Soil disturbance as a result of military action can range from a short-term reduction in fertility to complete destruction of the soil. A special problem is the restoration of agricultural soils. The most promising way to solve this issue is to use phytoextraction and phytostabilization methods, especially those that combine remediation measures with simultaneous economic benefits. R e cently, among phytoextraction strategies, preference has been given to growing plants that do not have the ability to hyperacc u mulate, but which , due to their rapid growth and the formation of a large biomass, can remove toxicants from the soil in large quantities. The idea of combining the restoration of contaminated lands with the production of biomass for phytomining and renewable energy is especially attractive. Phytostabilization strategies can be implemented using useful plants that do not acc u mulate pollutants in the final raw material, for example, some agricultural, forage and pasture crops ( Vicia villosa , Secale cereale , Zea majus , Lupinus luteus , Festuca sp . , Lolium perenne , etc.), energy crops ( Spartina pectinata , Miscanthus sp., etc.), essential oil plants ( Mentha×piperita , Melissa officinalis , Marrubium vulgare ). The attention of scientists is also drawn to the search for promising soil additives and the study of their application rates in order to improve soil conditions and increase biomass yields.

The use of indigenous AMF species from heavy metal contaminated areas can be a promising tool to support the phytostabilisation of such areas. The aim of the study was to evaluate the AMF species diversity in the roots of the perennial energy grasses Miscanthus × giganteus and Spartina pectinata grown in areas with different levels of heavy metal contamination with regard to the potential use of the dominant AMF species to support phytostabilisation of soils contaminated with Pb, Cd and Zn. Samples were taken from two sites with different levels of Pb, Cd and Zn contamination and from an uncontaminated site as a control. The AMF colonisation of the roots of Miscanthus × giganteus and Spartina pectinata was investigated. The composition of AMF species in the plant roots was determined by sequencing the D2 region of the LSU rDNA of Glomeromycota. Soil contamination had a significant effect on the composition of AMF communities in the roots. Diversispora and Claroideoglomus were the predominant genera in the communities in the heavily heavy metal contaminated area. The AMF communities at moderately contaminated and uncontaminated areas showed a similar structure, with Rhizoglomus as the dominant genus. Species such as Palaeospora spainiae, Rhizoglomus silesianum, Septoglomus sp., Septoglomus nigrum, Ambispora sp., Claroideoglomus etunicatum and Diversispora sp3. were identified exclusively in the roots of Miscanthus × giganteus and Spartina pectinata grown in contaminated areas. They could potentially be used to support phytostabilisation of areas contaminated with Pb, Cd and Zn, but further studies are needed.

Five C4 grasses (Bouteloua curtipendula, Schizachyrium scoparium, Andropogon gerardii, Sorghastrum nutans, Spartina pectinata) dominate different portions of a moisture gradient from dry to wet tallgrass prairies in the Upper Midwest of the United States. We hypothesized that their distributions may partly reflect differences in flooding tolerance and context-specific growth relative to each other. We tested these ideas with greenhouse flooding and drought experiments, outdoor mesocosm experiments, and a natural experiment involving a month-long flood in two wet-mesic prairies. Bouteloua promptly succumbed to inundation, so flooding intolerance likely excludes it from wet and wet-mesic prairies. Competition is likely to exclude short-statured Bouteloua from productive mesic sites. Schizachyrium is excluded from wet prairies by low flooding tolerance, demonstrated by all experiments. Sorghastrum had low flooding tolerance in both greenhouse and natural experiments, suggesting that physiological intolerance excludes it from wet prairies. Spartina had by far the greatest growth under the wettest mesocosm conditions; this and comparisons of species growth in monocultures vs. mixtures suggests that competition helps it dominate wet prairies. Indeed, quadrat presence of Spartina increased by 57% two years after flooding of two prairies, while that of upland grasses declined by 44%. The high flooding tolerance, lack of significant differences from other species in drought tolerance, and tall stature of Andropogon suggest that broad physiological tolerance combined with competitive ability allows it to thrive across the prairie moisture gradient. Flooding helps shape the distributions of dominant prairie grasses, and its effects may become more important as extreme rain events continue to increase.

