Bioenergy Crops Research Articles

Willingness to adopt green house gas mitigation measures: Agricultural land managers in the United Kingdom.

Rapid uptake of greenhouse gas (GHG) mitigation measures is central to reducing agricultural and land use emissions and meeting the UK Net Zero policy. The socioeconomic challenges and barriers to uptake are poorly understood, with yet unclear structural pathways to the uptake of GHG mitigation measures. Using an online survey of 201 agricultural land managers across the UK, and applying multiple linear regression and stepwise regression analysis, this research established farm and farmers' factors influencing perceptions and willingness to adopt GHG mitigation measures. The results consistently show that farm sector, farmers' business perception, and labour availability influence willingness to adopt GHG mitigation measures. Based on the farmers' qualitative feedback, other barriers to adoption include costs and concerns for profitability, lack of flexibility in land tenancy contracts, poor awareness and knowledge of the application of some GHG mitigation measures, perception about market demand e.g bioenergy crops, and scepticism about the future impacts of adopting varying GHG mitigation measures. In the midst of the ongoing net zero transition, this study identifies existing barriers to the uptake of GHG mitigation measures, and specifically, a substantial gap between farmers and the science of GHG mitigation measures and the need to incentivise a farm and farming community-led policy interventions to promote adoption of GHG mitigation measures.

Synergistic effect by Sorghum bicolor L., citric acid, biochar, and vermiwash amendment for the remediation of a mine-contaminated soil.

Phytoremediation is an in situ remediation and eco-friendly technique employing accumulator plant species to remove trace elements (TEs) from contaminated sites. Moreover, it has been demonstrated that both natural and synthetic amendments can enhance trace elements (TEs) phytoremediation from polluted soils through bioenergy crops. This work assessed the synergistic impact of two tested biochar (BC) from data palm (B1) and Prosopis (B2) (1.5%/ kg), citric acid (CA, 1.5 mmol/kg) and vermiwash (VW, 20 ml/kg) to enhance the remediation of tested TEs (Mn, Zn, Cd, Pb, Ni, Cu, and Fe) from Mahad AD'Dahab mine-contaminated soil by sorghum (Sorghum bicolor L.). The BC and CA amendments alone and combined with VW significantly augmented the proliferation and survival of sorghum grown in mine-contaminated soil. Considering the individual and combined applications of VW and BC, the influence on plant growth followed this order: K < VW < B2 < B1 < B1 + VW < B2 + VW < CA < CA + VW. Applying tested BC/CA and VW significantly increased chlorophyll compared to unamended soil. The outcomes revealed a substantial elevation in TE absorption in both shoot and root (p ≤ 0.05) with all tested treatments compared to the untreated soil (K). The combined application of CA and VW resulted in the most significant TE uptake of TEs at both the root and the shoot. Furthermore, adding CA or VW as a foliar spray enhanced the bioaccumulation factor (BCF) and translocation factor (TF) of studied metals. The combined addition of CA and foliar spraying of VW was more effective than the sole addition of CA or VW. Such increase reached 20.0%, 15.6%, 19.4%, 14.3%, 14.0%, and 25.6% of TF, and 13.7%, 11.9%, 8.3%, 20.9%, 20.5%,18.7%, and 19.8% of BCE for Cd, Cu, Fe, Mn, Ni, Pb, and Zn, respectively. This study highlights the efficiency of combining CA/BC with VW as a more viable option for remediating mine-contaminated soil than individual amendments. However, future research should prioritize long-term field trials to assess the efficiency of using citric acid and vermiwash for restoring contaminated mining soils.

Photosynthetic responses of switchgrass to light and CO2 under different precipitation treatments

