poster - International Conference of Agricultural Engineering

espectively, compared to that observed in T1NI. The period of water deficit in the crop cycle
(2008/2009) was not sharp as the observed in the previous cycle (third cycle), but even so
there is an increase in stem yield.
The total stem yield, of four cycles, in the treatments that received doses of vinasse (T3Iv
and T4IV) differed significantly from the control without irrigation (Table 2). The treatments
T3Iv and T4IV had the same total production of stems, and the final computation of these
treatments showed an increase of 40 Mg ha-1 compared to non-irrigated crop (T1NI). The
treatment T2I did not differ significantly from other treatments, getting an intermediate
production, between the non-irrigated and those who received vinasse. Increased production
of stem through the usage of irrigation has been reported by several studies over the years,
such as Inman-Bamber (2004) and Cruz and Dalri (2008). Several of these studies highlight
the importance of using irrigation on sugarcane, to promote the vertical growth of production,
reducing the horizontal expansion.
In the first and third cycle of sugarcane, the sugar yield was significantly different between
the treatments, as shown above. The crop evapotranspiration in these cycles was similar or
higher than the precipitation said before. In the first cycle, there is a superiority of T4IV (p>
0.05), with a sugar yield about 3.3 mg h -1 to more than in the non irrigated treatment. The
treatments T2I and T3Iv did not differ significantly of T1NI. In the third cycle, the treatments
with application of vinasse (T3Iv and T4IV), had higher sugar production when compared to
non irrigated treatment (T1NI). The gain achieved in the sugar yield by treatments T4IV and
T3Iv when compared to non irrigated treatment was 3 and 4 Mg ha-1 respectively. Pancelli &
Prado (2006) found that often the highest sugar productions are due the higher yield of
stems, and not in increase in the technological quality of the stems. According to the results
shown in Table 2, noted that the increase in the sugar yield on first and third cycle, was
caused primarily by increased production of stems.
The sugar yield did not showed significant difference between treatments in the second crop
cycle (Table 2), certainly this occurred due to the rainfall which occurred in this cycle. In the
fourth cycle in spite of differences in the production of stem, there was no effect on the
production of sugar, and the cycle precipitation was above of ETc in 192 mm, reduced the
effect of irrigation when compared to non-irrigated crop
The total sugar production in the four cycles was significant among treatments (Table 2), with
higher yield of treatments with vinasse. If compared to T1NI, the T4IV showed an increase of
8 Mg ha-1 when compared to T1NI, whereas the treatment T3Iv showed a significant
increase of 6 Mg h-1. As noted for the stems yield, the treatment T2I did not differ to the
other treatments. The vinasse fertigation in the four cycles yielded presented improvements
in the productive system and promoted an increase in the total sugar yield.
4. Conclusions
The disposal of vinasse in the production of sugarcane by subsurface drip irrigation did not
alter the technological quality. In the final computation, the application provided increases in
stem and sugar yield in comparison to traditional cultivation without irrigation.
There was a strong influence of climate in the production level and response irrigation. In the
cycles that the crop evapotranspiration was higher or similar the precipitation, the usage of
drip irrigation subsurface provided significant increases in the production of stems and
theoretical yield of sugar recoverable by at least one treatment. The final sum the treatments
fertirrigated with vinasse had a greatest yield of stalks and sugar compared to the nonirrigated
crop.
5. Reference list
Allen, R. G.; Pereira, L. S.; Raes, D.; Smith, M. (1998) Crop evapotranspiration – Gidelines
for computing crop water requirementes. Rome: FAO. (Irrigation and Drainage – 56).