Grassland Research最新文献

{"title":"Breeding for drought tolerance in perennial ryegrass (Lolium perenne L.) and tall fescue (Lolium arundinaceum [Schreb.] Darbysh.) by exploring genotype by environment by management interactions","authors":"Claudio C. Fernandes Filho,&nbsp;Mario H. Murad Leite Andrade,&nbsp;Jose A. Rodrigues Nunes,&nbsp;Joseph Wipff,&nbsp;Debra L. Hignight,&nbsp;Esteban F. Rios,&nbsp;Kevin Kenworthy,&nbsp;Kenneth Hignight","doi":"10.1002/glr2.12045","DOIUrl":"https://doi.org/10.1002/glr2.12045","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Drought-tolerant turfgrass cultivars are becoming more important each year as landscape irrigation practices are becoming more restrictive.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>In this study, we quantified the level of drought tolerance (DT) in perennial ryegrass and tall fescue genotypes across years under different mowing (MH) and fertility (FL) rates. A total of 48 ryegrass and 38 tall fescue genotypes were planted in 2011 at NexGen, Albany, OR. The trial was divided into three subtrials: (i) DT; (ii) MH and DT; and (iii) FL and DT.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The results showed that there was significant genetic variance for most of the traits in both species. The genotype × year interaction was predominantly simple, indicating small changes in genotype ranking for both species. Lower MH improved DT in perennial ryegrass, whereas higher MH resulted in greater DT in tall fescue. For both species, higher MH improved the population mean for turf quality. Higher FL inputs led to higher turf quality for both species, but it did not affect the DT response.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Using a selection index, six genotypes for perennial ryegrass and four for tall fescue were selected.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"2 1","pages":"22-36"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12045","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50116406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts of fire suppression on above-ground carbon stock and soil properties in Borana rangelands, southern Ethiopia","authors":"Kenea Feyisa,&nbsp;Sheleme Beyene,&nbsp;Ayana Angassa","doi":"10.1002/glr2.12043","DOIUrl":"https://doi.org/10.1002/glr2.12043","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Fire is a natural disturbance that releases carbon back into the atmosphere. Pastoralists have used fire for many thousands of years for rangeland management. The use of fire in the Borana rangelands of southern Ethiopia was a common practice to improve the productivity of the rangelands. However, the use of fire as a tool to manage rangeland was prohibited by government policy in the early 1970s.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>In this study, we assessed the long-term impacts of fire suppression on aboveground carbon stocks of woody and herbaceous biomass, soil organic carbon stocks, and total nitrogen stocks at burned versus adjacent unburned areas in the Borana rangelands of southern Ethiopia. The investigation was conducted in two locations: Dikale and Sanke. The upland location was represented by Dikale, while the bottomland location was represented by Sanke. Each study site was replicated three times, with burned versus adjacent unburned areas representing each replicate. Soil samples were collected in three soil depths (0–5, 5–15, and 15–30 cm), while vegetation attributes were collected from 60 plots within three burned and three adjacent unburned sites in each landscape.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The soil organic carbon stock and pooled carbon stock between burned and unburned sites across the two landscapes showed minimal variation. The above-ground carbon biomass accumulation for woody and herbaceous plants did not show any significant difference between burned and unburned sites both at the bottomland and upland areas. The total nitrogen contents recorded at uplands in burned sites were significantly (<i>p</i> &lt; 0.05) higher than the total nitrogen stocks for the unburned adjacent sites.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Burned areas accumulated relatively more carbon stocks in terms of herbaceous biomass (3.27 ± 0.43 Mg ha⁻¹) than the adjacent unburned areas (0.98 ± 0.43 Mg ha⁻¹). The results of the current study suggest that burning improved the carbon sequestration potential of herbaceous plants in arid savanna ecosystems.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"2 1","pages":"1-14"},"PeriodicalIF":0.0,"publicationDate":"2023-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50136455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feed profile analysis of oil palm-integrated beef cattle farming systems by metabolic energy budgeting and implications for beef production and pastoral system design","authors":"Januarius Gobilik,&nbsp;Hasbudie Baco,&nbsp;Mohd. Azid Kabul,&nbsp;Suhaimi Dollah,&nbsp;Stephen T. Morris,&nbsp;Cory Matthew","doi":"10.1002/glr2.12044","DOIUrl":"https://doi.org/10.1002/glr2.12044","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Oil palm is a tropical crop with worldwide plantings approaching 20 million ha and large areas in Indonesia, Malaysia and Thailand. The plantations are readily managed as silvopastoral systems incorporating cattle grazing (Oil Palm Silvopastoral System for Cattle, OPSC) but there is a need for analytical tools and data to understand system herbage supply and feed conversion efficiency (FCE).