Cultivation Of Bioenergy Crops Research Articles

Social Capital, Trust, and Cultivation of Bioenergy Crops: Evidence from Germany and Greece

In the move towards bioeconomy, little is known about the contribution of factors such as social capital and trust in farmers’ motivation for adopting innovative practices like the cultivation of drought-tolerant bioenergy crops. Based on the broad notion of social capital, this research investigates the level of trust in institutions, cooperation, and the cultural value of farming in Greece and in Germany. Focus group discussions and interviews with farmers show similar levels of trust in institutions in both countries. Trust in cooperation positively related to community social cohesion in Germany, in contrast to the predominant mistrust of formal and informal forms of cooperation in Greece. In Germany, the cultural value of farming, urban “demands” impeding traditional small-scale farming, and their primary role in producing and guarding the rural environment tend to hinder the adoption of bioenergy crop cultivations. In Greece, the marginalization of farming results in an uncertain/ambiguous farming self-concept and, in turn, to an easier adoption of innovations such as the cultivation of bioenergy crops. All three dimensions are pivotal in agriculture, rural development, and energy transition, as they affect how people relate to institutions and to each other and organize and perceive themselves in the current representations of rurality.

The potential for bioenergy generated on marginal land to offset agricultural greenhouse gas emissions in China

Rational use of marginal land for cultivation of bioenergy crops is an effective means to solve land use competition and is an important way to reduce greenhouse gas (GHG) emissions and improve energy supply. This study conducted an evaluation of the suitability of marginal land for growing energy crops in China during 1990–2020 using the GIS and multi-factor analysis method and revealed the quantitative relationship between bioenergy produced by marginal land energy crops and carbon reduction potential. The Intergovernmental Panel on Climate Change (IPCC) coefficient method and life cycle method were applied to measure the biofuel yield of the Jatropha curcas and assessed its potential to offset agricultural greenhouse gas emissions. The findings are: (1) The marginal land area available for energy crops in 2020 is 1.63 × 106 km2, which is 8.35 % lower than the area planted in 1990. (2) When the reclamation index is 60 %, all suitable marginal land can be used to grow energy crops, and biofuels can replace 3.31 × 1011 tons of conventional energy. (3) In 2020, agricultural greenhouse gas emissions will be 9.02 × 108 tons, and the potential of bioenergy crop cultivation to offset agricultural greenhouse gas emissions amounts to 4.31 × 108 tons, or 47.88 %. In the future, the pressure of agricultural GHG emission reduction will be further exacerbated by population growth and agricultural land supply, etc. Rational use of marginal land and development of bioenergy crops are effective ways for China to cope with climate change and realize its renewable energy strategy.

Assessing the sustainability of bioenergy pathways through a land-water-energy nexus approach

Bioenergy can significantly contribute to facilitating the transition to a self-sufficient low-carbon energy sector in Europe. The establishment of sustainable bioenergy systems needs ex-ante analysis that considers specific contexts and potential trade-offs, including competing uses of natural resources such as land, water and energy. The use of marginal and underutilized lands has been emphasized as a valuable strategy to overcome the food vs fuel paradigm and the direct and indirect land use change that can derive from the cultivation of bioenergy crops. Nevertheless, the fragmentation of these lands can significantly affect the energy efficiency of the systems, due to increased energy needs for inputs and transport, with trade-offs on the carbon footprint of the pathway. This study performs an ex-ante assessment of the sustainability of a short bioenergy pathway through the Land-Water-Energy nexus approach, by the iterative use of a web geographic information systems platform, developed on the methodology of the Global Bioenergy Partnership. The simulations show that the production of bioenergy from oilseed crops is expected to reduce greenhouse gas emissions by 73% compared to the reference emission value for fossil fuels in transport. The platform proofs to be effective and user-friendly for assessing and optimizing the intricate interlinkages among the various nexus domains that coexist within the bioenergy system based on the cultivation of underutilized land. Its use can facilitate the nexus operationalization serving as a timesaving decision-support tool for the development of sustainable bioenergy systems that contribute to the transition towards a low-carbon energy sector in Europe.

