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Fibrous forage and biomass crops such as grass and maize are used at large scale as feed for ruminants and feedstock for biogas production. These crops are typically harvested by chopping them in small particles which are light and suitable for partial pneumatic conveying, where the particle trajectory is determined by their aerodynamic properties. While the aerodynamic properties of many grains have been studied, no reports were found for perennial ryegrass. Chopped ryegrass samples of leaf blades and stems were collected in the fields. After imaging the fresh harvested particles to quantify their size and surface area, their terminal velocity was measured with the fluidised-bed method. The relationship between the mass, projected area and moisture content of the stems and blades with their terminal velocities were modelled. In line with theory, mass and moisture content was positively correlated with terminal velocity, while projected area was negatively correlated with it. Smaller terminal velocities were observed for the blades (1.75 m s−1) compared to the stems (4.44 m s−1). The drag coefficients of grass particles were calculated, and for blades it was negatively correlated with the particle Reynold's number lying within Newton's regime (103 < Re < 3 × 105), whilst no significant correlation was found for stems. The average drag coefficient of blades (0.75) was larger than stems (0.54). No significant effect (p-value <0.01) of moisture content on the drag coefficient of grass particles was observed. This confirms that the drag coefficient is a shape parameter, related to formation of airstreams around the particle. • Aerodynamic properties of ryegrass were quantified in a wind tunnel. • The terminal velocity of grass blades was 61% smaller than that of stems. • Terminal velocities can be predicted from mass, area and moisture content (R2 = 0.77). • Grass particles' drag coefficient was calculated and compared to similar materials. • The drag coefficient of grass blades was 39% larger than that of stems. [ABSTRACT FROM AUTHOR]

In situ stabilization and phytoextraction are considered as two convenient and effective technologies for the remediation of toxic elements (TEs) in soils. However, the effectiveness of these two remediation technologies together on the bioavailability and phytoextraction of TEs in field trials has not been explored yet. Specifically, the remediation potential of fly ash (FA; as stabilizing agent) and ryegrass (as a TE accumulator) intercropped with a target crop for soil polluted with multiple TEs has not been investigated yet, particularly in long-term field trials. Therefore, in this study, a six-month combined remediation field experiment of FA stabilization and/or ryegrass intercropping (IR) was carried out on the farmland soils contaminated with As, Cd, Cr, Cu, Hg, Ni, Pb and Zn where Zanthoxylum bungeanum (ZB) trees as native crops were grown for years. The treatments include soil cultivated alone with ZB untreated- (control) and treated-with FA (FA), produced by burning lignite in Shaanxi Datong power plant, China, soil cultivated with ZB and ryegrass untreated- (IR) and treated-with FA (FA + IR). This was underpinned by a large-scale survey in Daiziying (China), which showed that the topsoils were polluted by Cd, Cu, Hg and Pb, and that Hg and Pb contents in the Zanthoxylum bungeanum fruits exceeded their allowable limits. The TEs contents in the studied FA were lower than their total element contents in the soil. The DTPA-extractable TEs contents of the remediation modes were as follows: FA < FA + IR < IR < control. Notably, TEs contents in the ZB fruits were lowest under the FA + IR treatment, which were decreased by 27.6% for As, 42.3% for Cd, 16.7% for Cr, 30.5% for Cu, 23.1% for Hg, 15.5% for Ni, 33.2% for Pb and 38.1% for Zn compared with the control treatment. Whereas the FA + IR treatment enhanced TEs contents in ryegrass shoots and roots, and the TEs contents in ryegrass shoots were below their regulatory limits for fodder crops. The findings confirmed that the combined remediation strategy, i.e., FA (with low content of TEs) stabilization effect and intercropping of ZB (target crop) and ryegrass (accumulating plant) could provide a prospective approach to produce target plants within safe TEs thresholds with greater economic benefits, while remediating soils polluted with multiple TEs and mitigating the potential ecological and human health risk. Those results are of great applicable concern. [Display omitted] • Combined soil remediation by fly ash (FA) and intercropping (IR) is proposed. • Zanthoxylum Bungeanum used as a target crop and ryegrass as a hyperaccumulator. • FA + IR decreased the bioavailability of soil toxic elements (TEs) in soil. • TEs content was reduced in Zanthoxylum Bungeanum fruit while increased in ryegrass. • Passivation of FA and competition of ryegrass made soils and crops safe. [ABSTRACT FROM AUTHOR]

Oily sludges are generated in large quantities in petroleum refinery wastewater treatment plants. Given their complex composition, they are classified as hazardous waste. Selecting a single treatment technique for their remediation is challenging. This work aims to assess the extent of composting followed by phytoremediation on an oily sludge from an API separator unit, pre-treated by chemical oxidation with alkaline activated persulfate (PS). 18% of total petroleum hydrocarbons (TPH) were determined by IR spectroscopy. The aliphatic hydrocarbon content was 4714 ± 250 ppm by GC-FID, and aromatics were not detectable, suggesting a high amount of non-chromatographable complex hydrocarbons. The density of generalist and hydrocarbon-degrading populations of the oily sludge estimated by quantitative polymerase chain reaction (qPCR) evidenced an autochthonous microbiota with hydrocarbon-degrading capacity. The oxidative treatment with PS removed 31% of the TPH determined by IR after 20 days. The significant reduction of the native bacterial community was counterbalanced by coupling a composting treatment. Co-composting the sludge with goat manure and oat straw produced, after a year, a 96% reduction in TPH content, regardless of the oxidative pretreatment. Organic matter transformation was evidenced by the decrease of dissolved organic carbon (DOC) and the variation in E4/E6 ratio. The matrices obtained of composting were used as substrates for phytoremediation for 4 months. Ryegrass seeds were planted in both PS-treated and untreated sludge substrates. The presence of the plant grown in the pre-oxidised and composted substrate resulted in a higher aerial biomass of ryegrass (67%), an increase in enzymatic activities, and higher concentration of DOC, although without evidence of additional dissipation of TPH. The dynamics of the bacterial communities of the different substrates generated during the biological treatment were analyzed by Illumina NovaSeq DNA sequencing of 16S rRNA amplicons. The findings mirrored a succession compatible with that described in contaminated matrices, but also in other non-contaminated ones. According to these findings, an organic matter transformation process occurred, which included the complex hydrocarbons of the oily sludge, resulting in an active substrate that promoted the retention of nutrients and water and provided the necessary support for plant development. [Display omitted] • Oxidation of oily sludge with sodium persulfate reduced 31% of total hydrocarbons. • Co-composting with oily sludge was effective, although maturation could require longer time. • Plant growth in the oxidised-composted sludge is indicative of biological stability. • A bacterial succession was associated with the oxidation transformation process. [ABSTRACT FROM AUTHOR]

A key challenge for autonomous precision weeding is to reliably and accurately detect weed plants and crop plants in real time to minimise damage to surrounding crop plants while performing weeding actions. Specifically for a wheat farm, classifying ryegrass weed plants is particularly difficult even with human eyes since ryegrass shows visually very similar shape and texture to the crop plants themselves. A Deep Neural Network (DNN) that exploits the geometric location of ryegrass is proposed for the real time segmentation of inter-row ryegrass weeds in a wheat field. Our proposed method introduces two subnets in a conventional encoder-decoder style DNN to improve segmentation accuracy. The two subnets treat inter-row and intra-row pixels differently, and provide corrections to preliminary segmentation results of the conventional encoder-decoder DNN. A dataset captured in a wheat farm by an agricultural robot at different time instances is used to evaluate the segmentation performance, and the proposed method performs the best among various popular semantic segmentation algorithms. The proposed method runs at 48.95 Frames Per Second (FPS) with a consumer level graphics processing unit, thus is real-time deployable at camera frame rate. • Deep neural network is proposed to segment inter-row ryegrass in a wheat field. • Dataset is captured by an agricultural robot with different wheat growth stages. • Method outperforms five state-of-the-art methods especially on detecting ryegrass. • Mean accuracy increases by 1.97%, 8.95% for pixel-wise, object-wise segmentation. • Proposed method runs in real-time at 48.95 FPS using a consumer level GPU. [ABSTRACT FROM AUTHOR]

