Dactylis Glomerata Research Articles

Effect of incremental amounts of Asparagopsis taxiformis on ruminal fermentation and methane production in continuous culture with orchardgrass herbage

Enteric methane (CH4) emissions from ruminants are a significant contributor to total greenhouse gas emissions from the livestock sector. Previous research has demonstrated that the red seaweed Asparagopsis taxiformis strongly inhibits ruminal methanogenesis, but its effects on CH4 production, nutrient digestibility, and ruminal fermentation when added to a cool-season herbage diet have not been assessed. A 4-unit, single-flow continuous culture fermentor system fed orchardgrass (Dactylis glomerata L.) herbage was used to assess the effects of incremental addition of dietary A. taxiformis (0, 5, 10, or 15 g/kg DM) on nutrient digestibility, volatile fatty acid (VFA) concentration, pH, CH4 production, and N metabolism. Treatments were randomly assigned to fermentors in a randomized block design with 7 d of treatment adaptation and 3 d of sample collection. Fermentors were fed a total of 76 g of DM per day, split equally into 4 feedings (07:30, 10:30, 14:00, and 19:00 h). In the last 3 d of each experimental period, daily samples of total effluent were taken for analyses of ammonia N and VFA. One liter of effluent was collected daily (3 L total) for a composite sample that was blended and lyophilized for analysis of DM, ash, neutral and acid detergent fiber, crude protein, and total purines. Headspace CH4 concentration in each fermentor was measured every 15 min (192 readings/d) using a Fourier transform infrared gas analyzer, and pH was recorded every 2 min. Data were analyzed using the GLM procedure of SAS with orthogonal polynomial contrasts. Methane production in fermentors receiving all 3 levels of A. taxiformis was reduced by 99.9% within the first 24 h of each experimental period and remained predominantly below the limit of detection for the remaining 9 d. Apparent digestibility of neutral and acid detergent fiber, as well as apparent and true DM digestibilities, linearly decreased with A. taxiformis inclusion. Total VFA concentration decreased quadratically, and molar proportion of acetate decreased in a cubic manner. Overall, A. taxiformis acutely inhibited CH4 production in continuous cultures fed orchardgrass herbage, but also negatively affected fiber digestibility and total VFA concentration, especially at higher feeding rates. In vitro results indicated that A. taxiformis could be effective in reducing enteric CH4 production in grazing ruminants, but in vivo research is needed to determine how A. taxiformis may impact ruminal fermentation and milk production or average daily gain in grazing systems.

Selenium Uptake from Livestock Pasture Extremely Enriched in Selenium, Molybdenum and Uranium: A Field and X-ray Absorption Study

The agricultural soils of West Limerick, Ireland, contain very localised, extremely high natural Se concentrations that reach levels that are very toxic to grazing livestock. The Carboniferous shales that formed in anoxic deep-water marine environments are the source of the selenium, which, along with the other redox-sensitive elements of molybdenum, uranium, arsenic and vanadium, were mobilised and reprecipitated in post-glacial anoxic marshes. The result has been a history of selenosis and molybdenosis in livestock in this important dairy province. Soils collected at 10–20 cm from five different agricultural sites were analysed, and all yielded concentrations greatly in excess of the safe Se limits of 3–10 mg kg−1; the highest value recorded was 1265.8 mg kg−1 Se. The highest recorded value for Mo in these soils was 1627.5 mg kg−1, and for U, 658.8 mg kg−1. There was a positive correlation between Se, Mo U and organic matter in the soils. Analysis of non-accumulator pasture grasses (Lolium perenne (perennial ryegrass), Festuca arundinacea (tall fescue), Dactylis glomerata (cocksfoot) and Phleum pretense (timothy grass)) revealed the shoot/leaf to contain up to 78.05 mg kg−1 Se while Trifolium repens (white clover) leaves contained 296.15 mg kg−1 Se. An in situ growing experiment using the Se accumulator species Brassica oleracea revealed 971.2 mg kg−1 Se in the leaves of premier kale, which also contained 1000.4 mg kg−1 Mo. Translocation factors (TFs) were generally higher for Mo than Se across all plant species. Combined X-ray absorption near edge spectroscopy (XANES) with micro-X-ray fluorescence (μ-XRF) showed the Se was present in the soil predominantly as the reduced immobile phase, elemental Se (Se0), but also as bioavailable organoselenium species, mainly selenomethionine (SeMet). SeMet was also the main species identified within both the Se non-accumulator and Se accumulator plants. The Se soil–plant system in West Limerick is dominated by SeMet, and uptake into the cattle pasture results in selenosis in the grazing dairy herds. The hyperaccumulating Brassica oleracea species could be used to extract both the Se and Mo to reduce the toxicity of the blighted fields.

