Breaking Maize Monoculture with Soybeans and Oat Cover Crop in Béarn, France

This practice abstract details a two-year maize-soybean rotation with an oat cover crop implemented in Béarn, France, to break long-standing maize monoculture. The system reduces weed and pest pressure, cuts nitrogen requirements by 86 kg N ha⁻¹ (40% reduction), lowers costs by 7–9 € ha⁻¹, and increases direct margin by 5% (743 € ha⁻¹), especially beneficial during low maize price periods. The region’s warm oceanic climate (5°C winter, 20°C summer, 1100 mm annual rainfall), clay-silt soils (25% clay, 70% silt), and 4% organic matter support high yields (4.7 t ha⁻¹ for soybeans, 6 t DM ha⁻¹ for oats). The approach aligns with CAP requirements for crop diversification and enhances sustainability through improved soil health and pest management. ARVALIS. DivertIMPACTS practice abstract. Applicability: Rotation, multiple cropping; all year; suitable for maize monoculture regions.