Grass and Forage Science最新文献

{"title":"Canopy leaf area and leaf mass in the upper stratum of Urochloa hybrid ‘Mavuno’ grass subjected to nitrogen fertilisation","authors":"Raíne Fonseca de Mattos,&nbsp;Caroline Megumi Matuo,&nbsp;Valdo Rodrigues Herling,&nbsp;Adriano Rogério Bruno Tech,&nbsp;Lilian Elgalise Techio Pereira","doi":"10.1111/gfs.12614","DOIUrl":"https://doi.org/10.1111/gfs.12614","url":null,"abstract":"<p>Nitrogen (N) inputs are recognised to maximise herbage mass (HM) in tropical perennial grasses, whereas less is clear on their impact on HM distribution and the effects on leaf mass (LM) and leaf area index (LAI) in the upper stratum. This 2 year study, carried out in Pirassununga, Brazil, assessed the HM distribution in the upper (&gt;20 cm) and lower (&lt;20 cm) strata in <i>Urochloa</i> hybrid ‘Mavuno’ grass maintained under similar pre- and post-cutting canopy heights with contrasting N fertilisation rates applied after each cutting (no-nitrogen, 15, 30, and 45 kg N ha⁻¹). The relevance of specific leaf area (SLA), leaf N concentration (NLeaf), tiller weight (TW) and population density to the LM and LAI of the upper stratum were also examined. Mavuno grass expressed a stable HM &lt; 20 cm (59%–71% during Year I and 66%–80% for Year II), and apparent N fertilisation impacts on HM &gt; 20 cm were verified at specific regrowth cycles during Year II. Mavuno grass pastures expressed plasticity for adjustments on leaf, tiller and population attributes, which were modulated by both climatic conditions and N fertilisation. Under favourable growth conditions during Year I, fertilised pastures were able to sustain higher NLeaf and SLA but associated with lower TW, resulting in maximisation of LAI but not in LM in the upper stratum. During Year II, fertilised pastures expressed higher NLeaf, SLA, number of basal tillers, despite the lowest TW, which resulted in higher LAI and LM in the upper stratum compared with non-fertilised pastures. Our results highlighted that adjustments on leaf and population attributes within the canopy were driven to maximise the upper stratum LAI, being positively affected by N fertilisation.</p>","PeriodicalId":12767,"journal":{"name":"Grass and Forage Science","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50147680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of slurry application techniques on nitrous oxide emission from temperate grassland under varying soil and climatic conditions","authors":"John Kormla Nyameasem,&nbsp;Reiner Ruser,&nbsp;Christof Kluß,&nbsp;Christoph Essich,&nbsp;Mareike Zutz,&nbsp;Martin ten Huf,&nbsp;Caroline Buchen-Tschiskale,&nbsp;Heinz Flessa,&nbsp;Hans-Werner Olfs,&nbsp;Friedhelm Taube,&nbsp;Thorsten Reinsch","doi":"10.1111/gfs.12612","DOIUrl":"10.1111/gfs.12612","url":null,"abstract":"<p>The effect of slurry application techniques and slurry N stabilizing strategies on nitrous oxide emission from grasslands is poorly understood and, therefore, can result in large uncertainties in national/regional inventories. Field experiments were, thus, conducted to estimate the effect of different fertilization techniques on nitrous oxide (N₂O) emissions. Fertilizer was applied (135–270 kg N ha⁻¹ year⁻¹) as calcium ammonium nitrate (CAN), untreated or treated cattle slurry. The slurry was either treated with sulfuric acid (target pH = 6.0), applied using trailing shoes or treated with 3,4-dimethyl pyrazole phosphate and applied via slot injection. N₂O fluxes were sampled using the closed chamber technique. Cumulative N₂O emissions ranged 0.1–2.9 kg N ha⁻¹ year⁻¹ across the treatment, sites and years. The N application techniques showed inconsistent effects on soil mineral N content, cumulative N₂O emission and N yield. The fertilizer replacement value of slurry was low due to low N use efficiencies at the sites. However, a close positive relationship (<i>r</i> = 0.5; <i>p</i> = .013) between slurry value and biomass yield was observed, highlighting the benefit of high slurry value on crop productivity. N₂O-N emission factors were low for all treatments, including CAN, but were 2–6 times higher in 2019 than in 2020 due to lower precipitation in 2020. Variations in N₂O emission were largely explained by soil and climatic factors. Even with the low N₂O emissions, this study highlights the benefit (significant mitigation of N₂O emissions) of replacing the increasingly expensive chemical fertilizer N with input from slurry under favourable conditions for denitrification.