ABSTRACT Context. Under natural field conditions, plants confront the co-occurrence of stresses. A comprehensive insight into combined-stress tolerance is requisite to developing stress resilience in cultivars of oats (Avena sativa L.) for saline–alkaline soil. Aim. This study was undertaken to characterise diverse oat genotypes for seedling growth attributes under two saline and alkaline concentrations and under combined saline–alkaline conditions. Methods. We screened 105 accessions of the genus Avena with the following treatments: control, reverse osmosis water; moderate salinity (50 mM); high salinity (100 mM); moderate alkalinity (15 mM); high alkalinity (30 mM); combined moderate salinity–alkalinity (50 mM + 15 mM); and combined high salinity–alkalinity (100 mM + 30 mM). For saline treatments, NaCl and Na2SO4 salts were used in equimolar concentrations, and for alkaline treatments, NaHCO3 and Na2CO3. Key results. Analysis of variance showed significant (P ≤ 0.001) variation among treatments and genotypes. Principal component analysis revealed 83.3% of the total genetic variation accounted for in the first two principal components. Correlation analysis showed a significant positive correlation between final germination percentage and seedling vigour index. Stress tolerance index identified tolerant and sensitive oat genotypes under high saline and alkaline stress, and multi-trait stability analysis confirmed the stability of performance of some genotypes under the imposed treatments. Conclusions.According to the stress tolerance index and multi-trait stability analysis, genotypes IG-20-477, OS-377, IG-20-798 and IG-20-575 were found suitable for high saline–alkaline stress. Implications.The identified tolerant oat genotypes can be used as donors for the development of stress-resilient oat cultivars, and for generating mapping populations in oat.
抽象的上下文。在自然的田间条件下，植物面临着逆境的共存。对盐碱地燕麦品种的综合抗逆性研究是提高其抗逆性的必要条件。的目标。研究了不同燕麦基因型在盐碱两种浓度和盐碱复合条件下的幼苗生长特性。方法。采用反渗透水处理，筛选了105份苜蓿属植物;中等盐度(50 mM);高盐度(100 mM);中等碱度(15mm);高碱度(30mm);中盐碱度组合(50 mM + 15 mM);高盐碱性组合(100mm + 30mm)。盐水处理采用等摩尔浓度的NaCl和Na2SO4盐，碱性处理采用NaHCO3和Na2CO3盐。关键的结果。方差分析显示不同处理和基因型间差异显著(P≤0.001)。主成分分析表明，前两个主成分占总遗传变异的83.3%。相关分析表明，最终发芽率与幼苗活力指数呈极显著正相关。胁迫耐受性指标鉴定出高盐、高碱胁迫下耐受性和敏感性的燕麦基因型，多性状稳定性分析证实部分基因型在高盐、高碱胁迫下表现稳定。结论。根据抗逆性指数和多性状稳定性分析，筛选出适合高盐碱胁迫的基因型为IG-20-477、OS-377、IG-20-798和IG-20-575。的影响。鉴定出的耐受性燕麦基因型可作为抗逆性燕麦品种开发的供体，并可用于建立燕麦的定位群体。
{"title":"Salinity, alkalinity and their combined stress effects on germination and seedling growth attributes in oats (Avena sativa)","authors":"Shahid Ahmed, Richa Patel, Rajesh Kumar Singhal, Neeraj Kumar, Maneet Rana, Indu I, Subhash Chand, Amaresh Chandra","doi":"10.1071/CP22322","DOIUrl":"https://doi.org/10.1071/CP22322","url":null,"abstract":"ABSTRACT Context. Under natural field conditions, plants confront the co-occurrence of stresses. A comprehensive insight into combined-stress tolerance is requisite to developing stress resilience in cultivars of oats (Avena sativa L.) for saline–alkaline soil. Aim. This study was undertaken to characterise diverse oat genotypes for seedling growth attributes under two saline and alkaline concentrations and under combined saline–alkaline conditions. Methods. We screened 105 accessions of the genus Avena with the following treatments: control, reverse osmosis water; moderate salinity (50 mM); high salinity (100 mM); moderate alkalinity (15 mM); high alkalinity (30 mM); combined moderate salinity–alkalinity (50 mM + 15 mM); and combined high salinity–alkalinity (100 mM + 30 mM). For saline treatments, NaCl and Na2SO4 salts were used in equimolar concentrations, and for alkaline treatments, NaHCO3 and Na2CO3. Key results. Analysis of variance showed significant (P ≤ 0.001) variation among treatments and genotypes. Principal component analysis revealed 83.3% of the total genetic variation accounted for in the first two principal components. Correlation analysis showed a significant positive correlation between final germination percentage and seedling vigour index. Stress tolerance index identified tolerant and sensitive oat genotypes under high saline and alkaline stress, and multi-trait stability analysis confirmed the stability of performance of some genotypes under the imposed treatments. Conclusions.According to the stress tolerance index and multi-trait stability analysis, genotypes IG-20-477, OS-377, IG-20-798 and IG-20-575 were found suitable for high saline–alkaline stress. Implications.The identified tolerant oat genotypes can be used as donors for the development of stress-resilient oat cultivars, and for generating mapping populations in oat.","PeriodicalId":51237,"journal":{"name":"Crop & Pasture Science","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41468874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Tozer, Emma Noakes, G. Douglas, R. Greenfield, C. Cameron