Reseeding improved soil and plant characteristics of degraded alfalfa (Medicago sativa) grassland in loess hilly plateau region, China

It is of great significance for the sustainable development and feed supply of animal husbandry in the hilly region of Loess Plateau to improve the degraded alfalfa grassland scientifically and reasonably. We studied the effects of reseeding gramineous grass on soil physicochemical properties, microbial biomass, plant community characteristics and community nutrients of degraded alfalfa grassland based on four treatments: no reseeding, reseeding Elymus dahuricus, reseeding Dactylis glomerata, and reseeding Leymus chinensis. Soil physicochemical properties and microbial biomass were improved after reseeding E. dahuricus, and above-ground biomass and community coverage were increased by >30% compared with those without reseeding. The reseeding of E. dahuricus benefited soil properties, plant community characteristics, and community nutrients more than reseeding of D. glomerata and L. chinensis. Furthermore, a structural equation model (SEM) was established based on the analysis and screening of related variables to analyze the influence factors of reseeding on soil and community and their interactions in degraded grassland system. The SEM results showed that reseeding had significant effects on plant community characteristics, plant community nutrients and soil characteristics (P < 0.001), but the degree of influence decreased in turn. The interaction between soil characteristics and plant community characteristics was 18.72% higher than that between soil characteristics and plant community nutrients. We recommend reseeding of E. dahuricus as suitable method to improve degraded alfalfa grassland in the loess hilly plateau region.

Managing interspecies competition to improve spring pasture maturity, nutritive value, and biomass

AbstractIn much of the United States, wet springs often cause poor field conditions leading to harvest and/or grazing delays and subsequent reductions in forage nutritive value. The objective of this study was to compare monocultures and combinations of orchardgrass (Dactylis glomerata L.), chicory (Cichorium intybus L.), and white clover (Trifolium repens L.) to determine the effects of interspecies competition on plant maturity, nutritive value, and forage mass over two consecutive springs. It was hypothesized that shade and competition from chicory would delay orchardgrass maturity resulting in greater nutritive value and an extended harvest or grazing window for high‐nutritive value forage. Mixtures containing chicory delayed orchardgrass maturity by at least 9 days in the first spring as compared to orchardgrass monocultures and orchardgrass‐white clover mixtures. Even with decreased chicory mass in the second year (due to drought and winterkill), both 1:1:1 and 4:1:1 (ratio of seeds per hectare) orchardgrass–white clover–chicory mixtures provided greater forage mass and nutritive value (crude protein and net energy) yield over 2 years compared to an orchardgrass monoculture; however, only the 1:1:1 orchardgrass–white clover–chicory mixture provided greater benefits to forage mass and nutritive value yield when compared to orchardgrass–white clover mixtures that are commonly found on farms. This study showed that chicory inclusion provides benefits to orchardgrass and orchardgrass–white clover pastures when planted in appropriate seed proportions; however, increasing chicory longevity will require further investigation to provide continued benefits in perennial cool‐season grass and legume pasture systems.