Biomass can be used for electricity generation, especially in developing countries, but also in developed ones, where the utilization of renewable energy sources is being integrated into a sustainable economy. There are considerable differences in the scale of biomass use and in the technology of its processing. One of the most important sources of biofuel is the biomass of grass. This research aimed to determine the long-term effects of organic fertilizers on cellulose, hemicellulose, and lignin content in the biomass of three grass species: giant miscanthus (Miscanthus × giganteus), prairie cordgrass (Spartina pectinata), and switchgrass (Panicum virgatum L.) in the first three years of growth. The experiment was established in four replications on microplots of 2 m2 in April 2018. Before planting grass rhizomes, municipal sewage sludge (SS) and spent mushroom substrate (SMS) were introduced into the soil in various combinations. Biomass is harvested in December every year. The content of structural polysaccharides in the grass species statistically significantly varied in response to organic waste. Compared to other fertilizer combinations, SS application increased the content of cellulose in the biomass of Miscanthus giganteus (43.66% of DM) and Spartina pectinata (37.69% of DM) and hemicellulose in Spartina pectinata (27.80% of DM) and Panicum virgatum (23.64% of DM). Of the three species of grass, the chemical composition of Miscanthus giganteus cell walls was the most favorable for biofuel production, with the most cellulose and hemicellulose and the least lignin compared to other grass species. The content of lignin in the biomass of Miscanthus × giganteus and Spartina pectinata was the greatest on the plot with SMS and amounted to 7.79% of DM and 12.32% of DM, respectively. In the case of Panicum virgatum, the average content of lignin was similar across all fertilized plots, with 15.42% DM.

Abstract Due to the environmental consequences of annual‐dominated cropping systems, there is an increasing need to identify agronomic strategies that incorporate perennial crops. One strategy for increasing perennial cover is through the targeted use of annually harvested perennial food and bioproduct crops in buffer strips, which has the potential to create new revenue streams for farmers and substantially mitigate agricultural nutrient pollution from conventional cropping systems. As buffers are typically installed on marginal land, it is critical to understand how landscape position influences the success of perennial crops. The objectives of this study were to determine the relatively early influence of landscape position on the productivity of a variety of perennial crops and their subsequent soil nutrients and soil water storing capabilities. In this experiment, nine perennial (alfalfa, alsike clover, indiangrass, switchgrass, big bluestem, prairie cordgrass, intermediate wheatgrass, high‐diversity polyculture, low‐diversity polyculture) and two annual (corn, soybean) crops were planted across two landscape positions (hillslope and deposition). Plant biomass, plant tissue nitrogen, soil moisture, and soil NO3‐N and NH4‐N were measured and compared at two different locations in Minnesota. Overall, the polyculture mixes, and to some extent intermediate wheatgrass, performed the best with respect to biomass production while also providing ecosystem services across most soil by landscape position combinations tested in this study. However, there were some important findings specific to each soil and landscape position combination, mainly oriented toward biomass production. We also observed temporal patterns in soil moisture and depth‐related patterns in soil N reductions. This study presents an opportunity to optimize the use of perennial crops on marginal agricultural lands for improved environmental and economic benefit.

Prairie cordgrass (PCG) is a perennial crop which has the potential for biofuel production under marginal lands. The intercropping of a perennial legume, kura clover (KC) with PCG can reduce the use of chemical fertilizer while maintaining the soil hydro-physical conditions. The objective of this study was to compare the soil hydro-physical properties and greenhouse gas (GHG) fluxes under PCG intercropped with KC (PCG–KC), and PCG fertilized with graded levels of N (0, 75, 150, and 225 N kg ha−1). During the summer of 2021, soil samples (0–10 cm) were collected. Additionally, gas samples were collected weekly from April through September of the same year. Soil water retention, saturated hydraulic conductivity ( Ksat), thermal conductivity (λ), soil organic carbon (SOC), and total N (TN) concentrations were measured. Soil pore characteristics were measured using X-ray computed tomography. The PCG–KC had 1.42 g kg−1 TN and 24 g kg−1 SOC at 0–10 cm, non-significant to PCG-75, 150, and 225 N. Nonetheless, TN significantly increased in both PCG–KC and other fertilized treatments compared to the control. Intercropping boosted macroporosity (0.024 cm3 cm−3), Ksat (+50%), and lowered λ (−1%), compared to the N fertilized treatments. Soil cumulative CO2 under PCG–KC (1012.67 kg C ha−1) was similar to PCG-75, 150 N, but lower than PCG-225 N (1418.66 kg C ha−1). Overall, this study showed that PCG–KC can be a sustainable option over the use of N fertilizers since they had similar levels of hydro-physical characteristics and had a comparable ability to mitigate GHG emissions.