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Metabolic energy budgeting was used to estimate herbage harvested by cattle in three OPSC subsystems, 9 and 12 years after oil palm establishment, and FCE of the subsystems was determined. Understorey herbage was also analysed for nutritive value, botanical composition and herbage accumulation within one grazing-regrowth cycle.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The herbage-harvested estimate was 2.0−2.4 t dry matter (DM) ha⁻¹ year⁻¹ for 9 year old subsystems and 1.4−1.7 t DM ha⁻¹ year⁻¹ for a 12 year old subsystem. Herbage metabolisable energy (ME) was 8.3−8.5 MJ kg⁻¹ DM and crude protein (CP) was 15%−16% DM. FCE values for subsystems ranged from 32 to 94 kg DM kg⁻¹ liveweight-gain.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Herbage DM yield is declining, while herbage ME is marginal but CP is adequate. FCE is suboptimal but can be optimised by defining the trajectory of declining herbage production with canopy closure as plantations age and matching stocking rate to herbage supply using a comparative-stocking-rate-type statistic.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"2 1","pages":"56-68"},"PeriodicalIF":0.0,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12044","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50135418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of alfalfa fall dormancy using spaced plant and sward trials across multiple environments","authors":"Scott A. Newell,&nbsp;Daniel J. Undersander,&nbsp;Donald Viands,&nbsp;Julie Hansen,&nbsp;Steve Orloff,&nbsp;Daniel H. Putnam,&nbsp;E. Charles Brummer","doi":"10.1002/glr2.12042","DOIUrl":"https://doi.org/10.1002/glr2.12042","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Alfalfa is a globally important forage crop. Cultivars are characterized by fall dormancy (FD). FD affects biomass yield and winter survival and is used to identify appropriate growing regions of cultivars. It has historically been assessed by measuring the natural height of regrowth in autumn of spaced plants in the field. Because commercial alfalfa is normally grown as a solid planted sward, FD could be different if plants were grown under real production conditions. The objective of this experiment was to assess whether FD ratings obtained from swards were similar to those obtained on spaced plants.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We evaluated 20 alfalfa cultivars in field trials established in 2015 at five locations in the United States. We harvested the trials in early autumn and measured regrowth plant height approximately 3 weeks later in 2015 and 2016.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Autumn plant height responded as expected for the established check cultivars in all locations. Fall dormancy ratings for cultivars under both management systems were highly correlated.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Estimating FD from spaced plant height measurements in autumn is very robust, and using height data from sward plots gives equivalent results to that measured in spaced plant nurseries. This finding has many practical advantages.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"2 1","pages":"15-21"},"PeriodicalIF":0.0,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12042","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50148012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Management of re-established artificial grasslands via grazing or fencing: Effects on plant and soil properties","authors":"Jing Cao,&nbsp;Yiping Chen,&nbsp;Yao Jiang,&nbsp;Jingshu Chen,&nbsp;Junhua Wu","doi":"10.1002/glr2.12039","DOIUrl":"https://doi.org/10.1002/glr2.12039","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Revegetation is widely used in degraded grassland restoration. However, the responses of grassland plant and soil properties to fencing (FC) and grazing (GZ) remain poorly understood, especially the vegetation–soil coupling coordination (<i>C</i>_d) mechanism. This study explored single and interactive responses of vegetation and soil properties under FC and GZ after revegetation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A field experiment with FC and GZ treatments was conducted in Loess Plateau reconstructed grassland, with degraded grassland as the control (CK). Plant and soil properties and <i>C</i>_d were analyzed using the analytic hierarchy process (AHP) and principal component analysis (PCA).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The order of soil comprehensive evaluation (SCE) was GZ &gt; FC &gt; CK, while that of vegetation comprehensive evaluation (VCE) was FC &gt; GZ &gt; CK. The <i>C</i>_d of CK was 0.39 (mild imbalance), while the values of FC and GZ were 0.57 and 0.54, respectively (little coordination). The VCE/SCE of FC was 1.48 (soil lag type), and the values of GZ and CK were 0.69 and 0.35, respectively (vegetation lag and vegetation loss type, respectively).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Both GZ and FC improved <i>C</i>_d and facilitated recovery. However, degraded grasslands should be restored via moderate grazing for sustainable ecological and economic development.