Increased precipitation over land due to climate feedback of large-scale bioenergy cultivation

Bioenergy with carbon capture and storage (BECCS) is considered to be a key technology for removing carbon dioxide from the atmosphere. However, large-scale bioenergy crop cultivation results in land cover changes and activates biophysical effects on climate, with earth’s water recycling altered and energy budget re-adjusted. Here, we use a coupled atmosphere-land model with explicit representations of high-transpiration woody (i.e., eucalypt) and low-transpiration herbaceous (i.e., switchgrass) bioenergy crops to investigate the range of impact of large-scale rainfed bioenergy crop cultivation on the global water cycle and atmospheric water recycling. We find that global land precipitation increases under BECCS scenarios, due to enhanced evapotranspiration and inland moisture advection. Despite enhanced evapotranspiration, soil moisture decreases only slightly, due to increased precipitation and reduced runoff. Our results indicate that, at the global scale, the water consumption by bioenergy crop growth would be partially compensated by atmospheric feedbacks. Thus, to support more effective climate mitigation policies, a more comprehensive assessment, including the biophysical effects of bioenergy cultivation, is highly recommended.

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.

Comparative transcriptomic and metabolomic study reveal that exogenous 24‐epiandrosterone mitigate alkaline stress in broomcorn millet (Panicum miliaceum L.) via regulating photosynthesis and antioxidant capacity

AbstractGlobally, land alkalinization affecting agricultural development. Considering the increasingly serious effects of alkaline stress on agriculture and environment, phytoremediation may be an efficient way to addressed land alkalinization. Broomcorn millet (Panicum miliaceum L.) is a saline‐alkaline‐tolerant crop and bioenergy crop. However, the molecular mechanism of alkaline response on broomcorn millet remains large gap. To explore the alkaline stress on broomcorn millet and the mitigation of 24‐epicastasterone (BR), the effects of CK (nutrient solution only), CB (nutrient solution + 0.5 mg L−1 BR), AS (alkaline stress), and AB (alkaline stress + 0.5 mg L−1 BR) on TA289 (alkaline‐tolerant) and SA223 (alkaline‐sensitive) were investigated. Alkaline stress enhanced reactive oxygen species and membrane lipid peroxidation. BR boosted antioxidant enzyme activities to reduce oxidative stress. Simultaneously, BR attenuated Na+ toxicity and maintained ion homeostasis. Additionally, BR significantly maintained the physiological structure and photosynthetic properties. Transcriptomic and metabolomic analyses were applied to further evaluate the effect of BR on photosynthetic and antioxidant defense. The results showed that BR significantly reduced the transcriptional responses of photosynthesis and antioxidant defense and promoted the accumulation of effective metabolites such as biliverdin, l‐glutamate, and phosphoric acid. Taken together, BR application can significantly alleviate the damage of alkaline stress to broomcorn millet by altering transcriptional expression and metabolite accumulation and is a simple and effective strategy to alleviate alkaline stress. This study reveals the molecular mechanism of BR to enhance photosynthetic capacity and antioxidant defense of broomcorn millet under alkaline stress, which provides theoretical support for the cultivation of bioenergy crops on alkaline lands and the breeding of alkaline‐tolerant bioenergy varieties.

Temperature Changes Induced by Biogeochemical and Biophysical Effects of Bioenergy Crop Cultivation.

The production of bioenergy with carbon capture and storage (BECCS) is a pivotal negative emission technology. The cultivation of dedicated crops for BECCS impacts the temperature through two processes: net CO2 removal (CDR) from the atmosphere (biogeochemical cooling) and changes in the local energy balance (biophysical warming or cooling). Here, we compare the magnitude of these two processes for key grass and tree species envisioned for large-scale bioenergy crop cultivation, following economically plausible scenarios using Earth System Models. By the end of this century, the cumulative CDR from the cultivation of eucalypt (72-112 Pg C) is larger than that of switchgrass (34-83 Pg C) because of contrasting contributions of land use change carbon emissions. The combined biogeochemical and biophysical effects are cooling (-0.26 to -0.04 °C) at the global scale, but 13-28% of land areas still have net warming signals, mainly due to the spatial heterogeneity of the biophysical effects. Our study shows that the deployment of bioenergy crop cultivation should not only be guided by the principles of maximizing yield and CDR but should also take an integrated perspective that includes all relevant Earth system feedbacks.