• Genome-wide identification and comprehensive analysis of NAC gene family. • LpNAC genes expression analysis under various abiotic stress. • Candidate function gene identification based on phylogenetic analysis. NAC is one of the largest family of plant-specific transcription factors, and it plays important roles in plant development and stress responses. The study identified 72 LpNACs genes from the perennial ryegrass genome database. Gene length, MW and pI of NAC family transcription factors varied, but the gene structure and motifs were relatively conserved in bioinformatics analysis. Phylogenetic analyses of perennial ryegrass, rice and Arabidopsis were performed to study the evolutionary and functional relationships in various species. The expression of LpNAC genes that respond to various abiotic stresses including high salinity, ABA, high temperature, polyethylene glycol (PEG) and heavy metal was comprehensively analyzed. The present study provides a basic understanding of the NAC gene family in perennial ryegrass for further abiotic stress studies and improvements in breeding. [ABSTRACT FROM AUTHOR]

Three putative resistant (R1, R2, R3) and one susceptible (S) Lolium rigidum populations originating from Greece were studied for resistance to ALS and ACCase inhibiting herbicides, using whole plant, sequencing of als and accase gene, and in vitro ALS activity assays. The S and two R (R1, R2) populations were also evaluated for fitness in competition with wheat. The whole plant assay indicated unsatisfactory control of the R populations with mesosulfuron-methyl + iodosulfuron-methyl or pinoxaden application, whereas sequencing of the als gene revealed that all ALS-resistant individuals had a Pro-197 substitution by Leu, Glu, Ser, Ala, Thr, or Gln. In addition, the accase gene of all pinoxaden resistant individuals had an Ile-2041 substitution by Asn or Thr. Furthermore, sequencing of the individuals surviving mesosulfuron-methyl + iodosulfuron-methyl or pinoxaden treatment revealed co-existence of point mutations in the accase or als genes, respectively, demonstrating multiple resistance. The in vitro activity of the ALS enzyme confirmed that resistance to mesosulfuron-methyl + iodosulfuron-methyl was due altered target-site. The recorded higher vigor and greater competitive ability of S population against wheat as compared with that of the R populations suggests an associated fitness cost with multiple resistance. Pro197, Ile2041 and Trp2027 substitution in Lolium rigidum populations confers coexisted multiple resistance to ALS and ACCase inhibitors Unlabelled Image • Lolium rigidum populations with coexisted multiple resistance to herbicides. • Pro-197 mutation resulted in resistance to ALS inhibiting herbicides. • Ile2041 mutation resulted in resistance to ACCase inhibiting herbicides. • Lolium rigidum fitness cost was associated with multiple resistance. [ABSTRACT FROM AUTHOR]

• Epichloë festucae LaeA is required for compatible symbiosis with perennial ryegrass. • Δ laeA mutants show significantly increased epiphyllous growth. • Roles for laeA in plant-fungal symbiosis have been identified through transcriptomics. LaeA is a conserved global regulator of secondary metabolism and development in fungi. It is often required for successful pathogenic interactions. In this study, the laeA homologue in the fungal grass endophyte E. festucae was deleted and functionally characterised in vitro and its role in the mutualistic E. festucae interaction with Lolium perenne (perennial ryegrass) was determined. We showed that laeA in E. festucae is required for normal hyphal morphology, resistance to oxidative stress, and conidiation under nutrient-limited in vitro conditions. In planta studies revealed that laeA is expressed in a tissue-specific manner and is required to form a compatible plant interaction, with the majority of seedlings inoculated with a laeA deletion mutant either dying or being uninfected. In mature infected plants no difference was observed in the number or morphology of endophytic hyphae. However, the number of epiphyllous hyphae were greatly increased. Comparative transcriptomics analyses suggested roles for plant cell wall degradation, fungal cell wall composition, secondary metabolism and small-secreted proteins in Epichloë foliar symbiosis. [ABSTRACT FROM AUTHOR]

The symbiosis between Epichloë festucae and its host perennial ryegrass ( Lolium perenne ) is a model system for mutualistic interactions in which the fungal endophyte grows between plant shoot cells and acquires host nutrients to survive. E. festucae synthesises the siderophore epichloënin A (EA) via SidN, a non-ribosomal peptide synthetase (NRPS). EA is involved in the acquisition of iron, an essential micronutrient, as part of the process of maintaining a stable symbiotic interaction. Here, we mutated a different NRPS gene sidC and showed that it is required for production of a second siderophore ferricrocin (FC). Furthermore mutations in sidA, encoding an l -ornithine N 5 -monooxygenase, abolished both EA and FC production . Axenic growth phenotypes of the siderophore mutants were altered relative to wild-type (WT) providing insights into the roles of E. festucae siderophores in iron trafficking and consequently in growth and morphogenesis. During iron-limitation, EA is the predominant siderophore and in addition to its role in iron acquisition it appears to play roles in intracellular iron sequestration and oxidative stress tolerance. FC in contrast is exclusively located intracellularly and is the dominant siderophore under conditions of iron sufficiency when it is likely to have roles in iron storage and iron transport. Intriguingly, EA acts to promote but may also moderate E. festucae growth (depending on the amount of available iron). We therefore hypothesise that coordinated cellular iron sequestration through FC and EA may be one of the mechanisms that E. festucae employs to manage and restrain its growth in response to iron fluxes and ultimately persist as a controlled symbiont. [ABSTRACT FROM AUTHOR]

The effect of increasing the concentration of commercial pequi ( Caryocar brasiliense ) oil on fermentation characteristics and abundance of methanogens and fibrolityc bacteria was evaluated using the rumen simulation technique (Rusitec). In vitro incubation was performed over 15 days using a basal diet consisting of ryegrass, maize silage and concentrate in equal proportions. Treatments consisted of control diet (no pequi oil inclusion, 0 g/kg DM), pequi dose 1 (45 g/kg DM), and pequi dose 2 (91 g/kg DM). After a 7 day adaptation period, samples for fermentation parameters (total gas, methane, and VFA production) were taken on a daily basis. Quantitative real time PCR (q-PCR) was used to evaluate the abundance of the main rumen cellulolytic bacteria, as well as abundance of methanogens. Supplementation with pequi oil did not reduce overall methane production ( P = 0.97), however a tendency ( P = 0.06) to decrease proportion of methane in overall microbial gas was observed. Increasing addition of pequi oil was associated with a linear decrease ( P < 0.01) in dry matter disappearance of maize silage. The abundance of total methanogens was unchanged by the addition of pequi oil, but numbers of those belonging to Methanomassiliicoccaceae decreased in liquid-associated microbes (LAM) samples ( P < 0.01) and solid-associated microbes (SAM) samples ( P = 0.09) respectively, while Methanobrevibacter spp. increased ( P < 0.01) only in SAM samples. Fibrobacter succinogenes decreased ( P < 0.01) in both LAM and SAM samples when substrates were supplemented with pequi oil. In conclusion, pequi oil was ineffective in mitigating methane emissions and had some adverse effects on digestibility and selected fibrolytic bacteria. [ABSTRACT FROM AUTHOR]

The effect of electric fields on seed germination and development of ryegrass ( Lolium perenne L.) was studied in clean and contaminated soil with heavy metals and/or PAHs. The application of 0.2 DCV/cm in clean soil near ryegrass seeds enhanced the germination by 75%. The presence of contaminants in soil hindered the germination and growing of ryegrass. However, the application of DC electric field favored the germination and growing of plants compensating the negative effects of the contaminants. The electrode material in anodes has a decisive influence in the germination and growing of ryegrass. Stable anode materials have to be used to avoid the release of toxic ions in the soil that affect the development of the plant. Graphite anodes are very appropriate because they are inexpensive and does not generate toxic effects on plants. The electro-phytoremediation of mixed contaminated soil with ryegrass showed very promising results, especially AC electric fields. The tests with AC current showed the highest biomass production in a treatment of 1 month. The more biomass production the more removal of heavy metals and PAHs from soil. [ABSTRACT FROM AUTHOR]

