Global Change Biology Bioenergy最新文献

Understanding the effects of multiple global change drivers, for example, warming (W) and nitrogen (N) fertilization, is critical for accurately predicting ecosystem responses to climate change. This study investigates the main and interactive effects of soil warming and N fertilization on soil organic carbon (SOC), total nitrogen (TN), microbial biomass, extracellular enzyme activities (EEAs), and soil respiration (R_s) in a switchgrass (Panicum virgatum) cropland located in Middle Tennessee. The field experiment employed a split-plot design with two levels of warming (ambient and heated) and two levels of N fertilization (zero and 168 kg N ha⁻¹ year⁻¹). Hourly measurements of R_s, soil temperature (T), and volumetric moisture (M_v), along with biweekly SOC, TN, microbial biomass carbon (MBC) and nitrogen (MBN), and EEAs in soil samples (0–10 cm) were quantified consecutively for 1 year. Warming significantly increased T by 2.92°C, reduced M_v by 32%, and enhanced R_s by 19%, respectively, but significantly reduced nitrogen acquisition enzyme (N_acq), acid phosphatase (AP), peroxidase (PER), and oxidase (OX). Relative to unfertilized treatment, N fertilization significantly reduced R_s by 14%. There were no significant main or interactive effects of warming and N fertilization on MBC, MBN, SOC, TN, and C:N. A significant negative interaction of warming and N fertilization on R_s was observed, such that N fertilization suppressed R_s by 24% compared to unfertilized treatments under warming conditions. In addition, a significant negative interaction on PER and a significant positive interaction on AP were observed. These results suggest that warming significantly enhanced soil respiratory C losses, while N fertilization reduced this warming impact, likely through reduced enzyme activity and shifts in microbial community function and resource use. The need for long-term field trials is imperative to elucidate the mechanisms underlying these responses under the combined warming and N fertilization, particularly in bioenergy croplands.

Optimising the efficiency of applied nitrogen (N) fertilisers is essential to sustain agricultural systems. Substantial N losses continue through leaching, volatilisation, and denitrification processes. Co-application of organic amendments and biochar alongside synthetic fertilisers is a widely practiced strategy to enhance N retention, improve soil fertility and increase crop productivity. Previous studies have focused on the specific characteristics of soil amendments and the magnitude of yield change, while N use efficiency (NUE) and economic returns remain uncertain. This meta-analysis examined the effects of synthetic fertiliser applied alone, co-applied with biochar and co-applied with organic amendments, on crop yield, plant N uptake, NUE and economic return within rice cropping systems. Synthetic fertiliser and biochar applied alone increased rice yield by 69.2% ± 30.3 and 33.4% ± 34.9, respectively (Bootstrap 95% CI), whereas yield further increased by co-applying biochar (+104.8% ± 37.5) and organic amendments (+80.2% ± 18.2) with fertiliser compared with non-fertilised control. Co-applying organic amendments (+20.9% ± 29.7) and co-applying biochar (+35.1% ± 18.3) with synthetic fertiliser increased NUE compared with fertilised control. For rice crops under low N application (< 150 kg ha⁻¹), co-applying biochar with fertiliser increased yields more than co-applying organic amendments (+70.1% ± 0.7 vs. +52.5% ± 0.3, respectively). Within acidic soils, co-applying biochar with fertiliser (+72.9% ± 0.4) led to higher yield than co-applying organic matter (+36.0% ± 0.9), and among soils with high organic carbon concentration, co-applying biochar with fertiliser increased yield by 97.6% ± 1.6, compared with yield increases observed by co-applying organic matter with fertiliser at 29.4% ± 0.5 and fertiliser alone at 25.6% ± 0.2. The main factors driving rice yield were N application rate, co-application method and soil organic carbon concentration. Co-applying either biochar or organic amendments did not significantly differ in benefit–cost ratio with benefit–cost ratios of 35.1% ± 9.2 and 18.1 ± 26.5, respectively compared with fertilised control. Co-applying either biochar or organic amendments with synthetic fertilisers decreased N inputs and increased economic return, therefore improving sustainability in rice cropping systems.