</p>","PeriodicalId":12767,"journal":{"name":"Grass and Forage Science","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gfs.12612","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46305593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Forage intake and nitrogen metabolism of beef cattle grazing palisadegrass-calopo mixed pasture managed using canopy light interception","authors":"Jacqueline dos Santos Oliveira,&nbsp;Luis Depablos,&nbsp;Bruno Grossi Costa Homem,&nbsp;Igor Machado Ferreira,&nbsp;Robert Michael Boddey,&nbsp;Adenilson José Paiva,&nbsp;Márcio André Stefanelli Lara,&nbsp;Daniel Rume Casagrande","doi":"10.1111/gfs.12613","DOIUrl":"10.1111/gfs.12613","url":null,"abstract":"<p>To define the best grazing management strategy, it is important to assess animals' responses to variations in the structure and composition of tropical forages. This 2-year study evaluated animal response to Marandu palisadegrass (<i>Urochloa brizantha</i>)-calopo (<i>Calopogonium mucunoides</i>) mixed pastures managed under rotational grazing. Treatments consisted of three defoliation frequencies defined by rest periods interrupted at 90% (90LI), 95% (95LI) and 100% (100LI) of photosynthetically active radiation interception (LI). The stubble post-grazing height target was 15 cm. Statistical difference was declared at <i>p &lt; .</i>10. The 100LI had lowest crude protein (CP) and in vitro dry matter digestibility (IVDDM) for the Marandu palisadegrass (<i>p =</i> &lt;.001 both) and calopo (<i>p =</i> .003 and <i>p =</i> .067, respectively). Also, the OM digestibility decreased 7.0% in the 100LI condition than 90LI and 95LI treatment (<i>p =</i> .005). There was no difference in forage, grass, and legume intakes between the treatments (<i>p &gt;</i> .10). The 100LI treatment decreased CP intake from grass in 33.3% (<i>p =</i> &lt;.001) compared to other treatments. Greatest production of microbial N (<i>p =</i> .093) occurred with the 90LI treatment. The CP/digestible organic matter (DOM) ratio, urinary N excretion and retained N were lowest in the 100LI treatment (<i>p =</i> &lt;.001, <i>p =</i> .007 and <i>p =</i> .014, respectively). The recommendation for grazing between 90 and 95% of LI is recommended because of greater CP intake and N utilization for the animals and improved the nutritive value of Marandu palisadegrass and calopo mixed pastures.</p>","PeriodicalId":12767,"journal":{"name":"Grass and Forage Science","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44278718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Re-ensiling effects on inoculated sorghum: Intake, apparent digestibility, nitrogen balance, and animal feeding behaviour","authors":"Flávia Cristina de Oliveira e Silva,&nbsp;Naiara Taís Alves da Silva,&nbsp;Joana Ribeiro da Glória,&nbsp;João Carlos de Freitas Alves,&nbsp;Ana Luiza da Costa Cruz Borges,&nbsp;Lúcio Carlos Gonçalves,&nbsp;José Avelino Santos Rodrigues,&nbsp;Diogo Gonzaga Jayme","doi":"10.1111/gfs.12611","DOIUrl":"10.1111/gfs.12611","url":null,"abstract":"<p>This study aimed to determine whether using inoculants and re-ensiling in sorghum silages affect the intake and feeding behaviour, apparent digestibility, digestible energy, and nitrogen balance of sheep in maintenance. Half the sorghum was inoculated on the day of harvest, and the other half received the same inoculation volume but with water. Sorghum was ensiled in 100 experimental metal drum silos of 200 L covered with plastic: 50 silos with inoculants and 50 without them. After 56 days, 25 drums with inoculants and 25 without were exposed to air for 48 h. The other silos remained closed. The treatments were arranged in a 2 × 2 factorial scheme with inoculation and re-ensiling. The sheep received the silages after 211 days of ensiling and 155 days of re-ensiling to determine the intake, apparent digestibility, and feeding behaviour of animals. The experimental design was a simultaneous double 4 × 4 Latin square. The re-ensiling process increased silage pH, N-NH₃.TN⁻¹, butyric acid, and propionic acid. The inoculant increased propionic acid in ensiled and re-ensiled silages. Lactic acid concentration presented a statistical interaction with the inoculated and ensiled silage, 58% higher than the other treatment averages. The ADFap digestibility showed a complex interaction, in which the control ensiled and the inoculated and re-ensiled silages were about 35% lower than the inoculated ensiled silage. The Nbal:Nint ratio (g.g⁻¹) in the inoculated and re-ensiled silage had lower nitrogen retention than intake compared with the other treatments. These results indicate that exposing inoculated silages to air does not compromise their use in sheep feeding.