The effect of the combined application of nano-hydroxyapatite (NHAP) or nano-carbon black (NCB) on the phytoextraction of Pb by ryegrass was investigated as an enhanced remediation technique for soils by field-scale experiment. After the addition of 0.2% NHAP or NCB to the soil, temporal variation of the uptake of Pb in aboveground parts and roots were observed. Ryegrass shoot concentrations of Pb were lower with nano-materials application than without nano-materials for the first month. However, the shoot concentrations of Pb were significantly increased with nano-materials application, in particular NHAP groups. The ryegrass root concentrations of Pb were lower with nano-materials application for the first month. These results indicated that nano-materials had significant effects on stabilization of lead, especially at the beginning of the experiment. Along with the experimental proceeding, phytotoxicity was alleviated after the incorporation of nano-materials. The ryegrass biomass was significantly higher with nano-materials application. Consequently, the Pb phytoextraction potential of ryegrass significantly increased with nano-materials application compared to the gounps without nano-materials application. The total removal rates of soil Pb were higher after combined application of NHAP than NCB. NHAP is more suitable than NCB for in-situ remediation of Pb-contaminated soils. The ryegrass translocation factor exhibited a marked increase with time. It was thought that the major role of NHP and NBA might be to alleviate the Pb phytotoxicity and increase biomass of plants. [ABSTRACT FROM AUTHOR]

Biobeds are on-farm biodepuration systems whose efficiency rely on their high pesticide biodegradation capacity. We evaluated two optimization strategies, bioaugmentation and/or rhizosphere-assisted biodegradation, to maximize the dissipation capacity of biobeds. Iprodione was used as a model pesticide. Its dissipation and metabolism was determined in a biobed packing material inoculated with an iprodione-degrading Arthrobacter strain C1 (bioaugmentation, treatments B+C1) and/or seeded with ryegrass (rhizosphere-assisted biodegradation, treatments B+P). The impact of those strategies on the activity and composition of the microbial community was determined. Bioaugmentation accelerated the dissipation of iprodione which was further enhanced in the bioaugmented, rhizosphere-assisted treatment (treatment B+P+C1, Half-life (DT 50 ) = 3.4 d), compared to the non-bioaugmented, non rhizosphere-assisted control (DT 50 = 9.5 d, treatment B). Bioaugmentation resulted in the earlier formation of intermediate formation of metabolites I (3,5-dichlorophenyl-carboxamide), II (3,5-dichlorophenylurea acetate) and 3,5-dichloroaniline (3,5-DCA). The latter was further dissipated by the indigenous microbial community. Acid phosphatase (AP) and β-glucosidase (GLU) were temporarily stimulated in rhizosphere-assisted treatments, whereas a stimulation of the fluorescein diacetate (FDA) hydrolytic activity in the bioaugmented treatments coincided with the hydrolysis of iprodione. q-PCR showed that changes in the abundance of alpha-proteobacteria and firmicutes was driven by the presence of rhizosphere while bioaugmentation had no significant effect. [ABSTRACT FROM AUTHOR]

As supply chains of chemical fertilisers become more precarious, raw or derived bio-based fertilisers (herein referred to as bio-fertilisers) from the dairy processing industry could be good alternatives. However, their agronomic performance is relatively unknown, and where documented, the method to estimate this value is rarely presented. This pot study investigated aluminium-precipitated and calcium-precipitated dairy processing sludges (Al and Ca-DPS) and DPS-derived biochar as potential bio-fertilisers to grow ryegrass (Lolium perenne L.) and spring wheat (Triticum aestivum). The study aims were to examine how (1) application rate (optimal versus high) and (2) calculation methods (with and without chemical fertiliser response curves) can affect estimates of nitrogen and phosphorus mineral fertiliser equivalence value (N- and P-MFE) and associated agronomic advice. The results from both crops showed that for nitrogen application rates (125 or 160 kg ha−1 for ryegrass and 160 or 240 kg ha−1 for spring wheat) estimates of N-MFE increased for both Al-DPS and Ca-DPS as application rate increased. Dry matter yield response curves produced the highest % N-MFE results (e.g., ryegrass ∼50% and 70% for Al-DPS and Ca-DPS) with other calculation methods producing all similar results (e.g., ryegrass ∼20% for Al-DPS and Ca-DPS). For phosphorus application rates (40 or 80 kg ha−1 for ryegrass and 50 or 80 kg ha−1 for spring wheat), estimates of P-MFE did not increase with application rate. Negative P-MFE values obtained for Ca-DPS and DPS-biochar when growing ryegrass and spring wheat grain, respectively, indicated low plant available phosphorus. Overall, Al-DPS had better performance as a bio-fertiliser when compared to the other products tested. There was no significant difference between the two calculation methods of MFE, which suggests that the determination of MFE could be simplified by using one application as opposed to numerous application rates of fertilisers. Future work should focus on elucidating the N- and P-MFE of a wider range of DPS and STRUBIAS bio-fertilisers, and alternative methods should be investigated that enable a comparison across all bio-fertiliser types. [Display omitted] • Application rate and calculation methods affect agronomic performance outcomes. • High application rates of DPS increased N mineral fertiliser equivalence values. • Al-DPS showed best promise over Ca-DPS and biochar as a bio-based fertiliser. • N-MFE calculated based on dry matter yield was higher than N uptake. • Negative P-MFE values for Ca-DPS and DPS-biochar showed low plant available P. [ABSTRACT FROM AUTHOR]

Abandoned gold mining spoils pose socio-environmental, human, and animal health impacts and threaten sustainability of mineral extraction. Green trials and ecological solutions are required to effectively remediate these contaminated soils and mitigate the associated risks. Here, we carried out a pot experiment using a highly contaminated soil (mean total As = 5104.0 mg/kg) collected from an abandoned mine spoil in Ghana. We aimed to quantify the impacts of compost, iron oxide, and poultry manure on the mobilization, fractionation, and uptake of As by ryegrass (Lolium perenne). The soil amendments were applied at a rate of 5% (w/w) each, separately or in combination. We extracted the mine spoil soil readily-bioavailable As and specific-sorbed As, and determined the As contents in plant and the uptake after harvest. The plant transfer indices for soil-to-root (bioconcentration factor, BCF), soil-to-shoot (bioaccumulation concentration- BAC), and root-to-shoot (translocation factor- TF) were also calculated. Addition of manure increased the mining readily-bioavailable As by 243% and specific-sorbed As by 38%, as compared to the control. Manure addition further aided root As-uptake by 134%, whilst its combination with compost increased uptake by 101%. Lone addition of manure and in combination with compost resulted in BCF above 1, indicating increased As-phytostability. The presence of carbon and iron in the roots of the ryegrass sorbed or precipitated As limited its soil-to-shoot and root-to-shoot transfer. These findings indicate that manure alone and in combination with compost can be used to augment the phytoremediation efficiency of ryegrass in the As-contaminated spoil. [Display omitted] • Manure (M) increased the mining readily-bioavailable As and specific-sorbed As. • Manure addition aided root As-uptake by 134%, as compared to the control. • Manure-compost (CM) addition increased As root uptake by 101%. • Addition of M and CM resulted in bioconcentration ratio of As above 1. • Combined compost-iron oxide addition decreased As phytoavailability. [ABSTRACT FROM AUTHOR]