ABSTRACT Context. Tagasaste (Cytisus proliferus), a fast-growing leguminous tree, has potential to supplement pasture production in steep-hill country and to increase pasture resilience. Aims. In the companion paper, we quantified tagasaste production characteristics. Here, we determine the effect of proximity of 10-year-old tagasaste trees on productivity of eight pasture species including grasses (perennial ryegrass, Lolium perenne; cocksfoot, Dactylis glomerata; prairie grass, Bromus willdenowii; microlaena, Microlaena stipoides), perennial legumes (white clover, Trifolium repens; red clover, T. pratense; lotus, Lotus pedunculatus), and an annual legume (subterranean clover, T. subterraneum). Methods. A site was established in the East Coast region of the North Island of New Zealand on steep-hill country (>20° slope). Herbage production, nutritive value and survival of pasture species established as spaced transplants were measured over 3 years. Results. Cocksfoot had high survival, herbage production and metabolisable energy content but was negatively affected by proximity to tagasaste. Microlaena was not significantly affected by proximity to tagasaste; however, it was much less productive and had lower nutritive values than the other grasses. Only 40% of perennial ryegrass transplants survived 3 years, and survival of perennial legumes was negligible. Subterranean clover was able to set seed in the open and in shade. Conclusions. Cocksfoot was the most productive grass species, and microlaena was least affected by proximity to tagasaste. Given the poor persistence of perennial clovers, annual clovers may be better suited to a tagasaste silvopasture on steep, dry hillsides. Implications. Mixtures of cocksfoot and subterranean clover may be well suited to summer-dry hillsides, between and under trees in a tagasaste silvopasture. Microlaena may provide some forage and can maintain groundcover despite shade.
{"title":"Tagasaste silvopastures in steep-hill country. 2. Effect of increasing proximity to tagasaste on growth and survival of companion pasture species","authors":"K. Tozer, Emma Noakes, G. Douglas, R. Greenfield, C. Cameron","doi":"10.1071/cp22224","DOIUrl":"https://doi.org/10.1071/cp22224","url":null,"abstract":"ABSTRACT Context. Tagasaste (Cytisus proliferus), a fast-growing leguminous tree, has potential to supplement pasture production in steep-hill country and to increase pasture resilience. Aims. In the companion paper, we quantified tagasaste production characteristics. Here, we determine the effect of proximity of 10-year-old tagasaste trees on productivity of eight pasture species including grasses (perennial ryegrass, Lolium perenne; cocksfoot, Dactylis glomerata; prairie grass, Bromus willdenowii; microlaena, Microlaena stipoides), perennial legumes (white clover, Trifolium repens; red clover, T. pratense; lotus, Lotus pedunculatus), and an annual legume (subterranean clover, T. subterraneum). Methods. A site was established in the East Coast region of the North Island of New Zealand on steep-hill country (>20° slope). Herbage production, nutritive value and survival of pasture species established as spaced transplants were measured over 3 years. Results. Cocksfoot had high survival, herbage production and metabolisable energy content but was negatively affected by proximity to tagasaste. Microlaena was not significantly affected by proximity to tagasaste; however, it was much less productive and had lower nutritive values than the other grasses. Only 40% of perennial ryegrass transplants survived 3 years, and survival of perennial legumes was negligible. Subterranean clover was able to set seed in the open and in shade. Conclusions. Cocksfoot was the most productive grass species, and microlaena was least affected by proximity to tagasaste. Given the poor persistence of perennial clovers, annual clovers may be better suited to a tagasaste silvopasture on steep, dry hillsides. Implications. Mixtures of cocksfoot and subterranean clover may be well suited to summer-dry hillsides, between and under trees in a tagasaste silvopasture. Microlaena may provide some forage and can maintain groundcover despite shade.","PeriodicalId":51237,"journal":{"name":"Crop & Pasture Science","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58705793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sunil Kumar, A. Dixit, Tejveer Singh, Mukesh Choudhary, S. R. Kantwa
