Abstract
A chlorophyll meter is a
promising tool for monitoring the status of N through the green index (IV). The
hypothesis was that estimates from the use of a chlorophyll meter would be more
closely linked to the N harvested from dry matter than to wheat (Triticum aestivum L.) grain yield, which
is affected by climate variability. The objective was i) to determine IV
sensitivity to predict total dry matter (MST) and grain yield, protein content
and N-uptake, and ii) to evaluate N-availability at planting to establish reference
plots without N deficiencies by using a chlorophyll meter at different stages
of wheat cultivation and comparing field tests with a pot experiment. In 2010,
a nitrogen fertilization trial was conducted in pots, while in 2011 and 2012
the trials were conducted on two sites in SOB under no-tillage. In two (Z22 y
Z40) and three (Z22, Z40 y Z70) stages of the crop, chlorophyll meter readings
were taken for the field and pot trials, respectively. The field prediction of
MST and grain yield , protein content and N uptake with chlorophyll meter
readings showed significant regressions with low settings (R2 = 0.11
to 0.29). In the pot experiment, the prediction of N-uptake for the three
sampled stages increased, without differences in slopes and with a high setting
(R2=0.79). The chlorophyll meter would be a promising indicator of
N-uptake by the crop; in sub-humid regions, however, it would not be an
accurate tool to predict grain yield or protein content in wheat crops. Also, a
chlorophyll meter would be useful to estimate the available N needed by the
wheat crop and to determine the nutritional status of the plant.
Key words Green index; ACA 303; Sub-humid Region
Martínez
J.M., J.A. Galantini, M.R. Landriscini. 2015. Diagnóstico de fertilidad
nitrogenada en trigo con la utilización de un clorofilómetro en el Sudoeste
Bonaerense. Ciencia del Suelo 33(1)
31-43.
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