aimed to assess the overall effect of annual and perennial energy crops (maize: Zea mays and sainfoin: Onobrychis viciifolia) on the nematode communities under pure and mixed cultivation. Sainfoin had the highest nematode abundance, followed by the mixed culture and maize. Out of 38 identified genera, 19 were identified under maize, 31 under perennial sainfoin, 28 under annual sainfoin, 28 under perennial mixture, 20 under the annual mixture and 13 co-existed among these treatments. Of all the trophic groups, the bacterivores were the most abundant (738), followed by plant-parasitic nematodes (272), omnivores (230), fungivores (84), and carnivores (33). Nematode abundance was lower under the annual than perennial plots of both sainfoin and the mixed culture. The perennial plots were dominated by plant-parasitic nematodes. Our results support the idea that soil nematodes should be considered for inclusion in indices of soil quality through their contribution to soil processes. Also, soil nematodes and energy crops like sainfoin may increase the functional properties of agricultural ecosystems and allow better productivity and sustainability.

Utilization and development of biomass energy

As the depletion of fossil fuels becomes increasingly severe, it is crucial to find alternative and sustainable sources of energy. Biomass, which is the largest renewable energy source in the world, is considered an effective solution to the problem of fossil fuel scarcity due to its sustainability, eco-friendly nature, and the wide range of raw materials available. This paper analyzes the current energy situation, energy policies, opportunities, and challenges of biomass energy development in several countries across Europe, Asia, and America. Based on the research results, most countries are proactively seeking to transform their energy systems to ensure sustainable economic development, particularly by utilizing solid biomass, which includes the recycling of industrial and agricultural residues and the cultivation of energy crops. However, biomass energy also faces challenges such as the impact on biodiversity, complex production processes, and high costs.

(По)воєнні перспективи вирощування нішевих культур в аграрному секторі

The pre-war development of the agricultural sector of Ukraine has taken place according to the model of modernization, based on specialization, intensification and expansion of the scale of production. However, European experience shows that this model is viable only in conditions of stable markets. The economic crisis caused by the hostilities forces agricultural producers to change their specialization in favor of diversified production. One of the ways to raise the economic sustainability of farms is to expand their activities through the production of niche crops. The article reveals the relevance of the production of niche agricultural crops during the (post)war period. The authors outline the main advantages (higher sales price, better adaptability to weather and climate conditions, the possibility of balancing crop rotation, lower competition on the market, etc.) that shape the economic potential of the above mentioned crops, and highlight the risks (the need for special agricultural technologies, high production cost, high price volatility, etc.), which inhibit their cultivation. It is noted that the expansion of crop rotation due to the inclusion of leguminous niche crops should become part of a broader (post)war strategy for the sustainable development of Ukraine’s agricultural sector. Cultivation of niche vegetables is a component of resource-conserving agriculture, because crop rotation in vegetable production supports soil structure, controls soil erosion, and increases biodiversity. Obstacles to the spread of niche vegetable production are highlighted. The authors consider various new vegetables that are currently becoming part of the culture of consumption and have considerable prospects (sweet potato, Jerusalem artichoke, etc.), and point out the possibility of adapting the European experience of growing various vegetables in combination with the installation of solar panels (agrovoltaics). Under the conditions of (post)war recovery, the cultivation of niche energy crops would contribute to the diversification of agricultural production, strengthening the economic stability of agricultural producers, increasing the level of environmental friendliness of the energy sector, and shaping the energy independence of rural areas. The article highlights the European experience of mapping agro-ecological technologies, which will make it easier for agricultural producers to introduce new crops, in particular the niche ones, and technologies.

Formation of value-added products from the pyrolysis of date pits: A combined experimental–DFT approach

In arid and semiarid environments, bio-oil extraction from environmentally favorable and waste biomass is presently used as a mainstream strategy for the development of sustainable sources of energy. In keeping with this, we provide a thorough analysis of the pyrolysis of date palm pits here, focusing particularly on relevant thermal degradation profiles and pyrolytic products over a wide temperature range. Pyrolysis experiments were performed using a single-stage reactor at several temperature intervals. The temperature ranges were chosen following mass loss profiles of date pit biomass obtained by thermogravimetric analyzer (TGA) analysis. Density functional theory (DFT) calculations map out reaction pathways that dictate the decomposition of two model compounds that represented oxygen and nitrogen content in the collected condensed and non-condensed fractions. In-depth temperature-dependent profiles of pyrolytic products are thoroughly presented and analyzed. Analysis of products indicates the generation of a wide spectra of green diesel's ingredients of (i.e., long aliphatic compounds) and transportation fuels additives (alkylated benzenes). Aromatic compounds attain the highest fractions in the collected bio-oil at investigated temperature windows. Glucose derivatives appear in appreciable loads in the non-condensable fractions. The obtained mass loss curves reflect degradation curves for the most prominent biomass structural components; namely lignocellulosic, hemicellulose, and lignin. Findings presented herein shall be helpful to develop pyrolysis technologies that are suited for niche categories of biomass found in arid and semiarid regions where cultivation of standard energy crops is impractical.

