Impact of Irrigation on the Yield, Total Cost, and Its Influence on Hydraulic Conductivity in a Soil Under Vinasse Application

This study had the objective to evaluate the effect of irrigation and fertigation (N) in the crop yield and its impact on the total cost, in addition to its influence on the conductivity hydraulic capacity and logarithmic hydraulic conductivity in an Oxisol under vinasse application cultivated with sugarcane (second year), in state of Goiás, Brazil. The experimental design comprised randomized blocks in a 5 × 2 factorial scheme, with four replications. Treatments consisted of five levels of water replacement (100, 75, 50, 25 and 0%), with and without fertirrigation (N). The planting of sugarcane, cultivar RB85-5453, was performed in a double row (W-shaped), 8 m long, with 1.80 m spacing between the double rows, the distance between the crops in the double row was 0.40 m, with a total area of 52.8 m2 in each paddock. For treatments with water, replacement (WR) a drip tube was placed in the ground at a depth of 0.20 m among the furrows of the double row. The drip tube (DRIPNET PC 16150) comprised a thin wall, 1.0 bar pressure, nominal discharge 1.0 L h-1, and 0.50 m spacing between drippers. Nitrogen was applied by fertirrigation at a dose of 100 Kg ha-1, at 30-day intervals, with 10 applications throughout the development of the sugarcane culture. Potassium fertilization was fully realized at planting. The total cost with irrigation did not increase significantly with fertirrigation (< 3%) in an Oxisol under vinasse application.