Забруднення угідь унаслідок бойових дій: огляд рішень для подолання кризи

The purpose of this work is to analyze the types of pollution on the lands that have undergone hostilities and to review scientific research on this topic in order to find rational technological solutions to overcome the crisis. Methods and materials. The study is aimed at reviewing open scientific literary sources regarding the contamination of agricultural lands affected by the conduct of military operations. The research focuses on physical and chemical disturbances in the soil caused by military actions (bombing of land, land contamination by shrapnel remains, soil compaction by military equipment, chemical pollution by heavy metals, etc.) and land restoration methods. Research results. The primary task in eliminating the consequences of hostilities is the demining of land areas. There is a wide range of types of means for finding mines and machines for demining, in which the working body can be a reactive explosive device or a mechanical system in the form of a bucket, rollers of a rotating rotor, etc. Reclamation of lands disturbed as a result of military operations is carried out in two stages: technical and biological. The essence of the technical stage is to prepare the territories for the next target use. It consists in planning, as well as applying soil or fertile rocks to a leveled surface. The biological stage is a set of measures to restore the fertility of disturbed lands. It covers agrotechnical and reclamation measures aimed at restoring flora and fauna. To overcome the consequences of soil pollution by oil products and to compensate for nitrogen losses on land due to burning of fields, it is advisable to use active oil-oxidizing and regenerating soil microorganisms, by applying them with tillage and seeding units equipped with devices for applying liquid and dry complex fertilizers. Conclusions. Among the practical agrotechnical approaches to soil restoration after rough reclamation of land, the following can be distinguished: cultivation of bioenergy crops on damaged lands; application of minimal tillage technologies using organic waste and microbiological preparations; biotechnologies of soil remediation. In view of the technical and technological solutions of soil treatment for land restoration, each of the following consequences requires a special approach. Reclamation of damaged lands is advisable when experts estimate the terms of restoration of economic activity at no more than 15 years. If the soil cover needs a longer period for recovery, land conservation is carried out. Key words: soil pollution, hostilities, reclamation, remediation, land reclamation, soil treatment.

Stakeholders' Perception of Bioenergy Projects in Marginal and Underutilized Lands in Italy

Large land areas in European countries can be considered marginal, underutilized, and contaminated (MUC). Many recent studies have shown that bioenergy crop cultivation can make this land profitable, creating new income opportunities for local citizens without interfering with food production. However, farmers, landowners, and local communities must become more familiar with bioenergy systems, potential value chains, and markets. This paper aims to present the results of stakeholder consultations implemented in two case study areas in Italy, i.e., Basilicata and Sardinia, about the possible establishment of bioenergy systems in the MUC land available at the local level. Stakeholders' perceptions were collected through interviews conducted on a one-to-one basis and through multi-stakeholder working group meetings organized in the context of BIOPLAT-EU, an H2020 project aimed at promoting the efficacy and profitability of using MUC land for sustainable bioenergy production. By and large, the findings of the consultations indicate that local stakeholders are prone to accept the establishment of innovative bioenergy value chains based on the cultivation of MUC lands in their regions. The majority of them recognized that bioenergy could bring a wide range of benefits at the local level, not only in terms of environmental externalities but also of economic and social development, such as through the creation of new business and job opportunities, therefore serving to alleviate or prevent the land abandonment and population decline currently on-going in these areas.

Soil phosphorus drawdown by perennial bioenergy cropping systems in the Midwestern US