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"2 1","pages":"69-83"},"PeriodicalIF":0.0,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12039","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50134963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of sowing methods on nitrogen compounds and protease activities of whole-crop wheat silage","authors":"Liuxing Xu,&nbsp;Guojian Tang,&nbsp;Dan Wu,&nbsp;Jianguo Zhang","doi":"10.1002/glr2.12041","DOIUrl":"https://doi.org/10.1002/glr2.12041","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Whole-crop wheat (<i>Triticum aestivum</i>) has high nutritive value, and it has become one of the main sources of roughage for ruminants in some countries or regions. This study investigates the effects of no tillage on nitrogen compounds and protease activities of whole-crop wheat silage.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Wheat was planted on the 9th day (NB9) and 5th day (NB5) before rice harvest and on the first day after rice harvest. Sowing before harvest involved no tillage and sowing after rice harvest involved either no tillage (NA1) or conventional tillage (CK).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Compared to CK, the crude protein content of NB9 and NB5 decreased by 16.4% and 9.58%, respectively. With the delay of the sowing date, the contents of non-protein nitrogen, rapidly degraded protein, and slowly degraded protein in whole-plant wheat tended to increase. Compared to NA1 wheat silage, the NH₃-N content of NB9 and NB5 silages decreased by 52.7% and 34.4%, respectively. The acid protease activity of NA1 was significantly higher than that of other treatments (<i>p</i> &lt; 0.05).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>There was no significant difference in the degree of protein degradation between NA1 and CK silages. Although the degree of protein degradation in early sowing was low, the degree of fermentation was also weak.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"2 1","pages":"46-55"},"PeriodicalIF":0.0,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12041","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50151084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Leaf gas exchange characteristics, biomass partitioning, and water use efficiencies of two C4 African grasses under simulated drought","authors":"Kevin Z. Mganga,&nbsp;Jana Kuhla,&nbsp;Andrea Carminati,&nbsp;Johanna Pausch,&nbsp;Mutez A. Ahmed","doi":"10.1002/glr2.12040","DOIUrl":"https://doi.org/10.1002/glr2.12040","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Few studies have evaluated the effect of drought on the morpho-physiological characteristics of African C₄ grasses. We investigated how drought affects leaf gas exchange characteristics, biomass partitioning, and water use efficiencies of <i>Enteropogon macrostachyus</i> and <i>Cenchrus ciliaris</i>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The grasses were grown in a controlled environment under optimum conditions, that is, 70% of the maximum water-holding capacity (WHC) for the first 40 days. Thereafter, half of the columns were maintained under optimum or drought conditions (30% of maximum WHC) for another 20 days.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Under optimum conditions, <i>C. ciliaris</i> showed a significantly higher photosynthetic rate, stomatal conductance, and transpiration rate than <i>E. macrostachyus</i>. Drought decreased the photosynthetic rate, stomatal conductance and transpiration rate only in <i>C. ciliaris</i>. The net photosynthetic rate, stomatal conductance, and leaf transpiration of <i>E. macrostachyus</i> did not differ significantly under optimum and drought conditions. <i>E. macrostachyus</i> showed an increase in its water use efficiencies under drought to a greater extent than <i>C. ciliaris</i>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results demonstrate that <i>C. ciliaris</i> is more sensitive to drought than <i>E. macrostachyus</i>. The decrease in the intercellular CO₂ concentration and the increase in stomatal limitation with drought in <i>C. ciliaris</i> and <i>E. macrostachyus</i> suggest that stomatal limitation plays the dominant role in photosynthesis of the studied African C₄ grasses.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"2 1","pages":"37-45"},"PeriodicalIF":0.0,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12040","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50118173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal variations in nutritive and botanical composition properties of multispecies grazing swards over an entire dairy grazing season","authors":"Ciarán Hearn,&nbsp;Michael Egan,&nbsp;Mary Bridget Lynch,&nbsp;Christina Fleming,&nbsp;Michael O'Donovan","doi":"10.1002/glr2.12037","DOIUrl":"10.1002/glr2.12037","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Recently, there has been increasing interest in the use of multispecies (MS) swards in dairy grazing systems.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A plot grazing study was established to investigate the potential contribution of different sward species (perennial ryegrass, legumes and herbs) sown in grazing pastures. Ten sward mixtures were sown, ranging in complexity from a perennial ryegrass (PRG) monoculture to binary mixtures including either forage legumes or herbs to a five-species mixture; four different nitrogen (N) application rates of 0, 100, 150 and 200 kg N ha⁻¹ were applied to each sward.