Root mass vertical distribution of perennial cool-season grasses grown in pure or mixed swards

ABSTRACT: In this study we tested whether the root biomass of mixtures composed by grass species is greater than their respective monocultures. The treatments were monocultures of Arrhenatherum elatius, Festuca arundinacea, Dactylis glomerata, and a mixture of them, cultivated in a rich-soil environment. Root biomass was evaluated on a single evaluation per season at three soil depths (0-5, 5-10, and 10-20 cm). Mixed swards presented the greatest root biomass, and this was explained by a greater concentration in the topsoil layer (0-5 cm). These findings reinforce the need for permanent soil conservation practices to not jeopardize the benefits of the more abundant root biomass reported in the mixed swards.

Biochar-Assisted Phytostabilization for Potentially Toxic Element Immobilization

In response to the growing threat to the quality of the soil environment, new technologies are being developed to protect and remediate contaminated sites. A new approach, namely, assisted phytostabilization, has been used in areas contaminated with high levels of potentially toxic elements (PTEs), using various soil additives. This paper determined the effectiveness of biochar-assisted phytostabilization using Dactylis glomerata L. of soil contaminated with high concentrations of the selected PTEs (in mg/kg soil): Cu (780 ± 144), Cd (25.9 ± 2.5), Pb (13,540 ± 669) and Zn (8433 ± 1376). The content of the selected PTEs in the roots and above-ground parts of the tested grass, and in the soil, was determined by atomic absorption spectrometry (AAS). The addition of biochar to the contaminated soil led to an increase in plant biomass and caused an increase in soil pH values. Concentrations of Cu, Cd, Pb and Zn were higher in the roots than in the above-ground parts of Dactylis glomerata L. The application of biochar significantly reduced the total content of PTEs in the soil after finishing the phytostabilization experiment, as well as reducing the content of bioavailable forms extracted from the soil using CaCl2 solution, which was clearly visible with respect to Cd and Pb. It is concluded that the use of biochar in supporting the processes of assisted phytostabilization of soils contaminated with PTEs is justified.

Primera aproximación de carga animal óptima en cuyes al pastoreo durante la época lluviosa en la sierra peruana

Se realizó una primera aproximación de la carga animal óptima en cuyes al pastoreo durante la época lluviosa en la sierra del Perú, utilizando una pastura perenne asociada conformada por Lolium multiflorum, Lolium perenne, Dactylis glomerata, Trifolium pratense, Trifolium repens y Medicago sativa en función a la ganancia de peso vivo individual y por unidad de área, consumo de alimento, conversión alimenticia, rendimiento de pastura, costos de producción y ratio beneficio costo. Se emplearon 132 cuyes machos G de 15 días de edad en un diseño de bloques completos al azar con tres ciclos de engorde de 60 días como bloque y cuatro tratamientos correspondientes a cargas de 400 (T1), 500 (T2), 600 (T3) y 700 (T4) cuyes/ha/año. Se trabajó en áreas de 200 m2 de pastura donde pastorearon grupos de 8, 10, 12 y 14 cuyes en T1, T2, T3 y T4, respectivamente. Los resultados demostraron que no hubo efecto de la carga animal sobre la ganancia de peso individual, consumo de alimento, conversión alimenticia y rendimiento de pastura (p>0.05). Los efectos sobre la ganancia por unidad de área y ratio beneficio costo (p<0.05) fueron consecuencia directa y esperada del diferente número de animales entre cargas animales. El rango de carga animal fue insuficiente para determinar una carga óptima, de manera que tentativamente se sugiere utilizar la carga de 700 cuyes/ha/año, por ser la carga que favorece lograr más cuyes con parámetros productivos similares a cargas menores y mejores parámetros económicos.

Evaluation of source material for selection Dactylis glomerata in Primorsky Region conditions