AbstractWithout fertilization, harvest of perennial bioenergy cropping systems diminishes soil nutrient stocks, yet the time course of nutrient drawdown has not often been investigated. We analyzed phosphorus (P) inputs (fertilization and atmospheric deposition) and outputs (harvest and leaching losses) over 7 years in three representative biomass crops—switchgrass (Panicum virgatum L.), miscanthus (Miscanthus × giganteus) and hybrid poplar trees (Populus nigra × P. maximowiczii)—as well as in no‐till corn (maize; Zea mays L.) for comparison, all planted on former cropland in SW Michigan, USA. Only corn received P fertilizer. Corn (grain and stover), switchgrass, and miscanthus were harvested annually, while poplar was harvested after 6 years. Soil test P (STP; Bray‐1 method) was measured in the upper 25 cm of soil annually. Harvest P removal was calculated from tissue P concentration and harvest yield (or annual woody biomass accrual in poplar). Leaching was estimated as total dissolved P concentration in soil solutions sampled beneath the rooting depth (1.25 m), combined with hydrological modeling. Fertilization and harvest were by far the dominant P budget terms for corn, and harvest P removal dominated the P budgets in switchgrass, miscanthus, and poplar, while atmospheric deposition and leaching losses were comparatively insignificant. Because of significant P removal by harvest, the P balances of switchgrass, miscanthus, and poplar were negative and corresponded with decreasing STP, whereas P fertilization compensated for the harvest P removal in corn, resulting in a positive P balance. Results indicate that perennial crop harvest without P fertilization removed legacy P from soils, and continued harvest will soon draw P down to limiting levels, even in soils once heavily P‐fertilized. Widespread cultivation of bioenergy crops may, therefore, alter P balances in agricultural landscapes, eventually requiring P fertilization, which could be supplied by P recovery from harvested biomass.

Climate change mitigation potentials of biofuels produced from perennial crops and natural regrowth on abandoned and degraded cropland in Nordic countries

Bioenergy expansion is present in most climate change mitigation scenarios. The associated large land use changes have led to concerns on how bioenergy can be sustainably deployed. Promising win-win strategies include the production of perennial bioenergy crops on recently abandoned cropland or on cropland prone to land degradation, as perennial crops typically reduce soil erosion rates. Natural vegetation regrowth is an alternative nature-based solution that can also co-deliver negative emissions and other environmental benefits. In this study, we explore the potential to deploy bioenergy crops in Nordic countries (Norway, Sweden, Finland, and Denmark) on abandoned cropland and on cropland threatened by soil erosion and compare the achievable climate change mitigation benefits with natural regrowth. We found 186 thousand hectares (kha) of abandoned cropland and 995 kha of cropland threatened by soil erosion suitable for bioenergy crop cultivation. The primary bioenergy potential in the region is 151 PJ (PJ) per year, corresponding to 67–110 PJ per year of liquid biofuels depending on biorefinery technology. This has a climate change mitigation potential from −6.0 to −17 megatons of carbon dioxide equivalents (MtCO2eq) per year over the first 20 years (equivalent to 14–40% of annual road transport emissions), with high-end estimates relying on bioenergy coupled to carbon capture and storage (BECCS). On the same area, natural regrowth can deliver negative emissions of −10 MtCO2eq per year. Biofuel production outperforms natural regrowth on 46% of abandoned cropland with currently available biorefinery technologies, 83% with improved energy conversion efficiency, and nearly everywhere with BECCS. For willow windbreaks, improved biorefinery technology or BECCS is necessary to ensure the delivery of larger negative emissions than natural regrowth. Biofuel production is preferable to natural regrowth on 16% of croplands threatened by soil erosion with the current biorefinery technology and on 87% of the land area with BECCS. Without BECCS, liquid biofuels achieve larger climate benefits than natural regrowth only when bioenergy yields are high. Underutilized land and land affected by degradation processes are an opportunity for a gradual and more sustainable bioenergy deployment, and local considerations are needed to identify case-specific solutions that can co-deliver multiple environmental benefits.

Biomass dry matter yield of willow and Miscanthus in low‐input cropping on heavy clay soils in Ukraine

AbstractIn Ukraine, 6.5 million hectares of agricultural land characterized by heavy clay soil could be available for sustainable bioenergy crop cultivation because they are considered marginal for food crop cultivation. This study investigated the biomass dry matter yield (DMY) of willow (Salix triandra L. and Salix viminalis L.) and Miscanthus (Miscanthus × giganteus Greef et Deuter) at two experimental sites with heavy clay in Ukraine. To promote plant rooting and adaptation in the first year of cultivation under low‐input conditions, tillage, moisture‐retaining agents, foliar fertilization, planting density and row spacing were varied. Willow obtained notable DMY on hard clay soils (clay >50%). The variety ‘Tora’ revealed the best DMY performance, indicated by the highest increment (4.1–4.6 m) in the first year of the second cycle. The highest biomass DMY (28.8 Mg ha−1) was obtained at a planting density of 15 000 plants ha−1 and a row spacing of 0.75 × 1.50 m. However, neither willow nor Miscanthus allow for a feasible biomass production at clay contents above 64%, because the young roots are damaged and deprived of nutrients as the soil dries out. For Miscanthus, plowing provided better soil loosening and easier sprouting of rhizomes compared with mini‐till. The application of moisture‐retaining agent Aquasorb (200 kg ha−1) supported Miscanthus plants with moisture in the first year of vegetation, but it did not maintain soil moisture in the long term. Therefore, growing willow and Miscanthus on soils with clay contents above 64% is not feasible because the soil texture and tendency to crack significantly reduce the DMY. © 2022 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.