</p>","PeriodicalId":12767,"journal":{"name":"Grass and Forage Science","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48728679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Main ecological and environmental factors affecting forage yield and quality in alpine summer pastures (NW-Italy, Gran Paradiso National Park)","authors":"Andrea Mainetti,&nbsp;Simone Ravetto Enri,&nbsp;Marco Pittarello,&nbsp;Giampiero Lombardi,&nbsp;Michele Lonati","doi":"10.1111/gfs.12609","DOIUrl":"10.1111/gfs.12609","url":null,"abstract":"<p>Summer pastures in the European Alps play a crucial role in providing high quality forage for grazing livestock and encompass a wide variety of vegetation communities. The main issue of their management is the optimal exploitation of the available forage in relation to environmental constraints, aiming at obtaining the highest forage yield and quality from each vegetation community. In this work, we monitored six different vegetation communities characterized by contrasting topographic features and species compositions throughout the grazing season for two years. We performed botanical and phenological surveys, climate-related measurements, and herbage samplings to assess forage quantity and quality (i.e., digestibility and proximate composition, estimated by near-infrared reflectance spectroscopy). We analysed the influence of climatic, topographic, and vegetation variables on pasture herbage through univariate and multivariate analyses. The cover of wide-leaf grasses primarily promoted biomass production, which was in turn lowered by increasing elevation and slope. On the other hand, a minor effect on forage yield was observed for an increasing cover of sedges and rushes and mean temperatures. Climatic variables (especially water deficit) and advanced phenological stages were the main degrading factors of forage quality in terms of crude protein and digestibility, while enhancing fibre contents. At increasing cover of legumes, fibre content declined and digestibility increased consequently, while the abundance of other non-legume forbs played a significant role in lowering fibre content. Multivariate analysis highlighted the differing influence of single plant species on forage features even within the same functional species pool. However, attention should be paid to the toxicity and low palatability of some plants, especially forbs. Eutrophic vegetation communities, rich in wide-leaf grasses and legumes, could be maintained and enhanced through pastoral management to increase alpine pasture production and quality.</p>","PeriodicalId":12767,"journal":{"name":"Grass and Forage Science","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gfs.12609","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44237244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Agronomic and forage nutritive responses of Kentucky bluegrass dominated pastures in the northern Great Plains","authors":"David Toledo,&nbsp;Kendall Swanson,&nbsp;Miranda Meehan,&nbsp;Carl Dahlen,&nbsp;Rachael Christensen,&nbsp;Daniel Asplin","doi":"10.1111/gfs.12610","DOIUrl":"10.1111/gfs.12610","url":null,"abstract":"<p>Kentucky bluegrass (<i>Poa pratensis</i> L.) has become dominant in many portions of the northern Great Plains. During hot and/or dry periods, pastures consisting of mostly cool-season grasses will most likely lack the productivity and diversity needed to provide sufficient forage for livestock. Determining the impact of weather conditions on the variation of forage production and nutritive response of Kentucky bluegrass is becoming increasingly important to agricultural producers. Sampling occurred at the USDA Northern Great Plains Research Laboratory near Mandan, North Dakota, USA. Kentucky bluegrass samples were clipped every 2–3 weeks in mowed and unmowed unfertilized rangeland plots during the growing seasons of 2017 and 2018. Samples were dried, weighed, ground to pass a 1-mm sieve, and analysed for nutritive value. There are differences between the modelled supply of metabolizable energy and metabolizable protein and the requirements for cow-calf pairs for all years and most months. Early defoliation of Kentucky bluegrass decreases productivity and nutritive value as the grazing season progresses. Adjusting management to allow an adequate growth interval and plant canopy cover throughout the year can ensure a more consistent supply of Kentucky bluegrass. Our data and models provide a glimpse into future scenarios, which allow producers to be more proactive in dealing with Kentucky bluegrass and projected changes in climate.