Caroline Nicole Chappell, Marty Landon Marks, Katie Michelle Mason, Liliane Severino da Silva, Joshua Luke Jacobs, Mary Kimberly Mullenix, Sandra Leanne Dillard, Russell Brian Muntifering
Background
Native warm-season grass (NWSG) mixtures may provide a low-nitrogen (N)-input summer perennial forage option to extensively managed forage–livestock systems.
Methods
Mixed pastures of big bluestem (Andropogon gerardii Vitman), little bluestem (Schizachyrium scoparium Michx.), and indiangrass (Sorghastrum nutans L.) fertilized with 0 or 67 kg N ha−1 were continuously stocked with beef heifers and cows. Forage mass, nutritive value, and canopy heights were determined every 2 weeks during the grazing season. Stand persistence measures included the canopy cover and leaf area index (LAI) and plant crown density at spring emergence following 3 years of grazing management.
Results
Forage mass, canopy height, and stocking densities were greater for N-fertilized NWSG than unfertilized NWSG for the first 30 days of the growing season across the 3-year study. Forage NWSG fertilized with N had a greater decrease in LAI during the growing season (51% decrease) than unfertilized NWSG. Spring NWSG plant density estimates following 3 years of grazing did not differ across N management strategies.
Conclusions
Forage NWSG mixtures supported superior forage attributes and greater stocking densities early in the grazing season under low-level N than zero-N-input systems and may provide a low-N-input alternative for improved species use in southeastern US forage–livestock systems.
本地暖季草(NWSG)混合物可能为广泛管理的牧草-牲畜系统提供低氮(N)投入的夏季多年生饲料选择。方法采用大蓝茎(Andropogon gerardii Vitman)、小蓝茎(Schizachyrium scoparium Michx.)和印度草(Sorghastrum nutans L.)混合牧场，施肥0或67 kg N ha−1，连续放养肉牛和小母牛。放牧季节每2周测定一次牧草质量、营养价值和冠层高度。林分持久性测量包括3年放牧后林冠盖度、叶面积指数(LAI)和春季出苗期植物冠密度。结果在生长季的前30天，施氮的NWSG的饲料质量、冠层高度和载畜密度均大于未施氮的NWSG。与未施肥的NWSG相比，施氮的NWSG在生长季节的LAI下降幅度更大(下降51%)。放牧3年后的春季NWSG植物密度估计值在不同的氮管理策略下没有差异。结论在低氮条件下，牧草NWSG混合物在放牧季节早期比零氮输入系统具有更好的牧草属性和更高的放养密度，可能为改善美国东南部牧草-牲畜系统的物种利用提供低氮输入的替代方案。
{"title":"Forage production and persistence characteristics of grazed native warm-season grass mixtures with or without nitrogen fertilizer","authors":"Caroline Nicole Chappell, Marty Landon Marks, Katie Michelle Mason, Liliane Severino da Silva, Joshua Luke Jacobs, Mary Kimberly Mullenix, Sandra Leanne Dillard, Russell Brian Muntifering","doi":"10.1002/glr2.12028","DOIUrl":"10.1002/glr2.12028","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Native warm-season grass (NWSG) mixtures may provide a low-nitrogen (N)-input summer perennial forage option to extensively managed forage–livestock systems.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Mixed pastures of big bluestem (<i>Andropogon gerardii</i> Vitman), little bluestem (<i>Schizachyrium scoparium</i> Michx.), and indiangrass (<i>Sorghastrum nutans</i> L.) fertilized with 0 or 67 kg N ha<sup>−1</sup> were continuously stocked with beef heifers and cows. Forage mass, nutritive value, and canopy heights were determined every 2 weeks during the grazing season. Stand persistence measures included the canopy cover and leaf area index (LAI) and plant crown density at spring emergence following 3 years of grazing management.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Forage mass, canopy height, and stocking densities were greater for N-fertilized NWSG than unfertilized NWSG for the first 30 days of the growing season across the 3-year study. Forage NWSG fertilized with N had a greater decrease in LAI during the growing season (51% decrease) than unfertilized NWSG. Spring NWSG plant density estimates following 3 years of grazing did not differ across N management strategies.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Forage NWSG mixtures supported superior forage attributes and greater stocking densities early in the grazing season under low-level N than zero-N-input systems and may provide a low-N-input alternative for improved species use in southeastern US forage–livestock systems.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 3","pages":"157-165"},"PeriodicalIF":0.0,"publicationDate":"2022-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91456156","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}
Junbang Wang, Xinquan Zhao, Xihuang Ouyang, Liang Zhao, Wenying Wang, Chan Zuo, Zhenhua Zhang, Huakun Zhou, Alan Watson, Yingnian Li
Background
An accurate assessment of the carbon budget is a crucial part of projecting future climate change and its impact on ecosystems. Grasslands foster multiple ecological functions including support for wild animals and livestocks. Herbivores intake forage biomass carbon, then digest and metabolize, and finally retain some carbon. The carbon processes have not been well quantified, resulting in uncertainties in the estimation of regional carbon budgets for grassland ecosystems.