Vegetation of a hill grassland of the Paititi Natural Reserve (Pampa biome) and early detection of non-native species acting as invasive

Background and aims: Invasive species are the greatest threat to conservation. The objectives of this study were to identify the flora that thrive in a hill grassland of the Paititi Natural Reserve, to perform an early detection of non-native plant species that might be acting as invasive, and to establish the current situation of the native species considered threatened. M&amp;M: Following the altitudinal gradient, 14 sites were selected; the environmental characteristics and cover-abundance of the vascular plant species were recorded in each site. With the collected data, a Principal Coordinate Analysis (PCooA) was performed to group the sites into vegetation units that were later described considering environmental characteristics, identified species and plant community type. Additionally, the threatened species were specified, as well as the most abundant exotic ones, therefore considered invasive. Results: Total richness reached 370 species, 26.5% corresponding to non-native ones. Thirty threatened species were identified. The PCooA grouped the sites into eight vegetation units. The non-native species considered invasive were Dactylis glomerata, Senecio madagascariensis, Holcus lanatus and Racosperma melanoxylon, these last two reached the highest coverage-abundance values. Conclusions: To conserve biodiversity and minimize the invasion process, management efforts should be focused on monitoring the threatened species and controlling the advance of the non-native species acting as invasive. Early detection of those species in similar environments would be fundamental to facilitate rapid responses towards reducing invasions.

Intercropping of orchardgrass and alfalfa improves soil fertility, forage yield, feeding values and land use efficiency while limiting ruminal greenhouse gas emissions

AbstractIntercropping has been a globally accepted practice for forage production, however, consideration of multiple performance criteria for intercropping including forage production, feed use efficiency and ruminal greenhouse gas emissions needs to be further investigated. A two‐year field study was conducted to evaluate forage dry matter (DM) yield, nutritive value, feeding values and land‐use efficiency as well as ruminal carbon dioxide (CO2) and methane (CH4) emissions of intercropped orchardgrass (Dactylis glomerata) and alfalfa (Medicago sativa) sown in five intercropping ratios (100:0, 75:25, 50:50, 25:75, and 0:100, based on seed weight) and three nitrogen (N) fertilizer levels (0, 50, and 100 kg ha−1). Increasing alfalfa proportion and N fertilizer level increased soil nutrients and the two‐year total DM yield. Intercropping increased both land and nitrogen use efficiency (NUE) compared with monocultures. Greater NUE was obtained when N fertilizer was applied at 50 kg ha−1, compared with 100 kg ha−1. Increasing the proportion of alfalfa in intercrops increased the crude protein yield and rumen undegraded protein yield. Harvested forage intercrops were incubated with ruminal fluid for 48 h. Degraded DM yield, CO2 and CH4 emissions increased with increasing alfalfa proportion in intercrops. Overall, the 75:25 of orchardgrass‐alfalfa intercrops was recommended as the best compromise between high forage productivity, superior feed use efficiency and low ruminal greenhouse gas emissions through complementary effects. The results indicate that the appropriate N fertilization level would be 50 kg ha−1 for acquiring higher nitrogen use efficiency and forage productivity.

Drought survival and recovery in grasses: Stress intensity and plant-plant interactions impact plant dehydration tolerance.

Plant dehydration tolerance confers drought survival in grasses, but the mortality thresholds according to soil water content (SWC),vapour pressure deficit (VPD)and plant-plant interactions are little explored. We compared the dehydration dynamics of leaf meristems, which are the key surviving organs, plant mortality,and recovery of Mediterranean and temperate populations of two perennial grass species, Dactylis glomerata and Festuca arundinacea, grown in monocultures and mixtures under a low-VPD (1.5 kPa) versus a high-VPD drought (2.2 kPa). The lethal drought index (LD50 ), that is, SWC associated with 50% plant mortality, ranged from 2.87% (ψs = -1.68 MPa) to 2.19% (ψs = -4.47 MPa) and reached the lowest values under the low-VPD drought. Populations of D. glomerata were more dehydration-tolerant (lower LD50 ), survivedand recovered better than F. arundinacea populations. Plant-plant interactions modified dehydration tolerance and improved post-drought recovery in mixtures compared with monocultures. Water content as low as 20.7%-36.1% in leaf meristems allowed 50% of plants to survive. We conclude that meristem dehydration causes plant mortality and that drought acclimation can increase dehydration tolerance. Genetic diversity, acclimationand plant-plant interactions are essential sources of dehydration tolerance variability to consider when predicting drought-induced mortality.

