Biomass production and nutrient uptake from cover crops in Brazilian agriculture

In a scenario of global soil degradation from inadequate management, cover crops are increasingly promoted for their positive effects on soil health and ecosystem services. In Brazil, however, their use remains limited due to technical barriers and a lack of accessible data. In this systematic literature review, we extensively searched for data on biomass production and nutrient uptake of the primary cover crop families used in Brazilian agriculture. We aimed to map available research, identify knowledge gaps, and offer data to inform cover crop adoption. We retrieved over 1,300 articles from three databases, selecting 126 studies that yielded more than 1,000 observations of cover crops grown as single species or in mixtures. In total, 66 species and 58 multispecies mixes from seven botanical families were represented. Cover crop biomass production ranged from 0.33 to 17.9 Mg ha⁻¹, with an average carbon content of 44.8%, and C inputs varying from 489 to 2,898 kg ha⁻¹, decreasing from Poaceae to Brassicaceae . Nitrogen uptake ranged from 17 to 119 kg ha⁻¹, with the highest values in Fabaceae and similar uptake in Brassicaceae and Poaceae mixtures. Phosphorus and potassium uptake varied across species, with Poaceae showing the highest phosphorus and potassium, while mixtures had varied nutrient content, with limited data on phosphorus and potassium. Overall, these findings highlight the variability in nutrient uptake among different cover crop species and mixtures, providing valuable insights for optimizing cover crop selection to enhance soil health and nutrient management.