Methods
An animal metabolic carbon flux model was developed for herbivores in the Three-Rivers Headwaters region of China. The forage intake and metabolic carbon rates were estimated through metabolic body weight and daily digested measures for the main herbivore species.
Results
The carbon intake was 5.52 Tg C year−1 (45%) from partial aboveground biomass (12.2 Tg C year−1), in which 39.31% was released into the atmosphere by respiration CO2, 43.77% was returned to the ecosystem as feces and urine, and 16.96% was retained in herbivores for population regeneration or for human well-being.
Conclusions
This study, as the first research on this topic, quantified the carbon flux of herbivores and found livestock accounts for a major part of consumed carbon on grasslands, which is important for understanding regional carbon budgets to mitigate and adapt to climate change over grasslands worldwide.
{"title":"The role of herbivores in the grassland carbon budget for Three-Rivers Headwaters region, Qinghai–Tibetan Plateau, China","authors":"Junbang Wang, Xinquan Zhao, Xihuang Ouyang, Liang Zhao, Wenying Wang, Chan Zuo, Zhenhua Zhang, Huakun Zhou, Alan Watson, Yingnian Li","doi":"10.1002/glr2.12025","DOIUrl":"10.1002/glr2.12025","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>An accurate assessment of the carbon budget is a crucial part of projecting future climate change and its impact on ecosystems. Grasslands foster multiple ecological functions including support for wild animals and livestocks. Herbivores intake forage biomass carbon, then digest and metabolize, and finally retain some carbon. The carbon processes have not been well quantified, resulting in uncertainties in the estimation of regional carbon budgets for grassland ecosystems.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>An animal metabolic carbon flux model was developed for herbivores in the Three-Rivers Headwaters region of China. The forage intake and metabolic carbon rates were estimated through metabolic body weight and daily digested measures for the main herbivore species.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The carbon intake was 5.52 Tg C year<sup>−1</sup> (45%) from partial aboveground biomass (12.2 Tg C year<sup>−1</sup>), in which 39.31% was released into the atmosphere by respiration CO<sub>2</sub>, 43.77% was returned to the ecosystem as feces and urine, and 16.96% was retained in herbivores for population regeneration or for human well-being.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study, as the first research on this topic, quantified the carbon flux of herbivores and found livestock accounts for a major part of consumed carbon on grasslands, which is important for understanding regional carbon budgets to mitigate and adapt to climate change over grasslands worldwide.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 3","pages":"207-219"},"PeriodicalIF":0.0,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12025","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86488926","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}
Danica Parnell, Igor Kardailsky, Jacob Parnell, Warwick Brabazon Badgery, Lachlan Ingram
Background
Grasslands are the primary source of feed for grazing livestock, and as such, knowledge on how to best manage livestock and grasslands, through the use of spatiotemporal modelling, will assist in the long-term management of a valuable ecosystem resource.
Methods
This study was conducted over 14 months between March and April 2017 in Orange, NSW, Australia. The study evaluated sheep behaviour in relation to the presence of pasture species, environment and paddock structures, using random forest modelling, to predict sheep location under continuous high (HSR, 13 DSE ha−1) and low (LSR, 7 DSE ha−1) stocking rates.
Results
In the LSR, significant drivers included water, shade and fence lines (p < 0.01). In the HSR, only fence lines and available biomass were found to be significant (p < 0.01). The presence of green legumes in both stocking rates often increased residency by sheep. Animals spent more time together in the LSR, suggesting that social behaviour played a larger role than pasture quantity and quality in driving grazing behaviours.
