Grass and Forage Science最新文献

The local abiotic and environmental conditions of a grass-based farming system may influence the agricultural benefits of mixtures in comparison to pure stands. We investigated the effects of species identities and interactions between grass, legume, and herb species on dry matter yield and sward digestibility and explored how contrasting environments may affect these relationships. We established experimental plots across 11 mixtures and 4 monocultures of perennial ryegrass (Lolium perenne L.), chicory (Cichorium intybus L.), white clover (Trifolium repens L.), and red clover (Trifolium pratense L.) established at two seeding densities in two sites Brody and Szelejewo (Poland) and managed them over a 3-year period. The two sites were close geographically and had similar climates, but differed in soil types (Luvisols and Cambisols, respectively). We confirmed that the annual DM yields were generally higher on Cambisols soil as compared to Luvisols soil; both individual species effects and species interaction strengths differed across the two contrasting environments. The predicted annual DM yield for the 4-species mixtures in general gave comparable or higher yields compared to monocultures across the 3 years, with the mixtures giving around 10%–30% higher yields than the weighted average of the monocultures of the constituent species. Analysing the transgressive overyielding it turned out that there was no significant difference between the 4-species mixtures and best performing monoculture. The benefits of species diversity in our study was greater on less productive site because we found larger overyielding of the 4-species sward on the Luvisols soil than on the Cambisols soil. Additionally, the effect of mixtures composed by 4-species increased the yield stability compared to monocultures in the 3-year period of our study, particularly on Cambisols soil. Sward digestibility applied to average values did not differ much between sites with mixtures performing similarly to monocultures. The reason for that could have been the dynamics of sward botanical composition during study years shifted towards increased perennial ryegrass and decreased proportions of chicory in the sward as well as the observed phenomenon that the species in mixed swards progressed to successive growth stages more slowly than in pure sowing.

In the last decades, the progress in ryegrass (Lolium spp.) breeding was mainly on agronomic traits such as biomass yield, forage quality or disease resistance. However, for commercial success, a stable and high seed yield is a prerequisite for any cultivar. The realized seed yield is influenced by many different factors such as non-optimal pollination and fertilization, seed abortion and seed shattering. While seed shattering has been largely eliminated in major cereal crops such as rice, barley or sorghum during domestication, the trait has been largely neglected in ryegrass breeding programs. The close syntenic relationship of cereal and ryegrass genomes offers the opportunity to develop breeding approaches for reducing seed shattering in the latter by transferring knowledge from the former. The objectives of this review are to (1) give an overview on the knowledge of morphology on seed shattering in cereal crops and ryegrasses, (2) compare the genetic background underlying seed shattering in different species, (3) identify putative candidate genes controlling seed shattering in ryegrasses through comparative genomic analysis and (4) give an outlook on new breeding strategies resulting in low seed shattering cultivars of ryegrasses and related forage grass species.

Nitrogen (N) is one of the most important components of feeds and its quantification allows estimating protein equivalents, an important characteristic for diet formulation in ruminant nutrition. We aimed to evaluate N recovery in tropical forages using the Kjeldahl method with modifications involving a pre-digestion step with salicylic acid and, or a partial replacement of copper sulfate by titanium dioxide as a catalyst. Forty-eight study materials (i.e., tropical forages) were evaluated. Kjeldahl standard procedure was based on acid digestion with sodium sulfate and copper sulfate (20:1), followed by steam distillation in sodium hydroxide and titration with hydrochloric acid. The Kjeldahl variations were: salicylic acid as pre-treatment before digestion, titanium dioxide replacing 50% of copper sulfate as catalyst in the digestion mixture, and salicylic acid and titanium as described above. The Dumas method was used as standard method to verify N recovery through Kjeldahl procedures. The N concentrations of the study materials (Dumas method) ranged from 1.9 to 28.3 g/kg as-is. We found that all the methods were strongly and positively associated with each other (p < .01). All Kjeldahl methods produced N concentrations different from those obtained by the Dumas method (p < .01). The N recovery ranged from 0.971 to 0.980 for the different Kjeldahl methods. However, we did not find any difference between the different Kjeldahl methods regarding N concentrations (p≥ .89). The N recovery of the Kjeldahl method is not influenced by a pre-digestion with salicylic acid or by the partial replacement of copper sulfate with titanium dioxide as a catalyst.