The use of digestate in agriculture is an efficient way to recycle materials and to decrease the use of mineral fertilizers. The agronomic characteristics of the digestates can promote plant growth and soil properties after digestate fertilization but also harmful effects can arise due to digestate quality, e.g. pH, organic matter and heavy metal content. The objective of this study was to evaluate the differences and similarities in agronomic characteristics and the value of five urban waste digestates from different biogas plants treating either food waste, organic fraction of organic solid waste or a mixture of waste-activated sludge and vegetable waste. The digestate agronomic characteristics were studied with chemical analyses and the availability of nutrients was also assessed with growth experiments and soil mineralization tests. All studied urban digestates produced 5–30% higher ryegrass yields compared to a control mineral fertilizer with a similar inorganic nitrogen concentration, while the feedstock source affected the agronomic value. Food waste and organic fraction of municipal solid waste digestates were characterized by high agronomic value due to the availability of nutrients and low heavy metal load. Waste-activated sludge as part of the feedstock mixture, however, increased the heavy metal content and reduced nitrogen availability to the plant, thus reducing the fertilizer value of the digestate. [ABSTRACT FROM AUTHOR]

A strategy to control herbicide resistant weeds is to use an impact mill to devitalise weed seeds as they exit a combine harvester. To model the impact milling of weed seeds, the milling response was split into material and machine functions separating the effect of seed properties from mill design and operational parameters. The material function was determined by subjecting annual ryegrass seeds ( Lolium rigidum ) to multiple single sided impacts using a rotational impact tester. The number of impacts, impact speed and seed moisture content were varied. Seed devitalisation was measured by germinating seeds in soil bins in a controlled environment room. Seed devitalisation increased with the number of impacts, the impact speed and decreasing moisture content. Seed devitalisation did not depend on the order of an impact sequence when exposed to multiple impacts at three different speeds. A threshold minimum energy per impact of 0.3991 kJ kg −1 (equivalent to ∼ 28 m s −1 ) was observed, below which almost zero devitalisation occurred. A material function Mastercurve for devitalisation was developed using this threshold energy level and one other material parameter which described a seed's resistance to fracture. The Mastercurve was able to accurately predict ( r 2 = 0.94) devitalisation of annual ryegrass seeds (11.3% m.c.) by the number of impacts above the threshold speed and impact speed in any impact sequence. The Mastercurve presented will be able to be used in future studies with a machine function to design impact mills to mechanically devitalise annual ryegrass seeds. [ABSTRACT FROM AUTHOR]

A hardwood biochar was examined for its potential use as an amendment to aid in the phytostabilization of a severely-contaminated soil at a former sulfuric acid recycling factory site. The soil, which has remained unvegetated for nearly a century, contained high pseudo-total concentrations of lead, arsenic and antimony and was both highly acidic and hydrophobic due to the presence of petroleum-based acid tar. Three application approaches were tested with 10 and 20% (vol/vol) biochar: Incorporation into soil, top-dressing on the surface, and layering within the soil. The results suggest that the homogeneous mixing of the hardwood biochar into soil would not promote the long-term restoration at this site due to its inherently low alkalinity relative to the very high net acidity of the existing soil. In contrast, surface application of biochar resulted in the most successful growth of Canada wild-rye grass by exploiting the properties inherent to biochar alone. [ABSTRACT FROM AUTHOR]

Trace element (TE) contamination of soils is a worldwide problem. However, although not considered safe anymore for food production without clean-up, many of these soils may still be used to produce biomass for non-food purposes such as biochar. Exploring the suitability of such biochar for the amendment of low-fertility soil, we investigated growth and metal accumulation of ryegrass ( Lolium perenne , var. Calibra ) as well as soil microbial abundance on a non-contaminated soil after amendment with biochar from birch ( Betula pendula ) wood produced on TE contaminated soil in comparison to a treatment with birch wood biochar originating from non-contaminated soil. Biochars were produced from both feedstocks by pyrolysis at two temperatures: 450 and 700 °C. During the pyrolysis, in contrast to Cu, Fe, Mg, K, Mn and P, the elements Cd, Pb, S and Na volatilized. The root biomass of the biochar treated plants was lower than that of the non-amended plants, while that of the shoot was higher. Plant shoot K and Zn concentrations were increased significantly by up to 7- and 3.3-fold respectively. For P, Mg, Mn, Fe and Cu no significant increase in shoot concentration could be detected. Neither the TE-contaminated biochar, nor the non-contaminated biochar had adverse effect on the bacterial community of the soil. [ABSTRACT FROM AUTHOR]

Degraded landscapes, like those from abandoned mine areas, could be restored by revegetating them with appropriate plant species, after correction for acidity and improvement by adding exogenous organic material. Application of urban wastes to large areas of derelict land helps in the sustainable development of this landscape. However, the development of plant species in these soils could require in the future the management of possible pests or diseases by pesticide applications which could also affect plant yield. Therefore, ryegrass (Lolium perenne L.) was planted in a limed soil from the mining area of Riotinto (SW Spain), using an indoor pot experiment and the effects of amendment with sewage sludge, as well as irrigation with urban wastewater on plant uptake of the insecticide thiacloprid and the fungicide fenarimol were examined. Ryegrass biomass was reduced up to 3-fold by pesticide application. Fenarimol residues were the highest in soil, while those of thiacloprid were lower in soil and higher in ryegrass. Addition of sewage sludge and irrigation with wastewater led to a reduction of pesticide translocation to the aerial plant parts, representing a lower hazard to ryegrass quality grown in this mine soil. [Copyright &y& Elsevier]

This study was conducted to investigate the use of elevated carbon dioxide (CO2), plant growth-promoting rhizobacterium Burkholderia sp. D54 (PGPR) and ethylenediaminetetraacetic acid (EDTA) to enhance the phytoextraction efficiency of ryegrass in response to multiple heavy metal (or metalloid)-polluted soil containing zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb). All of the single or combined CO2, PGPR and EDTA treatments promoted ryegrass growth. The stimulation of ryegrass growth by CO2 and PGPR could primarily be attributed to the regulation of photosynthesis rather than decreased levels of Zn, As and Cd in the shoots. Most treatments seemed to reduce the Zn, As and Cd contents in the shoots, which might be associated with enhanced shoot biomass, thus causing a “dilution effect” regarding their levels. The combined treatments seemed to perform better than single treatments in removing Zn, As, Cd and Pb from soil, judging from the larger biomass and relatively higher total amounts (TAs) of Zn, As, Cd and Pb in both the shoots and roots. Therefore, we suggest that the CO2 plus PGPR treatment will be suitable for removing Zn, As, Cd and Pb from heavy metal (or metalloid)-polluted soils using ryegrass as a phytoremediation material. [Copyright &y& Elsevier]

Herbicide resistance is one of the most significant challenges for cropping systems that rely on herbicides for weed control. To address this challenge, mechanical weed control methods are being investigated that apply impact energy to weed seeds in the chaff after they exit the sieve of a combine harvester. A pendulum impact tester applying a double-sided impact and a rotational impact tester applying a single-sided impact were used to apply a single impact to annual ryegrass (Lolium rigidum) seeds. The impacted seeds were evaluated for physical damage and germination potential under controlled conditions using paper and soil. A logistic regression was used to model energy dose response for visibly damaged seeds and seed devitalisation based on: normal germinated seeds on paper; total germinated seeds on paper (normal + abnormal) and emerged seedlings in soil bins. The median effective dose (ED50) of impact energy for visibly damaging seeds was lower for the double-sided impact of the pendulum impact tester (6.5 mJ) compared to the single-sided impact of the rotational impact tester (8.7 mJ). However, the rotational impact tester was more efficient at devitalising seeds having a median effective dose of 7.1 mJ and 3.0 mJ for devitalisation based on both normal germination and total germination, respectively; compared to 15.7 mJ and 6.8 mJ, respectively for the pendulum impact tester. These energy values required to devitalise seeds is data that can be used in the design of machinery for mechanical weed seed control. [ABSTRACT FROM AUTHOR]