Abstract Intercropping kura clover ( Trifolium ambiguum ) (KC) with prairie cordgrass ( Spartina pectinata ) (PCG) has great potential for biofuel feedstock on marginal lands. This study evaluated the impacts of 10‐year PCG‐KC intercropping and PCG monoculture fertilized with different nitrogen (N) rates of granular urea (five treatments: PCG‐KC, PCG‐0N, PCG‐75N, PCG‐150N, and PCG‐225N) on soil biogeochemical properties: (i) in the surface soil (0‐ to 10‐cm depth) at three different sampling times during the crop growing season: spring (April, pre‐emergence), summer (June, active growth), and fall (November, post‐harvest); and (ii) at different soil depths (0–5, 5–15, 15–30, 30–45, and 45–60 cm) (only total carbon (C) and N) in fall 2021. All soil biogeochemical parameters were higher during summer as compared to spring and/or fall, except urease activity, ammonium‐N, microbial biomass C and N, and fluorescein diacetate (FDA). On average over the sampling times, PCG‐KC had significantly higher β‐glucosidase activity and hot‐water extractable organic N than PCG‐0N; but no significant difference between PCG‐KC and N‐fertilized PCG. Cold‐water extractable organic N was significantly lower than the highest N rate, but not significantly different from PCG‐0N and lower N rate treatments. Urease activity under PCG‐KC treatment was double that of PCG‐0N and PCG‐75N; FDA was higher in PCG‐KC than all monocultures. No treatment effect was found on soil total C and N, except that they decreased with depth. Overall, intercropping PCG‐KC showed some benefits in terms of promoting soil biogeochemical properties during crop growth periods, having lower residual reactive N in the soil, and maintaining biomass yield and quality on marginal lands.

Under changing climatic scenarios, grassland conservation and development have become imperative to impart functional sustainability to their ecosystem services. These goals could be effectively and efficiently achieved with targeted genetic improvement of native grass species. To the best of our literature search, very scant research findings are available pertaining to gene editing of non-cultivated grass species (switch grass, wild sugarcane, Prairie cordgrass, Bermuda grass, Chinese silver grass, etc.) prevalent in natural and semi-natural grasslands. Thus, to explore this novel research aspect, this study purposes that gene editing techniques employed for improvement of cultivated grasses especially sugarcane might be used for non-cultivated grasses as well. Our hypothesis behind suggesting sugarcane as a model crop for genetic improvement of non-cultivated grasses is the intricacy of gene editing owing to polyploidy and aneuploidy compared to other cultivated grasses (rice, wheat, barley, maize, etc.). Another reason is that genome editing protocols in sugarcane (x = 10-13) have been developed and optimized, taking into consideration the high level of genetic redundancy. Thus, as per our knowledge, this review is the first study that objectively evaluates the concept and functioning of the CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 technique in sugarcane regarding high versatility, target specificity, efficiency, design simplicity, and multiplexing capacity in order to explore novel research perspectives for gene editing of non-cultivated grasses against biotic and abiotic stresses. Additionally, pronounced challenges confronting sugarcane gene editing have resulted in the development of different variants (Cas9, Cas12a, Cas12b, and SpRY) of the CRISPR tool, whose technicalities have also been critically assessed. Moreover, different limitations of this technique that could emerge during gene editing of non-cultivated grass species have also been highlighted.

