Nutritional Efficiency for Fertigated Sugarcane Varieties Under Deficit Irrigation Strategies

ABSTRACT Among the many factors that limit sugarcane crop yield, the precise supply of nutrients and water under drip irrigation systems can be the shortcut to higher yields in the field. This research aimed to evaluate the nutritional efficiency of fertigated sugarcane varieties under deficit irrigation strategies. The experiment was conducted in a rain‐out shelter with the soil type Oxisol Typic Ustox. The experimental design adopted was randomized blocks, with three complete blocks. The treatments were distributed in a factorial scheme (4 × 8), totalling 32 treatments and 96 experimental plots. Four irrigation strategies and eight commercial sugarcane varieties (CTC15, CTC17, RB867515, RB92579, RB931011, RB966928, IAC5000 and NCo376) were studied. Leaf, sheath, pointer and stalk samples were ground for determination of macronutrient and micronutrient contents. All the nutrients had greater quantities allocated to the stalk. The CTC15 variety accumulated a greater quantity of nutrients and was more efficient in terms of gross sugar yield, whereas RB966928 was more efficient in terms of the production of total recoverable sugars and the production of apparent sucrose. The 100% irrigation level provided greater accumulation of nutrients in the aboveground parts, whereas the 50% irrigation level resulted in higher values of nutrient use efficiency.