Conclusions
Understanding how pasture type can influence grazing behaviours and also how animal behaviour affects pasture performance and utilisation is important in developing long-term sustainable management strategies on a paddock scale.
{"title":"Understanding sheep baa-haviour: Investigating the relationship between pasture and animal grazing patterns","authors":"Danica Parnell, Igor Kardailsky, Jacob Parnell, Warwick Brabazon Badgery, Lachlan Ingram","doi":"10.1002/glr2.12026","DOIUrl":"10.1002/glr2.12026","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Grasslands are the primary source of feed for grazing livestock, and as such, knowledge on how to best manage livestock and grasslands, through the use of spatiotemporal modelling, will assist in the long-term management of a valuable ecosystem resource.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This study was conducted over 14 months between March and April 2017 in Orange, NSW, Australia. The study evaluated sheep behaviour in relation to the presence of pasture species, environment and paddock structures, using random forest modelling, to predict sheep location under continuous high (HSR, 13 DSE ha<sup>−1</sup>) and low (LSR, 7 DSE ha<sup>−1</sup>) stocking rates.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>In the LSR, significant drivers included water, shade and fence lines (<i>p</i> < 0.01). In the HSR, only fence lines and available biomass were found to be significant (<i>p</i> < 0.01). The presence of green legumes in both stocking rates often increased residency by sheep. Animals spent more time together in the LSR, suggesting that social behaviour played a larger role than pasture quantity and quality in driving grazing behaviours.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Understanding how pasture type can influence grazing behaviours and also how animal behaviour affects pasture performance and utilisation is important in developing long-term sustainable management strategies on a paddock scale.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 3","pages":"143-156"},"PeriodicalIF":0.0,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76940559","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}
Previous studies have surveyed golf courses to determine nitrogen (N) fertilizer application rates on golf courses, but no previous studies have attempted to quantify how efficiently golf courses use nitrogen.
Methods
This study tests the ability of the growth potential (GP) N Requirement model as a benchmarking tool to predict a target level of N use on 76 golf courses in 5 regions of the US (Midwest, Northeast, East Texas, Florida, Northwest) and 3 countries in Europe (Denmark, Norway, UK).
Results
The ratio of the golf course-wide N application rate to the GP N requirement prediction (termed the nitrogen efficiency score or NES) was 0.27, indicating that golf courses used 73% less N than predicted by the model. As such, the GP N Requirement model needs to be recalibrated to predict N use on golf courses. This was achieved by adjusting the Nmax coefficient in the model. N rates on golf courses were widely variable both within and across regions. All regions had a coefficient of variation in N rates of 0.46 or greater.
Conclusions
The high variation in N rates, which is largely unexplained by climate, economic factors, grass type, and soil type, may be indicative of inefficient N use in golf course management.
{"title":"Quantifying golf course nitrogen use efficiency","authors":"Michael A. H. Bekken, Douglas J. Soldat","doi":"10.1002/glr2.12024","DOIUrl":"10.1002/glr2.12024","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Previous studies have surveyed golf courses to determine nitrogen (N) fertilizer application rates on golf courses, but no previous studies have attempted to quantify how efficiently golf courses use nitrogen.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This study tests the ability of the growth potential (GP) N Requirement model as a benchmarking tool to predict a target level of N use on 76 golf courses in 5 regions of the US (Midwest, Northeast, East Texas, Florida, Northwest) and 3 countries in Europe (Denmark, Norway, UK).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The ratio of the golf course-wide N application rate to the GP N requirement prediction (termed the nitrogen efficiency score or NES) was 0.27, indicating that golf courses used 73% less N than predicted by the model. As such, the GP N Requirement model needs to be recalibrated to predict N use on golf courses. This was achieved by adjusting the <i>N</i><sub>max</sub> coefficient in the model. N rates on golf courses were widely variable both within and across regions. All regions had a coefficient of variation in N rates of 0.46 or greater.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The high variation in N rates, which is largely unexplained by climate, economic factors, grass type, and soil type, may be indicative of inefficient N use in golf course management.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 3","pages":"174-186"},"PeriodicalIF":0.0,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12024","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88445290","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}
Tall fescue (Festuca arundinacea Schreb.) is an important cool-season perennial grass. Its persistence and forage yield can be severely affected by drought stresses during the hot, dry summers of the southern USA.