Abstract: Glyphosate is the world’s most important and widely used herbicide with a global market forecast to exceed a million metric tons before end of the current decade. While using 31P NMR in vivo to determine the fate of glyphosate in horseweed (Conyza canadensis (L.) Cronquist), we observed the glyphosate-induced appearance of an unexpected phosphorous containing compound that, in some cases, presented at millimolar concentrations [X. Ge, D.A. d’Avignon, J.J.H. Ackerman, R.D. Sammons, Rapid vacuolar sequestration: the horseweed glyphosate resistance mechanism, Pest Manag. Sci. 66 (2010) 345–348.]. Additional studies showed appearance of the same compound could be induced in ryegrass (Lolium multiflorum Lam) and other plant species by glyphosate exposure. We have isolated and identified the phosphorous containing compound as 2-C-methyl-d-erythritol-2,4-cyclopyrophosphate (MEcPP), one of the intermediates of the methylerythritol 4-phosphate (MEP) pathway, which is critical in plants for the production of isoprenoids. Herein, we describe conditions under which MEcPP can be produced in plants as well as the isolation and characterization of this metabolite. [Copyright &y& Elsevier]

Batch digestion of energy crops at mesophilic temperature indicates that the rate of anaerobic digestion of energy crops into methane may first reach its maximum rate after several days for energy crops such as maize, oat, ryegrass, and wheat that are less degradable than sugars and fats. Experiments show that the cumulative methane production pattern from energy crops rather follows a sigmoidal, and not exponential, curve shape. Implications are that optimal usage of energy crops should involve an evaluation of their degradation kinetics, specifically the rate of which they are converted into methane, and the optimal digester hydraulic retention time and or reactor configuration for the specific energy crop. [ABSTRACT FROM AUTHOR]

The effects of addition of carbonated residue mud (RMC) or seawater neutralized residue mud (RMS), at two rates, in the presence or absence of added green waste compost, on the chemical, physical and microbial properties of gypsum-treated bauxite residue sand were studied in a laboratory incubation study. The growth of two species commonly used in revegetation of residue sand (Lolium rigidum and Acacia saligna) in the treatments was then studied in a 18-week greenhouse study. Addition of green waste-based compost increased ammonium acetate-extractable (exchangeable) Mg, K and Na. Addition of residue mud at 5 and 10% w/w reduced exchangeable Ca but increased that of Mg and Na (and K for RMS). Concentrations of K, Na, Mg and level of EC in saturation paste extracts were increased by residue mud additions. Concentrations of cations in water extracts were considerably higher than those in saturation paste extracts but trends with treatment were broadly similar. Addition of both compost and residue mud caused a significant decrease in macroporosity with a concomitant increase in mesoporosity and microporosity, available water holding capacity and the quantity of water held at field capacity. Increasing rates of added residue mud reduced the percentage of sample present as discrete sand particles and increased that in aggregated form (particularly in the 1–2 and >10mm diameter ranges). Organic C content, C/N ratio, soluble organic C, microbial biomass C and basal respiration were increased by compost additions. Where compost was added, residue mud additions caused a substantial increase in microbial biomass and basal respiration. L. rigidum grew satisfactorily in all treatments although yields tended to be reduced by additions of mud (especially RMC) particularly in the absence of added compost. Growth of A. saligna was poor in sand alone and mud-amended sand and was greatly promoted by additions of compost. However, in the presence of compost, addition of carbonated mud had a marked depressive effect on both top and root growth. The significant positive effect of compost was attributed to substantial inputs of K and marked reductions in the Na/K ratio in soil solution while the depressive effect of RMC was attributed to its greater alkalinity and consequently higher concentrations of HCO3 − in solution. [Copyright &y& Elsevier]

The possibility of replacing net with film to tie large round bales for silage making was investigated. A specifically designed polyethylene film has been developed and used to replace the typical net wrapping. A film-tying device, which was already on the market, was fitted to a variable chamber round baler and used instead of the standard net-tying system. A total of 48 round bales, consisting of half Italian ryegrass and half lucerne were baled following a 2-day wilting period. Half of the bales were net-tied and the other half film-tied. The bales were wrapped with 4 or 6 layers of stretch film and stored outside, half on their ends and half on their curved surfaces, for 180 days. The mechanical, fermentative and microbiological aspects were investigated. The work rate was not affected by the tying method. No evident damage to the film used for tying was observed before or after ejection from the baler or after the mechanical handling using a typical bale squeeze. Plastic consumption for film-tying was slightly higher, but mould on the bale surface was reduced compared to the net-tying method. This study has shown that film-tying could represent an interesting alternative to net-tying when preparing round bales for making silage. [Copyright &y& Elsevier]

Abstract: Sequestration of paraquat away from its target site in the chloroplast has been proposed as a mechanism of paraquat resistance. However, no consensus has been reached as to where paraquat is sequestered. This study quantifies paraquat in leaf protoplasts of paraquat resistant (R) and susceptible (S) Lolium rigidum. Intact protoplasts were prepared from plants treated with commercial dose of paraquat for 2h. Paraquat absorbed by the leaf protoplasts was determined by light absorption of reduced paraquat following concentration and purification using a cation-exchange resin. Leaf protoplasts from treated paraquat resistant plants contained 2- to 3-fold more paraquat than leaf protoplasts isolated from susceptible plants. Since paraquat is not metabolised in L. rigidum and paraquat readily enters chloroplasts of both R and S plants, this greater amount of paraquat in leaf protoplasts of R plant must be kept away from the target site (chloroplast). This result indicates that paraquat resistance in L. rigidum is associated with a cytoplasmic mechanism, most likely a greater rate of vacuolar sequestration. [Copyright &y& Elsevier]

Abstract: Plant secondary chemicals can alter herbivores’ susceptibility to pathogens by weakening the host, by affecting exposure through feeding, or by synergizing or deactivating pathogenic microbes in the gut. This study examined how feeding on perennial ryegrass (Lolium perenne) with (E+) or without (E−) its alkaloid-producing fungal endophyte, Neotyphodium lolii, affects susceptibility of a grass-feeding caterpillar to a baculovirus. In separate experiments, black cutworms (Agrotis ipsilon) were reared on E+ or E− grass that had been sprayed with different rates of A. ipsilon multiple nucleopolyhedrovirus (AgipMNPV), or were droplet-fed a single dose of the virus while developing on those grasses. Larvae grew more quickly on E− than on E+ grass, and mortality from virus increased at higher doses, but there was no endophyte×virus interaction in either trial. Despite larger size, larvae that fed ad libitum on virus-sprayed E− grass died more quickly than counterparts feeding on virus-sprayed E+ ryegrass, but such an effect was not seen when the virus was consumed as a single dose. Together, the results suggest that feeding on E+ grass neither compromises nor synergizes infectivity of AgipMNPV in the A. ipsilon midgut. Reduced consumption or avoidance of less-palatable E+ grass could, however, decrease ingestion of virus and rates of subsequent mortality in the field. Net benefits of integrating endophytic grasses and baculoviruses for managing A. ipsilon may depend on the extent to which reduced intake of virus on E+ grass is counterbalanced by slower growth and increased mortality from other natural enemies. [Copyright &y& Elsevier]

Pyricularia oryzae isolates from Lolium spp. (annual ryegrass and perennial ryegrass) show evidence of recent events in evolution of this fungus. A wheat blast isolate found in Kentucky in 2011 was assumed to originate from annual ryegrass isolates. Genetic analyses revealed that the incompatibility between a Lolium isolate and common wheat cultivars is controlled by two gene pairs, Rmg6–A1 with a strong effect and R2-A2 with a weak effect, implying that this incompatibility is conditioned by simple gene-for-gene interactions. Disruption of the A1 avirulence gene led the Lolium isolate to gain virulence on common wheat. These results suggest a mechanism for host jumping by the blast fungus. [ABSTRACT FROM AUTHOR]