AbstractSwitchgrass (Panicum virgatum L.) is a prominent bioenergy crop with robust resilience to environmental stresses. However, our knowledge regarding how precipitation changes affect switchgrass photosynthesis and its responses to light and CO2 remains limited. To address this knowledge gap, we conducted a field precipitation experiment with five different treatments, including −50%, −33%, 0%, +33%, and +50% of ambient precipitation. To determine the responses of leaf photosynthesis to CO2 concentration and light, we measured leaf net photosynthesis of switchgrass under different CO2 concentrations and light levels in 2020 and 2021 for each of the five precipitation treatments. We first evaluated four light and CO2 response models (i.e., rectangular hyperbola model, nonrectangular hyperbola model, exponential model, and the modified rectangular hyperbola model) using the measurements in the ambient precipitation treatment. Based on the fitting criteria, we selected the nonrectangular hyperbola model as the optimal model and applied it to all precipitation treatments, and estimated model parameters. Overall, the model fit field measurements well for the light and CO2 response curves. Precipitation change did not influence the maximum net photosynthetic rate (Pmax) but influenced other model parameters including quantum yield (α), convexity (θ), dark respiration (Rd), light compensation point (LCP), and saturated light point (LSP). Specifically, the mean Pmax of five precipitation treatments was 17.6 μmol CO2 m−2 s−1, and the ambient treatment tended to have a higher Pmax. The +33% treatment had the highest α, and the ambient treatment had lower θ and LCP, higher Rd, and relatively lower LSP. Furthermore, precipitation significantly influenced all model parameters of CO2 response. The ambient treatment had the highest Pmax, largest α, and lowest θ, Rd, and CO2 compensation point LCP. Overall, this study improved our understanding of how switchgrass leaf photosynthesis responds to diverse environmental factors, providing valuable insights for accurately modeling switchgrass ecophysiology and productivity.

Biochar technology cannot offset land carbon emissions in Guangdong province, China

As a highly developed region, Guangdong province has substantial industrial emissions. Its subtropical monsoon climate, characterized by abundant hydrothermal conditions, contributes to a substantial biomass potential. The adoption of potential biomass-based carbon dioxide removal (CDR) technologies, such as biochar, presents an opportunity to mitigate emissions and work towards carbon neutrality in the future. However, the current state of the land carbon balance and the CDR potential of biochar in Guangdong province remains unclear. We first calculated the land carbon balance based on inventory data. Then we estimated the CDR potential of biochar derived from agricultural residues, forestry residues, and bioenergy crops cultivated on marginal lands in Guangdong province using life cycle analysis (LCA). Results show that Guangdong province has not yet achieved carbon neutrality, with a net emission (carbon emissions remaining after offsetting by carbon sinks) of 925.63 Tg CO2e (CO2 equivalent, 1Tg = 106 t) in 2021. Emissions from energy consumption account for the highest proportion, contributing 83.8% of total emissions. In the highest biomass utilization scenario, the maximum CDR potential of biochar derived from all biomass types reaches 84.30 Tg CO2e yr-1, which could offset 9.11% of net carbon emissions in Guangdong province. Our findings provide crucial guidance for setting emission reduction targets and implementing effective mitigation strategies in Guangdong province under temperature warming.Graphical

Potential of Miscanthus × giganteus as fuel in a suspended furnace

ABSTRACT Miscanthus is one of the potential bioenergy crops in the world. This non-woody biomass can grow almost anywhere and does not require high cultivation costs. Its energy content is approximately 525 GJ/ha/year, the highest among other non-woody biomass. This research aims to study the potency of Miscanthus × giganteus as fuel in a suspended furnace. Some combustion characteristics of Miscanthus particles were determined experimentally and numerically. At a 40°C/min heating rate, the particle's initial and active decomposition temperatures are 197 and 352°C, respectively. The study also reveals that the combustion mode of the Miscanthus particles was affected by the furnace temperature. At furnace temperatures of 300–400°C, the combustion mode of the Miscanthus particles refers to the simultaneous combustion model. While, at temperatures 450–600°C, its combustion produces extensive flames and is called the sequential combustion model. The extensive flames are useful in cyclone furnaces to maintain combustion stability. Under cold modelling, the average drag time of the representative particles with an equivalent diameter of 1384 µm, in a typical furnace, is 26.82 s, much higher than its combustion time of 11.25 s. This indicates that the particles can be burned out in a suspended state.

Reducing sectoral hard-to-abate emissions to limit reliance on carbon dioxide removal

To reach net-zero greenhouse gas targets, carbon dioxide removal (CDR) technologies are required to compensate for residual emissions in the hard-to-abate sectors. However, dependencies on CDR technologies involve environmental, technical and social risks, particularly related to increased land requirements for afforestation and bioenergy crops. Here, using scenarios consistent with the 1.5 °C target, we show that demand and technological interventions can substantially lower emission levels in four hard-to-abate sectors (industry, agriculture, buildings and transport) and reduce reliance on the use of bioenergy with carbon capture and storage. Specifically, demand measures and technology-oriented measures could limit peak annual bioenergy with carbon capture and storage use to 0.5–2.2 GtCO2e per year and 1.9–7.0 GtCO2e per year, respectively, compared with 10.3 GtCO2e per year in the default 1.5 °C scenario. Dietary change plays a critical role in the demand measures given its large share in residual agricultural emissions.

