Grasses doi: 10.3390/grasses3020008

Authors: Gabriela Ramírez-Ojeda Edith Ramírez-Segura Luis Ángel Barrera-Guzmán Abieser Vázquez-González

Arid and semi-arid areas are highly productive ecosystems that have a great diversity of species, among which grasses stand out. These species have ecological, environmental, and economic importance. The objective was to identify the ecological descriptors of 15 native species of grasses and diversity patterns through multivariate analysis techniques (principal component analysis, PCA, and cluster analysis, CA), in addition to identifying potential distribution areas (current and future) and regions of high and low diversity from 3841 accessions and 21 climatic variables. Among the main results, the extreme values, coefficient of variation, and median for each species could be determined. PCA determined that, with 10 variables, it was possible to explain 54.36% of the variation between the analyzed species. CA resulted in the formation of four statistically significant groups, with specific climatic characteristics. Regarding potential distribution areas and climate change, a reduction in distribution is expected (2050) on most of the current surface, with a possible opportunity zone in the north of the country. Finally, two hotspots (high diversity areas) and four coldspots (low diversity areas) were identified among the analyzed species. These results can be used to create strategies for sustainable use and the conservation of these resources.

Grasses doi: 10.3390/grasses3020007

Authors: Alexander Hernandez Kevin Jensen Steve Larson Royce Larsen Craig Rigby Brittany Johnson Claire Spickermann Stephen Sinton

Forage yield estimates provide relevant information to manage and quantify ecosystem services in grasslands. We fitted and validated prediction models of forage yield for several prominent grasses used in restoration projects in semiarid areas. We used field forage harvests from three different sites in Northern Utah and Southern California, USA, in conjunction with multispectral, high-resolution UAV imagery. Different model structures were tested with simple models using a unique predictor, the forage volumetric 3D space, and more complex models, where RGB, red edge, and near-infrared spectral bands and associated vegetation indices were used as predictors. We found that for most dense canopy grasses, using a simple linear model structure could explain most (R2 0.7) of the variability of the response variable. This was not the case for sparse canopy grasses, where a full multispectral dataset and a non-parametric model approach (random forest) were required to obtain a maximum R2 of 0.53. We developed transparent protocols to model forage yield where, in most circumstances, acceptable results could be obtained with affordable RGB sensors and UAV platforms. This is important as users can obtain rapid estimates with inexpensive sensors for most of the grasses included in this study.

Grasses doi: 10.3390/grasses3020006

Authors: Zinhle Mashaba-Munghemezulu Lwandile Nduku Cilence Munghemezulu George Johannes Chirima

Grasslands cover approximately 40% of the Earth’s surface. Thus, they play a pivotal role in supporting biodiversity, ecosystem services, and human livelihoods. These ecosystems provide crucial habitats for specialized plant and animal species, act as carbon sinks to mitigate climate change, and are vital for agriculture and pastoralism. However, grasslands face ongoing threats from certain factors, like land use changes, overgrazing, and climate change. Geospatial technologies have become indispensable to manage and protect these valuable ecosystems. This review focuses on the application of Google Earth Engine (GEE) in grasslands. The study presents a bibliometric analysis of research conducted between 2016–2023. Findings from the analysis reveal a significant growth in the use of GEE and different remote sensing products for grassland studies. Most authors reported grassland degradation in most countries. Additionally, China leads in research contributions, followed by the United States and Brazil. However, the analysis highlights the need for greater involvement from developing countries, particularly in Africa. Furthermore, it highlights the global distribution of research efforts, emphasizes the need for broader international participation.

Grasses doi: 10.3390/grasses3020005

Authors: Eduardo André Ferreira Joadil Gonçalves de Abreu Wininton Mendes da Silva Danielle Helena Müller Dalilhia Nazaré dos Santos Cassiano Cremon Oscarlina Lúcia dos Santos Weber Aaron Kinyu Hoshide Daniel Carneiro de Abreu Maybe Lopes Gonçalves José Advan Pereira Pedrosa Júnior

Gelatin industry residues are increasingly used as fertilizer and soil conditioner. However, correct residue dosage is critical for grass development and minimizing environmental impacts. This randomized block design study determined adequate dosage of mixed gelatin sludge (MGS) for Marandu grass production in wet/dry seasons in Brazil. Five MGS levels (0–200% of required nitrogen) were compared to mineral fertilizer. Agronomic/productivity characteristics, bromatological composition, macro/micronutrient composition of leaves, and soil chemical attributes were evaluated. Agronomic/productivity characteristics were influenced by MGS dose in both dry/rainy seasons, except for leaf blade pseudostem ratio and percentage of leaves/pseudostem. Bromatological composition was influenced by MGS doses in dry/rainy seasons except for dry/mineral material quantities. Marandu leaf tissue chemical composition was significantly influenced by MGS dose, except for potassium, boron, and iron. Chemical composition of four soil layers between 0 and 50 cm influenced MGS dose, except for pH, organic matter, magnesium, copper, manganese, and zinc. GMS dose for Marandu production should be 200% of nitrogen requirement. MGS application increased productivity/quality of Marandu grass. Macronutrients (nitrogen, phosphorus) and micronutrients (calcium, magnesium, sulfur, copper, and zinc) increased in Marandu grass and in the soil (calcium, sulfur, and sodium). The increased sodium level was not limiting.