Methods
One thousand tall fescue genotypes were evaluated in the greenhouse for high relative water content (RWC) and low cell sap osmotic potential (OP). Fifty contrasting genotypes for the two traits were identified and used in further greenhouse and field studies. These genotypes were also screened with 30% PEG8000. Root and shoot characteristics were studied in 10 genotypes.
Results
The genotypes differed for RWC (33.7%–97.3%, mean: 79.7%) and had an almost fivefold difference in OP (−0.5 to −2.4 MPa, mean: −1.2 MPa). Significant variation (p < 0.001) for the main effects of environment and genotypes was found for RWC and OP. Apart from the greenhouse trial, no correlation was found between RWC and OP, indicating that differences in RWC might have been due to factors other than osmotic adjustment. Genotypes with either long roots or high root weights, and high root/shoot ratios demonstrated high RWC and low OP.
Conclusions
Genotypes with consistently high RWC and low OP were identified and used for the development of mapping populations and transcriptome studies.
{"title":"Screening of tall fescue genotypes for relative water content and osmotic potential under drought stress","authors":"Francis M. Kirigwi, Malay C. Saha","doi":"10.1002/glr2.12021","DOIUrl":"10.1002/glr2.12021","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Tall fescue (<i>Festuca arundinacea</i> Schreb.) is an important cool-season perennial grass. Its persistence and forage yield can be severely affected by drought stresses during the hot, dry summers of the southern USA.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>One thousand tall fescue genotypes were evaluated in the greenhouse for high relative water content (RWC) and low cell sap osmotic potential (OP). Fifty contrasting genotypes for the two traits were identified and used in further greenhouse and field studies. These genotypes were also screened with 30% PEG8000. Root and shoot characteristics were studied in 10 genotypes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The genotypes differed for RWC (33.7%–97.3%, mean: 79.7%) and had an almost fivefold difference in OP (−0.5 to −2.4 MPa, mean: −1.2 MPa). Significant variation (<i>p</i> < 0.001) for the main effects of environment and genotypes was found for RWC and OP. Apart from the greenhouse trial, no correlation was found between RWC and OP, indicating that differences in RWC might have been due to factors other than osmotic adjustment. Genotypes with either long roots or high root weights, and high root/shoot ratios demonstrated high RWC and low OP.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Genotypes with consistently high RWC and low OP were identified and used for the development of mapping populations and transcriptome studies.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 2","pages":"84-93"},"PeriodicalIF":0.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82078417","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}
This study investigated the effects of daughter tiller removal on parent tiller development in Lolium perenne.
Methods
Plants of L. perenne were grown hydroponically to allow separation of roots by phytomer position on the tiller axis and allowed to form two daughter tillers. In Experiment 1, adult daughter tillers were excised and effects on subsequent main tiller growth were observed for 16 days, on average. In Experiment 2, the growth of main tillers with or without daughter tillers was compared over 90–100 days. Two cultivars, ‘Alto’ bred from New Zealand germplasm and ‘Aberdart’ bred from United Kingdom germplasm were tested.
Results
Excision of adult daughter tillers reduced the dry weight of older roots at the base of parent tiller axes and accelerated new phytomer appearance. Preventing tillers from forming daughter tillers by new tiller excision resulted in increased individual leaf and root dry weight in tillers without daughter tillers.
Conclusions
The data indicated that daughter tillers contributed substrate for root development of their parent tillers. The presence of daughter tillers reduced the size of their main tiller but greatly enhanced whole plant yield.