The livestock agriculture of temperate grasslands is a major provider of meat and milk to the world. These areas also deliver important ecosystem services and are central to tourism, amenity, and leisure in many countries. However, they are also major sources of pollution of waterways and of greenhouse gas emissions. In this review, we focus on how the genetic improvement of some of the major crop species of temperate grasslands can contribute to reduced environmental impacts and climate change mitigation including the enhancement of carbon sequestration. The main species considered are the ryegrasses and fescues and the clovers. With regard to diffuse pollution of waterways, increasing the efficiency with which the plant utilizes nitrogen and phosphorus has significant potential to reduce the amounts available for leaching and overland flow. This also allows reduced fertilizer use, in itself representing a significant saving of greenhouse gas emissions. Changes in the composition of the plant diet have the potential to increase the efficiency of nitrogen use in the tureen and reduce the amount of methane produced by enteric fermentation. Carbon sequestration in temperate grasslands may potentially be enhanced by understanding and altering root architecture and turn over and also litter composition. The role of forage breeding in improving soil quality and flood defense is also considered and wider aspects of the role of persistent perennial species discussed. To fully realize the potential of genetic improvement, breeding programs need to incorporate state-of-the-art genomics and also to be guided by modeling studies. An integrated approach combining the skills of animal scientists, soil scientists, and plant breeders within the context of life cycle analysis is required to find sustainable solutions to the challenge of maintaining the productivity of livestock agriculture while reducing its environmental footprint. [ABSTRACT FROM AUTHOR]

Nano-aluminum is being used in increasing quantities as energetic material. This research addresses the transport of two types of nanosized aluminum particles (with aluminum oxide, or carboxylate ligand coating, Alex and L-Alex, respectively) through sand columns along with associated environmental impacts on soil systems. Surface phenomena and pH are variables controlling the transport of nano-aluminum particles through porous media. pH environment controls solubility and electrostatic interactions between nano-aluminum particles and porous media. (i.e., changes in point of zero charge, agglomeration, etc.). Concentrations (up to 17mg/L) far greater than the World Health Organization guideline for Al in drinking water (0.2mg/L) were measured in columns’ leachates. Plant uptake studies, mineralization of radiolabeled glucose test and Microtox test were used to investigate the environmental impacts of nano-aluminum on soil communities and plants. It appears that the presence of nano-aluminum particles did not have an adverse effect on the growth of California red kidney bean (Phaseolus vulgaris) and rye grass (Lolium perenne) plants in the concentration range tested. California red beans did not show uptake of aluminum, while the situation was different for rye grass where a 2.5-fold increase in Al concentration in the leaves was observed as compared with control tests. Nano-aluminum particles in suspension do not appear to have an impact on the metabolic activity of Vibrio fischeri. However, when the nano-aluminum particles were amended to the soil, Alex aluminum resulted in a 50% reduction of light output at concentrations below 5000mg/L soil suspension concentration while L-Alex showed a similar effect at around 17,500mg/L and the control soil at 37,500mg/L. Soil respiration studies show that there are not statistical differences between the time and sizes of peaks in CO2 production and the total mineralization of glucose. [Copyright &y& Elsevier]

Abstract: The crystal structure of the sobemovirus Ryegrass mottle virus (RGMoV) has been determined at 2.9 Å resolution. The coat protein has a canonical jellyroll β-sandwich fold. In comparison to other sobemoviruses the RGMoV coat protein is missing several residues in two of the loop regions. The first loop contributes to contacts between subunits around the quasi-threefold symmetry axis. The altered contact interface results in tilting of the subunits towards the quasi-threefold axis. The assembly of the T=3 capsid of sobemoviruses is controlled by the N-termini of C subunits forming a so-called β-annulus. The other loop that is smaller in the RGMoV structure contains a helix that participates in stabilization of the β-annulus in other sobemoviruses. The loss of interaction between the RGMoV loop and the β-annulus has been compensated for by additional interactions between the N-terminal arms. As a consequence of these differences, the diameter of the RGMoV particle is 8 Å smaller than that of the other sobemoviruses. The interactions of coat proteins in sobemovirus capsids involve calcium ions. Depletion of calcium ions results in particle swelling, which is considered a first step in disassembly. We could not identify any density for metal ions in the proximity of the conserved residues normally involved in calcium binding, but the RGMoV structure does not show any signs of swelling. A likely reason is the low pH (3.0) of the crystallization buffer in which the groups interacting with the calcium ions are not charged. [Copyright &y& Elsevier]

Analyses of ribosomal ITS and chloroplast trnL–F sequences provide phylogenetic reconstruction for the festucoids (Poeae: Loliinae), a group of temperate grasses with morphological and molecular affinities to the large genus Festuca. Parsimony and Bayesian analyses of the combined ITS/trnL–F dataset show Loliinae to be monophyletic but unresolved for a weakly supported clade of ‘broad-leaved Festuca,’ a well-supported clade of ‘fine-leaved Festuca,’ and Castellia. The first group includes subgenera Schenodorus, Drymanthele, Leucopoa, and Subulatae, and sections Subbulbosae, Scariosa, and Pseudoscariosa of Festuca, plus Lolium and Micropyropsis. The second group includes sections Festuca, Aulaxyper, Eskia, and Amphigenes of Festuca, plus Vulpia, Ctenopsis, Psilurus, Wangenheimia, Cutandia, Narduroides, and Micropyrum. Subtribes Dactylidinae and Cynosurinae/Parapholiinae are sister clades and are the closest relatives of Loliinae. Vulpia is polyphyletic within the ‘fine-leaved’ fescues as revealed by the two genome analyses. Lolium is resolved as monophyletic in the ITS and combined analyses, but unresolved in the trnL–F based tree. Conflict between the ITS and the trnL–F trees in the placement of several taxa suggests the possibility of past reticulation events, although lineage sorting and possible ITS paralogy cannot be ruled out. [Copyright &y& Elsevier]

We traced the presence and distribution of Neotyphodium lolii within developing inflorescences and embryos of perennial ryegrass (Lolium perenne L.), cultivar “Grassland Nui,” by in situ immunolocalization of fungal proteins. Evidence is presented that the fungus penetrates through the rachilla at the base of the ovary, and localizes in a very precise and specific manner in the ovular nucellus, but never enters the embryo sac or the integuments. Young embryos do not contain mycelium, but as they mature the hyphae penetrate through the scutellum from a neighboring “infection layer”—a remnant of nucellus heavily colonized by the fungus–that is readily visible as a discrete area directly adjoining the base of embryo cavity. Our observations document that N. lolii is transmitted to the embryo exclusively via sporophytic maternal tissue.Index descriptors: Lolium perenne, Neotyphodium lolii, Antigens, Immunodetection in situ, Flowers, Seeds [Copyright &y& Elsevier]

Tall fescue (Lolium arundinaceum), an agronomically important forage grass, is typically associated with a mutualistic asexual fungus Neotyphodium coenophialum. Plant colonization is endophytic with no symptoms, and fungal growth is confined to the intercellular spaces. The endophyte enhances host fitness by providing protection from various abiotic and biotic stresses and by improving nutrient acquisition. By suppression subtractive hybridization (SSH) we identified 29 genes that are up-regulated or down-regulated in endophyte-infected tall fescue as compared to endophyte-free tall fescue. Of the genes that had matches to known genes present in the NCBI databases (approximately 50%), several had roles related to plant defense and stress tolerance. Differential expression of these genes was confirmed by semi-quantitative RT-PCR, competitive RT-PCR, and northern hybridization. Endophyte-associated changes in gene expression patterns were consistent among cultivars of tall fescue but differed in some other grass–endophyte associations. Our results indicate that both partners in this symbiosis are active participants, and that the endophyte may be suppressing at least one plant defense gene (putatively encoding PR-10). Further analyses of the differentially expressed genes should aid in understanding the fundamental nature of this mutualistic symbiosis and provide insight into the mechanisms of documented endophyte-enhanced plant improvements. [Copyright &y& Elsevier]