Natural soil inundation caused by frequent and intense precipitation affects carbon allocation in grassland biomass, ultimately leading to changes in soil carbon storage. Increasing forage diversity could provide resiliency to inundation of grassland. The objective was to evaluate forage and root biomass and C and N stocks in the soil particulate organic matter (POM) from pastures under recurring short-term inundation. Three forage species combinations were evaluated in an inundated (typically lasting for a few days after heavy rain events) and a non-inundated pasture: (1) predominantly tall-fescue (Festuca arundinacea Schreb.); (2) mixture of cool-season perennials composed of tall-fescue, orchardgrass (Dactylis glomerata L.), bluegrass (Poa pratensis L.) and white (Trifolium repens L.) and red clover (Trifolium pratense L.); (3) and cool-season mixture of perennials overseeded with oats (Avena strigosa Schreb.) and rye (Secale cereale L.). Roots and forage biomass were sampled during the growing seasons of 2021 and 2022. Soil POM was evaluated 2.5 years after establishment. Inundation reduced forage and root biomass mainly during periods of higher inundation frequency, leading to lower C-POM stocks (p < .05). Inundation caused a shift in the forage botanical composition, that is, higher occurrence of weeds and less productive grass species with shallow roots. The perennial cool-season mixture did not increase forage yield compared with tall fescue only but did increase root mass. This occurred mainly at deeper layers and, consequently, increased C-POM stocks (p < .05). Overseeding of winter annuals reduced overall forage production, despite increasing spring biomass when inundated in the first year, but reduced C and N-POM stocks (p < .05). Perennial cool-season forage mixtures can increase the resilience of pastures to inundation events and contribute to increased carbon sequestration in grasslands where inundation is prevalent.

Cytochrome P450s (CYPs) play crucial roles in regulating plant growth, development, and stress tolerance. In this study, a perennial ryegrass (Lolium perenne) CYP gene, LpCYP72A15, was identified as a candidate gene regulating plant osmotic stress tolerance based on a cDNA library screening in the background of yeast ∆hog1 mutant. LpCYP72A15 is localized in the plastids, and its expression was regulated by osmotic stress and ABA treatment. Overexpressing LpCYP72A15 significantly enhanced plant drought tolerance in both Arabidopsis and perennial ryegrass. Under drought stress, the transgenic ryegrass showed significant lower reactive oxygen species (ROS) levels, higher ROS-scavenging enzymatic activities, and higher soluble sugar contents than the wildtype plants. Transient over-expressing the gene also enhanced survival rates of ryegrass mesophyll protoplasts under H₂O₂-induced oxidative or mannitol-enforced osmotic stresses. Taken together, LpCYP72A15 confers oxidative- and osmotic-stress tolerances that positively regulates plant drought tolerance in perennial ryegrass.

The specialisation of agricultural systems in Western Europe and the intensification of livestock and cropping production are intrinsically linked to substantial resource inputs. This intensified approach frequently leads to nutrient surpluses and biodiversity loss, resulting in detrimental environmental impacts. A transformative agricultural shift is imperative in light of climate and environmental protection objectives. Addressing this need, the Lindhof eco-efficient pasture-based milk production initiative, initiated in 2016, is a tangible manifestation of a productive and profitable dairy system integrated within a ley-based Integrated Crop-Livestock System (ICLS). Operational at the organically managed Lindhof farm, this approach involves a rotational stocking system of spring-calving Jersey cows stocked on grass-clover-herb leys embedded within a cash crop rotation. The dairy cows benefit from these highly productive swards, rich in nutritive value comparable to concentrate feeding. At the same time, the cultivated crops derive advantages from the legacy effect of leys due to nutrient exchange facilitated by grazing excreta and residual crop matter. Compared to specialised systems, the ley-based ICLS emerges as an alternative dairy production paradigm that supports many ecosystem services – including minimised nutrient losses, a lower carbon footprint and positive contributions to agro-biodiversity. These outcomes are realised without compromising overall land-use efficiency while reducing environmental and social costs of 20–30 Eurocent per kg of milk produced compared to specialised systems. Thus, the ley-based ICLS conforms to the principles of ecological intensification, enhancing functional diversity within the agricultural landscape. Essentially, the Lindhof initiative represents a holistic and environmentally responsible approach to farming that could contribute to realising the EU Farm to Fork Strategy.