Socio-Economic and Environmental Implications of Bioenergy Crop Cultivation on Marginal African Drylands and Key Principles for a Sustainable Development

Africa has been a hotspot for the development of food and bioenergy crop cultivation since the 2000s, leading to systematic challenges towards its ability to become a bioeconomy. To reduce land-use conflicts with food crop cultivation, marginal African drylands (MADs) are proposed for sustainable bioenergy cropping systems (BCSs). This study reviews the foremost socio-economic and environmental challenges for BCSs on MADs, and the development of key principles for minimizing adverse outcomes towards a sustainable bioeconomy. Socio-economic prosperity in Africa depends on several systematic solutions, and BCSs that are based on perennial bioenergy crops are promising strategies as they provide a renewable and sustainable energy source for rural areas. However, critical multidimensional challenges such as poverty, food security, gender equality, access to energy, and environmental impact must also be considered to ensure long-term sustainability. This review argues for more transparent land sales/usage (considering the agricultural work of women) and more perennial bioenergy crops. In this context, key principles were derived for a people-centered bottom-up approach that is considered fundamental to ensure the sustainable development of BCSs on MADs in the future.

Defining potential valuables through the characterisation of lake sediments: case study in Arkelstorp bay, Sweden

This study aims to characterise and discuss the potential use of sediment from the Arkelstorp bay located in the south of Sweden. Sediments from the Arkelstorp bay is collected and analysed on nutrient content, age, and potential contaminants. No organic environmental pollutants are found and the metal content are not elevated but still problematically high. For example, the amount of cadmium per phosphorus is 480 mg Cd kg−1 P. However, as the carbon 14-datings showed, the sediment is preindustrial. Therefore, the amount of registered cadmium comes naturally from the surrounding environment. Arkelstorp sediments present the potential to become a source of nutrition in agriculture. The results show that the material is a good source of nutrients, with a nitrogen content of 18 g kg−1 dry matter (DM), phosphorus 0.8 g kg−1 DM and potassium 2.4 g kg−1 DM respectively. However, the metal content is problematic to use the material without any pre-treatment. On the other hand, bioenergy production is expected to increase in the future, where this resource could potentially be helpful for the cultivation of bioenergy crops.

Global cooling induced by biophysical effects of bioenergy crop cultivation

Bioenergy crop with carbon capture and storage (BECCS) is a key negative emission technology to meet carbon neutrality. However, the biophysical effects of widespread bioenergy crop cultivation on temperature remain unclear. Here, using a coupled atmosphere-land model with an explicit representation of lignocellulosic bioenergy crops, we find that after 50 years of large-scale bioenergy crop cultivation following plausible scenarios, global air temperature decreases by 0.03~0.08 °C, with strong regional contrasts and interannual variability. Over the cultivated regions, woody crops induce stronger cooling effects than herbaceous crops due to larger evapotranspiration rates and smaller aerodynamic resistance. At the continental scale, air temperature changes are not linearly proportional to the cultivation area. Sensitivity tests show that the temperature change is robust for eucalypt but more uncertain for switchgrass among different cultivation maps. Our study calls for new metrics to take the biophysical effects into account when assessing the climate mitigation capacity of BECCS.

