poster - International Conference of Agricultural Engineering

The fertilization growth and hardening were identical for the quantity of fertilizer
provided, but different in frequency of application, one, two, three or six times a week. Thus
the experiment consisted of the treatments shown in Table 1.
The fertilizers used in growing the seedlings were ammonium sulfate (20% N and 24%
S); monoamoniofosfato (MAP) purified (60% P 2 O 5 and 12% N), potassium nitrate (Krista K © )
(45% K 2 O and 12% N), calcium nitrate (15% N and 20% Ca). For fertilization hardening was
used potassium chloride (60% K 2 O). The fertilization of growth began 58 days after sowing or
staking and remained for a period of 30 days, and the fertilization hardening started on day
90 with 15-day duration.
For irrigation, the system used was micro-sprinkling. For the fertirrigation it was used
the subirrigation system to ensure uniformity of application of nutrient solution. Transpiration
was obtained by the method of weighing as described by Silva (2003).
Table 1. Concentration of fertilizer in nutrient solutions for different treatments.
Treatments
Fertilization growth
(mg L -1 )
Fertilization
hardening (mg L -1 )
N P K Ca S K
F1 1560.0 420.0 1080.0 1020.0 507.0 600.0
F2 780.0 210.0 540.0 510.0 253.5 300.0
F3 520.0 140.0 360.0 340.0 169.0 200.0
F6 260.0 70.0 180.0 170.0 84.5 100.0
F1, F2, F3 and F6: fertigation one, two, three and six times a week, respectively.
The experimental design was completely randomized, with four treatments, consisting
of five plots of 48 plants each and three central plants of each plot considered useful for
assessments, amounting to 15 plants per treatment. The results were submitted to variance
analysis technique. For significant effects were tested medium, by the Tukey test at 5%
probability.
3. Results e discussion
The species responded differently depending on the fertigation parceling (Table 2). For
Eucalyptus grandis the lowest values of transpiration were obtained when more concentrated
nutrient solutions (F1 and F2) were applied. Although statistically it was similar to the
treatment with a more dilute solution applied six times a week (F4). Eucalyptus uropyhlla had
an inverse to E. grandis, ie, the lowest values of transpiration were observed in plants
fertigated with more dilute solutions (F3 and F4). Although it did not differ statistically from
seedlings fertigated with the more concentrated solution (F1). Clonal seedlings E.grandis x
E.urophylla, the lowest values of transpiration were found in extreme treatments, ie, in
fertigated seedlings in solutions of lower and higher concentration (F1 and F4). The
seedlings of the F2 and F3 treatments were similar and showed the highest water loss by
transpiration.
When comparing each species in a nutrient solution it was observed that when the
plants were fertigated once a week, ie with more concentrated solution (F1), transpiration
values were similar for all. In the treatment F2, the species with lowest transpiration was E.
grandis, but it did not differ from clone E. grandis x E. urophylla, which in turn was similar to
E. urophylla. In the treatment F3 E. urophylla had the lowest transpiration, and the E.grandis
and the hybrid being statistically similar. With the treatment with the most diluted