Zoysiagrass is a valuable low maintenance warm-season turfgrass. Nitrogen management is one of the most important management practices that affect colour retention and winter hardiness. However, the N cycling during seasonal senescence and its interaction with low temperature acclimation are not well-understood. The objective of this experiment was to understand the initiation of senescence as affected by environmental signals and the contribution of chlorophyll and protein degradation to N metabolites. Two commercial cultivars (‘Meyer’ and ‘Zenith’), seven wild accessions of Z. japonica, one wild accession of Z. matrella, and one wild accession of Z. pacifica from China were tested. Mature plants were exposed to four sequential environmental conditions to simulate fall shortening light photoperiods and decreasing temperatures as low as 0°C. Major N containing compounds and key enzymes in N metabolism during the senescence and low temperature acclimation were measured. The results showed that accessions of zoysiagrass from low latitudes had higher chlorophyll retention and lower N recycle (low soluble protein and NH₄-N) than those from higher latitudes in a simulated late fall, indicating that different mechanisms were responsible for the senescence and low temperature acclimation. In general, chlorophyll and soluble protein concentration decreased during the senescence which led to an increase of total free amino acids, especially glutamine, prior to the low temperature dormancy. The changes in N metabolism and the N uptake were also reflected in the decrease of NO₃-N and increase of NH₄-N, as well as relevant enzyme activities in the key steps. The signal and regulation mechanism in N cycling during the seasonal senescence and acclimation requires further investigations.

Increasing N use efficiency (NUE) is desirable in turfgrass management. Traditional definition of NUE in turfgrass is essentially the inverse of nitrogen concentration in the clippings and is often evaluated once in a growing season. In this experiment, we followed the Brenderse and Aerts' definition of NUE as the product of mean residence time (MRT) and nitrogen productivity (NP). The objective of this experiment was to identify NP changes over time in Kentucky bluegrass cultivars at different N levels under deficit irrigation. Nine Kentucky bluegrass (Poa pratensis L.) and two hybrid bluegrass cultivars from 10 phenotypic classes were tested under N rates of 10 and 40 g m⁻². Deficit irrigation at 60% of the evapotranspiration was imposed. The results showed interaction effects on NP from N level, irrigation, and cultivar. Low-N treatment resulted in higher NP values as compared to high-N for ‘Merit’ and ‘Martha’. No NP difference existed between N or irrigation levels for ‘Blue ghost’, ‘Geronimo’, ‘Heidi’, ‘Bandera’, ‘Impact’, ‘Fielder’, ‘Jackrabbit’, and ‘Park’. ‘Rhythm’ showed lower NP values in high-N combined with full irrigation compared to other treatments. In general, increasing N levels resulted in lower NP, but higher nitrate reductase activity (NaR) and higher net photosynthesis. No N by irrigation interaction effect was detected for effective quantum yield or NaR. In conclusion, leaf-level NP was shown to be an effective parameter for in-season monitoring of the above-ground NUE of Kentucky bluegrass, which provided more dynamic information than clipping yields or a one-time NUE calculation based on traditional definition.

This study evaluated the fermentation characteristics, microbial diversity, chemical composition, and in vitro digestibility of forage peanut silage harvested at two regrowth ages and treated with microbial inoculants at different fermentation periods. A randomized block design was used, with two regrowth ages (R; 40 and 80 days), three microbial inoculants (I; control without inoculant [CTRL], strain AV14.17—Lactiplantibacillus pentosus strain AV14.17 [ISO], and commercial inoculant [CI] Sil-All 4 × 4 (Lallemand Animal Nutrition®, Patos de Minas-MG, Brazil), and four storage time (ST; 3, 14, 30, and 60 days after ensiling) arranged in a 2 × 3 × 4 factorial scheme, with four replications. The R × I × ST interaction had a significant effect (p ≤ .05) on the ammoniacal nitrogen content in relation to total nitrogen (NH₃-N/ total N) and on the yeast population. The I × ST interaction also had a significant effect (p ≤ .05) on pH, soluble carbohydrate, NH₃-N/total N, lactic acid bacteria, yeast, and filamentous fungi. Inoculated silages with ISO and CI showed lower pH and NH₃-N/total N values, as well as lower abundance of enterobacteria, yeast, and filamentous fungi. In silages inoculated with ISO, the relative abundance of genus Lactiplantibacillus was high and that of genus Enterobacter was low. Silages inoculated with ISO and CI showed predominance of the family Lactobacillaceae. The data support the recommendation to ensile forage peanut at both regrowth ages (40 and 80 days) associated with microbial inoculant application to promote improvements in the fermentation characteristics of the silage and a greater abundance of genus Lactiplantibacillus.