</p>","PeriodicalId":12767,"journal":{"name":"Grass and Forage Science","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49630571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving the accuracy of models to map alpine grassland above-ground biomass using Google earth engine","authors":"Yan Shi,&nbsp;Jay Gao,&nbsp;Gary Brierley,&nbsp;Xilai Li,&nbsp;George L. W. Perry,&nbsp;Tingting Xu","doi":"10.1111/gfs.12607","DOIUrl":"10.1111/gfs.12607","url":null,"abstract":"<p>Accurate modelling and mapping of alpine grassland aboveground biomass (AGB) are crucial for pastoral agriculture planning and management on the Qinghai Tibet Plateau (QTP). This study assessed the effectiveness of four popular models (traditional multiple linear regression (MLR), support vector machine (SVM), artificial neural network (ANN), and deep neural network (DNN)) with various input combinations (geospatial variables [GV], vegetation types [VT], field measurements [FM], meteorological variables [MV] and observation time [OT]) for AGB estimation based on a new framework for AGB modelling and mapping using Google Earth Engine. The results showed that the input feature of GV had a poor performance in AGB estimation (0.121 &lt; <i>R</i>² &lt; 0.591). FM improved the accuracy the most when incorporated with GV (0.815 &lt; <i>R</i>² &lt; 0.833). Although MV, VT and OT improved the accuracy (<i>R</i>²) only by 0.112–0.216 with an importance rank order of MV &gt; VT &gt; OT for machine learning models, their outputs could be used to map AGB. Grass AGB was less accurately predicted than shrub AGB, but the pooling of both VTs improved estimation accuracy (<i>R</i>²) by 0.171–0.269. The performance of the models followed the ranked order of DNN &gt; ANN &gt; SVM &gt; MLR. DNN had the highest accuracy (<i>R</i>² = 0.818) using all non-field measured variables (excluding FM) as the inputs, and it was successfully applied to a new dataset (not associated with the data used in the training and testing) with a <i>R</i>² of 0.676. This study presents an effective and operational framework for modelling and mapping grassland AGB. Accordingly, it provides the scientific foundations to determine of sustainable grazing carrying capacity in alpine grasslands.</p>","PeriodicalId":12767,"journal":{"name":"Grass and Forage Science","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gfs.12607","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41256729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The defoliation dynamics of a stockpiled native grassland pasture follow similar patterns between supplemented and unsupplemented beef calves","authors":"Fiorella Cazzuli,&nbsp;Carolina Bremm,&nbsp;Martín Jaurena,&nbsp;Dennis Poppi,&nbsp;Martín Durante,&nbsp;Marcelo Adolfo Benvenutti,&nbsp;Jean Victor Savian,&nbsp;Thais Devincenzi,&nbsp;Pablo Rovira,&nbsp;Ximena Lagomarsino,&nbsp;Andrés Hirigoyen,&nbsp;Fernando A. Lattanzi","doi":"10.1111/gfs.12608","DOIUrl":"10.1111/gfs.12608","url":null,"abstract":"<p>It is unclear to what extent and on which variables does supplementing beef cattle on native grasslands affect sward structure, specifically on the dynamics of its grazing horizons. Three hypotheses were tested: (i) during a grazing down process under similar forage allowance, supplemented animals take longer to finish each grazing stratum, than their unsupplemented counterparts, (ii) in both cases, the upper stratum will be heavily depleted before the subsequent strata are grazed, (iii) some species and/or forage fractions are consumed faster than others, regardless of the animals being supplemented (corn dried distillers grains with solubles, DDGS, at 0.7% of their body weight, BW, on a dry matter, DM, basis) or not. Three blocks of stockpiled native grasslands were used and split into two treatments plots (n = 6), on which either supplemented (S) or control (C) heifers of 10.6 ± 0.6 months of age and an initial BW of 143 ± 9 kg, were used. A 2.5 × 0.5 m observation grid was installed on the sward, generating 384 observation points on each plot. On these observation plots, sward height (SH) and visually assessed green forage mass percentage (%G) were registered every other day for 12 consecutive days. No differences were found between the horizontal grazing dynamics between supplemented and control animals in terms of how they switched from the upper grazing horizon to the successive ones. In both cases, when the upper grazing horizon was heavily depleted, the subsequent horizon was being depleted by its half. Differences of preference for C3 species over C4 was observed for both treatments, but this effect was more meaningful for control animals. Grazing time never fully compensated for the decline in intake rate during depletion throughout the grazing horizons. Pasture intake declined when the animals transition from grazing the top grazing horizons to the lower horizons, irrespective of the level of supplementation. Managing the sward structure in terms of sward height will be beneficial to maximizing individual animal performance, for both C and S animals. Native grasslands paddocks with a greater C3 gasses predominance will always be preferred to C4 dominated paddocks, regardless of an eventual supplementation practice.