A management proposition to preserve functional identity of grasses in mixed swards

AbstractThe diversity of traits plays a key role in the maximization of ecosystems' multi‐functionality, but interspecific competition in defoliated swards can lead to unpredictable changes in the functional traits over the plant community. However, we hypothesize that interrupting canopy regrowth at a height corresponding to critical leaf area index (LAI), associated with moderate intensity of defoliation, can be an effective management to preserve the functional traits of contrasting growth strategy grasses cultivated as a mixture. A 2‐year experiment was conceived to assess continuously several traits of three cool‐season perennial grasses (Arrhenatherum elatius [exploitative], Dactylis glomerata [moderately exploitative] and Festuca arundinacea [conservative]) cultivated as single species stand or as a mixture. Dactylis glomerata was the less productive stand but no difference was observed between the mixture and the most productive monocultures. No change was observed in functional traits, whether the species were cultivated as monoculture or as a mixture. The dissimilarities over traits and, therefore, the functional identity of contrasting growth strategy grasses growing in multi‐specific swards was preserved when canopy regrowth was interrupted at a height corresponding to the critical LAI associated with moderate intensity of defoliation. Since the diversity of traits maximizes ecosystem multi‐functionality, our findings provide a step forward towards designing management practices that enhance ecosystems services delivered by cultivated multi‐specific grasslands.

Integrated Transcriptomic and Metabolomics Analysis of the Root Responses of Orchardgrass to Submergence Stress.

Submergence stress can severely affect plant growth. Orchardgrass (Dactylis glomerata L.) is an important forage grass, and the molecular mechanisms of orchardgrass to submergence stress are not well understood. The roots of the flood-tolerant cultivar "Dian Bei" were harvested at 0 h, 8 h and 24 h of submergence stress. The combined transcriptomic and metabolomic analyses showed that β-alanine metabolism, flavonoid biosynthesis, and biosynthesis of amino acid pathways were significantly enriched at 8 h and 24 h of submergence stress and were more pronounced at 24 h. Most of the flavonoid biosynthesis-related genes were down-regulated for the synthesis of metabolites such as naringenin, apigenin, naringin, neohesperidin, naringenin chalcone, and liquiritigenin in response to submergence stress. Metabolites such as phenylalanine, tyrosine, and tryptophan were up-regulated under stress. The predominant response of flavonoid and amino acids biosynthesis to submergence stress suggests an important role of these pathways in the submergence tolerance of orchardgrass.

