Using Soil Apparent Electrical Conductivity (ECa) to Assess Responsiveness of Nitrogen Rates and Yield in Brazilian Sugarcane Fields

Abstract

The expansion of sugarcane production has led to increased nitrogen (N) fertilizer use, contributing to greenhouse gas emissions and environmental concerns. Optimizing N management is crucial for sustainable agriculture. Soil apparent electrical conductivity (ECa) has emerged as a valuable tool for mapping soil spatial variability and yield potential, potentially guiding more efficient fertilization strategies. This study evaluated sugarcane yield and N responsiveness across two areas with distinct soil types over two crop cycles. Experimental plots were classified into high (HC) and low (LC) ECa zones, with randomized blocks receiving four N rates and a control. Higher yields were generally observed in HC plots, except for the second ratoon in area 2 (Ultisol). HC plots required lower N rates to achieve maximum yield compared to LC plots. In area 1 (higher clay content), optimal N rates were lower than in area 2 (lower clay content), indicating that yield potential is linked to soil attributes and spatial variability. Although ECa alone may not define precise N doses, it effectively identifies zones with different yield potentials, supporting site-specific N management. These findings highlight the potential of ECa to improve nitrogen use efficiency and contribute to more sustainable sugarcane production.