Grasses doi: 10.3390/grasses3010004

Authors: Paolo Rivaldo Medina Quispe Marco Aurelio Arizapana-Almonacid Marcelo Daniel Nosetto

The high-Andean grasslands of Peru provide a wide range of goods and services, not only locally, but also regionally and globally. However, land-use change and global warming are threatening these ecosystems, of which soil organic carbon (SOC) is a key element affecting their sustainability. In this study, we have analyzed the variation of SOC stocks to a depth of 20 cm in 16 paired cropland and grassland sites located in the Sullccapallcca stream micro-watershed (elevation > 3600 m.a.s.l., Ayacucho, Peru). We have also analyzed the environmental controls on the SOC stocks and their variation with land-use change. We found that the studied high-Andean grasslands store high SOC contents (247 Tn SOC ha−1), whose spatial variability was partially explained by the slope of the terrain (r2 = 0.26, p < 0.05). Despite the higher NDVI, the conversion of these grasslands into croplands decreased the SOC stock by 39 Tn SOC ha−1 on average, a decrease that was more pronounced when the initial SOC content of the grassland was higher (r2 = 0.60, p < 0.05). This study provides the first evidence of the effects of land-use change on the SOC in the region, although the mechanisms involved still need to be investigated.

Grasses doi: 10.3390/grasses3010003

Authors: Gustavo Daniel Vega-Britez Marciana Retore Allison Manoel de Sousa Adrielly Lais Alves da Silva Carolina Marques Costa Carla Giselly de Souza Marcio Rodrigues de Souza Fernando Miranda de Vargas Junior

In Brazil, grazing is the main or only source of food for livestock. The appropriate combination of supplementation with concentrate in a lamb’s diet on pasture is an alternative that can be explored to use natural resources to produce quality meat. The aim of the current study was to evaluate the effects of different supplementation levels (0%, 1.5%, and 3% of BW) on the intake, performance, and production costs of lambs grazing on Aruana (Megathyrsus maximus) and Marandu (Brachiaria brizantha) grasses. Thirty-six non-castrated male Suffolk lambs (22.54 ± 2.72 kg) were used. The lambs were evaluated for nutrient intake and digestibility, such as dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and consumption in relation to body weight (% BW), in addition to the average daily gain (ADG), body condition score (BCS), and hot carcass weight (HCW), as well as the rising production cost of each system. The dry matter of the green leaf blades was influenced by the pasture type (p < 0.05), producing 1503.6 vs. 2977.4 kg/ha of Aruana and Marandu grasses, respectively. The concentrate supplementation level influenced the type of pasture (p < 0.05). A higher consumption of DM, CP, NDF, and organic matter was registered for the supplemented animals (p < 0.05) and on Aruana grass. The intake in relation to body weight was significantly influenced by the concentrate levels (p < 0.05). The empty body weight and HCW were significantly influenced by the supplementation levels (p < 0.05). The ADG and feed conversion (FC; kg DM/ADG) were influenced by the supplementation levels and type of pasture. The BCSs differed between the concentrate levels (p < 0.05). The supplementation improved dry matter digestibility. The ADG and FC were superior in the supplemented animals, with an advantage for those grazing on Aruana grass. The slaughter ADG was also higher in the supplemented animals. The lambs’ pasture comprising Aruana grass with 1.5% BW of concentrate supplementation showed improved production and economic results.

Grasses doi: 10.3390/grasses3010002

Authors: Andressa Radtke Baungratz Leonardo Piffer de Borba Bruna Martins de Menezes Jean Lucas Macari Porsch Tiago Venturini Rusbel Raúl Aspilcueta Borquis Eduardo Eustáquio Mesquita Ériton Egídio Lisboa Valente Vicente de Paulo Macedo

The objective was to characterize the nutrient and mineral composition of M. maximus cv Aruana grazed by lambs in a silvopastoral system or full sun with added nitrogen. The treatments are: (1) Aruana grazed in full sun with nitrogen fertilization, (2) Aruana grazed in full sun without nitrogen fertilization, (3) Aruana grazed in a silvopastoral system with nitrogen fertilization and (4) Aruana grazed in a silvopastoral system without nitrogen fertilization. The nutrient dynamics, urinary excretion of N and the amount returned of the nutrient were determined from four sheep in a Latin square experimental design; the analysis of the mineral composition of the leaves and stalks of the grass was carried out by collecting samples from the plots used, totaling six in each treatment evaluated. The silvopastoral system provided high levels of P and K in forage plants. Urinary N excretion and urine mineral contents were influenced by the systems evaluated and the use of N fertilizer. N did not show differences for leaves and canes.

Grasses doi: 10.3390/grasses3010001

Authors: Simone Magni Giuliano Sciusco Lisa Caturegli Mino Sportelli Tommaso Federighi Marco Fontanelli Alberto Minelli Joseph Scott McElroy Marco Volterrani

Hybrid Bermuda grasses (Cynodon dactylon × C. transvaalensis Burtt.-Davy) represent one of the greatest contributions to the growing quality of turfgrass in the warm season and transition zone areas of the world. Hybrid Bermuda grass production relies on vegetative propagation from sod or sprigs. In the past, efforts have focused on improving the technique of stolonizing (or sprigging) for establishment in new areas. Such propagation requires bulk harvesting and planting of all rhizomes and stolons. We have developed a novel method of propagation and establishment from a single node harvested from greenhouse grown stolons. Despite a stolon fraction bearing a single node being suitable for effectively propagating a warm-season turfgrass, the technique has been held as economically impractical until now. Our method has been developed to obtain the multiplication of plant material in soilless conditions by harvesting single-node sprigs, propagation of plants from the single nodes, and transplant of single plants in the field. The investigation aimed to identify values for method set-up. Indeed, node and internode size variability with differential between maximum diameters is crucial for discrimination. For Patriot Bermuda grass stolons, nodes exhibited a maximum diameter of 2.43 ± 0.46 mm, while internodes had a maximum diameter of 1.54 ± 0.16 mm. Based on these findings, a 2 mm sieve was selected, achieving an optimal ratio between the node fraction and internode residues. The sieve yielded 87% of node fractions and only 1% of internodes from the initial mix, demonstrating its efficacy. Further results for the transplanting phase indicated that a double release resulted in an average success rate of 98.8%, with only 6.9% blank cells when using a single release. The average was 149 plants per tray over 160 cells, representing a 93.1% success rate. These results underscore the efficiency and acceptability of the overall propagation process in alignment with market references.

