poster - International Conference of Agricultural Engineering

Table 1 - Reference evapotranspiration (ETo), total precipitation, usable precipitation
and irrigation levels applied at different replacement rates evaluated.
Treatment ETo * Total
precipitation
mm
Usable
precipitation
mm
Irrigation
water depth
50% of ETo 986,7 655,8
75% of ETo 1480
441,2 330,9
1149,1
100% of ETo 1973,4 1642,5
125% of ETo 2466,7 2135,8
a) b)
Figure 1 - Operation of the emitter (a) and partial view of the hybrid UENF / Caliman 01
papaya experiment (b).
2.2 Fertilization and irrigation management
Fertilization was made as indicated by Sobral et al, (2007), weekly using urea (44%
N), potassium chloride (56%K 2 O) and phosphoric acid (50% P 2 O 5 ).
The irrigation water depth, the amount of water application, and irrigation time was
determined by equations 2, 3 and 4, respectively, as proposed by Mantovani et al. 2006.
LB =
ETo.
Ks
− Pe
Ef
Equation 2
which:
LB = gross water depth (mm day -1 );
ETo = reference evapotranspiration second Penman-Monteith method (mm
day -1 );
Ks = percentage of wetted area by the issuer;
Pe = effective precipitation, in the period (mm);
Ef = irrigation efficiency.