{"title":"Effects of daughter tiller removal on shoot and root growth of the parent tiller in Lolium perenne","authors":"Arif Hasan Khan Robin, Cory Matthew","doi":"10.1002/glr2.12023","DOIUrl":"10.1002/glr2.12023","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>This study investigated the effects of daughter tiller removal on parent tiller development in <i>Lolium perenne</i>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Plants of <i>L. perenne</i> were grown hydroponically to allow separation of roots by phytomer position on the tiller axis and allowed to form two daughter tillers. In Experiment 1, adult daughter tillers were excised and effects on subsequent main tiller growth were observed for 16 days, on average. In Experiment 2, the growth of main tillers with or without daughter tillers was compared over 90–100 days. Two cultivars, ‘Alto’ bred from New Zealand germplasm and ‘Aberdart’ bred from United Kingdom germplasm were tested.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Excision of adult daughter tillers reduced the dry weight of older roots at the base of parent tiller axes and accelerated new phytomer appearance. Preventing tillers from forming daughter tillers by new tiller excision resulted in increased individual leaf and root dry weight in tillers without daughter tillers.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The data indicated that daughter tillers contributed substrate for root development of their parent tillers. The presence of daughter tillers reduced the size of their main tiller but greatly enhanced whole plant yield.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 2","pages":"103-110"},"PeriodicalIF":0.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75435671","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}
Valentin D. Picasso, Marisol Berti, Kim Cassida, Sarah Collier, Di Fang, Ann Finan, Margaret Krome, David Hannaway, William Lamp, Andrew W. Stevens, Carol Williams
Prevailing agricultural systems dominated by annual crop monocultures, and the landscapes that contain them, lack resilience and multifunctionality. They are vulnerable to extreme weather events, contribute to degradation of soil, water, and air quality, reduce biodiversity, and negatively impact human health, social engagement, and equity. To achieve greater resilience, stability, and multiple ecosystem services therein, and to improve socioeconomic outcomes, we propose a practical framework to gain multifunctionality at multiple scales. This framework includes forages within agroecosystems that have the essential structural features of diversity, perenniality, and circularity. These three structural features are associated with increased resilience, stability, and provision of several ecosystem services, which in turn improve human health and socioeconomic outcomes. This framework improves understanding of, and access to, tools and materials for promoting the adoption of diverse circular agroecosystems with perennial forages. Application of this framework can result in land transformations that solve sustainability challenges in agriculture if policy, economic, and social barriers can be overcome by a transdisciplinary process of equitable knowledge production.
{"title":"Diverse perennial circular forage systems are needed to foster resilience, ecosystem services, and socioeconomic benefits in agricultural landscapes","authors":"Valentin D. Picasso, Marisol Berti, Kim Cassida, Sarah Collier, Di Fang, Ann Finan, Margaret Krome, David Hannaway, William Lamp, Andrew W. Stevens, Carol Williams","doi":"10.1002/glr2.12020","DOIUrl":"10.1002/glr2.12020","url":null,"abstract":"<p>Prevailing agricultural systems dominated by annual crop monocultures, and the landscapes that contain them, lack resilience and multifunctionality. They are vulnerable to extreme weather events, contribute to degradation of soil, water, and air quality, reduce biodiversity, and negatively impact human health, social engagement, and equity. To achieve greater resilience, stability, and multiple ecosystem services therein, and to improve socioeconomic outcomes, we propose a practical framework to gain multifunctionality at multiple scales. This framework includes forages within agroecosystems that have the essential structural features of diversity, perenniality, and circularity. These three structural features are associated with increased resilience, stability, and provision of several ecosystem services, which in turn improve human health and socioeconomic outcomes. This framework improves understanding of, and access to, tools and materials for promoting the adoption of diverse circular agroecosystems with perennial forages. Application of this framework can result in land transformations that solve sustainability challenges in agriculture if policy, economic, and social barriers can be overcome by a transdisciplinary process of equitable knowledge production.</p>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 2","pages":"123-130"},"PeriodicalIF":0.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79224160","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}
Plants compete aboveground for light and belowground for patchily distributed nutrients. Defoliation causes an immediate loss of leaf area and photosynthetic capacity, leading to reduced root growth, with hypothesised implications for nutrient uptake and nitrogen use efficiency.
Methods
In Experiment 1, we grew single plants in split root boxes with N supplied equally or unequally, with half the plants subject to repeated defoliation to quantify the impact of each treatment. In Experiment 2, we grew pairs of Poa annua plants in three-chamber split root boxes, with N supplied either to the outer chambers (no competition) or to a shared centre chamber (competition), to quantify the influence of defoliation on root competition.
Results
In Experiment 1, defoliation caused a significant decrease in root mass but did not affect root distribution between chambers, while differential N supply led to an 11% increase in shoot mass. In Experiment 2, strong root competition was seen in undefoliated plants under competitive conditions. Where one plant was defoliated, the other exhibited increased shoot mass and N content in competitive, but not noncompetitive conditions.