Cost‐effective use of abandoned agricultural land for biofuel production

AbstractBiofuel can be used to abate greenhouse gas emissions in the transport sector, by replacing fossil fuel. To avoid the problem of competition with food production, the use of abandoned agricultural land (AAL) for production of the feedstock for biofuel has been proposed. AAL has generally low productivity but has also low opportunity costs, and production of perennial bioenergy crops on it can lead to carbon sequestration. A spatially explicit optimization model of biofuel production and transport fuel consumption, applied to Sweden, was used for an analysis of how AAL can alter costs for greenhouse gas emissions abatement. Results show that, compared to the case without AAL, AAL could decrease the costs of reducing greenhouse gas emissions by 29%, for emissions reductions equivalent to 50% of current emissions from gasoline in Sweden. The carbon sequestration from establishing perennial bioenergy crops on AAL is the main driver of the positive results. High carbon sequestration on AAL implies larger emissions reduction for a given volume of biofuel, and the results show that the total biofuel production can be both smaller and larger with AAL. The use of arable land for biofuel production is generally smaller with AAL, but larger at some of the highest analyzed target levels. The low AAL feedstock costs contribute to lower costs of the total biofuel production, which pushes for more total biofuel production and less fuel use reduction and therefore counteracts the reduced use of arable land.

A comparative analysis of perennial grass–legume mixtures for biomethane production

Examining the case of Lithuania, this study comparatively analyzed five perennial grass–legume mixtures in terms of biomethane production. Every mixture was divided into two parts: long (during the fifth year or beyond) and short (during the first four years) time periods. The analysis includes three types of perennial bell grass: Timothy, P. Ryegrass, C. Cocksfoot, and one legume grass Red clover. With this study, we aimed to evaluate how perennial grass–legume mixtures can promote biomethane uptake in Lithuania. Through analyzing the efficiency and consequences of government subsidy measures, this study aimed to address the question of how governmental assistance can promote the growth of the biomethane industry, specifically focusing on the utilization of perennial grass–legume mixtures. This study used seven financial indicators, including subsiding policy, in order to gain a deeper understanding of mixtures for biomethane production. The analysis revealed that the best mixtures for biomethane production with subsidies were the second (Red clover 35 % + Timothy 45 % + Ryegrass 20 % grass mixture) and fourth scenarios (Red clover 55 % + Ryegrass 45 % grass mixture). The first (Red clover 35 %. + Timothy 25 % + Ryegrass 20 % + Cocksfoot 20 % grass mixture), third (Red clover 55 % + Timothy 45 % grass mixture), and fifth scenarios (Red clover 55 % + Cocksfoot 45 % grass mixture) had the smallest positive effects. The results showed that, in Lithuania, in order to encourage farmers to produce biomethane, subsidy policies are needed. Incentives for engaging with this activity are necessary, as the income earned does not cover the costs incurred; unfortunately, biomethane production is unprofitable without subsidy. As such, our recommendation is to develop a long-term subsidy policy to promote biomethane production, focusing on the effectiveness, particularly in the Lithuanian context, of utilizing mixtures of perennial grasses. Further research and policy interventions are needed to address the opportunities associated with scaling synergy between perennial energy cops and environmental sustainability in bioenergy crop cultivation.

Sustainability of Alternative Energy Sources: Thermo-Gravimetric Analysis of Energy Crops in Ekiti State, Nigeria

Ekiti State is a farming region with the ability to produce biomass reserves, which include yet refined crop cultivation product leftovers like sugar cane, corn cobs, palm husk shells, and okanagan wood, for use as fuel. The vast energy-generating potential of crops for use in industry and household applications is examined in this article. Biomass crops were subjected to a thermogravimetric examination to determine their unique thermal activity in an airtight and benign atmosphere with a temperature increase of 10°C per minute up to 800°C. The decrease in weight pattern was shown to be similar across all four waste specimens. Three reactive regions were identified during the nitrogen-rich environment assessment, which correlate to water loss, flammable generation, and char breakdown. Three response domains in an air system corresponded to the degradation, burning, and drying of char. The proximate and ultimate evaluation outcomes demonstrated that each of the bioenergy crop leftovers under investigation is fit for gas extraction and fuel combustion to meet power and thermal needs. The computational and experimental analysis revealed that Okanagan wood has the highest calorific value which indicates the highest heat values and considered the best for biomass energy production in Ekiti State for entrepreneurial venture.