Fire Hazard: Undesirable Ecosystem Function of Orchard Vegetation

Fires will become an increasingly frequent perturbation even under the conditions of the mild climate zone and will interfere with the agricultural landscape. Fire is a natural phenomenon, and depending on ecosystems, vegetation may develop and contribute to the occurrence and spread of fire. Vegetation of the sour cherry orchard located in the climatically dry conditions of the South Moravian Region, Czech Republic (CR), was evaluated. Vegetation assessment was performed using phytocenological relevé. In each variant, 10 relevé were recorded. Coverage of the found species was estimated directly in percentages. Moreover, the maximum height in the stand was measured for each type of plant. Biomass of individual plant species was calculated, using the biomass index (IB) equation. The IB values of individual plant species in the treatments were processed by employing a multidimensional analysis of the ecological data. Different vegetation management practices in an orchard change the species diversity of the vegetation and thus the fire hazards in the orchard conditions. Grassy interrow has the most grass biomass during the entire vegetation season, and therefore represents the greatest hazard and spread of fire. The most important grasses include Arrhenatherum elatius, Dactylis glomerata, Festuca pratensis, Lolium perenne, and Poa pratensis. On the contrary, bare soil conditions in the interrow are most suitable for annual species, and this is the place with the highest changes in the number of species during the growing season. Biomass of the orchard vegetation combined with dry and warm weather increases the fire hazard. Annual and perennial grasses have very good potential for the production of biomass, which increases the hazard of fire. The nature of the vegetation in the orchards has the potential for the actual start of a fire and its subsequent spread, however, under other environmental conditions. During hot and dry weather, dead biomass may accumulate resulting in increasing the hazard of large wildfires. Varied orchard management practices lead to a higher diversity of vegetation and make orchards, islands of biodiversity in the agricultural landscape.

Comparative transcriptomic analysis of the gene expression and underlying molecular mechanism of submergence stress response in orchardgrass roots.

Submergence stress creates a hypoxic environment. Roots are the first plant organ to face these low-oxygen conditions, which causes damage and affects the plant growth and yield. Orchardgrass (Dactylis glomerata L.) is one of the most important cold-season forage grasses globally. However, their submergence stress-induced gene expression and the underlying molecular mechanisms of orchardgrass roots are still unknown. Using the submergence-tolerant 'Dianbei' and submergence-sensitive 'Anba', the transcriptomic analysis of orchardgrass roots at different time points of submergence stress (0 h, 8 h, and 24 h) was performed. We obtained 118.82Gb clean data by RNA-Seq. As compared with the control, a total of 6663 and 9857 differentially expressed genes (DEGs) were detected in Dianbei, while 7894 and 11215 DEGs were detected in Anba at 8 h and 24 h post-submergence-stress, respectively. Gene Ontology (GO) enrichment analysis obtained 986 terms, while Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis obtained 123 pathways. Among them, the DEGs in plant hormones, mitogen-activated protein kinase (MAPK) and Ca2+ signal transduction were significantly differentially expressed in Dianbei, but not in Anba. This study was the first to molecularly elucidate the submergence stress tolerance in the roots of two orchardgrass cultivars. These findings not only enhanced our understanding of the orchardgrass submergence tolerance, but also provided a theoretical basis 36 for the cultivation of submergence-tolerant forage varieties.

THE COMPARATIVE STUDY OF SOME MIXTURES OF PERENNIAL FORAGE GRASSES AND LEGUMES FOR THE ESTABLISHMENT OF TEMPORARY MEADOWS IN THE CENTRAL ZONE OF OLTENIA

The establishment of temporary meadows is not a new problem, but it has been the subject of long researches. When achieving this objective, a mixture of perennial species must be taken into account that corresponds from the point of view of the pedo-climatic zone, the technical and economic possibilities, the purpose and the duration designed. (Vidican Roxana and al. 2002). Our research shows that complex mixtures of perennial species (grasses and legumes) are the most suitable for establishing temporary meadows. For the S.C.D.A. experimentation area Şimnic Craiova the mixture consisting of Medicago sativa 40% + Dactylis glomerata 20% + Festucaarundinacea 20% + Loliumperenne 20%, achieved substantial harvest productions, namely 8,7-9 t/ha s.u.

Herbage yield stability of cocksfoot (Dactylis glomerata L.) genotypes across rain-fed environments