Conclusions
Our data suggest that plant belowground competitive success following defoliation may be strongly influenced by the spatial distribution of soil resources.
{"title":"Defoliation affects the root competitive balance for N between Poa annua plants grown in a split-root box","authors":"Sayuki Mori, Louis John Irving","doi":"10.1002/glr2.12022","DOIUrl":"10.1002/glr2.12022","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Plants compete aboveground for light and belowground for patchily distributed nutrients. Defoliation causes an immediate loss of leaf area and photosynthetic capacity, leading to reduced root growth, with hypothesised implications for nutrient uptake and nitrogen use efficiency.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>In Experiment 1, we grew single plants in split root boxes with N supplied equally or unequally, with half the plants subject to repeated defoliation to quantify the impact of each treatment. In Experiment 2, we grew pairs of <i>Poa annua</i> plants in three-chamber split root boxes, with N supplied either to the outer chambers (no competition) or to a shared centre chamber (competition), to quantify the influence of defoliation on root competition.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>In Experiment 1, defoliation caused a significant decrease in root mass but did not affect root distribution between chambers, while differential N supply led to an 11% increase in shoot mass. In Experiment 2, strong root competition was seen in undefoliated plants under competitive conditions. Where one plant was defoliated, the other exhibited increased shoot mass and N content in competitive, but not noncompetitive conditions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our data suggest that plant belowground competitive success following defoliation may be strongly influenced by the spatial distribution of soil resources.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 2","pages":"94-102"},"PeriodicalIF":0.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85381024","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}
Hao Yang, Karl Auerswald, Xiaoying Gong, Hans Schnyder, Yongfei Bai
Background
C4 plants have increased substantially during the past several decades in the grasslands of the Mongolian Plateau due to regional warming. Here, we explore how the patterns of abundances of C4 annuals and C4 perennials change over space and time.
Methods
A total of 280 sites with C4 plants were surveyed in four types of grasslands in 9 years. The relative biomasses of C4 plants (PC4), C4 annuals (PA4), and C4 perennials (PP4) were calculated. Structural equation modeling was used to analyze the drivers of changes in PA4 and PP4.
Results
At the regional scale, PA4 on average was 11% (±19%, SD) and PP4 was 13% (±19%, SD). Spatially, C4 annuals dominated the C4 communities within an east–west belt region along 44° N and tended to spread toward northern latitudes (about 0.5°) and higher altitudes in the east mountainous areas. The abundance of C4 annuals decreased, while that of C4 perennials increased. The patterns of C4 annuals and C4 perennials were mainly controlled by temperature, growing season precipitation, and dynamics between the two life forms.
Conclusions
C4 annuals exhibited competitive advantages in normal and wet years, while C4 perennials had competitive advantages in dry years. Grazing as a main human disturbance increased C4 annuals, but had no significant effect on C4 perennials.
{"title":"Climate and anthropogenic drivers of changes in abundance of C4 annuals and perennials in grasslands on the Mongolian Plateau","authors":"Hao Yang, Karl Auerswald, Xiaoying Gong, Hans Schnyder, Yongfei Bai","doi":"10.1002/glr2.12019","DOIUrl":"10.1002/glr2.12019","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>C4 plants have increased substantially during the past several decades in the grasslands of the Mongolian Plateau due to regional warming. Here, we explore how the patterns of abundances of C4 annuals and C4 perennials change over space and time.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A total of 280 sites with C4 plants were surveyed in four types of grasslands in 9 years. The relative biomasses of C4 plants (P<sub>C4</sub>), C4 annuals (P<sub>A4</sub>), and C4 perennials (P<sub>P4</sub>) were calculated. Structural equation modeling was used to analyze the drivers of changes in P<sub>A4</sub> and P<sub>P4</sub>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>At the regional scale, P<sub>A4</sub> on average was 11% (±19%, SD) and P<sub>P4</sub> was 13% (±19%, SD). Spatially, C4 annuals dominated the C4 communities within an east–west belt region along 44° N and tended to spread toward northern latitudes (about 0.5°) and higher altitudes in the east mountainous areas. The abundance of C4 annuals decreased, while that of C4 perennials increased. The patterns of C4 annuals and C4 perennials were mainly controlled by temperature, growing season precipitation, and dynamics between the two life forms.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>C4 annuals exhibited competitive advantages in normal and wet years, while C4 perennials had competitive advantages in dry years. Grazing as a main human disturbance increased C4 annuals, but had no significant effect on C4 perennials.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 2","pages":"131-141"},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78527319","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}
Nictor Namoi, David Archer, Todd S. Rosenstock, Chunhwa Jang, Cheng-Hsien Lin, Arvid Boe, DoKyoung Lee
Background
Decisions regarding the conversion of land from an existing crop to bioenergy crops are critical for the sustainable production of both food and fuels. This study seeks to establish criteria for delineating land as “economically marginal”, and thus suited for growing switchgrass.