Grasses doi: 10.3390/grasses2040019

Authors: Michael D. Casler Blair L. Waldron

Meadow fescue, Schedonorus pratensis (Huds.) P. Beauv., has recently been discovered as a common but previously unknown pasture grass in the Driftless Area of the upper Mississippi River Valley, USA. Preliminary data also indicated that many meadow fescue pastures were infected with an endophytic fungus, Epichloë uncinata (W. Gams, Petrini & D. Schmidt) Leuchtm. & Schardl. Therefore, the objective of this study was to determine if the endophyte impacts agronomic fitness of the host meadow fescue. Meadow fescue plants from eight farm sites were intensively sampled, and endophyte infection levels were determined to range from 82 to 95%. Paired endophyte-infected (E+) and endophyte-free (E−) meadow fescue subpopulations from each collection site were then created, and were subsequently compared for greenhouse and field drought tolerance, forage mass, and persistence under frequent defoliation. There was no impact of the endophyte under a wide range of drought conditions for either greenhouse or field studies. Furthermore, there was a small forage-mass-enhancement effect in the E+ subpopulation for only one of the eight collection sites. The only consistent effect was an average of 9% increased ground cover (persistence) in endophyte-infected meadow fescue under frequent defoliation. As per other studies, enhanced root growth, fungal-disease resistance, and/or reduced insect feeding could be mechanisms for this increased survivorship. We conclude that the meadow fescue endophytes present in the Driftless Area do not help protect their host from drought or provide any consistent forage-growth enhancement; however, we found evidence that the endophyte provides some protection against frequent defoliation at low residual sward heights.

Grasses doi: 10.3390/grasses2040018

Authors: Roy Lubke

The goals of a “restoration” programme are often not clearly defined, which may radically influence the course of the change effected by the “restoration”. In this paper, I examine many restoration studies worldwide, the goals and the practice that was followed. Grasses often play an important role in both the succession and restoration processes. In Johannesburg, South Africa, wind-blown dust caused by gold mining was a problem in the early 20th century, so the goal was to stabilise the tailings. This was achieved by establishing vegetation on the dumps or revegetation of the land on which the tailings were deposited. Stabilisation of the Cape Flats was the goal in the late 19th century to allow easy movement along sandy roads in the region and marram grass was introduced from Europe specifically for this purpose. Revegetation with a different vegetation type is often a logical option where land use is of paramount importance. Replacement with crop plants or grasses is where the previous vegetation is replaced by an alternative land use that will be of benefit to the local people. The terms “rehabilitation” and “restoration” are often used interchangeably. Early researchers on the subject pointed out that rehabilitation is on the trajectory to full restoration or the original former state of the degraded site. In this review, the rehabilitation processes are discussed following dune mining in South Africa and at sites in Mozambique.

Grasses doi: 10.3390/grasses2040017

Authors: Nthabeliseni Munyai Abel Ramoelo Samuel Adelabu Hugo Bezuidenhout Hassan Sadiq

The Nama Karoo biome is one of the least well-studied biomes in the semi-arid region of South Africa, and essential baseline biodiversity data for this region are lacking. The aim of the present study was to examine the influence of environmental factors on the species diversity and richness of Mountain Zebra National Park, South Africa, which includes this vital biome. Vegetation data were obtained using the step-point method. Both species richness and diversity were unaffected by slope, aspect, coarse fragments, and soil texture. Multiple linear regression analyses indicated that a combination of four variables (nitrogen, clay, and sand contents, and longitude) should be included in the optimal model for species richness, and the optimal model for species diversity also revealed four influencing variables: soil organic carbon, clay and sand contents, and longitude. Overall, both species richness and diversity could be predicted by a combination of climatic, topographic, and soil properties. The findings of this study can be used as a reference for the effects of environmental factors on plant species richness and diversity in semi-arid environments.

Grasses doi: 10.3390/grasses2040016

Authors: Elisha Leon Martin Hughes Oral Daley

Supplementing tropical grasses with leguminous forages is known to improve the nutritive value of forage-based diets. However, it is not clear how basal grass forages supplemented with Kudzu (Pueraria phaseoloides) affect the nitrogen (N) and crude protein (CP) fractions of grass/legume forages. The aim of this study was to determine the N and CP fractions and in vitro ruminal CP degradability of Brachiaria hybrid (B. ruziziensis × B. decumbens × B. brizantha) and elephant grass (Pennisetum purpureum) supplemented with Kudzu at a target CP content of 133 ± 0.6 g/kg of dry matter (DM). The grass/legume forages were evaluated for total N, buffer-soluble N (BSN), buffer-insoluble N (BISN), non-protein nitrogen (NPN), neutral detergent-insoluble N (NDIN), acid detergent-insoluble N (ADIN), CP fractions A, B1, B2, B3, C, rumen-degradable protein (RDP), rumen-undegraded protein (RUP), and in vitro ruminal CP degradability. The CP concentration of Kudzu was 217 g/kg DM, while grass forages ranged between 79.9 and 112 g/kg DM. The BISN, CP degradability parameters b, and potential degradability were approximately 56, 41, and 74%, respectively, higher in grass forages supplemented with Kudzu. The concentrations of RUP in the grass forages (23.9–32.5 g/kg DM) were significantly improved when they were supplemented with Kudzu (72.0–79.9 g/kg DM). Therefore, we concluded that basal grass forages supplemented with Kudzu to a target CP content can improve the amount of RUP supplied by the forage portion of the diet. This can have a positive effect on forage utilization and animal performance while reducing the cost to feed for ruminants.