Developing high-efficiency fertilizers with less environmental footprint is essential for sustainable cropping systems. This study evaluated a biochar mineral complex (BMC) to reduce nutrient leaching and increase nutrient use efficiency (NUE), yield, and economic productivity. The novel BMC was produced by pyrolyzing minerals and organic feedstocks. The BMC was co-applied with organic fertilizers to potting media using two methods: (1) rotary incorporation at 10%, 20%, and 50% rates, and (2) applied as a layer in the middle of the pot at 50% rate, and compared with synthetic and organic fertilizer controls. Nutrient availability and leaching, NUE, crop biomass, yield, and net income were examined. The BMC-layered at 50% rate with organic fertilizer improved nitrogen (N) and potassium (K) use efficiencies by +103% and +158%, respectively, compared with synthetic fertilizer and N, phosphorus (P), and K use efficiencies by +60%, +134%, and +92%, respectively, compared with organic fertilizer. Applying BMC at 50% rate reduced potting costs by 12% and 20% compared with organic and synthetic fertilizers, respectively. The BMC-layered at 50% rate increased net income than synthetic fertilizer, achieving comparable income to organic fertilizer. Balanced nutrient fluxes in the rhizosphere increased NUE, sustained plant growth, and yielded results comparable to synthetic and organic fertilizers despite lower input rates. Co-applying BMC-layered at 50% rate reduced nutrient leaching and led to increased NUE by improving CEC, physical entrapment, and surface bonding within the rhizosphere compared with incorporation methods. Therefore, applying a BMC-layer at the 50% rate is recommended to maximize nutrient use without decreasing yield within fertilizer-intensive and soilless cropping systems.

Developing high-efficiency fertilizers with less environmental footprint is essential for sustainable cropping systems. This study evaluated a biochar mineral complex (BMC) to reduce nutrient leaching and increase nutrient use efficiency (NUE), yield, and economic productivity. The novel BMC was produced by pyrolyzing minerals and organic feedstocks. The BMC was co-applied with organic fertilizers to potting media using two methods: (1) rotary incorporation at 10%, 20%, and 50% rates, and (2) applied as a layer in the middle of the pot at 50% rate, and compared with synthetic and organic fertilizer controls. Nutrient availability and leaching, NUE, crop biomass, yield, and net income were examined. The BMC-layered at 50% rate with organic fertilizer improved nitrogen (N) and potassium (K) use efficiencies by +103% and +158%, respectively, compared with synthetic fertilizer and N, phosphorus (P), and K use efficiencies by +60%, +134%, and +92%, respectively, compared with organic fertilizer. Applying BMC at 50% rate reduced potting costs by 12% and 20% compared with organic and synthetic fertilizers, respectively. The BMC-layered at 50% rate increased net income than synthetic fertilizer, achieving comparable income to organic fertilizer. Balanced nutrient fluxes in the rhizosphere increased NUE, sustained plant growth, and yielded results comparable to synthetic and organic fertilizers despite lower input rates. Co-applying BMC-layered at 50% rate reduced nutrient leaching and led to increased NUE by improving CEC, physical entrapment, and surface bonding within the rhizosphere compared with incorporation methods. Therefore, applying a BMC-layer at the 50% rate is recommended to maximize nutrient use without decreasing yield within fertilizer-intensive and soilless cropping systems.