Soil carbon stocks and water stable aggregates under annual and perennial biofuel crops in central Ohio

Biofuels have the potential to mitigate global warming by partially replacing fossil fuels. Long-term cultivation of bioenergy crops may affect soil quality and C exchange between the soil-plant-atmosphere continuum depending upon crop type and duration of cultivation. Thus, studies are needed to compare the impact different bioenergy crops have on soil organic carbon (SOC) stocks to estimate the net C mitigation potential of these crops. This study reports on changes in soil properties and C stocks after eight years of annual no-till (NT) corn (Zea mays L.), sorghum (Sorghum bicolor L.), perennial switchgrass (Panicum virgatum L.), miscanthus (Miscanthus x giganteus), and polyculture prairie cultivation in central Ohio. Perennial biofuel crops (PBCs) improved soil health by reducing soil bulk density, increasing soil porosity, and improving soil aggregate stability compared to those under annual bioenergy crops (ABCs). Changes were most prominent in the surface 0–10 cm soil layer. Bulk density decreased by 14.4% and 12.8% under PBCs and 6.0% and 5.7% under ABCs in the 0–10 cm and 10–20 cm depths, respectively. Water stable aggregate values in the PBC systems were 29.6% (0–10 cm) and 23.0% (10–20 cm) greater than those in the ABC systems with maximum and the minimum values observed under miscanthus (95.1%) and corn (70.2%). PBC systems retained 71% of overall aggregates within the > 4.75 mm size fraction after wet sieving and 2% in the < 0.25 mm size fraction, compared to ABCs retaining 20% and 28% of total aggregates within these two aggregate size fractions, respectively. C and N accumulation were greater in macroaggregates (>0.25 mm) compared to microaggregates (<0.25 mm). The SOC stock within the first eight years of the study decreased by 8.25 Mg C ha−1 (annual rate of −1.03 Mg C ha−1 y−1) for the ABC systems. In contrast, the SOC stock under PBCs for the first eight years increased by 7.94 Mg C ha−1 at an annual rate of 0.99 Mg C ha−1 y−1. These data indicate that PBCs enhanced SOC stocks and provided the dual benefit of increasing SOC stock and improving soil properties. The rate and cumulative amount of SOC sequestration were the highest under miscanthus and the least under sorghum. However, more information is needed on the C life-cycle of biofuel crops and profile C changes to evaluate the net C mitigation potential.

Marginal lands for bioenergy in China; an outlook in status, potential and management

AbstractEnergy consumption and CO2 emissions have been increasing continuously over the past few decades in China and there is a pressing need to replace the fossil fuel‐based economy with an efficient low‐carbon system, tailor‐made to future requirements. China is starting an energy transition with the aim of building an energy system for the future. China has made tremendous progress in increasing the amount of renewable energy and reducing the cost of renewable energy over the last 20 years. According to the 14th 5 year plan, China aims to incorporate 20% of renewable energy to the primary energy mix and attain 27% reduction in CO2 emissions. Bioenergy crops constitute a significant proportion of biomass‐based bioenergy and have recently been promoted by the Chinese Government to help overcome food and fuel conflict. Steps are being taken to promote bioenergy crops on marginal lands in China, and various regions across the country with soil marginality have been evaluated for bioenergy crop cultivation. The present paper reviews the status of bioenergy in China and the potential status of marginal lands from different regions of China. It also elaborates on some of the policies, subsidies and incentives allocated by the Chinese Government for the promotion of biomass‐based energy. Land management and plant improvement strategies were discussed, which are effective in making marginal lands suitable for bioenergy crop cultivation. Managing planting strategies, intercropping and crop rotation are effective management practices used in China for the utilization of marginal lands. A national investigation is desirable for creating an inventory of technical and economic potential of biomass feedstocks that could be planted on marginal lands. This would assist with highlighting the pros and cons of using marginal lands for bioenergy production and effective policy making.

