Sugarcane bagasse amendment mitigates nutrient leaching from a mineral soil under tropical conditions

Large quantities of organic by-products are generated by the sugarcane industry during sugar extraction process. These by-products may be used as soil amendments to improve soil quality, as nutrient leaching is common in mineral soils of Florida in USA due to their sandy texture and frequent rain events. A soil column study was designed to evaluate the effects of bagasse application at 85 t ha−1 of fresh bagasse, 170 t ha−1 of fresh bagasse, and 170 t ha−1 of fresh bagasse + nitrogen (N) on the leaching potential of carbon (C), N, phosphorus (P), and potassium (K). Bagasse was incorporated within the topsoil (0–15 cm) in outdoor soil columns exposed to natural conditions, with periodical irrigation during the experiment. After approximately 57 weeks, the distributions of C, N, P, and K were evaluated at three soil depths (i.e., 0–15, 15–30, and 30–53 cm) within the soil columns. Total organic C (TOC), N, and P in leachates decreased significantly from the soils amended with bagasse compared with the control with no bagasse and no N. Based on K content changes in the columns, bagasse could also be utilized as a potential source of K for plants. Overall, application of bagasse as a soil amendment might be an effective way to sustainably reutilize organic by-products while reducing concerns regarding major nutrients entering groundwater resources. The results of this study could assist in developing nutrient management plans of using sugarcane bagasse as a potential soil amendment in mineral soils.