ABSTRACT Context. In developing countries there is a preference to grow food crops rather than forage. However, suitable food–fodder based systems ensure year-round green fodder availability for profitable livestock production. Aims. This study aimed to determine whether including single cut Egyptian clover (SEC) in the existing cropping systems could improve system productivity, forage availability and economic returns. Method. Nine SEC based cropping systems were tested in a randomised complete block design with three replications. Key results. Sorghum–SEC–wheat (late sown) cropping system produced 18% greater wheat equivalent yield compared with a popularly adopted sorghum–wheat system (8.9 Mg ha−1). The water productivity (1.80 kg m−3) of this system was also improved in the sorghum–multi-cut Egyptian clover system (1.74 kg m−3). There was a marginal increase in dry matter yield and crude protein content of the succeeding sorghum crop when it was rotated with Egyptian clover. The inclusion of Egyptian clover also improved the soil organic carbon (23%) and available nitrogen (15%) compared with cereal–cereal systems. The findings identify a sustainable intensification option in the sorghum-based cropping system with short duration Egyptian clover (single cut) as an economically feasible and ecologically effective approach. Conclusion. Integration of single cut Egyptian clover in sorghum–wheat rotation as a catch crop recorded greater system productivity, water-use efficiency and economic returns to achieve the sustainable crop intensification. Implication. The SEC can be an effective option for diversification and intensification of cropping systems to improve fodder availability, yield, boost income and improve soil health.
{"title":"Inclusion of Egyptian clover improves the value of sorghum-based cropping systems","authors":"Sunil Kumar, A. Dixit, Tejveer Singh, Mukesh Choudhary, S. R. Kantwa","doi":"10.1071/cp22139","DOIUrl":"https://doi.org/10.1071/cp22139","url":null,"abstract":"ABSTRACT Context. In developing countries there is a preference to grow food crops rather than forage. However, suitable food–fodder based systems ensure year-round green fodder availability for profitable livestock production. Aims. This study aimed to determine whether including single cut Egyptian clover (SEC) in the existing cropping systems could improve system productivity, forage availability and economic returns. Method. Nine SEC based cropping systems were tested in a randomised complete block design with three replications. Key results. Sorghum–SEC–wheat (late sown) cropping system produced 18% greater wheat equivalent yield compared with a popularly adopted sorghum–wheat system (8.9 Mg ha−1). The water productivity (1.80 kg m−3) of this system was also improved in the sorghum–multi-cut Egyptian clover system (1.74 kg m−3). There was a marginal increase in dry matter yield and crude protein content of the succeeding sorghum crop when it was rotated with Egyptian clover. The inclusion of Egyptian clover also improved the soil organic carbon (23%) and available nitrogen (15%) compared with cereal–cereal systems. The findings identify a sustainable intensification option in the sorghum-based cropping system with short duration Egyptian clover (single cut) as an economically feasible and ecologically effective approach. Conclusion. Integration of single cut Egyptian clover in sorghum–wheat rotation as a catch crop recorded greater system productivity, water-use efficiency and economic returns to achieve the sustainable crop intensification. Implication. The SEC can be an effective option for diversification and intensification of cropping systems to improve fodder availability, yield, boost income and improve soil health.","PeriodicalId":51237,"journal":{"name":"Crop & Pasture Science","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58705622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jackson Nkoh Nkoh, Peng Guan, Ren-yong Shi, Ruhai Wang, Jiu‐yu Li, R. Xu