Bioenergy crop rotation for phytoremediation of heavy metal contaminated soils at Mahd AD'Dahab mine, Kingdom of Saudi Arabia

Phytoremediation is a viable approach in order to mitigate toxic soil levels and, therefore, the associated impacts of HMs. This approach requires the assessment of contaminated sites and the selection of reportedly efficient phytoremediators, which might contribute to facilitating the practical implementation of phytoremediation in polluted soils. In a twelve-month microcosm experiment, Indian mustard (Brassica juncea) and rapeseed (Brassica napus) plants were planted over the winter season. Subsequently, maize (Zea maize) was planted after the harvest of these plants. Oil crop rotation systems might promote tested HM removal (Cu, Cd, Fe, Ni, Mn, Zn, and Pb) from the Mahd AD'Dahab mine-contaminated soil and provide higher biomass than single crops. The results indicated that both the rapeseed maize and Indian mustard maize rotation showed the highest phytoextraction efficiency compared to a single crop. The extraction of Zn, Pb, Ni, Mn, Fe, Cu, and Cd are 18, 27, 29, 24, 23, 24, and 28%, respectively, for Indian mustard-maize rotation, although 17, 27, 31, 24, 21, 23, and 26% respectively for rapeseed-maize rotation. The short rotation strategy could be helpful in landscaped and controlled access to the polluted sites. The utilization of short-rotation phytoremediation has the potential to emerge as a financially viable approach for the management of polluted areas. This method involves enhancing biomass yield through the implementation of phytomanagement techniques such as fertilization, irrigation, and coppicing, thereby capitalizing on the benefits associated with both biomass production and landscape management.

Soil nematodes as a monitoring tool of bioenergy crop production management: The case of Miscanthus giganteus cultivation on different soil types

Soil nematodes as a monitoring tool of bioenergy crop production management: The case of Miscanthus giganteus cultivation on different soil types

Registration of ‘Independence’ switchgrass

AbstractSwitchgrass (Panicum virgatum L.), a valuable forage and bioenergy crop, is established more easily than other native perennial warm‐season grasses, but its establishment is still slower than that of annual crops. Vigorous switchgrass establishment is crucial for achieving its full potential yield and for effectively competing with weeds for water and nutrient availability. To satisfy this demand, ‘Independence’ (Reg. no. CV‐295, PI 704577) switchgrass was developed at the University of Illinois at Urbana‐Champaign. Independence was selected for establishment vigor, winter survivorship, and high biomass yield for two cycles from ‘Kanlow’. It is characterized by rapid establishment, robust seedling growth, and the capacity to achieve peak production by the second year. Independence is well adapted to USDA hardiness zones 5b–7b. In field experiments conducted from 2016 to 2017, averaged over seven locations and all years, Independence annually yielded 13 Mg ha−1 of biomass, outperforming ‘Cave‐in‐Rock’ by 31%, ‘Liberty’ by 15%, ‘Shawnee’ by 42%, ‘Summer’ by 81%, and ‘Sunburst’ by 129%. In wet marginal sites in Illinois from 2020 to 2023, Independence exhibited an average biomass yield of 12 Mg ha−1, outperforming Shawnee by 31%, Liberty by 27%, and Kanlow by 19%, indicating its potential use on less productive land for annual crops. Independence was publicly released by the University of Illinois at Urbana‐Champaign in October 2021.

Marginal land in China suitable for bioenergy crops under diverse socioeconomic and climate scenarios from 2020 to 2100