We have characterized a cold-induced, boiling stable antifreeze protein. This highly active ice recrystallization inhibition protein shows a much lower thermal hysteresis effect and displays binding behavior that is uncharacteristic of any AFP from fish or insects. Ice-binding studies show it binds to the (1 0 1¯ 0) plane of ice and FTIR studies reveal that it has an unusual type of highly β-sheeted secondary structure. Ice-binding studies of both glycosylated and nonglycosylated expressed forms indicate that it adsorbs to ice through the protein backbone. These results are discussed in light of the currently proposed mechanisms of AFP action. [Copyright &y& Elsevier]

The efficacy of biological control agents is affected by numerous cultural conditions. This study was undertaken to determine how the efficacy of Dilophospora alopecuri inoculum was affected by various conditions, including length of fermentation, moisture content, and growth substrate. Dilophospora alopecuri (Fr.) Fr. provides biological control of the organisms (Rathayibacter toxicus and Anguina funesta) responsible for annual ryegrass toxicity. The effectiveness of D. alopecuri inoculum was evaluated under different conditions for establishment in ryegrass. Prolongation of incubation of the inoculum for 3–10 weeks had no significant effect on the inoculum as a biological control agent. The effect of inoculum moisture content was mixed. With wheat as the substrate, air-drying the inoculum had no apparent effect. However, with ryegrass as the substrate, air-drying the inoculum decreased the effectiveness of the inoculum in the field experiment but not in the pot experiment. The substrate itself also had a significant effect. In the pots, application of colonized ryegrass gave a mean of 56.9 infected inflorescences per pot compared to 30.4 for colonized wheat. In the field experiment, 87.5% of plots inoculated with colonized ryegrass had 25 or more infected inflorescences, twice that of plots treated with colonized wheat. [Copyright &y& Elsevier]

Salinity is a major abiotic stress that adversely affects turfgrass growth. Clinoptilolite zeolite, a silicon (Si)-rich mineral, may allow these plants to cope with salinity. Therefore, in the present study, the effects of ordinary clinoptilolite zeolite (OZ) and potassium-enriched clinoptilolite zeolite (K-EZ) on the growth of perennial ryegrass (Lolium perenne L.) were assessed under salinity stress. Perennial ryegrass seeds were cultured in soil mixtures amended, or not, with OZ or K-EZ, then exposed to three salinity levels (0, 50 or 100 mM NaCl) for three months. Control plants were grown in the same soil mixture without zeolites, but not exposed to salinity. In salinity, the application of both types of zeolite significantly decreased Na content by 44.36% and 21.31%, but increased K content by 272.34% and 81.59%, as well as the K/Na ratio by 590.47% and 129.43%, in shoots and roots, respectively, compared to the no-zeolite treatment. Similarly, Si content in shoots increased by 28.33%. Amending the soil mixture with zeolite, especially K-EZ, enhanced relative water content, membrane stability index, total chlorophyll content, total soluble proteins, peroxidase and superoxide dismutase activities but reduced the contents of total soluble carbohydrates, hydrogen peroxide, and malondialdehyde in saline conditions. Shoot and root dry weight, root volume and root/shoot ratio also improved. Soil amendment with both forms of zeolite, as a Si-rich mineral, partially offset the negative impacts of salinity on perennial ryegrass, although K-EZ had more noticeable positive and beneficial effects. The amendment of growth media with zeolite may be an effective sustainable management practice for turfgrass used in landscaping and sports fields exposed to saline water. [Display omitted] • Effect of clinoptilolite zeolite (mainly SiO 2) on perennial ryegrass was assessed. • At 100 mM NaCl, OZ and K-EZ increased root/shoot ratio by 12.55% and 57.83%. • Zeolites reduced Na (−32.84%) but increased K (176.96%) in shoots and roots under salinity. • Zeolites increased POD (67.09%) and SOD (141.11%) activities under salinity. • Application of both types of zeolites successfully mitigated salinity's adverse effects. [ABSTRACT FROM AUTHOR]

• Trichoderma stimulates resistance against to Pyricularia oryzae in Lolium multiflorum. • Coated seeds of L. multiflorum with T. atroviride reduces the severity of P. oryzae. • Silicon is accumulated in the leaves and improves the resistance to blast. • Biochemical and physical defenses are related to the protective action against blast. Ryegrass (Lolium multiflorum L.) is a forage species with a high content of protein and good palatability and digestibility. In winter, it is frequently used in southern Brazil as feed for livestock. The high humidity in this region is propitious for gray leaf spot, a disease caused by Pyricularia oryzae , considered to be the region's main biotic problem. In this study, we aimed to evaluate the effect of three types of management, namely seed coating with Trichoderma atroviride (T), application of silicon in the soil (Si), and combination of both treatments (TSi), to reduce the severity of gray leaf spot. In the first phase, the capacity of 10 native isolates of Trichoderma spp. were evaluated in vitro for direct inhibition of P. oryzae based on tests of dual cultures (DC), antibiosis for volatile (Vol), and non-volatile compounds (Nvol). In vivo trials involved the ability to induce resistance responses, such as quantifying severity (SEV) and number of lesions (NL) per cm2 of leaf area. In the second phase, the efficacy of T, Si, and TSi was tested under greenhouse conditions. The lesion expansion rate (LER), relative efficiency of infection (RIE), SEV and NL were measured (after inoculation with P. oryzae), and in parallel the activities of the enzymes superoxide dismutase (SOD), catalase (CAT), peroxidase (POX) and phenylalanine ammonia-lyase (PAL) were quantified (at 24, 48, 72, and 96 h). The strain TR10 (identified by polyphasic taxonomy as T. atroviride) showed one of the highest inhibition values in Vol (23%) and DC (35%). Plants from seeds treated with the strain TR10 had the lowest levels of SEV (5.5%) and NL (3), in contrast with the other strains according to analysis of variance. Under greenhouse conditions, significant differences (P < 0.0001) were found for LER, RIE, NL and SEV in T, Si, and TSi concerning TE (control treatment). The defense response of T was related to the activities of CAT, POX, and PAL (mainly), while for Si, other mechanisms, which were not evaluated in this study, might have contributed to disease reduction, and TSi did not show an additive effect. The treatment of seeds with T. atroviride and the application of Si in the soil improved the resistance of L. multiforum against infection by P. oryzae. [ABSTRACT FROM AUTHOR]

Separation of slurries can facilitate the nutrient management on farms through nutrient partitioning between the liquid and the solid fraction. The distribution of nutrients in the slurry fractions depends largely on the type of separator used. The current study assessed the separation efficiency of a two-step separation treatment of pig slurry including in-series a screw press and a centrifuge followed by acidification (to pH 5.9) of the final liquid effluent. The system concentrated 73.8% of the slurry's Phosphorus (P) content, 52.6% of Total solids (TS) and 14.4% of total Nitrogen to the solid fraction. The apparent N recovery from ryegrass fertilized with the raw slurry and non-acidified liquid fractions was not decreased by the separation treatment. The acidified liquid fraction showed 28% and 9% higher apparent N recovery compared to the raw slurry and the non-acidified liquid effluent from the centrifuge respectively. The biochemical methane production potential (B o) of the acidified liquid fraction was reduced by 50% and 25%, compared to the non-acidified counterpart and the raw slurry, respectively. The results highlight the potential of a double separation system coupled with acidification of the liquid fraction, to extract P into a solid fraction which can be transported outside the farm, and to increase N utilization from the liquid fraction when this is used as organic fertiliser on or nearby the farm. The study further highlights the potential to reduce CH 4 emissions from slurry storage after mechanical separation and acidification of the liquid slurry fraction. • The two-stage slurry separation reduces P content in the liquid fraction by 74%. • Slurry separation did not decrease the N fertilizing value of the liquid products. • Acidification increase the apparent N recovery from liquid slurries. • Acidification reduces the biochemical methane potential of slurries. [ABSTRACT FROM AUTHOR]

