Characterization of bermudagrass (Cynodon dactylon L.) germplasm for nitrogen use efficiency

Abstract

Bermudagrass is the most important warm-season pasture in the Southern USA with exceptional forage production potential and abiotic stress tolerance. However, it requires high nitrogen (N) supply to reach its full biomass and quality potential. Our objectives were to: (1) develop a nitrogen use efficiency (NUE) screening protocol for bermudagrass in controlled or semi-controlled conditions, (2) identify contrasting genotypes for NUE from natural variants and, (3) develop a knowledge base of NUE in bermudagrass. A collection consisting 290 Cynodon sp. genotypes was first pre-screened in the greenhouse. Thirty-nine genotypes with high NUE, five with low NUE were selected for further evaluations along with 5 checks in greenhouse and hoophouse under four N rates. Biomass, crude protein and N content were evaluated. N uptake efficiency (NUpE), N utilization efficiency (NUtE) and NUE were calculated based on biomass production. Genotypes showed significant influences (P \ 0.0001) in all of the response variables. The genotype 9 N rate interaction was not significant for NUE in both environments. NUE had strong correlation with biomass production and NUpE, which got stronger as N rates increased. In N limiting conditions, bermudagrass showed a trade-off between biomass maintenance and crude protein content. Lower N applications increased biomass production over crude protein. However, when N is abundant the crop has the ability to improve crude protein. Several genotypes presented high NUE due their high NUtE and NUpE. Genotypes with contrasting NUE were selected and subjected to further field evaluation. Superior genotypes for NUE will be used in the breeding program to enhance NUE in bermudagrass.

Sows-Gilts Stocking Rates and Their Environmental Impact in Rotationally Managed Bermudagrass Paddocks

“…In the southeast of the USA, different cultivars of bermudagrass have shown good potential for this purpose. However, differences in the nitrogen use efficiency among cultivars have been found [42]. Previous studies have shown annual uptake values for this species in the range of 314 to 382, and 44 kg ha −1 yr −1 of N and P, respectively.…”

“…Therefore, it is necessary to manage the paddock in such a way that those service areas can be buffered by grassed areas to minimize runoff and erosion. The morphological and physiological traits of bermudagrass, a warm season perennial species adapted to different types of soils and climates, that shows aggressive growth, good grazing tolerance, and ability to produce biomass of good quality forage when soil nutrients are not limiting [42], make this grass suitable for this kind of systems. Its growth habit and reproductive mechanisms (rhizomes, stolons, and extensive root mass) allowed it to endure the grazing, rooting, trampling and lounging behaviour of the sows, and to recover during the rest periods between successive grazings.…”

“…An additional benefit of the system implemented in this study is the use of a perennial species of forage to minimize nitrate leaching [42,75]. The larger root biomass of perennial forages and their nutrient uptake reduce leachate under the root zone in comparison with annual crops [76].…”

Opportunities for Increased Nitrogen Use Efficiency in Wheat for Forage Use

“…Schneider-Canny et al [ 30 ] also reported the limitation of smaller pots in bermudagrass. Since higher plant mass per pot volume decreases plant growth and can affect differences between treatments, proper pot size is important [ 31 ].…”

EFICIENCIA AGRONÓMICA DE NITRÓGENO Y PRODUCCIÓN DE Cynodon plectostachyus (K. Schum.) Pilg. EN FUNCIÓN DE DOS FRECUENCIAS DE CORTE

“…En estudios realizados en zonas tropicales y subtropicales se ha encontrado que el pasto estrella presenta buen potencial de crecimiento, rendimiento y calidad nutritiva para la producción láctea, manejando los días adecuados de rotación y recuperación en conjunto con la fertilización, para optimizar su rendimiento, calidad y persistencia (López et al, 2010;Yong et al, 2012;Villalobos y Arce, 2013;2014). Las especies de pasto Cynodon son de metabolismo fotosintético C 4 , por lo que pueden acumular mayor materia seca en relación a los pastos C 3 , se cultivan ampliamente en zonas tropicales y subtropicales, y responden a la fertilización nitrogenada para incrementar el rendimiento y calidad nutritiva (Yong et al, 2014;Cristiano et al, 2015;Taffarel et al, 2016;Borges et al, 2017;Schneider et al, 2019).…”