ABSTRACT Context. Carbon (C) and nitrogen (N) transformation processes in soils play an important role in the fluctuation of soil pH. Incorporation of chitosan and crop straws, byproducts from fishery and agriculture, into acidic soils can increase soil pH through decarboxylation, decomposition, N immobilisation and ammonification. Aims. The study was designed to evaluate the transformation of organic N and C from chitosan and/or crop straws and their effects on soil physicochemical properties. Methods. Chitosan, rice straw and maize straw were incubated with two acidic Ultisols from Langxi (Soil 1) and Yingtan (Soil 2) differing in initial pH. Six treatments were prepared in triplicate: control (no amendment), 4% chitosan, 4% rice straw, 4% maize straw, 2% chitosan + 2% rice straw, and 2% chitosan + 2% maize straw. Soil pH, N transformation and CO2 evolution were estimated at different time intervals. Key results. After 40 days of incubation, control soil pH decreased by 0.35 and 0.32 units for Soils 1 and 2, respectively. Rice straw, maize straw, chitosan, rice straw–chitosan and maize straw–chitosan significantly increased soil pH by 0.51, 0.17, 2.27, 1.78 and 2.02 units for Soil 1, and 0.71, 0.16, 0.67, 0.49 and 0.68 units for Soil 2 (P < 0.01). The respective treatments decreased exchangeable acidity by 62%, 51%, 95%, 95% and 95% for Soil 1 and 75%, 69%, 88%, 88% and 87% for Soil 2. In treatments containing chitosan, the pH increase resulted from ammonification of organic N and mineralisation of organic C, with the effect higher in Soil 1 than Soil 2. Conclusions. Amending acidic soils with chitosan and crop residues can effectively increase soil pH and slow soil acidification rate. Implications. This study provides useful information for amelioration of acidic soils.
{"title":"Role of carbon and nitrogen mineralisation of chitosan and crop straws in ameliorating acidity of acidic Ultisols","authors":"Jackson Nkoh Nkoh, Peng Guan, Ren-yong Shi, Ruhai Wang, Jiu‐yu Li, R. Xu","doi":"10.1071/cp23088","DOIUrl":"https://doi.org/10.1071/cp23088","url":null,"abstract":"ABSTRACT Context. Carbon (C) and nitrogen (N) transformation processes in soils play an important role in the fluctuation of soil pH. Incorporation of chitosan and crop straws, byproducts from fishery and agriculture, into acidic soils can increase soil pH through decarboxylation, decomposition, N immobilisation and ammonification. Aims. The study was designed to evaluate the transformation of organic N and C from chitosan and/or crop straws and their effects on soil physicochemical properties. Methods. Chitosan, rice straw and maize straw were incubated with two acidic Ultisols from Langxi (Soil 1) and Yingtan (Soil 2) differing in initial pH. Six treatments were prepared in triplicate: control (no amendment), 4% chitosan, 4% rice straw, 4% maize straw, 2% chitosan + 2% rice straw, and 2% chitosan + 2% maize straw. Soil pH, N transformation and CO2 evolution were estimated at different time intervals. Key results. After 40 days of incubation, control soil pH decreased by 0.35 and 0.32 units for Soils 1 and 2, respectively. Rice straw, maize straw, chitosan, rice straw–chitosan and maize straw–chitosan significantly increased soil pH by 0.51, 0.17, 2.27, 1.78 and 2.02 units for Soil 1, and 0.71, 0.16, 0.67, 0.49 and 0.68 units for Soil 2 (P < 0.01). The respective treatments decreased exchangeable acidity by 62%, 51%, 95%, 95% and 95% for Soil 1 and 75%, 69%, 88%, 88% and 87% for Soil 2. In treatments containing chitosan, the pH increase resulted from ammonification of organic N and mineralisation of organic C, with the effect higher in Soil 1 than Soil 2. Conclusions. Amending acidic soils with chitosan and crop residues can effectively increase soil pH and slow soil acidification rate. Implications. This study provides useful information for amelioration of acidic soils.","PeriodicalId":51237,"journal":{"name":"Crop & Pasture Science","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58706451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pasture legumes play a key role in productive and sustainable livestock production systems. Pasture legumes produce feed for livestock that generally has high