Fecha/hora: 14/05/2024 04:35:22

Biblioteca(s): 	INIA La Estanzuela.	
Fecha corriente: 	03/09/2020	
Fecha de la última actualización: 	03/09/2020	
Autoria: 	ERRECART, P,M.; MARINO, M.A.; AGNUSDEI, M.G.; LATTANZI, F.; DURAND, J-L	
Afiliación: 	PEDRO MANUEL ERRECART, Unidad Integrada Balcarce (Instituto Nacional de Tecnología Agropecuaria EEA Balcarce-Facultad de Ciencias Agrarias Universidad Nacional de Mar del Plata), Ruta Nacional 226 km 73.5, Balcarce, Argentina.; MARÍA ALEJANDRA MARINO, Unidad Integrada Balcarce (Instituto Nacional de Tecnología Agropecuaria EEA Balcarce-Facultad de Ciencias Agrarias Universidad Nacional de Mar del Plata), Ruta Nacional 226 km 73.5, Balcarce, Argentina.; MÓNICA GRACIELA AGNUSDEI, Unidad Integrada Balcarce (Instituto Nacional de Tecnología Agropecuaria EEA Balcarce-Facultad de Ciencias Agrarias Universidad Nacional de Mar del Plata), Ruta Nacional 226 km 73.5, Balcarce, Argentina.; FERNANDO A. LATTANZI, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; JEAN-LOUIS DURAND, Unité de Recherche Pluridisciplinaire Prairies Plantes Fourragères (URP3F), INRA, Route de Saintes, Lusignan, France.	
Título: 	The intensity of water stress dictates whether the N status of temperate-type perennial grass swards is affected by drought.	
Año de publicación: 	2020	
Fuente/Imprenta: 	Field Crops Research, 15 October 2020, Volume 257, Article number 107928. Doi: https://doi.org/10.1016/j.fcr.2020.107928	
DOI: 	10.1016/j.fcr.2020.107928	
Idioma: 	Inglés	
Notas: 	Article history: Received 28 February 2020/ Received in revised form 23 July 2020/ Accepted 27 July 2020. Corresponding author:
E-mail address: errecart.pedro@inta.gob.ar (P.M. Errecart).	
Contenido: 	Abstract:Temperate-type, summer-active cool-season perennial grasses are frequently exposed to dry spells during the warm season due to the high atmospheric demand and fast soil desiccation. Since water availability is essential for sward nitrogen (N) uptake and most mineral N is located in the topsoil, water stress may hinder sward N nutrition if it reduces N supply. In hydro-halomorphic soils, imbalances between soil N supply and sward N demand during summer could be further aggravated by, first, the limited water holding capacity of the topsoil, and second, potential availability of water from deep, N-poor soil horizons that are kept moist by a shallow water table. The aim of this work was to quantify the effect of N and water availability on N status and productivity of temperate-type perennial swards growing in a hydro-halomorphic soil of the Flooding Pampa. During two consecutive years, shoot and root dynamics, as well as radiation capture, N nutrition index (NNI), soil water availability and leaf water potential were followed over six weeks long mid-summer regrowths of old stands (>9 years) of temperate-type tall fescue [Lolium arundinaceum (Schreb.) Darbysh.] sown on a typical Natraqualf soil in Balcarce, Argentina. Swards were either rainfed or irrigated and fertilized with either 40 or 200 kg de N ha?1. Root systems were large (5.8?9.3 Mg DM roots ha?1), but concentrated mostly in the 0.2 m topsoil (66%?75% of root biomass or length). Despite invariably high available water below 0.4 m throughout both experimental periods, rainfed swards faced transient episodes of water stress whenever the upper soil layer dried out. Tall fescue swards were strongly co-limited by water and N during summer, showing comparable, very high responses to both N addition and irrigation. Further, forage yield showed synergistic increases when swards received both supplemental water and N simultaneously. This was mainly due to consistent synergistic responses in radiation use efficiency and leaf lifespan. Sward NNI was depressed only by an historically severe drought but was not altered when water stress intensity was lower, close to average for the season in the area. Therefore, the major causes of typically low summer productivity of temperate-type tall fescue growing in hydro-halomorphic soils of the Flooding Pampa are the intrinsic effects of low N and low water availability, with only uncommonly extreme water stress episodes reducing yield indirectly through an aggravation of crop N status.	
Thesagro: 	ESTRES HIDRICO; NITROGEN.	
Thesaurus NAL: 	FORAGE YIELD; NITROGEN NUTRITION INDEX; RESOURCE CO-LIMITATION; ROOTS; WATER-NITROGEN INTERACTION.	
Categoría del tema: 	--	
Registro original: 	INIA La Estanzuela (LE)	
Ejemplares: 	LE - (103175-1) - PXI - AP - DD - PP/Field Crops Research/2020 -  -  - DIS