ABSTRACT Maximizing the development of renewable energy plays a critical role in mitigating the climate crisis. Marginal land provides space for the development of biomass energy; however, it remains unclear how the amount and spatial distribution of marginal land that is suitable for energy crop development will change in the future. Here, we project energy marginal land changes in China following the shared socioeconomic pathway (SSP) and/or representative concentration path (RCP). We provide datasets of marginal land, agriculturally suitable land, and potentially suitable for energy crops under historical scenarios and six future scenarios (i.e. SSP1–1.9, SSP1–2.6, SSP4–3.4, SSP2–4.5, SSP4–6.0, and SSP3–7.0) for the period 2020–2100, with a spatial resolution of 5 km. Under the six scenarios, from 2020–2100, the area of suitable marginal land ranged from 1.90–16.28 (Jatropha curcas L.) to 37.37–73.97 (Panicum virgatum L.) (×104 km2), depending on the choice of energy crops and climate scenario. Based on the growing suitability of eight important bioenergy crops—Ricinus communis L., Saccharum officinarum L., Pistacia chinensis Bunge, Panicum virgatum L., Jatropha curcas L., Miscanthus giganteus J., Manihot esculenta Crantz, and Sorghum bicolor Moench—our dataset can be used to identify suitable locations for specific energy crops. This new synthetic dataset could support the development of multiscenario-based solutions related to carbon neutrality, ecosystem services, and energy transition.

Altering plant carbon allocation to stems has distinct effects on rhizosphere soil microbiome assembly, interactions, and potential functions in sorghum

AbstractAltering plant carbon allocation from leaves to stems is key to improve biomass for forage, fuel, and renewable chemicals. The sorghum dry stalk (D) locus controls a quantitative trait for sugar accumulation, with enhanced carbon allocation in the stems of juicy green (dd) sorghum but reduced carbon allocation in that of dry white (DD) sorghum. However, it remains unclear whether altering sorghum sugar accumulation in stem affects below‐ground microbiome. Here we investigated sorghum rhizosphere soil microbiome in near isogenic lines with different magnitude of carbon allocations and accumulation in the stems. Results showed that enhanced carbon accumulation in stems of juicy green sorghum results in stronger selection in rhizosphere microbiome assembly. The rhizosphere soil microbial communities selected in juicy green sorghum tended to be fast‐growing microbial taxa which possessed potential functions that would promote higher potential capacity to use chemically labile carbon sources and potentially result in higher potential decomposition rates. We found the rhizosphere microbes selected by juicy green sorghum form weaker interactions than dry white sorghum. This is the first comprehensive study revealing how the different magnitude of carbon allocations to stems regulates microbial community assembly, microbial interaction, and microbial functions. This study indicates that future plant modification for bioenergy crops should also consider the impacts on belowground microbial community without compromising the sustainability.

Nitrogen acquisition and retention pathways in sustainable perennial bioenergy grass cropping systems

AbstractPerennial tall grasses show promise as bioenergy crops due to high productivity and efficient nutrient use. Ongoing research on bioenergy grasses seeks to reduce their reliance on synthetic nitrogen (N) fertilizer, the manufacture of which relies on fossil fuel combustion. Excessive use of fertilizers also causes adverse environmental consequences and leads to the evolutionary loss of plant traits beneficial to sustainable N cycle. Notably, perennial tall grasses have exhibited the potential to maintain high biomass yield without the need for N fertilizer or causing soil N depletion. Perennial grasses can be adept at interacting with their microbial partners to facilitate N acquisition and retention via mechanisms such as biological N fixation and nitrification inhibition. These inherent N management traits should be preserved and optimized at the this early stage of bioenergy grass breeding programs. This review examines the impact of external N on bioenergy grass production and explores the potential of leveraging advantageous N‐cycling attributes of perennial tall grasses, laying groundwork for future management and research efforts. With minimized dependency on external N input, the cultivation of perennial energy grasses will pave the way toward more resilient agricultural systems and play a significant role in addressing key global energy and environmental challenges.

Transcriptional, metabolic, physiological and developmental responses to nitrogen limitation in switchgrass (Panicum virgatum)

Sustainable switchgrass production (Panicum virgatum) as a bioenergy crop hinges partly on efficiently using soil macronutrients, especially nitrogen (N). In this study, switchgrass plants were grown under four different N conditions (6.0 mM KNO3, N-replete control; 2.0 mM, mild limitation; 0.6 mM, moderate limitation; and 0.2 mM, severe limitation). Subsequently, the physiological, metabolic, and transcriptomic responses of switchgrass roots and shoots to N limitation were determined.Moderate N limitation marked a tipping point for large changes in plant growth, root-to-shoot ratio, root system architecture (root surfaces and specific root length - SRL) and total nitrogen content. Integrating metabolic data and transcriptomic analyses revealed that N limitation reduced switchgrass photosynthetic capacity and carbon(C)-fixation activities. Our results indicate that switchgrass balances C-fixation with N-assimilation and N transport and recycles N-compounds by rerouting C-flux from glycolysis, the oxidative branch of the pentose phosphate pathway (OPPP), and from the tricarboxylic acid (TCA) cycle in an organ-specific manner. The energy and reduction power so generated, and C-skeletons appear to be directed towards N uptake, biosynthesis of energy storage compounds with high C/N ratio such as sucrose, non-N-containing lipids, and various branches of secondary metabolism. Taken together, the findings of this study provide new insights into how switchgrass plants adapt to N limitation.