Methods
In this case study of an Illinois agricultural field, the profitability of switchgrass, with farmgate prices of $44 Mg−1, $66 Mg−1, or $88 Mg−1, was compared to corn and soybean crop prices. Further, the study also evaluates the profitability of switchgrass when replacing corn-based yield estimates from the Soil Productivity Index (SPI) of Illinois.
Results
Based on a dry-matter yield of 10.45 Mg ha−1, switchgrass can compete with soybeans only at the high price of $88 Mg−1, but depending on location, can compete with corn at $66 Mg−1. Across Illinois, at $88 ha−1, all Illinois land with SPI < 100% and 95% of land under SPI class C (SPI 100–116) is profitable under switchgrass. Switchgrass may not be profitable relative to corn grown in the SPI class A (SPI > 133) and only 7% of class B (SPI 117–132).
Conclusions
Our results show that land with drainage and erosion limitations is economically marginal when corn and soybean yields are low, and the farmgate price for switchgrass is greater than $66 Mg−1. However, this may not be possible on land where switchgrass is replacing frequent soybean rotations (corn–soybean ratio ≤ 1). Land used to produce only soybeans may only be marginal at the farmgate price of $88 Mg−1. Further studies need to be conducted to identify how much land can be converted to switchgrass without harming corn production.
{"title":"How profitable is switchgrass in Illinois, USA? An economic definition of marginal land","authors":"Nictor Namoi, David Archer, Todd S. Rosenstock, Chunhwa Jang, Cheng-Hsien Lin, Arvid Boe, DoKyoung Lee","doi":"10.1002/glr2.12017","DOIUrl":"10.1002/glr2.12017","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Decisions regarding the conversion of land from an existing crop to bioenergy crops are critical for the sustainable production of both food and fuels. This study seeks to establish criteria for delineating land as “economically marginal”, and thus suited for growing switchgrass.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>In this case study of an Illinois agricultural field, the profitability of switchgrass, with farmgate prices of $44 Mg<sup>−1</sup>, $66 Mg<sup>−1</sup>, or $88 Mg<sup>−1</sup>, was compared to corn and soybean crop prices. Further, the study also evaluates the profitability of switchgrass when replacing corn-based yield estimates from the Soil Productivity Index (SPI) of Illinois.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Based on a dry-matter yield of 10.45 Mg ha<sup>−1</sup>, switchgrass can compete with soybeans only at the high price of $88 Mg<sup>−1</sup>, but depending on location, can compete with corn at $66 Mg<sup>−1</sup>. Across Illinois, at $88 ha<sup>−1</sup>, all Illinois land with SPI < 100% and 95% of land under SPI class C (SPI 100–116) is profitable under switchgrass. Switchgrass may not be profitable relative to corn grown in the SPI class A (SPI > 133) and only 7% of class B (SPI 117–132).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results show that land with drainage and erosion limitations is economically marginal when corn and soybean yields are low, and the farmgate price for switchgrass is greater than $66 Mg<sup>−1</sup>. However, this may not be possible on land where switchgrass is replacing frequent soybean rotations (corn–soybean ratio ≤ 1). Land used to produce only soybeans may only be marginal at the farmgate price of $88 Mg<sup>−1</sup>. Further studies need to be conducted to identify how much land can be converted to switchgrass without harming corn production.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 2","pages":"111-122"},"PeriodicalIF":0.0,"publicationDate":"2022-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75633936","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}
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