Uso de un clorofilómetro para el diagnóstico de fertilización nitrogenada en la región del sudoeste bonaerense en trigo de secano sobre dos antecesores
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2016-12
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Facultad de Ciencias Agrarias - UNR
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El clorofilómetro se podría utilizar en estadios avanzados del cultivo con el objetivo de evaluar si existe deficiencia de nitrógeno (N). Los objetivos de este estudio fueron: i) evaluar la producción de trigo (Triticumaestivum L.) con dos antecesores, ii) medir el efecto de los antecesores sobre el índice de verdor (IV) mediante el uso del clorofilómetro, y iii) verificar el uso del clorofilómetro en estadios avanzados del trigo para predecir el efecto de aplicaciones foliares de N sobre la producción y calidad del trigo en un sitio de la región semiárida del sudoeste bonaerense (SOB). Se realizó un ensayo de fertilización en trigo (cultivar Buck Malevo) bajo siembra directa sobre dos cultivos antecesores: trigo y arveja (Pisumsativum L.). Sobre cada antecesor, se aplicó N en emergencia (0, 25, 50, y 100 kg N ha-1) como urea (46-0-0) en forma manual. En antesis, se realizaron lecturas de IV sobre la última hoja expandida y se realizó una fertilización foliar con 25 kg N ha-1. En madurez fisiológica se midió la biomasa total aérea (MST), rendimiento, N absorbido por el cultivo, y proteína. El antecesor arveja incrementó la producción de MST, el N absorbido y el rendimiento de grano, sin tener efecto sobre la proteína. Con fertilización foliar la proteína mostró aumentos significativos, independientemente del cultivo antecesor. El clorofilómetro es una herramienta útil que puede utilizarse en estadios avanzados para mejorar la calidad del trigo en ambientes semiáridos como en el área en estudio.
The chlorophyll meter could be used to improve the diagnosis of nitrogen (N) deficiency. The objectives of this study were to: i) evaluate wheat (Triticumaestivum L.) yield after two previous crops, ii) assess the effect of the previous crop on the green index (IV) by chlorophyll meter readings, and iii) verify the usefulness of the chlorophyll meter in advanced growth stages of wheat to predict the effect of foliar N application on wheat production and quality in the semiarid region of the southwest of Buenos Aires province. In 2011, a fertilization trial on wheat (cultivar Buck Malevo) was conducted under no-tillage after two contrasting previous crops: wheat and pea (Pisumsativum L.). In each case, different N rates (0, 25, 50, and 100 kg N ha-1) in the form of urea (46-0-0) were applied manually at crop emergence. At anthesis, chlorophyll meter readings were taken in the last expanded leaf and in one half of each plot a foliar N fertilizer was applied at a rate of 25 kg N ha-1. At physiological maturity, total aerial biomass (MST), grain yield, crop N uptake, and protein content were determined. Pea as a previous crop increased the production of MST, grain yield and N uptake, but no effect was detected on protein. Protein content was significantly increased by foliar N fertilizer application, regardless of previous crop. The chlorophyll meter is a useful tool that could be used in advanced stages of wheat to fine-tune the diagnosis of N needs. which would allow improving grain quality in the semiarid environment studied.
The chlorophyll meter could be used to improve the diagnosis of nitrogen (N) deficiency. The objectives of this study were to: i) evaluate wheat (Triticumaestivum L.) yield after two previous crops, ii) assess the effect of the previous crop on the green index (IV) by chlorophyll meter readings, and iii) verify the usefulness of the chlorophyll meter in advanced growth stages of wheat to predict the effect of foliar N application on wheat production and quality in the semiarid region of the southwest of Buenos Aires province. In 2011, a fertilization trial on wheat (cultivar Buck Malevo) was conducted under no-tillage after two contrasting previous crops: wheat and pea (Pisumsativum L.). In each case, different N rates (0, 25, 50, and 100 kg N ha-1) in the form of urea (46-0-0) were applied manually at crop emergence. At anthesis, chlorophyll meter readings were taken in the last expanded leaf and in one half of each plot a foliar N fertilizer was applied at a rate of 25 kg N ha-1. At physiological maturity, total aerial biomass (MST), grain yield, crop N uptake, and protein content were determined. Pea as a previous crop increased the production of MST, grain yield and N uptake, but no effect was detected on protein. Protein content was significantly increased by foliar N fertilizer application, regardless of previous crop. The chlorophyll meter is a useful tool that could be used in advanced stages of wheat to fine-tune the diagnosis of N needs. which would allow improving grain quality in the semiarid environment studied.
Palabras clave
aplicación n foliar, cultivo antecesor, índice de verdor