Abstract As the demand for renewable energy sources with reduced carbon emissions to the atmosphere increases, bioenergy crops remain an attractive alternative to fossil fuels. Another appeal of bioenergy crops is the potential utilization of marginal lands not suitable for food crops. Prairie cordgrass is a perennial warm‐season polyploid grass species that is considered a bioenergy crop that also exhibits a high tolerance for salinity and flooding. The ploidy level of prairie cordgrass has previously been suggested to correlate with agronomic traits. However, little is known about the agricultural performance of prairie cordgrass on marginal lands and if a correlation of ploidy level and stress tolerance exists. In this experiment, the productivity of tetra‐, hexa‐, and octoploids was investigated when grown on three different marginal sites, including waterlogged, saline, and low‐nutrient gravelly soils. Here, we found that prairie cordgrass populations annually produced dry biomass on a wet marginal site comparable to normal cropland. However, the productivity was remarkedly decreased at both a salt‐affected site and a limestone mine reclamation site. We were unable to conclude that different ploidy levels affected the biomass yield of prairie cordgrass grown under abiotic stress. However, there was a differential response of populations to various types of marginal sites. These results indicate potential genetic resources for developing breeding targets and identifying mechanisms of abiotic stress tolerance. Moreover, we highlight the need to generate diverse ploidy levels of prairie cordgrass in the same genetic backgrounds for future testing.

Increasingly cultivated all over the world, energy crops, with their large biomass production, can be used to produce liquid biofuel and biogas. The aim of the research was to evaluate the yield and selected energy parameters of prairie cordgrass (Spartina pectinata L.) treated with different doses of municipal sewage sludge and mushroom substrate. Heat of combustion, calorific values and ash content were investigated in the first three years of its cultivation. Carried out between 2018 and 2020, the research was based on a field experiment established at an experimental facility in Central-Eastern Poland. Organic waste doses, each of them introducing 170 kg N ha−1, were applied once in spring 2018 before planting pieces of Spartina pectinata rhizomes. The experimental factors (organic waste doses and years of research) significantly affected the yield of prairie cordgrass. Significantly, the highest yield of its biomass was produced in response to municipal sewage sludge applied together with mushroom substrate (O25 + PP75) and in response to mushroom substrate applied on its own (SMS). Those values, averaged over three years of research, were, respectively, 4.23 and 4.18 Mg ha−1. Organic waste treatment had a significant impact on ash content in dry matter. On average, the highest ash content in dry matter was recorded in response to mushroom substrate (5.73%) and the lowest (4.98%) in plants treated with the highest dose of sewage sludge together with the lowest dose of mushroom substrate (O75 + PP25). The higher dry matter content in plant biomass was, the better the energy parameters were.

The aim of the study was to assess the effect of silage additive containing heterofermentative lactic acid bacteria (LAB) strain of Lactobacillus buchneri species on ensiling quality, as well as methane yield and the kinetics of biogas production from ensiled perennial energy grasses: Miscanthus × giganteus (miscanthus), Spartina pectinata (cordgrass), Panicum virgatum (switchgrass) and Andropogon gerardii (big bluestem). The listed plants are not commonly used for biogas production, their susceptibility to ensiling is also little known, hence the need to investigate their suitability for these processes. Effective methods for increasing the biogas yield from biomass are still demand, hence the research on the use of LAB for this purpose. After harvesting the grasses were cut and ensiled in barrels with and without (controls) the usage of commercial silage inoculant containing Lactobacillus buchneri LN40177. After 90 days of ensiling obtained silages were analysed in order to compare their chemical composition: organic acids content, the loss of dry matter, the differences in particular fibres composition. The silages were then subjected to methane fermentation using OxiTop® sensors and exposed to air in order to check their aerobic stability. The silages prepared with LAB additive had higher concentration of acetic acid than the control silages prepared without LAB addition, which contributed to increased aerobic stability but had no effect on the methane yield of miscanthus, switchgrass and big bluestem. Using the microbial inoculant during ensiling had beneficial effect in terms of reducing the duration of biogas production process from obtained silages: lag phase was shortened, daily biogas production rate was increased and 90% of biogas was produced in a shorter period of time compared to the control silages from investigated grasses. The modified Gompertz model well reflected the kinetics of biogas production process.