Cultivation of bioenergy crops in Gujarat state: a consultative survey process to understand the current practices of landowners

Bioenergy crops can contribute to the reduction of overall consumption of fossil fuels; however, India is a heavily populated agriculture economy demanding huge amounts of food and energy, so use of agricultural lands to produce energy crops puts a direct pressure on agri-based economy. A collaborative project for development of Sustainable Advanced Lignocellulosic Biofuel Systems was launched in 2012 between USA and India emphasizing high biomass bamboo, sorghum and pearl millet feedstock cultivation at marginal ecologies in 9 villages of 3 districts of Gujarat state in India. A baseline survey was conducted by interviewing 415 households followed by focus group discussion to understand socioeconomic profile of the targeted region, agricultural practices, awareness and inclination of local growers toward commercialization of biofuels crops. Survey data were analyzed using SPSS statistical tool. The survey showed that land holding of 2.5–5 acres and 5–10 acres was prevalent, with rain-fed and borewell irrigation and average soil quality having medium to shallow deep soil structure. Annual income from farm showed positive association with soil quality, while lower productivity from bad-quality soil. Households were interested to grow biofuel crops only if they give better net profit as compared to current crops. Good land quality, larger cultivated area and joint family had relatively less risk of bioenergy crop production than the counterpart. Household having above poverty line (77.8%) signified annual income of more than 10,000 INR. Lower literacy rate showed that 5–15% of the members migrated out of village for temporary seasonal livelihood. The districts were well connected with roads with enough frequency of state and private vehicles, railways, government postal services, mobile phone network and round the time electricity for household entitled the districts to penetrate bioenergy market. Leveraging available infrastructure and adopting large-scale co-operative mechanized farming, crop rotation within agro-forestry system, diversification of food, fiber and energy crops through policy support would bring economic and environmental benefits along with new market, job creation and bioenergy industries at surveyed ecology.

Prospects of Bioenergy Cropping Systems for A More Social-Ecologically Sound Bioeconomy

The growing bioeconomy will require a greater supply of biomass in the future for both bioenergy and bio-based products. Today, many bioenergy cropping systems (BCS) are suboptimal due to either social-ecological threats or technical limitations. In addition, the competition for land between bioenergy-crop cultivation, food-crop cultivation, and biodiversity conservation is expected to increase as a result of both continuous world population growth and expected severe climate change effects. This study investigates how BCS can become more social-ecologically sustainable in future. It brings together expert opinions from the fields of agronomy, economics, meteorology, and geography. Potential solutions to the following five main requirements for a more holistically sustainable supply of biomass are summarized: (i) bioenergy-crop cultivation should provide a beneficial social-ecological contribution, such as an increase in both biodiversity and landscape aesthetics, (ii) bioenergy crops should be cultivated on marginal agricultural land so as not to compete with food-crop production, (iii) BCS need to be resilient in the face of projected severe climate change effects, (iv) BCS should foster rural development and support the vast number of small-scale family farmers, managing about 80% of agricultural land and natural resources globally, and (v) bioenergy-crop cultivation must be planned and implemented systematically, using holistic approaches. Further research activities and policy incentives should not only consider the economic potential of bioenergy-crop cultivation, but also aspects of biodiversity, soil fertility, and climate change adaptation specific to site conditions and the given social context. This will help to adapt existing agricultural systems in a changing world and foster the development of a more social-ecologically sustainable bioeconomy.

Interspecific Variations in the Growth, Water Relations and Photosynthetic Responses of Switchgrass Genotypes to Salinity Targets Salt Exclusion for Maximising Bioenergy Production

The expansion in the cultivation of bioenergy crops to saline lands is of importance for ensuring food security as long as high productivity is maintained. The potential of switchgrass to grow under saline conditions was examined in three genotypes from a early seedling growth to full maturity at 50, 100, 200 and 300 mM of sodium chloride (NaCl). The carbon assimilation rates were generally lower and correlated to stomatal closure in plants exposed to salinity in all the tested genotypes. Based on the results of ion concentrations in different parts of the plant, switchgrass genotypes differed in their responses to NaCl. The Alamo genotype excluded salt from the roots, whereas Trailblazer and Kanlow accumulated it in the root, stem and leaf tissues. The increased leaf salt concentration was accompanied by a higher proline concentration in the 200 and 300 mM NaCl treatments toward the end of the experiment. Overall, Alamo showed the highest yields at all salinity levels, indicating that excluding salt from the roots may result in a better performance in terms of biomass production. The accumulation of salt observed in Kanlow and Trailblazer resulted in lower yields, even when other mechanisms, such as the production of salt glands, were observed, especially in Kanlow. These results suggest that the Alamo genotype has the ability to maintain high yields under saline conditions and that this characteristic could be further exploited for maximizing bioenergy production under saline conditions.