Increasing demand for multiuse crops in the bioeconomy highlights the potential of industrial hemp (Cannabis sativa L.). However, its regional implementation, particularly in Southern Germany, remains limited. This study examines the industrial hemp value web in the Swabian Alb, assessing its agricultural system resilience through a comprehensive framework of 65 indicators encompassing environmental, social, and economic dimensions. Data were collected through 19 in-depth stakeholder interviews (representing a 76% response rate), elucidating value web dynamics and deconstructing the systemic barriers–regulatory, infrastructural, and economic–that inhibit hemp's full potential. The Swabian Alb, characterised by strong research networks and sustainability awareness, exhibited a volatile hemp cultivation area, decreasing by 56.9% to 25 ha in 2024 compared to 2023. Results reveal a sharp divergence in performance: while hemp provides significant public goods through soil improvement and biodiversity support (e.g., pollen provision and insect habitat), it performs poorly in private goods due to high labour intensity, financial risk, and low revenue. The study identifies a critical infrastructural gap in regional fibre processing and a market frustrated by niche demand. We conclude that sustainable development requires shifting the narrative away from the ‘miracle plant’ myth toward a realistic communication of challenges, supported by targeted policy interventions, consumer education, and secured sales agreements. These findings provide a roadmap for transitioning industrial hemp from a research-driven niche to a resilient bioeconomic staple.

Increasing demand for multiuse crops in the bioeconomy highlights the potential of industrial hemp (Cannabis sativa L.). However, its regional implementation, particularly in Southern Germany, remains limited. This study examines the industrial hemp value web in the Swabian Alb, assessing its agricultural system resilience through a comprehensive framework of 65 indicators encompassing environmental, social, and economic dimensions. Data were collected through 19 in-depth stakeholder interviews (representing a 76% response rate), elucidating value web dynamics and deconstructing the systemic barriers–regulatory, infrastructural, and economic–that inhibit hemp's full potential. The Swabian Alb, characterised by strong research networks and sustainability awareness, exhibited a volatile hemp cultivation area, decreasing by 56.9% to 25 ha in 2024 compared to 2023. Results reveal a sharp divergence in performance: while hemp provides significant public goods through soil improvement and biodiversity support (e.g., pollen provision and insect habitat), it performs poorly in private goods due to high labour intensity, financial risk, and low revenue. The study identifies a critical infrastructural gap in regional fibre processing and a market frustrated by niche demand. We conclude that sustainable development requires shifting the narrative away from the ‘miracle plant’ myth toward a realistic communication of challenges, supported by targeted policy interventions, consumer education, and secured sales agreements. These findings provide a roadmap for transitioning industrial hemp from a research-driven niche to a resilient bioeconomic staple.

The demand for fats, oils, and greases (FOG) as biofuel feedstocks has increased in recent years. Further expansions will have uncertain, but potentially significant, effects on food prices, greenhouse gas emissions, and the U.S. farm economy. To address the market-mediated effects of expanding FOG feedstock consumption, U.S. transportation fuel program regulations are being changed in contradictory and precedent-setting ways. On the one hand, the largest U.S. state (California) is curtailing crediting for vegetable oil feedstocks. On the other hand, federal programs are restricting incentives for imported waste feedstocks like used cooking oil and tallow. These policy changes have created uncertainty about the “FOG” that will be used in biofuels production, since assessing the net effect of these changes is challenging. In this paper, I calculate the effect that these revised and proposed policies have on FOG feedstock incentives. First, I describe how federal and state transportation fuel programs incentivize FOG feedstock consumption. Second, I calculate how program adjustments change the incentives for various FOG feedstocks. I find that the changes have little net effect on U.S. soybean oil and distiller's corn oil (DCO) biomass-based diesel (BBD) incentives in California. Elsewhere in the U.S., soybean oil BBD incentives increase. In contrast, incentives for BBD produced with imported feedstocks are considerably reduced. In summary, the revisions imply that FOG feedstock incentives will be higher for DCO than for other feedstocks.