Vegetation patterns during salt marsh restoration reflect underlying processes related to colonization, reproduction, and interactions of halotolerant plants. Examining both pattern and process during recovery is valuable for understanding and managing salt marsh restoration projects. We present a decade of vegetation dynamics during salt marsh restoration (2011–2020) at a study site in the Bay of Fundy with megatidal amplitudes, strong currents, cold winter temperatures, and ice. We mainly investigated reproduction (asexual and sexual) and associated spread rates of Spartina grasses, and their health-related states (stem density, canopy height, and percent flowering) which help inform the probability of processes occurring. We also estimated modes of colonization and began quantifying the effects of interspecific interactions and environmental conditions on plant state. Spartina pectinata was the only pastureland plant to survive dike-breaching and saltwater intrusion in 2010; however, it was stunted compared to reference plants. Spartina pectinata patches remained consistent initially, before decreasing in size, and disappearing by the fifth year (2015). This early dynamic may provide initial protection to a developing salt marsh before Spartina alterniflora becomes established. Spartina alterniflora first colonized the sites in year 2 (2012), likely via deposition of rhizomal material, and then spread asexually before seedlings (sexual reproduction) appeared in year 4 (2014). Vegetation cover subsequently increased greatly until near-complete in year 9 (2019). The early successional dynamics of S. pectinata and S. alterniflora occurred spatially independently of each other, and likely contributed to sediment retention, creating an improved environment for S. patens, the dominant high marsh species in our region. Spartina patens have been slowly spreading into restoration sites from high elevation areas since year 6 (2016). We expect that competition between S. alterniflora and S. patens will result in the typical distinct zonation between high and low marsh zones. A next study will use the quantified processes for spatial-explicit modeling to simulate patterns of vegetation recovery, and to evaluate different salt marsh restoration strategies for the Bay of Fundy and elsewhere. Thus, proper identification and quantification of pattern-building processes in salt marsh vegetation recovery, the focus of our present study, was an essential step.

Finding Promising Candidates for Wet Growing Conditions: The Effect of Two Row Spacings on Biomass Production of Four Bioenergy Prairie Cordgrass Populations in a Wet Marginal Land

Growing dedicated bioenergy crops on marginal land can provide beneficial outcomes including biomass production and energy, resource management, and ecosystem services. We investigated the effects of harvest timing (peak standing crop [PEAK] or after killing frost [KF]) and nitrogen (N) fertilizer rates (0, 56, and 112 kg N ha−1) on yield, nutrient concentrations, and nutrient removal rates of perennial grasses on a wet marginal land. We evaluated three monocultures, including switchgrass (Panicum virgatum L., SW), Miscanthus x giganteus (MG), prairie cordgrass (Spartina pectinata Link, PCG), and a polyculture mixture of big bluestem (Andropogon gerardii Vitman), Indiangrass (Sorghastrum nutans (L.) Nash), and sideoats grama (Bouteloua curtipendula Torr., MIX). Increasing the application of N did correlate with increased biomass, concentration, and subsequent removal of nutrients across almost all treatment combinations. In all grass treatments except MG, PEAK harvesting increased yield and nutrient removal. At PEAK harvest, switchgrass is ideal for optimizing both biomass production and nutrient removal. While our results also suggest short-term plasticity for farmers when selecting harvest timing for optimal nutrient removal, KF harvest is recommended to ensure long-term stand longevity and adequate nutrient removal. If the KF harvest is adopted, MG would be the ideal option for optimizing biomass yield potential. Additionally, we found that the yield of polyculture did not vary much with harvest timing, suggesting better yield stability. Future studies should give consideration for long-term evaluation of polyculture mixtures to assess their biomass yields and nutrient removal capacities.

Third and fourth year biomass yields of Miscanthus x giganteus, switchgrass, big bluestem, and prairie cordgrass in southern Manitoba, Canada: Latitude of origin affects biomass yield among native grasses

Agricultural practices of perennial energy crops affect nitrogen cycling microbial communities