nutritive value and symbiotic biological nitrogen (N) fixation is a major source of N for pasture-based livestock production. However, there are challenges to find pasture legumes species and cultivars that are productive and persistent in the broad range of climates, soil types and management systems across Australia. The Australian Grassland Association (AGA) research symposium ‘Pasture legumes for sustainable productive systems’ addressed these challenges. The symposium was held at the University of Western Australia in Perth during 4–6 July 2023. The symposium covered themes on the use of legume and mixed pastures in changing and variable climates, developing new pasture legumes and future directions for pasture legume research. This Special Issue of Crop & Pasture Science presents the key scientific papers from the symposium. The important role that pasture legumes have played in the pastoral industries of New Zealand was reviewed by Moot (2023), who highlighted that understanding the genotype, environment and management interactions was key to successful integration of legume on farms. The interactions between genotypes and the environment were further explored in relation to flowering time of important pasture legumes (Haling et al. 2023; Goward et al. 2023). Exploring the production and persistence of pasture legumes under variable climates was a focus of the symposium. Stutz et al. (2023) evaluated the role of summer active legumes to support livestock finishing systems in southern Australia and finding that lucerne was the most reliable option on suitable soil types, but some alternative species were worthy of further investigation. Smith et al. (2023) provided a comprehensive review of the potential role for strawberry clover. Hardseededness breakdown patterns (Newell et al. 2023) and persistence of pasture legumes (Hayes et al. 2023) were explored in south-eastern Australia where again the importance of understanding the phenology and seed characteristics was highlighted. Pasture legume improvement was an important theme of the symposium. The development of sterile leucaena to reduce weed risk was reported by Real et al. (2023). An approach to overcome physiological seed dormancy in annual legumes to assist with speed breeding of pastures was described (Peck et al. 2023). Badgery et al. (2023) reviewed the role that pasture legumes and herbs can have in reducing enteric methane emissions from ruminant animals, highlighting an important future research area in pasture-based livestock production. This was the sixth in a series of AGA research symposia following on from the ‘Australian Legume Symposium’ (2012), ‘Perennial Grasses in Pasture Production Systems’ (2014), ‘Livestock Productivity from Pastures’ (2017), ‘Soil Constraints to Pasture Productivity’ (2019), and ‘Resilience i
牧草豆科植物在生产性和可持续畜牧业生产系统中发挥着关键作用。牧草豆科植物为牲畜提供饲料，通常具有较高的营养价值，共生生物固氮是放牧牲畜生产的主要氮源。然而，在澳大利亚各地广泛的气候、土壤类型和管理制度下，寻找具有生产力和持久性的牧场豆科植物物种和栽培品种是一项挑战。澳大利亚草原协会(AGA)研究研讨会“可持续生产系统的牧场豆科植物”解决了这些挑战。研讨会于2023年7月4日至6日在珀斯的西澳大利亚大学举行。研讨会的主题包括:在变化多变的气候条件下利用豆科植物和混合牧草，开发新的豆科牧草和豆科牧草研究的未来方向。本期《作物与牧场科学》特刊收录了本次研讨会的主要科学论文。Moot(2023)回顾了牧场豆科植物在新西兰畜牧业中发挥的重要作用，他强调了解基因型、环境和管理的相互作用是豆科植物在农场成功整合的关键。进一步探讨了基因型与环境的相互作用与重要牧草豆科植物开花时间的关系(Haling et al. 2023;Goward et al. 2023)。探讨不同气候条件下牧草豆科植物的产量和持久性是研讨会的一个重点。Stutz等人(2023)评估了夏季活性豆科植物在支持南澳大利亚牲畜育肥系统中的作用，并发现在合适的土壤类型上，苜蓿是最可靠的选择，但一些替代物种值得进一步调查。Smith等人(2023)对草莓三叶草的潜在作用进行了全面的综述。在澳大利亚东南部研究了牧草豆科植物的硬种分解模式(Newell et al. 2023)和持久性(Hayes et al. 2023)，再次强调了了解物候和种子特性的重要性。牧草豆科作物改良是本次研讨会的一个重要主题。Real等人(2023)报道了开发无菌合欢草以降低杂草风险。介绍了一种克服一年生豆科植物种子生理休眠的方法，以帮助牧场快速繁殖(Peck et al. 2023)。Badgery等人(2023)回顾了牧草豆类和草本植物在减少反刍动物肠道甲烷排放方面的作用，强调了以牧草为基础的畜牧业生产中一个重要的未来研究领域。这是继“澳大利亚豆科植物研讨会”(2012年)、“牧场生产系统中的多年生草”(2014年)、“牧场的牲畜生产力”(2017年)、“土壤对牧场生产力的制约”(2019年)和“面对变化的弹性-未来牧场”(2021年)之后，AGA系列研究研讨会的第六次。AGA的成立是为了促进以牧场为基础的工业的持续改进和发展。这是通过提供一个论坛来实现的，该论坛汇集了广泛的行业利益相关者，以便:
{"title":"Australian Grassland Association research symposium 2023: pasture legumes for sustainable productive systems","authors":"B. Cullen","doi":"10.1071/CP23162","DOIUrl":"https://doi.org/10.1071/CP23162","url":null,"abstract":"Pasture legumes play a key role in productive and sustainable livestock production systems. Pasture legumes produce feed for livestock that generally has high nutritive value and symbiotic biological nitrogen (N) fixation is a major source of N for pasture-based livestock production. However, there are challenges to find pasture legumes species and cultivars that are productive and persistent in the broad range of climates, soil types and management systems across Australia. The Australian Grassland Association (AGA) research symposium ‘Pasture legumes for sustainable productive systems’ addressed these challenges. The symposium was held at the University of Western Australia in Perth during 4–6 July 2023. The symposium covered themes on the use of legume and mixed pastures in changing and variable climates, developing new pasture legumes and future directions for pasture legume research. This Special Issue of Crop & Pasture Science presents the key scientific papers from the symposium. The important role that pasture legumes have played in the pastoral industries of New Zealand was reviewed by Moot (2023), who highlighted that understanding the genotype, environment and management interactions was key to successful integration of legume on farms. The interactions between genotypes and the environment were further explored in relation to flowering time of important pasture legumes (Haling et al. 2023; Goward et al. 2023). Exploring the production and persistence of pasture legumes under variable climates was a focus of the symposium. Stutz et al. (2023) evaluated the role of summer active legumes to support livestock finishing systems in southern Australia and finding that lucerne was the most reliable option on suitable soil types, but some alternative species were worthy of further investigation. Smith et al. (2023) provided a comprehensive review of the potential role for strawberry clover. Hardseededness breakdown patterns (Newell et al. 2023) and persistence of pasture legumes (Hayes et al. 2023) were explored in south-eastern Australia where again the importance of understanding the phenology and seed characteristics was highlighted. Pasture legume improvement was an important theme of the symposium. The development of sterile leucaena to reduce weed risk was reported by Real et al. (2023). An approach to overcome physiological seed dormancy in annual legumes to assist with speed breeding of pastures was described (Peck et al. 2023). Badgery et al. (2023) reviewed the role that pasture legumes and herbs can have in reducing enteric methane emissions from ruminant animals, highlighting an important future research area in pasture-based livestock production. This was the sixth in a series of AGA research symposia following on from the ‘Australian Legume Symposium’ (2012), ‘Perennial Grasses in Pasture Production Systems’ (2014), ‘Livestock Productivity from Pastures’ (2017), ‘Soil Constraints to Pasture Productivity’ (2019), and ‘Resilience i","PeriodicalId":51237,"journal":{"name":"Crop & Pasture Science","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44367657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Context and aims. Freshly harvested seeds of temperate annual pasture legume species have physiological dormancy (PD), which delays the growth of the next generation and is thus an impediment to speed breeding. The aim of this study was to develop a method or methods of PD breaking that can achieve high germination (≥90%) within 5 days of picking freshly harvested seed. Methods. In a series of experiments, PD breaking methods by themselves and in combination were tested on burr medic (Medicago polymorpha). The most promising methods were then tested on other annual medic species (Medicago spp.), subterranean clover (Trifolium subterraneum), and alternative species from six genera. Key results. The successful PD breaking method involved drying pods overnight at 45°C, extracting and scarifying seed, placing seed on filter paper in a Petri dish along with non-dormant seed, imbibing seed with 4 μM benzylaminopurine, sealing the Petri dish, and incubating in the dark at 15°C. Highly dormant genotypes required the additional treatment of removing the testa. Conclusions. We have developed an effective way of breaking seed PD in the 11 pasture legumes species from the seven genera tested. The rapid breaking of seed PD will assist speed breeding of annual pasture legumes, making it less laborious and time-bound than currently used methods. Implications. The PD breaking methods are expected to assist basic science studies of annual pasture legume species and may be applicable to other species and genera.
