Fecha/hora: 08/06/2024 18:09:15

Biblioteca(s): 	INIA La Estanzuela.	
Fecha corriente: 	28/11/2018	
Fecha de la última actualización: 	28/11/2018	
Autoria: 	NÚÑEZ, A.; MORON, A.	
Afiliación: 	AGUSTIN NUÑEZ RUSSI, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; DAVID ALEJANDRO MORON YACOEL, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay.	
Título: 	Potassium dynamics in western uruguayan agricultural mollisols.	
Año de publicación: 	2017	
Fuente/Imprenta: 	Communications in Soil Science and Plant Analysis, 30 November 2017, Volume 48, Issue 21, Pages 2558-2572.	
DOI: 	10.1080/00103624.2017.1416134	
Idioma: 	Inglés	
Notas: 	Article history: Received 4 January 2017 // Accepted 13 November 2017.	
Contenido: 	ABSTRACT.
Knowledge of soil potassium (K) dynamics and quantification of plant-available K reserves are essential for the correct management of this nutrient. The objectives of this study, conducted in six Uruguayan mollisols, were to (i) determine the contribution of plant-available nonexchangeable K to plant nutrition, (ii) compare the ability of the ammonium acetate (NH4OAc) method and the sodium tetraphenylboron (NaBPh4) method to determine plant-available K, and (iii) quantify the effect of K fixation and release processes on the ability of both methods to estimate changes in K availability due to different K balances. In a greenhouse experiment, perennial ryegrass (Lolium perenne, cv. Horizon) was grown over a period of 320 days in six soils fertilized with 0, 100, 200, and 400 mg K kg?1. We measured plant K uptake and the changes in soil K status related to different K balances using NH4OAc and NaBPh4. Use of NaBPh4 resulted in a more accurate determination of plant-available K (R2 = 0.97 vs. 0.78) and soil K balance (R2 = 0.73 vs. 0.63), but neither of the methods was suitable for identifying positive K balances. However, when positive balances were established by K addition and incubation without plant growth, both methods related well with K balances. Again, NaBPh4 was better than NH4OAc (R2 = 0.98 and 0.88, respectively). The more accurate determination of plant K uptake and the strongest relationship with K balance of NaBPh4 was due to the extraction of exchangeable K plus a proportion of plant-available nonexchangeable K. Soil?plant interactions enhance soil K fixation in forms that are available to plant absorption but are not extractable by the chemical methods considered in this study. 
© 2017 Taylor & Francis.	
Palabras-Clave: 	ILLITE; NONEXCHANGEABLE POTASSIUM; POTASSIUM RESERVES; SODIUM TETRAPHENYLBORON.	
Categoría del tema: 	--	
Registro original: 	INIA La Estanzuela (LE)	
Ejemplares: 	LE - (102628-1) - PXI - AP - DD -  -  -  - DIS