Assessment of phytotoxicity bioassay and metal accumulation potential of Ricinus communis L. genotypes during cultivation in iron mine soil of Jharkhand, India

ABSTRACTS Seed germination and early seedling growth are crucial characteristics for determining a plant species ability to survive in stressed soil including mine soil (MS). In the present study, four genotypes of castor bean (Ricinus communis L.) an industrially important bioenergy crop, were grown in iron MS with different treatments of garden soil (GS) (0%, 25%, 50%, 75%, and 100%) to examine germination, growth indices (tolerance index (TI), seedling vigor index (SVI)) and metal accumulation potential. The study recorded significantly high germination, growth and biomass in 75% GS treatments and for the cultivar MSC-55. The TI was highest in 75% GS treatments for all genotypes, with no significant difference. The metal accumulation potential of castor was evaluated for Fe, Pb, Cu and Ni, all of which were detected in high concentration in iron MS. The translocation factors (TF) for Fe and Ni were recorded <1 for all genotypes which imply metals are stabilized in the castor roots, although for Cu and Pb it was found >1. The bioaccumulation factor was recorded highest for Fe (1.224–7.433) and Pb (0.846–9.056) for all genotypes. Furthermore, the root accumulation of Fe, Pb and Ni was observed highest with 8039.20, 177.70 and 88.10 mg kg−1, respectively. The metal extraction ratio (MER) for Fe and Pb showed the highest. Overall, the highest MER was recorded in order of MSC-55 > Leetos > Swati-1515 > Sai-33. The finding of the study indicates that the genotypes MSC-55 followed by Leetos can grow in MS and accumulate multiple metals in their root and shoots and can be employed as phytostabilizers and phytoextractors.

Four sugarcane ScDIR genes contribute to lignin biosynthesis and disease resistance to Sporisorium scitamineum

Sugarcane (Saccharum spp.) is a major sucrose and bioenergy crop in the world. The fungal pathogen Sporisorium scitamineum causes sugarcane smut, a devastating disease that destroys stalks and reduces sugar content in sugarcane. This disease can be controlled most effectively by applying smut-resistant sugarcane varieties. Previous studies have shown that Dirigent (DIR) genes are involved in the synthesis of the lignin precursor pinoresinol, which plays a crucial role in plant resistance to biotic stresses. However, the immune response of the DIR homologs in sugarcane (ScDIR) has not been reported yet. In this study, we found that the lignin content of smut-resistant sugarcane varieties (ZZ1, ZZ6, and ZZ9) was significantly higher than that of smut-susceptible varieties (GT42, ROC22, and FN41), and the lignin content of sugarcane increased after smut infection. The smut-resistant and smut-susceptible clones derived from the same genetic population (ROC25 × YZ89-7) showed similar patterns. Quantitative real-time PCR assays revealed that among the 64 DIR genes in sugarcane, ScDIR5, ScDIR7, ScDIR11, and ScDIR40 showed elevated expression after S. scitamineum infection. In vitro coupling reactions showed that the four corresponding ScDIR proteins could mediate the coupling of coniferyl alcohol and its conversion into the lignin precursor pinoresinol. Overexpression of the four ScDIR genes in Nicotiana benthamiana enhanced disease resistance to the fungal pathogens Sclerotium rolfsii, Rhizoctonia solani, and Botrytis cinerea. Moreover, transgenic sugarcane overexpressing these ScDIR genes showed enhanced resistance to smut disease. Taken together, our findings provide evidence that sugarcane ScDIR genes can improve the resistance of plants to fungal pathogens and highlight their potentials in sugarcane breeding for disease resistance.