Dactylis glomerata is an upland loose-flattened perennial herb, the most shade-tolerant of the common grasses. Low winter hardiness is an obstacle to the wide use of Dactylis glomerata as a grassland crop and a limiting factor for the release of varieties in the Primorsky Region. The devel- opment of highly winter-hardy intensive types of dwarf Dactylis glomerata is an important area of breeding work. The study aims to study promising source material of Dactylis glomerata for further use in creating new winter-hardy, high-yielding varieties. The authors have identified types for the yield of intensive varieties by studying the collection of Dactylis glomerata for the period 2018-2020 in the conditions of the Primorsky Region. The Dactylis glomerata plants reach full development and the highest yields in the third year of life. In terms of green matter yields in the two years of use, several Dactylis glomerata exceed the standard by 29-34%. These are variety samples 41821 Wild (Norway), 40280 Wild (Altai), and Sverdlovchanka 86 (Ural Agricultural Research Institute). The va- rieties Sverdlovchanka 86 (Urals Agricultural Research Institute), Dikorastushchaya (Primorskaya local) and 32028 Dikorastushchaya (Arkhangelskaya region) were distinguished by seed yield in the two years of use, having exceeded the standard by 113-153%. The winter hardiness of plants in the first winter is a limiting factor for Dactylis glomerata in Primorsky Krai conditions. The identified differences in the winter hardiness of plants allow the best of them to be used in selection. In the col- lection nursery of Dactylis glomerata, a variety of varieties with 100% winter hardiness of plants in the first winter after sowing were: 48113 Aukstuole (Lithuania), 41821 Wild (Norway), 40896 Wild (Kazakhstan), Sverdlovchanka 86 (Agricultural Research Institute), Wild (Primorsky Region).

The whole-genome and expression profile analysis of WRKY and RGAs in Dactylis glomerata showed that DG6C02319.1 and DgWRKYs may cooperate in the immunity against rust

Orchardgrass (Dactylis glomerata) is one of the top four perennial forages worldwide and, despite its large economic advantages, often threatened by various environmental stresses. WRKY transcription factors (TFs) can regulate a variety of plant processes, widely participate in plant responses to biotic and abiotic stresses, and are one of the largest gene families in plants. WRKYs can usually bind W-box elements specifically. In this study, we identified a total of 93 DgWRKY genes and 281 RGAs, including 65, 169 and 47 nucleotide-binding site-leucine-rich repeats (NBS-LRRs), leucine-rich repeats receptor-like protein kinases (LRR-RLKs), and leucine-rich repeats receptor-like proteins (LRR-RLPs), respectively. Through analyzing the expression of DgWRKY genes in orchardgrass under different environmental stresses, it was found that many DgWRKY genes were differentially expressed under heat, drought, submergence, and rust stress. In particular, it was found that the greatest number of genes were differentially expressed under rust infection. Consistently, GO and KEGG enrichment analysis of all genes showed that 78 DgWRKY TFs were identified in the plant–pathogen interaction pathway, with 59 of them differentially expressed. Through cis-acting element prediction, 154 RGAs were found to contain W-box elements. Among them, DG6C02319.1 (a member of the LRR-RLK family) was identified as likely to interact with 14 DGWRKYs. Moreover, their expression levels in susceptible plants after rust inoculation were first up-regulated and then down-regulated, while those in the resistant plants were always up-regulated. In general, DgWRKYs responded to both biotic stress and abiotic stress. DgWRKYs and RGAs may synergistically respond to the response of orchardgrass to rust. This study provides meaningful insight into the molecular mechanisms of WRKY proteins in orchardgrass.

Analysis of migration of pathogenic drug-resistant bacteria to soils and groundwater after fertilization with sewage sludge

The paper discusses the analysis of the effect of using sewage sludge for fertilization on the level of soil and groundwater contamination with drug-resistant bacteria. Other sanitary contaminants in these environments were also analysed. Composted sewage sludge was introduced into the sandy soil over a period of 6 months. The examinations were conducted under conditions of a lysimetric experiment with the possibility of collecting soil leachates (in natural conditions). The following doses of sewage sludge were used: 0, 10, 20, 30 and 40 t/ha calculated per experimental object containing 10 kg of sandy soil. The research were carried out within the time frame of one year. Dactylis glomerata grass was grown on the fertilized soils. In soils and leachates from soils (which may have polluted groundwater) collected from fertilized experimental objects, the sanitary condition and quantity of drug-resistant bacteria (mainly from the families Enterobacteriaceae and Enterococcus ) were analysed one year after fertilization. Their drug resistance to selected antibiotics was also analysed based on current recommendations.