Grasses doi: 10.3390/grasses2030015

Authors: Aiming Qi Louise Whatford Sophie Payne-Gifford Richard Cooke Steven Van Winden Barbara Häsler David Barling

Grassland is grouped into temporary, permanent, and rough grazing types in the United Kingdom (UK), making up more than 60% of the national agricultural land area. It provides avenues for grazed fodder or ensiled forage contributing a large proportion of the diets consumed by cattle and sheep. The official agricultural census data in 2011 to 2020 showed that, on average, UK cattle and sheep farming can produce meat to satisfy 83.3 and 100.8% of domestic cattle beef and sheep meat consumption levels, respectively. Out of the large agricultural census datasets, we used the populations of cattle and sheep, as well as the UK definition of a standard livestock unit (SLU), to normalise the respective herd populations into a total standard livestock unit (TSLU). We then used the annual domestic meat production in dressed carcass weight to calculate cattle and sheep meat productivity per SLU. Using the potential herbal dry matter yields per year and areas of the different grassland types across the UK, the potential total available pasture feed was calculated. This potential production of herbal biomass was translated into the potential carrying capacity expressed in a TSLU. This total potential carrying capacity was partitioned into cattle and sheep sectors so that the routes of pasture-based-only options with which to produce ruminant meat to meet the current UK domestic consumption demands were assessed. The estimated mean potential annual pasture forage feed in 2011–2020 was approximately 82.0 million (M) metric tonnes (t), which can be translated into a potential carrying capacity of 17.9 M SLUs compared with the current mean 9.36 M SLUs in the survey data of the UK. With the ratio of sheep to cattle at 8.2:25 in the national TSLU, the UK national demands at present consumption levels of cattle and sheep meat can be arithmetically met with pasture grass utilisation rates at or above 65% and 50% by cattle and sheep farming systems, respectively.

Grasses doi: 10.3390/grasses2030014

Authors: Fiorella Cazzuli Martín Durante Andrés Hirigoyen Javier Sánchez Pablo Rovira Virginia Beretta Alvaro Simeone Martín Jaurena Jean Victor Savian Dennis Poppi Fabio Montossi Ximena Lagomarsino Santiago Luzardo Gustavo Brito José Ignacio Velazco Fernando Alfredo Lattanzi Carolina Bremm

Previous studies on winter supplementation of growing cattle grazing stockpiled native Campos grasslands suggest that forage allowance (FA), herbage mass, and weather conditions before and during the supplementation period could all affect supplement feed efficiency (SFE)—that is, the difference or change in average daily gain (ADG) between supplemented (S) and control (C) animals (ADGchng, kg) per unit (kg) of supplement dry matter (DM) intake. In this study, we analyse data from fifteen collated winter supplementation trials carried out in Uruguay between 2004 and 2018. The working hypotheses of this research paper were: (i) that average substitution rates are positive, and (ii) that ADGchng is not constant throughout the supplementation period and that its variation may be attributed to sward, animal or weather variables. There were two main objectives: (i) to estimate the average supplement substitution rate (sSbR, kg forage, f, dry matter, DM intake reduction: kg supplement DM intake) and potential herbage intake substitution rate (hSbR, kg fDM intake reduction: kg fDM intake of control animals), and its association with SFE, and, (ii) to assess the existence of different phases and supplementation response patterns and its association with other relevant variables. Estimated substitution rates were always positive (sSbR = 0.3–1.1 kg/kg; hSbR = 0.1–0.3 kg/kg) and were negatively and moderately associated with SFE. Supplementation proved to be a dynamic process where three possible supplementation responses over the supplementation period were identified (linear, quadratic and Weibull). While linear patterns did not appear distinctly associated with any particular set of variables, quadratic models were mostly associated with herbage biomass and substitution rates, whereas Weibull models were the clearest in their association with frosts. Regardless of the response pattern, at the beginning of the trials it was the animals’ body weight and supplement quality that most influenced supplement response, whereas towards the end, supplementation intake, supplemented animals’ ADG and forage quality played a more relevant role. The estimated parameters and response patterns are expected to be used as inputs in decision support systems for livestock farmers in the future.

Grasses doi: 10.3390/grasses2030013

Authors: Dilini Weerathunga Deepani Udagama Shane Campbell David Barber Piyatilak Weerasinghe

Low pasture biomass production and fodder scarcity are among the major challenges affecting productivity of dairy cattle farms in Sri Lanka. As a potential solution to this, two Napier hybrid cultivars, CO-5 and Sampoorna, were recently introduced, and a field experiment was conducted to evaluate their growth, dry matter production, and nutritional composition from May to September 2020 to identify the optimum stage of harvest during the Yala season of the year. Plant measurements and samples were collected at five harvest intervals (4, 6, 8, 10, and 12 weeks after planting, respectively), with the plant samples subjected to biomass and nutritional assessments. The number of tillers and leaf length significantly differed (p = 0.01) between the two cultivars at 4 weeks harvesting interval (HI), whilst the number of leaves differed at 12-week HI, respectively. Dry matter yield increased (p = 0.16) almost linearly, whilst crude protein declined exponentially with CO-5 greater than Sampoorna (p = 0.057; 9.3% vs. 8.7%), with increasing harvesting intervals, respectively. In vitro organic matter digestibility and in vitro metabolizable energy contents were similar across weeks 4, 6, and 8 but then decreased. This study demonstrates that higher dry matter yields (12.54 t/ha) can be obtained through harvesting both cultivars at 12 week HIs, but from a nutritional perspective, harvesting at 6 week HIs during Yala season of the year would be optimum for farmers.