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Species abundance for all sward species components was associated with the interaction of time point and sward mixture; species abundance for all sward components, except PRG, was associated with the interaction of N application and sward mixture. The interactions of time point and sward mixture, and time point and N application rate, were associated with all analysed sward chemical components, except for sward digestibility.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Increased N application rates reduced the level of clover in all sward mixtures. Increased levels of white clover led to increased sward crude protein levels; the inclusion of ribwort plantain led to some seasonal variation in the nutritive value of swards.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 4","pages":"221-233"},"PeriodicalIF":0.0,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85241224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving bermudagrass in the Southeastern United States with alfalfa as an alternative nitrogen source in grazing systems","authors":"Justin C. Burt,&nbsp;Lisa L. Baxter,&nbsp;Christopher G. Prevatt,&nbsp;Mary Kimberly Mullenix,&nbsp;R. Lawton Stewart Jr.,&nbsp;Jennifer J. Tucker","doi":"10.1002/glr2.12038","DOIUrl":"https://doi.org/10.1002/glr2.12038","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Bermudagrass (<i>Cynodon</i> spp.) is one of the most common perennial warm-season forages grown in the Southeastern United States. The incorporation of alfalfa (<i>Medicago sativa</i>) into bermudagrass pastures could serve as an alternative source of nitrogen (N) while also improving the nutritive value of the forage base.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A 2-year grazing evaluation arranged in a randomized complete block design was conducted from May to September 2018 (Year 1) and May–August 2019 (Year 2) in Tifton, GA, USA. The objective was to compare the production of alfalfa–bermudagrass mixed pastures (BGA) with bermudagrass monoculture pastures with (BGN) or without (BG) the application of synthetic nitrogen on forage production and stocker cattle performance.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Differences were observed for average daily gain (<i>p</i> = 0.10), gain per hectare (<i>p</i> = 0.02) and stocking rate (<i>p</i> = 0.01), in that BGA was greatest compared to BGN and BG, which did not differ from each other. Furthermore, BGA had increased forage crude protein (<i>p</i> = 0.01) and total digestible nutrients (<i>p</i> = 0.01) compared to BGN and BG. Finally, BGA provided the greatest economic return per hectare compared to BG or BGN.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These data illustrate improved animal performance and forage nutritive value using alfalfa–bermudagrass systems and offer a viable option for producers seeking alternatives to synthetic N sources for bermudagrass pastures in the Southeastern United States.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 4","pages":"280-289"},"PeriodicalIF":0.0,"publicationDate":"2023-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12038","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137698805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Switchgrass sward establishment selection is consistent across multiple environments and fertilization levels","authors":"Neal W. Tilhou,&nbsp;Michael D. Casler","doi":"10.1002/glr2.12035","DOIUrl":"10.1002/glr2.12035","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Strong selection can occur during switchgrass sward establishment. Differences in establishment selection due to environment or management could provide information on genotype-by-environment variation and could influence strategies for breeding perennial grasses.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Leaf samples were collected before sward establishment and from 3-year-old swards for two breeding groups (lowland and hybrid) at three locations. Within two locations, samples were collected from paired fertilized (112 kg N ha⁻¹) and unfertilized plots. Allele frequencies from pooled DNA samples were studied through multivariate analysis of variance, genomewide trait predictions (heading date and winter survivorship), and genomically estimated breeding values (GEBVs) for individual sward survival within an independent data set.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>This study found only minor variations in selection due to location or management. Predicted heading dates of the hybrid population had significant changes due to fertilization and location. There were strong correlations among sward establishment survival GEBVs between growing environments (hybrid <i>r</i> = 0.77; gulf <i>r</i> = 0.97). Interestingly, this study found a small number of genotypes that were over-represented in established swards across all growing environments.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study reinforces a prior report of selection during sward establishment and indicates that only a small degree of establishment selection is location-specific within these diverse growing conditions.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 4","pages":"252-261"},"PeriodicalIF":0.0,"publicationDate":"2023-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12035","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76613841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}