Cocksfoot (Dactylis glomerata L.) is a cool-season perennial grass that naturally grows in semi-steppe rangelands in Iran. In recent years, as a result of climate change, coupled with high livestock grazing, rangeland productivity has decreased. This study aimed to analyse the stability of forage dry matter (DM) production of 36 cocksfoot genotypes across four rain-fed environments (Ardebil, Zanjan, Hamadan, and Kermanshah) in Iran. At each location, an experiment was conducted using a randomised complete-block design (RCBD) with three replications over 2 years. The result of combined analysis of variance (ANOVA) across locations showed significant effects of environment (E), genotype (G), and GE interaction (P &lt; 0.01) for DM yield. The E, G and GE interaction effects accounted for 33.19%, 17.98% and 40.52% of the total variance respectively. The GE interaction was subsequently investigated using regression stability, Additive Main effects and Multiplicative Interaction (AMMI), and genotype main effect (G) plus genotype–environment (GE) interaction (GGE) biplot analysis. According to the regression method, genotypes G2, G3, G11 and G12 with a slope close to unity, coupled with high production, had good general stability in all locations. In addition, some genotypes were specifically identified for poor- and high-performing environments. According to the AMMI-2, IPC1 vs IPC2 biplot, genotypes G2, G10, G11, G14 and G15, placed close to the origin of the biplot coupled with higher production, showed general stability in all environments. The best genotypes for the respective environments were also determined. Using the GGE biplot, genotypes G2, G3, G11 and G12 were more stable in all environments. Therefore, on the basis of all analytical methods, three local genotypes, G2 (Karaj), G3 (Marand) and G11 (Qazvin), and a foreign genotype, G14 (from, USA), were identified as most suitable genotypes for breeding improved varieties and cultivation in the study locations and similar areas.

Research on the Exploitation of Temporary Meadows in a Mixed System under the Conditions of Central Moldavia, Romania

The study of temporary meadows is of particular scientific importance, because they make possible the edification and characterization of some essential aspects regarding the relationship between the diversity, stability and maturity of ecosystems; the relationships between species; the biological balance between natural and artificial ecosystems; aspects that are greatly debated nowadays. They can replace degraded permanent meadows, or on arable land intended for fodder. When creating the mixtures, the basic requirement that must be taken into account is that they form a uniform grass cover and are well adapted to stationary conditions. The importance of developing temporary meadows led to the initiation of studies at ARDS Secuieni, starting with 2017, with the aim of creating the best mixtures adapted to the pedo-climatic conditions in the area. The results obtained in the conditions of Central Moldavia showed that fertilization with different doses of fertilizer influenced the production of dry matter compared to the non-fertilized variants. The variant fertilized with the dose of N80P40 kg/ha had the highest fodder production, i.e.16.13 t/ha d.m.; the difference compared to the control was quite a significant one; and the lowest production was obtained with the control variable (N0P0), i.e. 9.47 t/ha d.m. Analysing the data obtained, it can be easily noticed that, in the variants studied, there were five production cuttings; alternating hay mowing with that for simulating grazing (mixed regime). Analysing the results obtained, for the first cutting, regarding the influence of fertilization and the mixture used on the percentage of grass and leguminous species, it was found that in the mixture of 85% grasses (Dactylis glomerata 60% + Lolium perenne 25%) and 15% perennial leguminous (Lotus corniculatus 15%), the percentage of grasses participation in the grass cover was between 64.5% for the variant fertilized with N40P40 and 86.0% for the variant fertilized with N80P40. The leguminous that are part of the grass cover were between 12.7% for the variant fertilized with N80P40 and 34.6% for the variant fertilized with N40P40, and the percentage of participation of various species was between 0.5% and 1.4%. The participation percentage of perennial grasses and leguminous varied depending on the dose of fertilizer applied, and the quality of the fodder obtained was good for all the mixtures studied, being primarily determined by the doses of fertilizers administered, but also by the species and the proportion of their participation in the sowing rate under the conditions of Central Moldavia from 2017 to 2020.