Grasses doi: 10.3390/grasses2030012

Authors: Leonard M. Lauriault Eric J. Scholljegerdes Jason E. Sawyer

The optimum grazing management practices to sustain or increase grassland resilience must be determined. The effects of the current and previous year’s stocking densities (light, medium, and heavy stocking densities of 0.53, 0.89, and 1.24 AU ha−1, respectively) at the same stocking rate (35 AUD ha−1 yr−1) of yearling heifers (Bos taurus) grazing predominately blue grama [Bouteloua gracilis (Willd. ex Kunth) Lag. ex Griffiths] pastures on animal gains and pasture mass during the growing season were evaluated at New Mexico State University’s Rex E. Kirksey Agricultural Science Center at Tucumcari, NM USA, over three years. Previous grazing management had no influence on animal performance (p > 0.14) but seasonal average daily gains and total gains ha−1 were decreased from low- to high-density grazing (p < 0.002). Nevertheless, for grassland resilience, when low followed either high or medium, blue grama mass increased compared to low following low. Alternatively, when medium followed high, blue grama mass was reduced, but when high followed either low or medium, forage mass numerically increased (p < 0.0117 for the previous × current year’s stocking density interaction). Consequently, short-duration, high stocking density may be best using multiple pastures, each with the same grazing period each year to allow for a long-duration rest. Otherwise, during persistent drought, a longer-duration, medium stocking density could be used to allow for recovery.

Grasses doi: 10.3390/grasses2020011

Authors: Luis Alonso Villalobos-Villalobos Rodolfo WingChing-Jones

Accurate estimates of forage biomass allow for better adjustments of stocking rate, carrying capacity, and dry matter intake in livestock operations. Among the most common methods to estimate biomass are platemeters, for which specific calibration equations have been developed for temperate conditions. However, platemeters are not commonly used in tropical livestock operations where their goodness of fit to estimate forage biomass remains unknown. In this study, we aimed to compare three methods (the rising platemeter, Botanal®, and hand-clipping) to estimate forage biomass throughout one year on perennial ryegrass (Lolium perenne), Kikuyu (Cenchrus clandestinus), and African stargrass (Cynodon nlemfuensis Vanderyst) pastures in Costa Rica. Estimates of forage biomass were consistently greater with the platemeter than with the Botanal® and clippings across the three grass species evaluated. In Ryegrass pastures, the residual standard deviation (1845 kg DM ha−1) of forage biomass estimated with the platemeter was two- and four-fold with respect to Stargrass and Kikuyu pastures (935 and 447 kg DM ha−1), respectively. Although platemeters are straightforward methods for biomass estimation in pastures, our data suggest that their use and implementation in tropical pastures may lead to overestimating indicators such as stocking rate and carrying capacity. We suggest developing calibration equations specific for tropical conditions that consider our findings as an input to adjust the sampling procedure necessary to improve the accuracy of platemeters and foster greater adoption among livestock producers.

Grasses doi: 10.3390/grasses2020010

Authors: Iuli Caetano da Silva Brandão Guimarães Thiago Henrique da Silva Cristina Cirino Picchi Romualdo Shigueo Fukushima

Reliable forage analysis is crucial for proper ration formulation of ruminant herds. Through its fast, inexpensive, and non-destructive procedures, near-infrared spectroscopy (NIRS) has become a valuable method for forage evaluating. Notwithstanding, NIRS needs calibration before routine analysis. In addition, to evaluate the best method for lignin quantification in Urochloa spp. grasses is crucial under a digestibility perspective in grass-fed ruminant production. The aims of this study were to use 149 samples from different Urochloa species to develop NIRS calibration curves (partial least squares regressions) for acid detergent lignin (ADL), acetyl bromide lignin (ABL), as well as for ash, cell wall (CW), neutral detergent fiber (NDF), acid detergent fiber (ADF), in vitro DM digestibility (IVDMD), and in vitro NDF digestibility (IVNDFD). Moreover, the aim of this study was to correlate the in vitro digestibility with lignin quantification methods: ADL and ABL. Near-infrared spectroscopy showed potential for the quantification of Urochloa spp. properties, such as lignin contents (ADL and ABL) and ash, CW, NDF, ADF, IVDMD, and IVNDFD. However, calibrations performed using NIRS to measure ADF, ADL, IVDMD, and IVNDFD need to be thought about with caution before their utilization as a routine analysis for determining the potential for nutrient measurement and digestibility of Urochloa spp. grasses. In addition, the ABL method used for lignin quantification was better correlated with IVDMD and IVNDFD than the ADL method.

Grasses doi: 10.3390/grasses2020009

Authors: Ousmane Diatta Daouda Ngom Ousmane Ndiaye Sékouna Diatta Simon Taugourdeau

This study describes the structure and phenology of Sahelian rangelands during the rainy season. It was undertaken on a grazed plot and a fenced plot. Measurements were taken every 10 days over two rainy seasons between July and October 2018 and between August and October 2019. The measurements included the phenological stage, the vegetative and flowering height, the coverage, and the phytomass. The results showed that phytomass did not systematically differ between grazed and fenced plots. Flowering started as early as mid-July, but most of the plants flowered in early October. Flowering and fruiting occurred earlier (based on the number of days after the first rain) in the late rainy season (2019) than in the early one (2018). These stages reached their peak in October; senescence began in October. Vegetative height, reproductive height, and coverage were similar between the two years. Height peaks were similar, but they were reached earlier (based on the number of days after the first rain) in the late rainy season than in the early one. Coverage peaks were similar (59.8% in the early rainy season vs. 65.8% in the late one). Vegetative height (around 30 cm), reproductive height (around 36 cm), and coverage (around 60%) reached their maximum in October, but reproductive height was greater than vegetative height. These parameters were lower at the grazed site compared to the fenced site, and flowering started earlier at the grazed site. The pasture had a negative impact on coverage, height, and early flowering. Structure and phenology were more sensitive than to changes in rainfall between years. Phenology results will help determine the best time to harvest the phytomass (phytomass stock), as the nutritional quality of the forage is known to decrease after fruiting.