{"title":"Development of methods to overcome physiological seed dormancy of temperate annual pasture legumes to assist speed breeding","authors":"D. Peck, A. Humphries, R. Ballard","doi":"10.1071/CP22314","DOIUrl":"https://doi.org/10.1071/CP22314","url":null,"abstract":"ABSTRACT Context and aims. Freshly harvested seeds of temperate annual pasture legume species have physiological dormancy (PD), which delays the growth of the next generation and is thus an impediment to speed breeding. The aim of this study was to develop a method or methods of PD breaking that can achieve high germination (≥90%) within 5 days of picking freshly harvested seed. Methods. In a series of experiments, PD breaking methods by themselves and in combination were tested on burr medic (Medicago polymorpha). The most promising methods were then tested on other annual medic species (Medicago spp.), subterranean clover (Trifolium subterraneum), and alternative species from six genera. Key results. The successful PD breaking method involved drying pods overnight at 45°C, extracting and scarifying seed, placing seed on filter paper in a Petri dish along with non-dormant seed, imbibing seed with 4 μM benzylaminopurine, sealing the Petri dish, and incubating in the dark at 15°C. Highly dormant genotypes required the additional treatment of removing the testa. Conclusions. We have developed an effective way of breaking seed PD in the 11 pasture legumes species from the seven genera tested. The rapid breaking of seed PD will assist speed breeding of annual pasture legumes, making it less laborious and time-bound than currently used methods. Implications. The PD breaking methods are expected to assist basic science studies of annual pasture legume species and may be applicable to other species and genera.","PeriodicalId":51237,"journal":{"name":"Crop & Pasture Science","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46746230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michael Fitzgerald, Deirdre Harvey, J. Friedl, D. Rowlings, J. Condon, W. Dougherty
ABSTRACT Context. Dairy pasture production is reliant on fertiliser to supply nitrogen (N); however, fertiliser N-use efficiency (FNUE) is low and N can be lost to the environment. Aims. The aim of this study was to track the fate of N fertiliser applied in a pasture system of ryegrass (Lolium multiflorum, temperate grass) oversown into kikuyu (Pennisetum clandestinum, tropical grass). Methods. We used 15N-labelled urea to track the residual plant uptake of a one-off application of 15N over three pasture cuts subsequent to the first cut in the kikuyu growing season from February 2018 to April 2018 (Experiment 1), followed by total soil and plant recoveries of 15N over a 12-month period (Experiment 2). Total N treatment rates were 0, 120, 240 and 480 kg N ha−1 year−1, consisting of application events of 40 kg N ha−1. In Experiment 1, 15N was applied only at the first fertilisation, whereas in Experiment 2, 15N-labelled urea was applied at each fertilisation event. Key results. In Experiment 1, uptake of residual 15N fertiliser in the pasture biomass was <6%. In Experiment 2, FNUE was 29–32% and unaccounted 15N fertiliser was 22–142 kg N ha−1, across the 120, 240 and 480 kg N ha−1 year−1 treatments. Conclusions. Recovery of 15N residual fertiliser did not increase with N rate and was attributed to the mass increase in soil 15N recovery. FNUE in the pasture did not decrease with N rate. Unaccounted 15N increased with N rate. Implications. Existing and alternative N and pasture management strategies such as clover and multi-species pasture need to be implemented and explored to reduce the amount of unaccounted N in dairy pasture production.
{"title":"Fate of fertiliser nitrogen in a ryegrass–kikuyu dairy pasture system","authors":"Michael Fitzgerald, Deirdre Harvey, J. Friedl, D. Rowlings, J. Condon, W. Dougherty","doi":"10.1071/cp22410","DOIUrl":"https://doi.org/10.1071/cp22410","url":null,"abstract":"ABSTRACT Context. Dairy pasture production is reliant on fertiliser to supply nitrogen (N); however, fertiliser N-use efficiency (FNUE) is low and N can be lost to the environment. Aims. The aim of this study was to track the fate of N fertiliser applied in a pasture system of ryegrass (Lolium multiflorum, temperate grass) oversown into kikuyu (Pennisetum clandestinum, tropical grass). Methods. We used 15N-labelled urea to track the residual plant uptake of a one-off application of 15N over three pasture cuts subsequent to the first cut in the kikuyu growing season from February 2018 to April 2018 (Experiment 1), followed by total soil and plant recoveries of 15N over a 12-month period (Experiment 2). Total N treatment rates were 0, 120, 240 and 480 kg N ha−1 year−1, consisting of application events of 40 kg N ha−1. In Experiment 1, 15N was applied only at the first fertilisation, whereas in Experiment 2, 15N-labelled urea was applied at each fertilisation event. Key results. In