Prairie cordgrass (Spartina pectinata Link) is a native perennial warm-season (C4) grass common in North American prairies. With its high biomass yield and abiotic stress tolerance, there is a high potential of developing prairie cordgrass for conservation practices and as a dedicated bioenergy crop for sustainable cellulosic biofuel production. However, as with many other undomesticated grass species, little information is known about the genetic diversity or population structure of prairie cordgrass natural populations as compared to their ecotypic and geographic adaptation in North America. In this study, we sampled and characterized a total of 96 prairie cordgrass natural populations with 9315 high quality SNPs from a genotyping-by-sequencing (GBS) approach. The natural populations were collected from putative remnant prairie sites throughout the Midwest and Eastern USA, which are the major habitats for prairie cordgrass. Partitioning of genetic variance using SNP marker data revealed significant variance among and within populations. Two potential gene pools were identified as being associated with ploidy levels, geographical separation, and climatic separation. Geographical factors such as longitude and altitude, and environmental factors such as annual temperature, annual precipitation, temperature of the warmest month, precipitation of the wettest month, precipitation of Spring, and precipitation of the wettest month are important in affecting the intraspecific distribution of prairie cordgrass. The divergence of prairie cordgrass natural populations also provides opportunities to increase breeding value of prairie cordgrass as a bioenergy and conservation crop.

Abstract Prairie cordgrass (PCG) ( Spartina pectinata Link) has been the focus of much scientific attention recently for use in biofuel applications, as it grows well on marginal lands that are unsuitable for row crops. This study investigated how the intercropping of kura clover (KC) ( Trifolium ambiguum M. Bieb) with PCG for 8 yr affects soil carbon (C) and nitrogen (N) fractions compared with N fertilization on marginally yielding croplands in South Dakota. This study was initiated in 2011 with five treatments: intercropping PCG with KC (PCG‐KC), and PCG with N fertilizer at four levels: 0 kg N ha –1 (PCG‐0N), 75 kg N ha –1 (PCG‐75N), 150 kg N ha –1 (PCG‐150N), and 225 kg N ha –1 (PCG‐225N). Soil samples were collected in 2018 and analyzed for permanganate oxidizable C and N, stable C and N, mineralized C and N, dissolved organic C and N, and particulate organic C and N. Further, C and N management indices were calculated from these data. Results showed that permanganate oxidizable C and N and particulate organic C and N were generally higher under PCG‐KC than under PCG‐0N and PCG‐75N but similar to PCG‐150N and PCG‐225N. Dissolved organic C and N and C mineralization were higher under PCG‐KC compared with fertilized and unfertilized PCG. Prairie cordgrass–kura clover (190.10) recorded a 91% higher N management index than PCG‐75N (99.66) but was similar to PCG‐150N (165.70) and PCG‐225N (163.10). This study concludes that growing KC–PCG mixture rather than using N fertilizers would have an overall positive effect on marginally yielding cropland soils.

The bio-based economy concept requires using biomass not only for energy production but also for bioactive compound extraction, application or biotransformation. This study analyzed the possibility of obtaining bioactive compounds from biomass before its transformation into biofuel. This involved an analysis of the total content of polyphenols (TPC), flavonoids (TFC), and spectral analysis using Fourier transform infrared spectroscopy (QATR- FTIR) as well as analysis of the antioxidant activity of extracts from selected perennial herbaceous crops cultivated on marginal lands in Poland. The extracts were obtained by supercritical carbon dioxide extraction (scCO2) or scCO2 with water as a cosolvent (scCO2/H2O) from biomass of the following plants: Helianthus salicifolius, Silphium perfoliatum, Helianthus tuberosus, Miscanthus × giganteus, Miscanthus sacchariflorus, Miscanthus sinensis and Spartina pectinata. The biomass was harvested twice during the growing period (June and October) and once after the end of the growing period (February). For most of the analyzed extracts obtained from biomass at the growing stage using scCO2 or scCO2/H2O, a higher TPC was noted than for samples of semi-wood or straw biomass obtained after the end of the growing period. Higher contents of polyphenolic compounds were recorded in extracts obtained using scCO2/H2O. A positive correlation between TPC and antioxidant activity was noted for the analyzed substrates. Flavonoid contents varied in the analyzed samples, and higher contents were generally obtained in scCO2 extracts from biomass harvested at the beginning of the growing period. A high diversity of extract compositions was confirmed by spectral analysis. The presented data can be used at the initial stage of planning a biorefinery.

Third and Fourth Year Biomass Yields of <i>Miscanthus X Giganteus</i>, Switchgrass, Big Bluestem, and Prairie Cordgrass in Southern Manitoba, Canada: Latitude of Origin Affects Biomass Yield Among Native Grasses