Soil physical quality response to management systems in a long‐term sugarcane trial

Abstract

AbstractIn order to support sugarcane growth for biofuel production without compromising the environmental sustainability, this work aims to assess the physical quality of soils cultivated under different long‐term tillage and management systems to identify the system that most contributes for a sustainable sugarcane production. Visual assessments and soil sampling to determine physical soil quality indicators were performed in sugarcane plots managed with no‐tillage (NT) and conventional tillage (CT) with 0 (CT0–NT0) and 4 (CT4–NT4) Mg ha−1 of lime and in an adjoining area with native forest. In general, the results from traditional indicators showed no statistical difference between the different sugarcane cultivation systems and the different depths, so were not sensitive to identify the best tillage and management system in relation to soil physical quality for soils cultivated with sugarcane. However, even without statistical difference, three indicators presented limiting values for plant growth and development (Bd, ASW, and S index) in at least two sugarcane cultivation systems and one depth. Although all the systems showed a good soil structural quality in surface, the visual assessments suggest a poor and unsatisfactory soil structural quality in the subsurface of CT0, CT4, and NT0 (3.7 ± 0.2, 3.3 ± 0.6, and 3.7 ± 0.7 in Visual Evaluation of Soil Structure [VESS] and 2.2 ± 0.3, 3.1 ± 1.0, and 3.6 ± 1.1 in Rapid Diagnosis of Soil Structure [DRES], respectively), requiring immediate management changes, while structural quality in NT4 (2.6 ± 0.9 and 3.9 ± 0.7, in VESS and DRES, respectively) was considered good. Thus, NT4 is suggested as the tillage and management system that least compromises structural quality of soils cultivated with sugarcane, and it is considered a viable alternative to promote soil conservation, as well as environmental and economical sustainability for sugarcane cultivation, as this system corrects soil acidity, minimally disturbs the soil, and maintains the soil cover, thus delivering ecosystem services.