This study investigated the effects of pristine biochar (BC) and magnesium-treated biochar (Mg-BC), applied at 0%, 1%, and 2.5% (w/w), on the relationship between P fractions and GHG emissions in two degraded soils. Soil physiochemical properties were improved in response to BC and Mg-BC treatments. Enzyme activities increased with BC and Mg-BC treatments, where Mg-BC showed better effects. Similarly, increasing biochar did increase the labile-P pool while decreasing the moderately labile P (MP) and residual P pools in both soils, and the effects observed under Mg-BC treatment were more pronounced than those in the BC treatment. Compared to CK, BC and Mg-BC increased CO₂ emissions by 76%–138% and 44%–127% in red soil, and by 14%–33% and 8%–23% in black soil, respectively. In contrast, N₂O emissions decreased by 11%–29% and 17%–44% in red soil, and by 12%–23% and 16%–31% in black soil, respectively. Multivariate redundancy analysis revealed that biochar-induced improvement in labile P, enzyme activities, and soil properties were positively correlated with CO₂, whereas negatively associated with N₂O emission. The structural equation modeling (SEM) revealed that biochar type and dose had a minor influence on CO₂ emissions, but on the other hand, considerably decreased N₂O emissions (R² = 0.82–0.89) by increasing soil nutrients (SOC, NH₄, AP, and LP) in black soil, and pH, enzymes, and soil nutrients in red soil. Our results demonstrated that biochar application reduces N₂O emissions by improving soil pH, nutrients, and enzyme activities in degraded soils, with a greater impact under Mg-BC treatment.

This study investigated the effects of pristine biochar (BC) and magnesium-treated biochar (Mg-BC), applied at 0%, 1%, and 2.5% (w/w), on the relationship between P fractions and GHG emissions in two degraded soils. Soil physiochemical properties were improved in response to BC and Mg-BC treatments. Enzyme activities increased with BC and Mg-BC treatments, where Mg-BC showed better effects. Similarly, increasing biochar did increase the labile-P pool while decreasing the moderately labile P (MP) and residual P pools in both soils, and the effects observed under Mg-BC treatment were more pronounced than those in the BC treatment. Compared to CK, BC and Mg-BC increased CO₂ emissions by 76%–138% and 44%–127% in red soil, and by 14%–33% and 8%–23% in black soil, respectively. In contrast, N₂O emissions decreased by 11%–29% and 17%–44% in red soil, and by 12%–23% and 16%–31% in black soil, respectively. Multivariate redundancy analysis revealed that biochar-induced improvement in labile P, enzyme activities, and soil properties were positively correlated with CO₂, whereas negatively associated with N₂O emission. The structural equation modeling (SEM) revealed that biochar type and dose had a minor influence on CO₂ emissions, but on the other hand, considerably decreased N₂O emissions (R² = 0.82–0.89) by increasing soil nutrients (SOC, NH₄, AP, and LP) in black soil, and pH, enzymes, and soil nutrients in red soil. Our results demonstrated that biochar application reduces N₂O emissions by improving soil pH, nutrients, and enzyme activities in degraded soils, with a greater impact under Mg-BC treatment.

More and new sources of biomass are needed for renewable energy and renewable products for the bioeconomy. A leading new source of biomass is the highly sustainable perennial grass crop Miscanthus. The majority of the Miscanthus crop comprises a clone of Miscanthus × giganteus (M × g) of limited genetic variation and poor yield under dry growth conditions. The parental species of M × g, M. sacchariflorus and M. sinensis, are distributed over a large geographical range in Eastern Asia and may be used to improve on M × g. From breeding trials, we selected seven novel hybrids and two control genotypes including M × g. We grew these in a field experiment on drought-prone soil in Germany with and without irrigation. To identify superior Miscanthus types, we estimated radiation use efficiency (RUE), yield and water use efficiency (WUE) from within-season measurements made over three contrasting growing seasons. Temporal variations in RUE and WUE for different genotypes varied significantly and two novel hybrids, WAT6 and WAT8, achieved the highest yields. To achieve goodness of fit to yield measurements, genotype-specific parameters for process descriptions in the model MiscanFor were adjusted for the two superior genotypes. These parameters included earlier shooting and an increased threshold of overheating. When the model was run over ten years, despite generating the highest yield values, WAT8 accumulated less biomass than WAT6 over the longer term. The response of WUE to variation in soil capillary pressure and vapour pressure deficit was examined. WUE of M × g increased with the severity of water stress then declined again. The superior yielding genotypes were more able to sustain biomass accumulation and/or water use under the highest stress. We believe that combining physiology with crop modelling is a powerful way to inform genetic and agronomic improvements needed to secure the future supply of biomass for the bioeconomy.