Grasses doi: 10.3390/grasses2020008

Authors: Katy E. Chapman Kristina S. Walker

Understanding greenhouse gas (GHG) emissions from turfgrass allows managers to make cultural management decisions to reduce GHG emissions. The objective of this study was to evaluate fertilizer source [urea (URE), polymer-encapsulated urea (POL), and milorganite (MIL)] and site location (green, wet rough, and dry rough) on GHG [carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)] emissions. Greenhouse gas data, soil temperature, soil moisture, canopy greenness, and turfgrass quality were collected. High soil temperature and moisture were correlated with soil CO2 and N2O flux. The wet rough fluxed more soil CH4 across the 2-year study. The POL fluxed the highest amount of soil CO2, while POL and MIL fluxed the largest amount of soil N2O on the wet rough. Milorganite and POL increased canopy greenness in both roughs during the spring. On the green, URE produced greater canopy greenness in the spring and fall. Our results indicate that when soil moisture and temperature are high, turfgrass managers should employ methods of reducing soil temperatures that do not increase soil moisture to reduce GHG emissions. Under warm and wet conditions, gaseous losses of GHGs are accelerated with slow-release fertilizers.

Grasses doi: 10.3390/grasses2020007

Authors: Fleming Sena Campos Gherman Garcia Leal de Araújo Welson Lima Simões Thieres George Freire da Silva Miguel Júlio Machado Guimarães Cleyton de Almeida Araújo Amélia de Macedo Getúlio Figueiredo de Oliveira Tiago Santos Silva Anderson de Moura Zanine Daniele de Jesus Ferreira Hactus Souto Cavalcanti Glayciane Costa Gois

The objective of this study was to evaluate the characteristics and recovery of minerals in silages of sorghum cv. IPA 2502 irrigated with different leaching fractions of brackish water. Sorghum cultivation was carried out in the field in a randomised block design, with four replications and four irrigation leaching fractions (0%, 5%, 10%, and 15%). From the harvested plant material, five silos per treatment, with five repetitions, were arranged in a completely randomised design for ensiling. Leaching fractions did not alter the levels of nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur in sorghum. The sodium content showed a quadratic response to the leaching fractions, which was also observed for iron, manganese, and chloride. In silage, an increasing linear effect was found for nitrogen, whereas for phosphorus, potassium, and sulfur, the contents were reduced with the addition of the leaching fraction. The contents of copper, iron, zinc, and chloride in silages responded in a quadratic way. The use of brackish water, especially the 15% leaching fraction, in the cultivation of sorghum enhances the mineral contents and the recovery of some macro- and micro-nutrients after the ensiling process.

Grasses doi: 10.3390/grasses2020006

Authors: Ruka Kiyama Yoshitaka Uchida

In large hayfields belonging to intensive dairy systems, satellite remote-sensing data can be useful to determine the hayfield yield and quality efficiently. In this study, we compared the land survey data of hayfield yield, and its quality parameters such as crude protein and neutral detergent fiber digestibility (NDF), with the Sentinel-2 satellite image data for thirteen hayfield paddocks in Kamishihoro region, Hokkaido, Japan. Commonly used indices derived from the satellite image data, including the Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI), were used to assess the hayfield yield and quality. In this region, hayfields are usually harvested twice yearly, in early summer (first harvest) and late summer (second harvest). As result, the Sentinel-2 data could predict the pasture growth and quality for the first harvest better than those for the second harvest. The EVI and the index based on the bands B8a and B7 were the best predictors for the biomass and NDF for the first harvest, respectively. However, the satellite-image-based predictors were not found for the second harvest. Towards the second harvest season, the color of the hayfield surface became more heterogeneous because of the flowering of weeds and uneven pasture growth, which made it challenging to predict pasture growth based on the remote-sensing data. Our land survey approach (quadrat-based sampling from a small area) should also be improved to compare the remote-sensing data and the pasture with uneven growth.

Grasses doi: 10.3390/grasses2010005

Authors: Carlindo S. Rodrigues Luís H. A. de Matos Douglas dos S. Pina Vagner M. Leite Paula de A. Silva Robério R. Silva Taiala C. de J. Pereira Henry D. R. Alba Gleidson G. P. de Carvalho

Nitrogen (N) is a nutrient used worldwide in pasture fertilization. However, it is a very volatile element. Furthermore, inappropriate use promotes environmental pollution and economic losses. The present study was carried out to evaluate the effects of the N source on the productivity and N utilization efficiency in Xaraés grass (Brachiaria brizantha cv. Xaraés) under tropical conditions. The randomized complete block design was used in a 3 × 2 × 4 factorial scheme: three seasons (rainy, dry, and transition), two N sources (fast-release = conventional urea, and slow-release = treated urea), and four N doses (0, 80, 160, and 240 kg N/ha/year). Forage accumulation per day differed (p < 0.0001) with the season and N dose. The interaction between those showed a positive linear effect (p < 0.0001) during the rainy season and transition. With increasing N doses, there was a linear increase in annual dry matter production and N accumulation. However, the N utilization efficiency (p < 0.0001) was reduced. Nitrogen sources did not affect forage accumulation and N utilization efficiency. Therefore, it is not recommended to replace fast-release nitrogen fertilization (conventional urea source) with a urease inhibitor (slow-release N source), promoting benefits with lower production costs.

