Chia (Salvia Hispanica L.) is a Mexican ancestral crop that for
its nutritional properties presents high demand in the international
market, its growth rate is 239% annually and it is estimated that by
2020 its sales will be $ 1.2 billion dollars [1]. Since 1917, it has been
reported that the maximum attainable seed yield (SY) on chia is
close to 3.0 t ha-1 [2-5]; however, the SY that the farmers commonly
achieve in commercial plots is lower, and on average it only is 0.36
t ha-1 [6]. According to [7], the low productivity on chia due to their
agronomic management has not been modernized, and to this date
it still is cultivated mainly on rainy season, and the use of fertilizers,
pesticides and improved varieties is scarce. The plasticity of
the chia to adapt and produce under a low-input systems has
led erroneously to assume that it presents low requirements of
water and fertilizer [8,9], and also it resists the attack of pests and
diseases [10].
Therefore, although its integration into the modern agriculture
started since 1991, to this date is unknown how the production
controllable factors (improved varieties, planting date irrigation,
plant density, and other ones), and particularly the fertilization
with macro and micronutrients affects their productivity. Regarding
with the nitrogen fertilization, the consulted literature indicates
that the higher nitrogen rate evaluated on chia is 45 kg ha-1[11]. If it
is assumed that this specie take up 80% of this rate, and it produces
16.7 kg of seed per each kg of N absorbed, the maximum attainable
SY could be 601 kg ha-1 .Considering that this value is consistent
with the SY achieved at 1935 [12] when the nitrogen use was scarce
[13], we developed the hypothesis that the inadequate nutrition
could be the main cause because the SY on chia has not improved in
the last 83 years. To confirm this assumption, during 2016-2017 we
conducted two trials to evaluate the response of four chia varieties
to different nitrogen rates.
The findings of both these studies showed that under
of edaphoclimatic conditions of Toliman Jalisco, México, the
productive potential of chia (2.21 t ha-1) is six times higher than
the world average (0.36 t ha-1), and also, that it can be increased
by using improved varieties combined with an adequate nitrogen
fertilization [7]. The application of 100 kg N ha-1 along with the
use of the experimental genotype G-39 (during 2018, Nutrilite Co.
will patent this genotype with the name of ¨Rehnborg¨) allowed
to obtain a SY of 2.21 t ha-1, and even, when the G-39 cultivar is
established in an optimal sowing date, the SY is close to 3.0 t ha-1
[14]. These results differ that those reported in other parts of the
world, because the most of them found no response of the chia
crop to nitrogen application [15,16]. The study published by [7]
is the first one where the response of the chia crop to nitrogen
fertilization is based on the SY, and the results obtained clearly
suggest that in order to improve the potential productive on
chia, besides developing yielder cultivars, there should also be
generated fertilization norms that ensure the adequate nutrition of
this oilseed. Historically the nitrogen fertilization is the agronomic
practice that has most helped to increase the crop yields [13,17-
20] and, according to our results we estimated that the nitrogen
fertilization could help to raise on 63% the SY on chia.