</p>","PeriodicalId":12767,"journal":{"name":"Grass and Forage Science","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42557471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stocking method effects on forage accumulation, canopy attributes, and nutritive value of grazed Mulato II brachiariagrass pastures","authors":"Otávio Goulart de Almeida,&nbsp;Carlos Guilherme Silveira Pedreira,&nbsp;Solange Garcia Holschuch,&nbsp;Gabriel Baracat Pedroso,&nbsp;Junior Issamu Yasuoka,&nbsp;Valdson José da Silva","doi":"10.1111/gfs.12606","DOIUrl":"10.1111/gfs.12606","url":null,"abstract":"<p>Rotational stocking (RS) is generally associated with the intensification of pasture-based animal production systems, although many studies have shown little advantage over continuous stocking (CS). The objective of this research was to describe and explain the effects of two average canopy heights (20 and 30 cm) and three stocking methods (CS; rotational stocking with lenient defoliation, RSL; and rotational stocking with moderate defoliation, RSM) on forage accumulation (FA), vertical distribution of plant-part components, and nutritive value of ‘Mulato II’ hybrid brachiariagrass (<i>Brachiaria</i> spp. syn. <i>Urochloa</i> spp.) during two summer rainy seasons in Piracicaba, São Paulo, Brazil. Pastures were maintained at average canopy height of 20 and 30 cm under CS, and treatments under RSL and RSM were imposed by variations of ±20 and 30% of the average canopy heights, representing defoliation intensities of 33 and 47% of the pre-graze heights, respectively. The FA was not affected by CS, RSL, RSM stocking methods, averaging 8090 kg DM ha⁻¹ year⁻¹. Canopy bulk density and distribution of plant-part components in the canopy profile were better at the average canopy height of 20 cm, accompanied by the greater nutritive value. The leaf bulk density was generally greater in RSM compared to CS. Pastures under CS had greater crude protein and in vitro digestible matter, and lesser neutral detergent fibre concentrations. Mulato II brachiariagrass should be managed at an average height of 20 cm under CS.</p>","PeriodicalId":12767,"journal":{"name":"Grass and Forage Science","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42229081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mixtures of grasses: An alternative to traditional pasture monocultures in the tropics","authors":"Cauby Medeiros-Neto,&nbsp;Rodrigo Amorim Barbosa,&nbsp;Daniel Schmitt,&nbsp;Tiago Miqueloto,&nbsp;Sila Carneiro da Silva,&nbsp;André Fischer Sbrissia","doi":"10.1111/gfs.12605","DOIUrl":"10.1111/gfs.12605","url":null,"abstract":"<p>A two-year experiment assessed herbage production and above- and below-ground characteristics of a highly productive monoculture (‘BRS Zuri’ guineagrass [<i>Panicum maximum</i> Jacq.]) and two mixtures of three grasses (Mixture 1: ‘BRS Zuri’ guineagrass, ‘BRS Xaraés’ palisadegrass [<i>Brachiaria brizantha</i> Stapf.], and ‘Basilisk’ signalgrass [<i>Brachiaria decumbens</i> Stapf.]; Mixture 2: ‘BRS Quênia’ guineagrass [<i>Panicum maximum</i> Jacq.], ‘Marandu’ palisadegrass [<i>Brachiaria brizantha</i> Stapf.], and ‘BRS Paiaguás’ palisadegrass [<i>Brachiaria brizantha</i> Stapf.]), cultivated in the Brazilian tropical savanna. Mixtures 1 and 2 were subjected to two grazing intensities (removal of 40 or 60% of pre-grazing height) and ‘BRS Zuri’ guineagrass monoculture was defoliated to a single grazing intensity of 50%. Treatments were randomly assigned to fifteen 0.25-ha plots and managed under intermittent stocking by cattle. Herbage accumulation rate was similar among pastures and years (<i>p</i> &gt; .1). The root mass in the tussocks did not differ (<i>p</i> &gt; .1), with mean values ranging between 0.62 to 1.81 kg DM m⁻². Root density in the tussock interspaces was greater in the mixtures (<i>p</i> &lt; .001), regardless of seasons (<i>p</i> = .405) and years (<i>p</i> = .292). The mixtures were dominated by guineagrass (70%) and palisadegrass (30%) at the end of the experiment, with the population of ‘Basilisk’ and ‘BRS Paiaguás’ being completely suppressed throughout the experimental period. Mixing guineagrass and brachiariagrasses can be an alternative to the traditional pastoral systems in the tropics, as it does not compromise herbage production and presents a capacity to produce more roots than a very productive monoculture of ‘BRS Zuri’ guineagrass.</p>","PeriodicalId":12767,"journal":{"name":"Grass and Forage Science","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42875603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}