Grasses doi: 10.3390/grasses2010004

Authors: Huakun Zhou Xiaoyuan Yang Chenyu Zhou Xinqing Shao Zhengchen Shi Honglin Li Hongye Su Ruimin Qin Tao Chang Xue Hu Fang Yuan Shan Li Zhonghua Zhang Li Ma

The alpine grasslands of the Qinghai–Tibet Plateau are one of the most famous grazing ecosystems in the world, providing a variety of ecosystem functions and services. The rate of grassland degradation has been slowed by the implementation of national grassland restoration projects, but the degradation of grasslands on the Qinghai–Tibet Plateau has not yet been fundamentally reversed, and some grasslands are still degraded to varying degrees. The main causes of grassland degradation on the Qinghai–Tibet Plateau are both human and natural factors. Human factors include overgrazing, over-cultivation, indiscriminate digging and mining, mineral resource development, infrastructure construction and use, and tourism development. Natural factors include climate change, wildlife destruction, pests, etc. Based on the principles of restoration ecology, a number of effective practices and integrated management responses for restoring degraded grasslands have been developed on the Qinghai–Tibet Plateau. The degraded grassland restoration practices include fencing, fertilization, sown grassland establishment, rodent control, and grazing management. Based on these practices, the comprehensive restoration of degraded grasslands and the establishment and sustainable management of sown grasslands in the alpine grasslands of the Qinghai–Tibet Plateau should be further strengthened, and research on the mechanisms of grassland degradation and restoration should be further developed.

Grasses doi: 10.3390/grasses2010003

Authors: Clara Fariña Valeria Aramayo Daiana Perri Valeria Martín Albarracín Fernando Umaña Octavio Augusto Bruzzone Marcos H. Easdale

Distinguishing the contributions of different vegetation cover such as shrubs and grasses components into the primary production in arid and semi-arid rangelands is a key step to understanding changes at a landscape scale. The aim was to assess the contribution of shrubs, grasses and bare soil components into a total biophysical variable at a patch level, and the relationship between that biophysical variable and remote sensing vegetation index, in a grass–shrub steppe from North-West Patagonia, Argentina. We conducted a field survey in the period 2015–2017 to analyzing the relationship between monthly values of Normalized Difference Vegetation Index (NDVI) of two grasses, two shrub species and bare soil, weighted by their cover area at a patch level, and the concomitant patch NDVI records, respectively. The contribution of the patch components to the total NDVI value at a patch level was additive. The relationship between the weighted NDVI of patch components and the concomitant NDVI value at a patch level along time was linear for perennial grasses and deciduous shrub–grass patches, but linearity was not significant for most perennial shrub–grass patches. Differences among patch compositions and their surface reflectance suggest the need to move forward in a more precise distinction of the floristic composition of patches, to better understanding their contribution to NDVI temporal dynamics at a landscape scale.

Grasses doi: 10.3390/grasses2010002

Authors: Fernando H. Oreja Mateo Stempels Elba B. de la Fuente

Large crabgrass (Digitaria sanguinalis) is one of the most problematic weeds in summer crops in Argentina. Emergence throughout the season of several cohorts allows the weed to escape postemergence control. Demographic models are useful tools to understand and compare the effect of different agronomic management decisions on weed population growth, as well as to identify critical functional stages that affect population growth rates. The objectives of this work were (i) to study population dynamics of D. sanguinalis in soybean, (ii) to determine the effect of glyphosate application timing on weed demographic parameters and soybean yield losses, and (iii) to evaluate the effect of weed density on soybean yield loss. A field experiment was conducted in two locations, in a completely randomized design with three replicates. Treatments included a control without glyphosate and glyphosate applied at soybean stages V4 or R1. The demographic stages (initial seedbank, seedlings, and adult plants) and parameters (establishment, survival, and fecundity) were estimated. Reproductive organs were evaluated in each cohort, including raceme per plant, spikelets per raceme, and seeds per spikelet. Weed and crop biomass and yield crop were assessed at harvest. Three cohorts were identified, the first of which emerged in November and contributed 93% of the total seedlings and 71% of the total adults. Glyphosate applied at V4 reduced the survival rate of the first cohort, as well as the total shoot biomass and the fecundity rate, increasing the biomass and crop grain yield. Both application timings affected tillers per plant, racemes per tiller, and fertile spikelets per raceme. Glyphosate at R1 did not effectively reduce weed competition, but reduced seed production as application at V4. Yield losses estimated with the model of the rectangular hyperbola according to weed density showed a yield loss at low densities (I) of 18%, and a maximum yield loss (A) of 82%. To avoid yield losses, herbicide applications targeting the first cohort are more effective than later applications targeting subsequent cohorts. However, at both times glyphosate applications reduced the number of seeds entering the seedbank, and therefore the population growth rate.

Grasses doi: 10.3390/grasses2010001

Authors: Raquel Souza Ricardo Edvan Larissa Fontes Tairon Dias e Silva Alex da Silva Marcos Araújo Rafael Miranda Ronaldo Oliveira Elzania Pereira Evyla Andrade José Pereira Filho Leilson Bezerra

The objective of this study was to evaluate the morphological characteristics, yield and chemical composition of grasses in degraded areas subjected to pasture recovery methods. The randomized block design in a factorial scheme (4 × 5) with four replications (blocks) was used. The first factor was composed of four methods of pasture recovery: Closed pasture (CLP); Weed control (WC); Soil fertilization (SF); and Weed control + Soil fertilization (WC + SF). The second factor was composed of five species used for pasture recovery: Brachiaria brizantha cv. Marandu, Brachiaria brizantha cv. MG5, Brachiaria brizantha cv. MG4, Andropogon gayanus cv. Planaltina and Panicum maximum cv. Mombaça. The structural characteristics of green biomass yield, dry biomass yield and chemical composition were assessed in those grasses. An effect of the interaction (p < 0.05) between forage species and recovery methods on number of clumps, plant height and clump diameter, with superiority for cultivar MG4 in the WC + SF method. The green biomass yield was low in the evaluated grasses because of the advanced stage of the degradation of the pastures. Dry biomass yields increased (p < 0.05) when the WC + SF method was adopted, with a good response of grass MG4. There was an interaction (p < 0.05) between species and recovery methods on dry matter, mineral matter and neutral detergent fiber contents of the grasses, especially Marandu grass. The different types of grasses responded positively to the methods of pasture recovery with increased biomass and nutritional quality.