Modeling net ecosystem exchange of CO2 with gated recurrent unit neural networks

The complex forcing mechanisms of biophysical drivers on ecosystem productivity, as well as some unknown relationships, stipulates the application of artificial intelligence techniques in modeling the ecosystem carbon cycle. In particular, various deep learning algorithms have been successfully applied to comprehend temporal relationships, though some issues regarding capturing temporal features for modeling CO2 fluxes across time scales remain unsolved. In this study, a gated recurrent unit (GRU) model was trained for simulating half-hourly net ecosystem exchange of CO2 (NEE) using 12-year continuous flux data (2009–2020) from seven experimental bioenergy crops in southwest Michigan, USA. The fields were historically managed either as corn-soybean rotation agricultural (AGR) or Conservation Reserve Program (CRP) lands and planted to no-till corn (AGR-C and CRP-C), restored-prairie (AGR-Pr and CPR-Pr), switchgrass (AGR-Sw and CRP-Sw) and smooth brome grass (CRP-Ref). We compared NEE simulations for the entire year, growing season, and non-growing season datasets, and analyzed relative importance of biophysical variables on variations of NEE. GRU performed well in simulating NEE at single site, with R2 of 0.89–0.93, 0.85–0.90, and 0.61–0.85 for the annual, growing season, and non-growing season datasets, respectively, which provided comparable accuracy and 6 % of run-time shorter than those of long short-term memory. R2 reached 0.70 and 0.80 across all sites and unique land-cover types. Radiation parameters contributed most to the variability of NEE. Contributions of individual variables appear more complex during the non-growing season and include incoming shortwave radiation, day of year, temperature, Monin-Obukhov stability, wind direction, and soil water content. The six most important forcing variables are consistent with our current understanding, although their ranked importance varied by ecosystem type and modeling scale. These results bring renewed insights in modeling observations at seasonal scales and provide guidance for variable selection to scale up measurements from one site to multiple land-cover types across the landscape.

Efficiency of weed control in winter pea in the Right Bank Forest Steppe of Ukraine

Purpose. To analyze the features of weed control in winter pea in the Right Bank Forest Steppe of Ukraine. Methods. The research was conducted at the Salyvonky State Enterprise of the Institute of Bioenergy Crops and Sugar Beet of the National Academy of Agrarian Sciences of Ukraine (Bila Tserkva district, Kyiv region) in 2020–2023. The agronomic practices used in the experiment were conventional for the zone of insufficient moisture of the Right Bank Forest Steppe of Ukraine, with the exception of the studied elements. Results. The development of the concept of autumn weed control for winter pea from requires a fairly competent selection of herbicides, taking into account weather forecasts, the specifics of the effect of active substances on weeds and cultivated plants, etc., as conditions for sowing winter pea do not allow to effectively apply conventional weed control system with the use of soil tillage and, if necessary, the limited application of herbicides during the vegetation season. This is explained by the fact that the terms for soil preparation and sowing are quite limited, and soil herbicides at high air temperatures work unpredictably and have limited efficiency in case of moisture deficit. Herbicide Corum, developed by combination of active substances bentazone (480 g/l) and imazomox (22 g/l), had better indicators in terms of total efficiency at an increased application rate (1.5 l/ha) – 92.9% in the BBCH 12 and 91.7% in the BBCH 14. At the same time, the efficiency of an application rate of 1.25 l/ha was within 80%. The latter is probably related not only to the autumn conditions of application of the [reparation, but also to the fact that such species as Fumaria officinalis, Sinapis arvensis, Solanum nigrum and thistles sprouted later, when the main mass of weeds was already in a development stage that was less sensitive to low rates of the herbicide. Conclusions. The application of Corum herbicide in the BBCH 12 at an application rate of 1.25 l/ha contributed to the destruction of 73.8% and an application rate of 1.5 l/ha resulted in 86.7% of weeds. When the herbicide was applied in BBCH 14, the total efficiency of crop treatment at an application rate of 1.25 l/ha was higher by 2.4% and at a rate of 1.5 l/ha it was higher by 1.2% compared to application in the BBCH 12. This is due to the fact that Chenopodium album, Amaranthus retroflexus, Polygonum convolvulus, Persicaria maculosa, Solanum nigrum, Polygonum lapathifolium and thistles sprouted in the pea crops, and the herbicide was highly effective against them. On the other hand, weed plants that sprouted earlier continued to vegetate and were already less sensitive even to increased application rates of herbicide. The application of the maximum recommended application rates was, for the most part, the most effective measure to reduce the number of weeds in winter pea crops. At the same time, such rates affected crop plants, causing stress, especially in the late periods of growth and development, which further affected the formation of pea yield. Therefore, the use of herbicides in the late phases of crop development should be avoided.