Efficacy and safety of a drug-free, barrier-forming nasal spray for allergic rhinitis: randomized, open-label, crossover noninferiority trial

Background Symptoms of allergic rhinitis can be reduced by nonpharmacological nasal sprays that create a barrier between allergens and the nasal mucosa. A new nasal spray (AM-301) containing the clay mineral bentonite was tested for its ability to reduce symptoms to grass pollen. Methods This open label, crossover, noninferiority trial compared the efficacy and safety of AM-301 to that of hydroxypropyl methylcellulose (HPMC; Nasaleze Allergy Blocker), an established barrier method. Adults with seasonal allergic rhinitis were exposed to Dactylis glomerata pollen, in the Fraunhofer Allergen Challenge Chamber, first without protection and then protected by HPMC or AM-301 (7 days apart). Efficacy was assessed from total nasal symptom score (TNSS), nasal secretion weight, and subjective rating. The primary endpoint was the difference, between AM-301 and HPMC, in least square mean change in TNSS over a 4-hour exposure to allergen. Results The study enrolled 36 persons, and 35 completed all study visits. The mean TNSS was 5.91 during unprotected exposure, 5.20 during protection with HPMC, and 4.82 during protection with AM-301. The difference in least square means between the two treatments was -0.39 (95% CI, -0.89 to 0.10), establishing the noninferiority of AM-301. No difference in mean weight of nasal secretions was observed between the treatments. Efficacy was rated as good or very good for AM-301 by 31% and for HPMC by 14% of subjects. 16 subjects reported adverse events with a relationship to AM-301 or HPMC; most adverse events were mild and none was serious. Conclusions AM-301 demonstrated noninferiority towards HPMC in the primary endpoint and was perceived better in subjective secondary endpoints. Both barrier-forming products had a persisting protective effect over 4 hours and were safe. Trial registration German Clinical Trial Register (DRKS00024356). EUDAMED (CIV-20-10-034870). Key words: Allergen challenge, Allergy, Bentonite, Dactylis glomerata, Hydroxypropyl methylcellulose, Medical device, Nasal spray, Pollen, Rhinorrhea, Thixotropy

Agronomic Evaluation of the Results of Selection within Early Maturing Dactylis glomerata Germplasm

Selection from novel orchardgrass (Dactylis glomerata L.) germplasm sources resulted in the development of an early maturing orchardgrass population. Fifty-eight families comprise this population and were evaluated under frequent and infrequent harvest intervals at Lewiston and Millville, UT, field locations during 2013 and 2014. The objective of this study was to characterize the performance of the individual families when compared with the check cultivars ‘Icon’, ‘Paiute’, and ‘Potomac’. Across the locations and harvest intervals, individual families produced greater herbage dry mass and nutritive value than the check cultivars. Only for maturity (cv. Paiute) did one of the included commercial checks possess a trait value among the statistically greatest for all families. Twenty-two half-sib families were among the families with the statistically earliest maturity, and between three and eight families were among the families with the statistically greatest trait values for herbage dry mass, crude protein, in vitro true digestibility, neutral detergent fiber, and water soluble carbohydrate concentration. Overall, based on the performance of its component families, this early maturing orchardgrass population exhibited potential for developing improved cultivars for both frequent and infrequent harvest management.

Recycling of Blast Furnace and Coal Slags in Aided Phytostabilisation of Soils Highly Polluted with Heavy Metals

(1) Background: The growing demand for developing new methods of degraded land remediation is linked to the need to improve the soil environment, including post-industrial soils. Biological methods such as the aided phytostabilisation technique are the most common methods applied to achieve effective remediation. This study aimed to determine the technical potential of methods using novel or yet not used soil amendments, such as blast furnace slag (BFS) and coal slag (CS), with Dactylis glomerata L. as a test plant. (2) Methods: The experiment was conducted on post-industrial area soil with high concentrations of Cu (761 mg/kg), Cd (23.9 mg/kg), Pb (13,539 mg/kg) and Zn (8683 mg/kg). The heavy metal content in roots and the above-ground parts of plants and soil was determined by flame atomic absorption spectrometry. (3) Results: The addition of BFS to the soil was the most effective in increasing Dactylis glomerata L. biomass yield. The Cu, Cd, Pb, and Zn concentrations were higher in the roots than in the above-ground parts of the plants. BFS and CS induced a considerable increase in soil pH, compared to the control treatment. The addition of BFS also produced the greatest significant decrease in the Pb content in soil following the phytostabilisation process. (4) Conclusions: In view of the above, the use of BFS in the aided phytostabilisation in soils contaminated with high levels of Cu, Cd, Pb, and Zn can be recommended for larger-scale in situ projects.