Grasses doi: 10.3390/grasses1010005

Authors: Cristina Pornaro Alberto Novello Micheal Fidanza Stefano Macolino

For aesthetic considerations, grass clippings are removed from lawns during mowing. When turfgrass clippings are returned, this practice is called “mulching” or grasscycling. Thus, grasscycling has increasingly become a standard practice for low-input lawns managed under a simpler maintenance system, and grasscycling has many environmental benefits. Primarily, grasscycling facilitates an increase in soil nitrogen content and soil carbon sequestered by the turfgrass ecosystem. Several studies reported that grasscycling positively influences turfgrass colour and quality. When clippings are returned, turfgrass colour and quality can be maintained with a lower amount of fertilisation than turfgrass with clipping removal. Together with these positive effects, grasscycling practices can contribute to an increase of thatch in the turfgrass sward, while its influence on weed invasion is still questionable. This grasscycling practice can result in a maintenance cost-savings and represent a low-input approach to turfgrass management in terms of nutrients returned and utilised by the turfgrass, and with carbon (C) emissions mitigated and C sequestered. The unwelcome appearance linked to grass clipping residues and vegetation on the turfgrass canopy can be easily obviated by the use of machinery that delivers clippings forcefully toward the ground to incorporate them into the verdure or by using mowers that produce clippings small enough to be returned and quickly decomposed.

Grasses doi: 10.3390/grasses1010004

Authors: Fabio Gresta

As Editor-in-Chief, I am very proud to announce the launch of Grasses (ISSN: 2813-3463) [...]

Grasses doi: 10.3390/grasses1010003

Authors: Jefferson Santana da Silva Carneiro Rubson da Costa Leite José Moisés Ferreira Junior Álvaro José Gomes de Faria Sérgio Henrique Godinho Silva Antonio Clementino dos Santos Rubens Ribeiro da Silva

Most Brazilian pastures are in some stage of degradation, either by the reduction of soil fertility or inadequate management. The objective of this study was to diagnose the stage of pasture degradation and the diagnosis and management of the spatial variability of available phosphorus (P) and potassium (K+). A total of 100 soil samples were collected at a depth of 0–20 cm for available P and K+ contents determination. Geostatistical analyses of the obtained data were carried out to produce maps of the spatial distribution of available P and K+, using kriging, and allow the recommendation of fertilizers doses. The cost/benefit ratio of fertilizer recommendation and application was evaluated at fixed and variable rates. The different stages of pasture degradation were directly related to the reduction of soil fertility, as well as to the adopted management. The variability of soil available P and K+ presented spatial dependence, and the pattern of distribution resulted in the stage of the pasture degradation. The diagnosis of the level of pasture degradation associated with the use of geostatistical techniques under a precision agriculture perspective favors the efficient use of fertilizers, as well as correct decision-making and cost reduction regarding soil management.

Grasses doi: 10.3390/grasses1010002

Authors: Zhenyin Bai Aomei Jia Dongwei Liu Chengyu Zhang Mingjun Wang

The Sanjiang Plain is famous for its concentrated distribution of natural wet grasslands. These wet grasslands are an important source of seasonal pasture or hay in the area. However, changes in community structure and ecosystem function have already occurred in wet grasslands because of overgrazing and climate change, resulting in severe grassland degradation. Exploring a reasonable grazing management strategy is crucial for improving grassland species diversity, increasing grassland productivity, and maintaining sustainable grassland utilization. We investigated the effects of five grazing management (GM) strategies (no grazing through the growing season (CK), spring grazing exclusion (Spr-GE), summer grazing exclusion (Sum-GE)), autumn grazing exclusion (Aut-GE), and grazing through the growing season (G)) on the productivity, community composition and structure of wet grasslands in the Sanjiang Plain under three grazing intensities (GI) (light (L), moderate (M), and heavy (H)). Results showed that Spr-GE and Sum-GE were beneficial in increasing total aboveground biomass (AGB), but decreased plant community diversity in Spr-GE due to increased intraspecies and interspecies competition. The exclusion of different seasonal grazings changed the composition of plant communities. At the level of functional groups and dominant species, Spr-GE had a significant effect on most functional groups and dominant species’ characteristics, while Aut-GE had little effect on most functional groups and dominant species’ characteristics. However, different functional groups and dominant species had different responses to seasonal grazing exclusion. In addition, under M, there were significantly improved grassland total AGB and PF AGB. The results indicated that Spr-GE with M may be an effective livestock-management strategy to protect grassland vegetation and community diversity, as well as to restore degraded grassland.

Grasses doi: 10.3390/grasses1010001

Authors: Leonard M. Lauriault Mark A. Marsalis Shad H. Cox Glenn C. Duff

Winter annual cereal forages perform well in semiarid, subtropical regions forming, a significant component of livestock operations for autumn through spring stocker cattle (Bos taurus) backgrounding in either grazeout or graze-grain systems; however, little information is available about their relative seasonal productivity and animal preference. Seasonal growth and regrowth under grazing and grazing preference of oat (Avena sativa), rye (Secale cereale), triticale (×Triticosecale rimpaui Wittm.), and wheat (Triticum aestivum) were compared over two years at New Mexico State University’s Rex E. Kirksey Agricultural Science Center at Tucumcari. Seasonlong (Nov–Apr) average forage dry matter yield was rye > oat > wheat > triticale (5.03, 4.44, 3.58, and 2.79 Mg ha−1, respectively; p < 0.0001). Rye also had greater average monthly growth than the other cereals, among which there was no difference (1.58, 1.05, 0.96, and 0.85 Mg ha−1 mo−1 for rye, oat, wheat, and triticale, respectively; p < 0.0331). Growth of ungrazed cereals was reduced in mid-winter and regrowth of grazed forage did not equal removal by growing cattle. When given a preference and allowed to deplete available forage, growing cattle preferred oat followed by rye, then wheat and triticale. Regrowth of grazed forage did not differ among cereals.