Native and invasive bunchgrasses have different responses to trail disturbance on California coastal prairies

Ecosystems often experience small-scale disturbances through recreational foot and bike traffic. The intermediate disturbance hypothesis predicts that frequent disturbances in grasslands can negatively impact native species and lead to invasion by disturbance-adapted, non-native species. Disturbance studies often examine intentional or unintended larger scale disturbances, but do not commonly focus on common small-scale disturbances such as those caused by trampling along trails. As such, we were interested in how trail disturbance affects the vegetative growth and reproductive output of in situ native (Danthonia californica Bol. and Stipa pulchra Hitchc.) and invasive (Dactylis glomerata L. and Holcus lanatus L.) perennial bunchgrasses commonly found on California coastal prairies. We measured the basal circumference and seed production of plants located on-trail and off-trail on five coastal prairies in Santa Cruz, CA, USA. We hypothesized that native grasses located on-trail would have lower growth and reproductive output and non-native grasses would be unaffected. We found that native and non-native plants had differences in growth and reproductive output on-trail and off-trail. S. pulchra had lower reproductive potential (via culm sterility) with trail disturbance, whereas both native grasses showed evidence of compensatory growth on-trail. Invasive non-native D. glomerata and H. lanatus growth was unaffected by trail disturbance, but H. lanatus had lower reproductive output on-trail. Results suggest that it may be prudent to restore trails with disturbance tolerant species like D. californica and use less tolerant species like S. pulchra further into the central habitat space.

Chemical composition, nutritional and energy value of perennial cereal grasses depending on fertilizer

Purpose. To establish changes in the chemical composition, nutritional value and energy intensity of various types of perennial grasses feed under the influence of mineral fertilizers. Methods. General scientific – hypotheses, inductions and deductions, analogies, generalizations, and special – field, laboratory, analytical, mathematical-statistical, calculation-comparative. Results. The results of research on the content of organic and mineral substances in various types of perennial grasses feed, its nutritional value and energy intensity on sod-podzolic soils of the Carpathian region are presented. Conclusions. Nitrogen has the most positive effect on the chemical composition of cereal grass stands. With the fractional application of nitrogen fertilizers in a dose of N90 under each mowing against the background of application of P60K60, the content of crude protein in the dry mass of various types of grasses increased from 10.3-11.5% to 14.5-15.6%, or by 3.1- 4.0%, protein – from 7.6-8.0% to 10.0-10.8%, or by 2.2-2.4%, as well as tendentious crude fat, and the content of nitrogenfree extractive substances decreased from 46.8-51.2 to 41.9-45.9%, or by 4.2-4.9%. At the same time, the supply of digestible protein of the feed unit increased from 107-110 g to 142-152 g, or by 35-42 g. With the application of P60K60, compared to the variant without fertilizers application, the phosphorus content in the dry mass of grasses increased by 0.02-0.04% and that of potassium – by 0.20-0.36%. Most of these mineral elements, as well as raw ash, were accumulated by the Dactylis glomerata. Due to the improvement in quality through introduction of N90, perennial grasses are suitable for the production of high-quality grass feed, in particular hay, haylage and green fodder of the 1st class and artificially dried grass feed of the 3rd class.

Short-Term Exposure of Dactylis glomerata Pollen to Atmospheric Gaseous Pollutants Is Related to an Increase in IgE Binding in Patients with Grass Pollen Allergies.

The concentrations of nitrogen dioxide (NO2) and tropospheric ozone (O3) in urban and industrial site atmospheres are considered key factors associated with pollen-related respiratory allergies. This work studies the effects of NO2 and O3 on the protein expression profile and IgE binding in patients with grass allergies to Dactylis glomerata pollen extracts. Pollens were collected during the flowering season and were exposed to NO2 and O3 in a controlled environmental chamber. The amount of soluble protein was examined using the Bradford method, and the protein expression profile and antigenic properties were analysed using the immunoblotting and enzyme-linked immunosorbent assay (ELISA), respectively. Our results showed apparent inter-sera differences concerning the number and intensity of IgE reactivity, with the most prominent at bands of 55 kDa, 35, 33, and 13 kDa. In the 13 kDa band, both gases tend to induce an increase in IgE binding, the band at 33 kDa showed a tendency towards a reduction, particularly pollen exposed to O3. Reactive bands at 55 and 35 kDa presented an increase in the IgE binding pattern for all the patient sera samples exposed to NO2, but the samples exposed to O3 showed an increase in some sera and in others a decrease. Regarding the ELISA results, out of the 21 tested samples, only 9 showed a statistically significant increase in total IgE reactivity after pollen exposure to the pollutants. Our study revealed that although airborne pollen allergens might be affected by air pollution, the possible impacts on allergy symptoms might vary depending on the type of pollutant and the patient's sensitisation profile.