Assessment of the Prospects of Polish Non-Food Energy Agriculture in the Context of a Renewable Energy Source

This paper describes examples of energy crops that are profitable to burn, and whose cultivation is not complicated or expensive. Rapid growth of biomass, especially the green mass of energy crops, is indicated, which means that, in relation to fossil fuels, energy crops are considered renewable raw materials. An assessment of Polish non-food energy agriculture was conducted in the context of the prospects of a renewable energy source, namely, biomass. Recommendations for crop cultivation, the size of possible yields and the most important parameters of the obtained biomass, which have the greatest impact on the suitability of energy use, are presented. Materials of biological origin for combustion are divided into three groups: wood waste, by-products and plant products for the energy industry. It is indicated that 2 tons (Mg) of dry wood or straw is energetically equivalent to 1 Mg of coal, and 1 m3 of biogas is energetically equivalent to 1 kg of Polish coal. A novelty of this article is the interpretation of obtaining primary energy, including energy from renewable sources, in the European Union and Poland, taking into account the production of wood waste, straw, cereals and energy crops. The mechanism of the impact of the production parameters of energy crops was revealed during the prepared analysis of the prospects of Polish energy agriculture. Additionally, we conducted an analysis of the potential of biomass as a source of energy in the context of: obtaining primary energy, including energy from renewable sources, in the European Union and Poland; the number of biogas plants in Poland; and the area of agricultural land that is potentially useful for the cultivation of energy crops.

Using Landfill Sites and Marginal Lands for Socio-Economically Sustainable Biomass Production through Cultivation of Non-Food Energy Crops: An Analysis Focused on South Asia and Europe

Food security and energy transition are among the current major global environmental challenges. Although these issues individually are significant in their own right, they are connected to each other in a nexus with different interrelationships and dependencies. In the quest for non-fossil alternatives for energy, cultivation of bioenergy crops has become an important part of the energy policy in many countries. In this regard, the use of fertile agricultural land for growing crops for energy production rather than for food supply affects the global food security. Recent conflicts and the geopolitical crisis in Europe, leading to increased food, fuel, and fertiliser prices, the existing climate crisis, and the crisis caused due to the COVID-19 pandemic, have further reinforced the understanding of this nexus, with certain countries mulling limiting biofuel production from agricultural land and others banning food grain exports to safeguard food supply. The idea of growing non-food energy crops on marginal lands in general and closed landfill sites in particular is hence ever more relevant, to avoid land-use concurrence between food needs and energy needs. Landfilling has been the dominant waste management strategy until recently in European countries and is still the dominant mode of waste management in low-income regions like South Asia. This paper provides a review of the economic as well as environmental benefits of growing Ricinus communis L., Jatropha curcas L., and Populus deltoides as energy crops on closed landfill sites in the South Asian context. While as the cultivation of Miscanthus X Giganteus, Silphium perfoliatum L., and Panicum virgatum (Switchgrass) is reviewed in the European context. The cultivation of non-food energy crops like these on closed landfill sites and marginal lands is presented as a potential component of an integrated food-energy policy, with an increased relevance in the current times. In the current times of multiple crises, this measure is of increasing relevance as a part of the overall strategy to achieve resilience and environmental sustainability.

Breeding of sugar beet hybrids suitable for the production of biofuel

The development of bioenergy in Ukraine requires the cultivation of energy crops as renewable sources of energy. Sugar beet hybrids created using valuable sterile and fertile forms can have a breeding perspective as a raw material for the production of biofuel. Therefore, the goal is to create experimental hybrids of sugar beets with high energy output, suitable for obtaining alternative types of biofuel, and to select the best of them. When creating sugar beet hybrids, 6 pollensterile and fertile samples of different ecological and genetic origins were used. The stages of the breeding process were the breeding of the original parental components, their evaluation by combining ability, and the formation of sugar beet hybrids based on the best of them. The method of multi-tester top-crosses and field tests of experimental sugar beet hybrids were applied. It was found that the parental components of sugar beet significantly differed among themselves in terms of bioethanol yield, the indicators of which ranged from 2.06 to 2.43 t/ha (TCS lines) and 2.23 to 2.73 t/ha (pollinators). The highest energy yield in topcross hybrids of sugar beets was noted in combinations created with the participation of polliniferous samples Iv.24869 (61.5 GJ/ha) and Iv.24845 (58.4 GJ/ha). Their effects of ZKZ were reliably positive and amounted to 6.7 and 4.0 GJ/ha, respectively. Numbers 1233-Jan.3 (2x) and 1183 02024 (2x) were recognized as the best pollinators of sugar beets. In the genotypic structure of variability of the "sugar yield" trait, the total share of the influence of valuable additive gene complexes of sugar beet parental forms (51 %) was almost equal to the share of non-additive interaction of components (49 %). By the method of combinatorial breeding, two new hybrid genotypes of sugar beets, suitable for the production of biofuel from renewable sources, were created, in which the energy yield exceeded the group standard by 10.6 and 12.6 %. Key words: bioenergy, sterile forms, pollinators, sugar beet hybrids, combining ability, energy output.

