Cover crops as a sustainable strategy to increase black bean productivity in southern Brazil

Resumo

Cover crops are globally recognized for their potential to improve agricultural soil quality. The use of cover crops, either as single species or in mixtures (mixes), is an effective agronomic practice for sustainable agricultural production, minimizing dependence on external inputs. This study evaluated the effect of winter cover crops on the subsequent cultivation of black bean (Phaseolus vulgaris L.) in Southern Brazil over two growing seasons. Different winter cover crops were tested, both individually and in mixtures, including: black oat (Avena strigosa Schreb); black oat + common vetch (Vicia sativa L.); black oat + common vetch + rye (Secale cereale L.) + forage radish (Raphanus sativus L.) + white lupin (Lupinus albus L.) and control (bare soil). Treatments were arranged in a split-plot experimental design. Yield components and grain yield of black bean grown in succession to the cover crops were determined, with or without supplemental nitrogen fertilization, across two growing seasons (2023/2024 and 2024/2025). Results demonstrated significant increases in black bean productivity in the second season, with 22% in black oat alone, 17% in combination with common vetch, and 22% in mixed species compared to bare soil, even in the absence of nitrogen fertilization. These findings highlight the potential of cover crops to improve soil fertility and reduce dependence on chemical fertilizers. Therefore, cover crops proved to be an effective strategy to enhance black bean productivity, reinforcing the importance of sustainable agricultural practices that improve soil quality and reduce environmental impacts.