Modeling Pinus radiata D. Don growth and pasture production under different land uses and climate scenarios

Yield-SAFE is a biophysical model to predict long-term production according to light and water availability in agricultural, forest, and agroforestry systems. The Yield-SAFE model should be calibrated and validated for the highest number of tree species and crops to be used as a management tool that takes into account climate change. This study aimed to calibrate and validate the Yield-SAFE model for Pinus radiata D. Don and sown pasture (Dactylis glomerata L.) to estimate the production in (1) forest systems, (2) agricultural systems, and (3) silvopastoral systems established in Galicia (NW Spain) under different conditions of climate: (i) reference “current” climate from 1961 to 1990, (ii) climate from 2021 to 2050, and (iii) climate from 2051 to 2080. The Yield-SAFE model can now be used to assess the long-term productivity of P. radiata D. Don and D. glomerata L. under different land uses and climate conditions. The Yield-SAFE model simulated similar tree and pasture growth in all scenarios of climate because the inter-annual variation of climate was small. However, tree growth estimated with the Yield-SAFE model was higher in the silvopastoral systems than in the forest systems, indicating that land use had more impact on land productivity than climate. Therefore, in regions such as Galicia, the Yield-SAFE model could be used as a tool to support the land use change in an agroforestry context, whilst also including climate scenarios which is considered a valuable solution to mitigate the effect of climate change.

Research on the Influence of Fertilization System on the Production and Sustainability of Temporary Grasslands from Romania

The analysis of the impact of the organic and mineral fertilization systems on the production and sustainability of the temporary grasslands in Romania represents a decisive step in establishing the optimal management in such a technology. The purpose of this research is to determine the influence of these two types of fertilization on hay production, floristic structure, chemical composition–nutritional quality, economic efficiency, and sustainability, in order to improve the cultural technology. The study was carried out in the area of Horezu, Romania. A mixture of five fodder plants was used in the study—Dactylis glomerata, Phleum pratense, Festuca pratensis, Lolium perenne, and Lotus corniculatus—which were sown in two fertilization systems: mineral and organic. The research was carried out between 2017 and 2020, very different years from a climatic point of view. The year 2017 was used to establish the autumn experience, so it is incomplete and was not used in the interpretation of the obtained results. The results of our research contribute to the implementation of better technology for the cultivation of temporary grasslands because the statistical interpretation established that they are significant for all the objectives pursued: production, floristic and chemical composition, and economic efficiency. We recommend small farmers reconsider the use of an organic fertilization system, as they can achieve maximum efficiency, improvement of all physical and chemical properties of the soil, and reduction of feed contamination.

Variability in size and shape of polylobed leaf phytoliths in three populations of Dactylis glomerata L.

The article presents the results of morphometric study of polylobed trapeziform phytoliths of the leaf epidermis of Dactylis glomerata. The relevance of the study lies in the difficulty of establishing the limit of phytolith variability when using morphometry for paleoecological purposes. The studies were performed according to the recommendations of the International Committee for Phytolith Morphometry using the ImageJ software and its PhytolithsBatch plugin. For the first time, the characteristics of the parameters of the size and shape of polylobed trapeziform phytoliths are given. Previously, the study of these particles was not carried out due to their absence in cultivated cereals. The variability of the studied particles within populations and between representatives of individual populations is considered. The length of the phytolith and related indicators are subject to the greatest variability, the width and inscribed radius are the most stable.