Effects of soil physics, chemistry, and microbiology on soil carbon sequestration in infertile red soils after long‐term cultivation of perennial grasses

AbstractDetermining the effect of perennial energy crop (PEC) cultivation on soil organic carbon (SOC) in marginal land soil is vital for carbon neutrality and bioeconomy development. However, a comprehensive and systematic evaluation of the response of SOC content to different PECs and its underlying drivers is still lacking. We used soil data collected from infertile red topsoil (0–20 cm) after 10 years of cultivation with Miscanthus (MS), Panicum virgatum (SG), and Saccharum arundinaceum (SA) to explore the changes in SOC stock induced by PEC. The roles of physical, chemical, and microbiological factors driving the increase in the SOC stock were investigated. Results revealed that SA and MS enhanced SOC stock by 87.97% and 27.52% relative to the uncultivated control. Conversely, PEC increased the percentage of soil mega‐aggregates, geometric mean diameters, soil chelate iron (Fe), and aluminum (Al) oxides, and reduced soil acidity for the infertile red soils. In addition, fungal richness and diversity for PEC soils were enhanced compared to the unplanted soil. It is possible that PEC cultivation reduced the relative abundance of copiotrophic fungi but increased the relative abundance of oligotrophic fungi. Furthermore, variance partitioning analysis revealed that chemical and microbiological factors accounted for 80.54% of the total variation for the SOC stock. The partial least squares path model showed that PEC cultivation enhanced soil carbon (C) stock via soil deacidification and increased soil bacterial function. In conclusion, this study confirms the SOC sequestration potential of PEC cultivation in marginal land and the underlying mechanism driving SOC stock. The main positive factors controlling soil C sequestration included “pH,” while the negative factors were “bacterial community,” “fungal community,” and “bacterial function.” Our research may help encourage and support decision‐makers of wasted marginal land conversion to PEC cultivation.

The Role of Agricultural Biomass as a Renewable Energy Source in European Union Countries

The aim of the research is to assess the potential of agricultural biomass available in European Union countries that can be used for energy purposes. The research took into account the potential of agricultural biomass from: straw from cereal crops, hay from permanent grasslands, natural fertilizers from animal husbandry, cultivation of energy crops on fallow land and waste wood from permanent crops. The study estimated the theoretical potential presenting the energy value of all existing agricultural biomass resources in EU countries and the technical potential taking into account agricultural biomass resources that are not used in agriculture. The research was based on Eurostat data for 2019. The conducted research shows that European Union countries are characterized by a significant potential of agricultural biomass. However, due to the high demand for this resource in agriculture, about 15% of the existing potential can be used for energy purposes. Among the analyzed sources, the highest potential is characterized by straw from cereal crops and by the cultivation of energy crops on fallow land. The conducted research also indicates a large spatial differentiation of the potential of agricultural biomass in European Union countries, which may have a negative impact on the economic efficiency of using this renewable energy source.

Marginal land conversion to perennial energy crops with biomass removal enhances soil carbon sequestration

AbstractMarginal land conversion to perennial energy crops can provide biomass feedstocks and climate change mitigation. However, the effect of perennial energy crop cultivation on soil organic carbon (SOC) sequestration and its underlying mechanism in marginal land still remains incomplete. Here, SOC turnover, stability, and its potential sequestration were evaluated based on 10 years of land use change from C3 grass‐dominated marginal land to C4 energy crops Miscanthus and switchgrass cultivation. The naturally occurring 13C signature down to 60 cm depth was used to determine the energy crops‐derived C. Compared to reference marginal land, Miscanthus plantation increased the SOC stock at 0–60 cm depth by 17.8% and 64.3% in bulk and root zone, respectively. Similarly, the SOC stock under switchgrass was also 16.5% and 93.0% higher in bulk and root zone than in reference marginal land, respectively. The higher SOC stock in the root zone of switchgrass relative to Miscanthus was supported by the higher contribution of C4‐derived C to SOC (44.5% vs. 32.4%). The mean residence time of old C was higher under switchgrass than Miscanthus in the bulk zone across 0–60 cm (p < 0.05) but remained the same at 0–20 cm in the root zone. Specific SOC mineralization and temperature sensitivity were lower in soils under Miscanthus and switchgrass compared to reference marginal land. The partial least squares path model revealed that perennial energy crop cultivation enhances soil C stock via increased C4‐derived C input and reduced mineralization. In conclusion, marginal land conversion to perennial energy crops is a win–win strategy for C sequestration to mitigate climate change and support the growing bioenergy sector with biomass supply.