Utilization of bagasse as a soil amendment in sugarcane production on mineral soils in Florida

A 4-year study tested the feasibility of using bagasse as a soil amendment in sugarcane production on a commercial field with mineral soil in Florida. The experiment was established as a completely randomized design trial with three rates of fresh bagasse applications: approximately 5 cm of bagasse, 10 cm of bagasse, and 10 cm of bagasse + nitrogen (N), which are equivalent to 85 t ha–1, 170 t ha–1, and 170 t ha–1 + 336 kg ha–1 ammonium nitrate, respectively. A control (no bagasse and no N added) was also included. As each treatment and the control had three replicates, there were 12 plots (6.5 ha each in size) totaling over 77 ha. The high pH of the soils is a result of years of mixing underlying limestone (calcium carbonate) bedrock with the topsoil. Overall results indicate that bagasse application positively affected the accumulation of soil organic matter during a short-term period, resulting in higher water-holding capacity and lower bulk density. The high rate of bagasse application had a positive effect on N accumulation, extractable phosphorus (P) and potassium (K) contents during the short term. One single application of bagasse significantly increased the first-year sugarcane biomass and sugar yield by approximately 23%. An overall higher application rate of bagasse (10 cm) was recommended as it showed significantly positive effects on soil health indicators and had a longer effect on increasing sugarcane biomass and sugar yield. There is potential to incorporate bagasse into commercial sugarcane production grown on mineral soils in Florida.