Experiment 1, uptake of residual 15N fertiliser in the pasture biomass was <6%. In Experiment 2, FNUE was 29–32% and unaccounted 15N fertiliser was 22–142 kg N ha−1, across the 120, 240 and 480 kg N ha−1 year−1 treatments. Conclusions. Recovery of 15N residual fertiliser did not increase with N rate and was attributed to the mass increase in soil 15N recovery. FNUE in the pasture did not decrease with N rate. Unaccounted 15N increased with N rate. Implications. Existing and alternative N and pasture management strategies such as clover and multi-species pasture need to be implemented and explored to reduce the amount of unaccounted N in dairy pasture production.","PeriodicalId":51237,"journal":{"name":"Crop & Pasture Science","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58705905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shengjing Shi, S. Wakelin, E. Gerard, S. Young, C. van Koten, J. Caradus, A. Griffiths, R. Ballard, M. O’Callaghan
ABSTRACT Context. Biological nitrogen (N) fixation through the rhizobia–legume symbiosis is a sustainable and cost-effective source of N for agriculture. In New Zealand (NZ), white clover (Trifolium repens) is a key component of pastures and rhizobial inoculation of clover is widely used. The current commercial inoculant for white clover, TA1, was isolated in Australia in the 1950s and may not be the best partner for modern white clover cultivars. Aims. To identify Rhizobium leguminosarum bv. trifolii (Rlt) isolates suitable for use in NZ pastures. Methods. The symbiotic potential of >230 isolates collected from throughout NZ was evaluated in plant bioassays. Selected isolates were further evaluated in pot and field trials. Key results. Approximately 40% of NZ isolates supported better clover growth than TA1 under N-limited conditions in vitro. Of 24 Rlt isolates evaluated in a glasshouse trial, five produced significantly higher clover biomass than TA1. Three (S11N9, S20N7, S4N6) of nine isolates evaluated in two field trials in 2018–2019 significantly increased clover growth (12–38%) compared with paired uninoculated clover at several harvests, whereas inoculation with TA1 did not improve yield. In a third trial in 2020, S11N9 and S20N7 increased clover growth compared with the uninoculated control at two of three harvests; S4N6 performed better than TA1 at one harvest. When tested with four white clover cultivars, five Rlt isolates had higher symbiotic potential than TA1. Conclusions. Inoculating white clover would be beneficial if improved inoculant isolates were available. Implications. We recommend some NZ Rlt isolates could be developed into commercial inoculants to improve white clover performance in NZ.
{"title":"Screening and field evaluation of white clover rhizobia for New Zealand pastures","authors":"Shengjing Shi, S. Wakelin, E. Gerard, S. Young, C. van Koten, J. Caradus, A. Griffiths, R. Ballard, M. O’Callaghan","doi":"10.1071/cp22405","DOIUrl":"https://doi.org/10.1071/cp22405","url":null,"abstract":"ABSTRACT Context. Biological nitrogen (N) fixation through the rhizobia–legume symbiosis is a sustainable and cost-effective source of N for agriculture. In New Zealand (NZ), white clover (Trifolium repens) is a key component of pastures and rhizobial inoculation of clover is widely used. The current commercial inoculant for white clover, TA1, was isolated in Australia in the 1950s and may not be the best partner for modern white clover cultivars. Aims. To identify Rhizobium leguminosarum bv. trifolii (Rlt) isolates suitable for use in NZ pastures. Methods. The symbiotic potential of >230 isolates collected from throughout NZ was evaluated in plant bioassays. Selected isolates were further evaluated in pot and field trials. Key results. Approximately 40% of NZ isolates supported better clover growth than TA1 under N-limited conditions in vitro. Of 24 Rlt isolates evaluated in a glasshouse trial, five produced significantly higher clover biomass than TA1. Three (S11N9, S20N7, S4N6) of nine isolates evaluated in two field trials in 2018–2019 significantly increased clover growth (12–38%) compared with paired uninoculated clover at several harvests, whereas inoculation with TA1 did not improve yield. In a third trial in 2020, S11N9 and S20N7 increased clover growth compared with the uninoculated control at two of three harvests; S4N6 performed better than TA1 at one harvest. When tested with four white clover cultivars, five Rlt isolates had higher symbiotic potential than TA1. Conclusions. Inoculating white clover would be beneficial if improved inoculant isolates were available. Implications. We recommend some NZ Rlt isolates could be developed into commercial inoculants to improve white clover performance in NZ.","PeriodicalId":51237,"journal":{"name":"Crop & Pasture Science","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58706221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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