Sugarcane expansion in Brazilian tropical soils—Effects of land use change on soil chemical attributes

Abstract

Land use change (LUC) in Brazil for sugarcane ethanol production has raised concerns about its potential environmental impacts. Soil quality is a key indicator to infer about the environmental sustainability of Brazilian ethanol production. Our objective was to quantify the effects of the most common LUC sequence associated with sugarcane expansion (i.e., native vegetation to pasture to sugarcane) on chemical attributes in tropical soils. Soil sampling was carried out in three study sites located in central-southern Brazil, primary sugarcane region of production and expansion of the world. Overall, long-term conversions from natural ecosystems to extensive pasturelands decreases available P, S, Ca, Mg and B contents. In addition, the LUC leads to soil acidification and decreases of CECpH7, indicating that pasturelands have poor soil chemical quality. The LUC from pasture to sugarcane increases soil nutrient levels and reduces the soil acidity due to inputs of lime and fertilizers. Despite that, increments of available P and base saturation are necessary to achieve ideal soil chemical conditions to sugarcane growth. Overall, our findings suggest that sugarcane expansion in Brazil replacing pasturelands will promotes improvements on soil chemical quality. Nevertheless, sugarcane expansion can be associated with management strategies to increase soil organic matter and improve the soil fertility, reducing the environmental and economic costs associated with ethanol production in Brazil.