Fertilization and soil correction timing with limestone and calcium and magnesium oxide in sugarcane cultivation

Sugarcane is predominantly cultivated in highly weathered and acidic tropical soils, making soil correction and fertilization management essential for sustaining productivity in ratoon systems. This study aimed to evaluate the effects of limestone and calcium and magnesium oxides application, as well as to determine the optimal timing for fertilization in sugarcane. The experiment was conducted under field conditions in Pedras de Fogo, Paraíba, Brazil, using a randomized complete block design in a split-plot scheme over time. Seven treatments were evaluated, combining soil amendments (limestone or Ca and Mg oxides) with fertilization timings (0, 15, and 30 days after harvest) and the control treatment (fertilization 0 days after harvest). Soil chemical attributes were monitored at 30, 90, 150, and 270 DAH, at a depth of 0-0.20 m and 0-0.25 m, while leaf nutrient concentrations were assessed at 90 and 270 DAH. Tillering and productivity were also determined 90 days after harvest and at the end of the crop cycle, respectively. Fertilization timing significantly influenced nutrient dynamics in soil and plant tissue. The treatment with limestone associated with fertilization at 15 days after harvest (T3) showed the best agronomic performance, promoting higher soil levels of phosphorus, potassium, and calcium, greater tillering, and the highest productivity. Throughout the crop cycle, reductions in soil potassium, cation exchange capacity, and pH were observed, while soil zinc and foliar concentrations of calcium, magnesium, copper, manganese, and zinc increased at 270 days after harvest. In contrast, the highest foliar concentrations of nitrogen, phosphorus, and potassium occurred at 90 days after harvest.The application of limestone combined with fertilization at 15 days after harvest is the most effective strategy for improving soil chemical attributes and crop performance under the studied conditions.