• The PKS7 in C. purpurea was found to be responsible for the biosynthesis of depsides. • Lecanoric acid and ethyl lecanorate were isolated from C. purpurea OE:: PKS7 mutant. • Cytotoxicity of lecanoric acid and ethyl lecanorate was studied. • Ethyl lecanorate showed neurotoxic effect with an IC 50 value of 54 µM on CCF cells. Claviceps purpurea is a plant pathogenic fungus which is still highly relevant in modern agriculture as it infects grasses such as rye and wheat. The disease caused by the consumption of contaminated grain or flour has been known since the Middle Ages and is termed ergotism. The main cause for the toxicity of this fungus is attributed to the ergot alkaloids. Apart from these alkaloids and the ergochromes known as ergot pigments, the secondary metabolism of C. purpurea is not well investigated. This study demonstrated the function of the polyketide synthase PKS7 in C. purpurea by determining the effect of its overexpression on metabolite profiles. For the first time, the depsides lecanoric acid, ethyl lecanorate, gerfelin, and C10-deoxy gerfelin were discovered as secondary metabolites of C. purpurea. Additionally, to estimate the contribution of isolated secondary metabolites to the toxic effects of C. purpurea , lecanoric acid, ethyl lecanorate, and orsellinic acid were tested on HepG2 and CCF-STTG1 cell lines. This study provides the first report on the function of C. purpurea PKS7 responsible for the production of depsides, among which lecanoric acid and ethyl lecanorate were identified as main secondary metabolites. [ABSTRACT FROM AUTHOR]

Phytoremediation-assisted electrokinetic-bioremediation is a novel technology for soil remediation. We aimed to study the effects of a plant (ryegrass) on electrokinetic-bioremediation in n -hexadecane-contaminated soil. After treatment for 40 days, the n -hexadecane degradation ratio of electrokinetic-bioremediation-ryegrass (EK-Bio-RG) was 4.86% higher than that of electrokinetic-bioremediation (EK-Bio) (p < 0.05), with a maximum constant degradation rate (107.23 ± 4.62 mg kg−1· d−1). Owing to the improved electrical conductivity, 73.28% of the initial current was maintained on the 40th day in EK-Bio-RG, which was 1.62 times that in EK-Bio. Furthermore, ryegrass reduced the soil zeta potential, which indicated the alleviation of the soil electric double layer compression and prevention of the aggregation of small soil colloids into larger ones. The fine colloidal structure was conducive to mass transfer in electrokinetic-bioremediation. An analysis of the microbial community showed that the degradation of n -hexadecane was mainly attributable to gram-positive bacteria, and a new microbial community was gradually constructed in the rhizosphere, which still metabolized n -hexadecane. The results indicated that the sustainability of the electrokinetic effect was improved combined with ryegrass, and the harmonious micro-environment in the rhizosphere was constructed which furtherly optimized the EK-Bio technology to remediate organics-polluted soil. Image 1 • Ryegrass enhanced the degradation process of n -hexadecane. • Ryegrass-planting prolonged the efficient process of electrokinetics. • Ryegrass improved the soil structure destroyed by the electrokinetic effect. • A new rhizosphere microbial community with degradation effect was established. [ABSTRACT FROM AUTHOR]

Cropping of maize (Zea mays L.) on sandy soil in wet climates involves a significant risk for nitrogen (N) losses, since nitrate added in fertilizers or produced from residues and manure may be lost outside the period with active crop N uptake. This one-year lysimeter experiment investigated the potential of Vizura®, a formulation for liquid manure (slurry) with the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP), to mitigate nitrous oxide (N 2 O) emissions and nitrate (NO 3 −) leaching from a coarse sandy soil cropped with maize. Maize followed grass-clover (Lolium perenne L. -Trifolium pratense L.) with spring incorporation and was fertilised with cattle slurry. A total of 12 treatments in triplicate were included in a factorial experiment with 1 m2 large and 1.4 m deep lysimeters: 1) with or without spraying the above-ground biomass of grass-clover with DMPP before incorporation; 2) application of cattle manure with or without DMPP, or no fertilization; and 3) natural rainfall or extra rain events to represent wet spring conditions, which were simulated with an automated and programmable irrigation system. Around 20 kg N ha−1 was returned to the soil in grass-clover above-ground biomass, and 145 kg N ha−1 in cattle manure. Cumulative annual N 2 O emissions ranged from 0.4 to 1.3 kg N ha−1, with between 49 and 86% of emissions occurring during spring. Manure application increased N 2 O emissions, while extra rainfall had no effect. The mitigation of N 2 O emissions by DMPP ranged from 46 to 67% under natural, and from 44 to 48% under high rainfall conditions. Total annual NO 3 − leaching ranged from 65 to 162 kg N ha−1. The extent of NO 3 − leaching to 1.4 m depth during spring was low, and instead most (72–83%) of total annual NO 3 −-N leaching was recorded during autumn before harvest. The extra rainfall during spring increased NO 3 −-N leaching in the pre-harvest period, but it is not clear to what extent this was associated with the N in grass-clover residues or manure applied in spring, or from N mineralisation below the root zone. Despite evidence for a reduction of NO 3 − leaching in three of four scenarios, overall this effect was not significant. No DMPP was detected in leachates. In conclusion, DMPP significantly reduced N 2 O emissions from cattle manure on this sandy loam soil independent of rainfall, while there was no significant effect on NO 3 − leaching. The results indicate that N 2 O emissions and NO 3 −-N leaching were partly derived from below-ground sources of N not affected by DMPP, which should be further investigated to better predict the mitigation potential of nitrification inhibitors. • A lysimeter facility was used for growth of maize after grass-clover on coarse sandy soil. • The nitrification inhibitor DMPP reduced N 2 O emissions from manure irrespective of rainfall. • Simulation of extra rainfall during spring increased NO 3 - leaching irrespective of DMPP. • Treating grass-clover with DMPP before incorporation did not reduce N 2 O or NO 3 - leaching. • Analyses of DMPP in selected leachate samples did not show evidence for leaching losses. [ABSTRACT FROM AUTHOR]

The success of phytoremediation is dependent on the exposure of plants to contaminants, which is controlled by root distribution, physicochemical characteristics, and contaminant behavior in the soil environment. Whilst phytoremediation has been successful in remediating hydrocarbons and other organic contaminants, there is little understanding of the impact of non-aqueous phase liquids (NAPLs) on plant behavior, root architecture and the resulting impact of this on phytoremediation. Light NAPLs (LNAPLs) may be present in pore spaces in the capillary zone as a continuous or semi-continuous phase, or as unconnected ganglia which act as individual contaminant sources. Experimental work with ryegrass (Lolium perenne) grown under hydroponic conditions in idealised pore scale models is presented, exploring how plant growth, root distribution and development, and oil removal are affected through direct physical contact with a model LNAPL (mineral oil). In the presence of low levels of LNAPL, a significant decrease in root length was observed, whilst at higher LNAPL levels root lengths increased due to root diversion and spreading, with evidence of root redistribution in the case of LNAPL contamination across multiple adjacent pores. Changes to root morphology were also observed in the presence of LNAPL with plant roots coarse and crooked compared to long, fine and smooth roots in uncontaminated columns. Root and shoot biomass also appear to be impacted by the LNAPL although the effects are complex, affected by both root diversion and thickening. Substantial levels of LNAPL removal were observed, with roots close to LNAPL sources able to remove dissolved-phase contamination, and root growth through LNAPL sources suggest that direct uptake/degradation is possible. Image 1 • Roots can co-exist with non-aqueous phase liquids. • Greater and more distributed root growth with non-aqueous phase liquids. • Non-aqueous phase liquids reduce above ground biomass development. • Non-aqueous phase liquid phytoremediation through removal of dissolved phase oil. [ABSTRACT FROM AUTHOR]